diff options
Diffstat (limited to '')
32 files changed, 7407 insertions, 1329 deletions
diff --git a/third_party/rust/hashbrown/.cargo-checksum.json b/third_party/rust/hashbrown/.cargo-checksum.json index 5561cde80d..0c5744048e 100644 --- a/third_party/rust/hashbrown/.cargo-checksum.json +++ b/third_party/rust/hashbrown/.cargo-checksum.json @@ -1 +1 @@ -{"files":{"CHANGELOG.md":"ade49a29d368e16ce508aee91b477ecbad7e2e52eb6fee7b4c1fc86199963f0e","Cargo.toml":"421b3a71d97faf0a7e52c3b2bfbe0f1c036b9dbf6232b4e5b41221bb54358f5a","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"ff8f68cb076caf8cefe7a6430d4ac086ce6af2ca8ce2c4e5a2004d4552ef52a2","README.md":"a536b3bb3f3521e59836080f05a4783150fa8484f759a31468ce3b6dba1f33eb","benches/bench.rs":"aadc39d815eadf094ed9357d946319df2d93194203bbccb7c33cea6951d654df","benches/insert_unique_unchecked.rs":"cb84275f22d5f95a5ac995ac6b2df74ffcf342765b401d27c95f2955c7b7cb9f","clippy.toml":"7535949f908c6d9aea4f9a9f3a7625552c93fc29e963d059d40f4def9d77ea7b","src/external_trait_impls/mod.rs":"d69528827794524cfd9acbeacc1ac4f6131e3c7574311e6d919f818f65fbff07","src/external_trait_impls/rayon/helpers.rs":"ba105bf0853ebc45157f22116ad0f55d3bdab75e721d8e7a677c7b912d0c0c6d","src/external_trait_impls/rayon/map.rs":"2809e2a0071db8101c38789deb955f3830c5c3455eb1794ff64a0cf2ceb53fc7","src/external_trait_impls/rayon/mod.rs":"156de9c1ad0123334ea3b7e5a17444faf1b8bf971aa88a1f23e2f2d1c3021141","src/external_trait_impls/rayon/raw.rs":"e62c5f3ca5fffea47357e64b6f8c34cec94af62d9bd28a2b87934da46c22b66e","src/external_trait_impls/rayon/set.rs":"c4c44d44e56c2f59e9e1355662e29d8744ac96645ca4414127a359fb46cb0fbf","src/external_trait_impls/serde.rs":"0bc1a1f218d1ae7a5262557a5e3737b9334caf7d50c136dbdc75ff75680c223b","src/lib.rs":"c82fbee9684bfff40ef55d5f0c9f855c11f71f9fd1720fb084ef8331bdbc41d8","src/macros.rs":"36fe532656879c80f7753d13354b889f5b45caef451a1bb3a27dbc32d74c9878","src/map.rs":"df39edae67c569378dea9a4d928685cb4d06569712c6ac36a54df76fb5d87fe3","src/raw/alloc.rs":"184a0345bc2c7544b65c28724063be26b1f2b28dbaaa028a0b01192ccac25557","src/raw/bitmask.rs":"820d90b19b7e3433a1048ace008c9526331cd53a576cb0cfc1ff9960b6fe52f8","src/raw/generic.rs":"f5013a50d6d82d5cc8bad8b8c26c24d00fa810197f9f123256c58ac92e0d98f9","src/raw/mod.rs":"fa38247c6b3bd70636be50400debb9966a3446d49ee13e4f4e2dfe4ceed1b201","src/raw/sse2.rs":"838cfdb1daa1e70951ed25f985283b8b7ab4b46fa130f92eda152047ce6086f6","src/rustc_entry.rs":"cdd70972cba5b79ca1cad79869cb5e184d6dc4798ef90822e966ef89679ba011","src/scopeguard.rs":"d13de1b12897add7fe1c3eba6f906c9cc09d86509b6cfe06b95d63803fe9265c","src/set.rs":"6877d4a42eeadd681e3b8881528e4b20f14cfedbc11e9318bfcf425ef96d1546","tests/hasher.rs":"9a8fdf67e4415618e16729969c386eefe71408cded5d46cf7b67d969276a3452","tests/rayon.rs":"83d5289771542203f539a41cccb889fbe7ce70f5adf5b903ac9f051e3ba13cfa","tests/serde.rs":"6bac8054db722dd049901b37a6e006535bac30f425eb5cd91af19b5bc1dfe78e","tests/set.rs":"01cf39efb04646ef4c63a809ebb96dfa63cfec472bf8bdb6c121f6526d40c40e"},"package":"8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"}
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\ No newline at end of file diff --git a/third_party/rust/hashbrown/CHANGELOG.md b/third_party/rust/hashbrown/CHANGELOG.md index 3354b54bb3..8c4068089a 100644 --- a/third_party/rust/hashbrown/CHANGELOG.md +++ b/third_party/rust/hashbrown/CHANGELOG.md @@ -7,35 +7,157 @@ and this project adheres to [Semantic Versioning](https://semver.org/). ## [Unreleased] +### Changed + +- Changed `hash_set::{Entry, VacantEntry}::insert` to return `OccupiedEntry`. (#495) + +## [v0.14.5] - 2024-04-28 + +### Fixed + +- Fixed index calculation in panic guard of `clone_from_impl`. (#511) + +## ~~[v0.14.4] - 2024-03-19~~ + +This release was _yanked_ due to a breaking change. + +## [v0.14.3] - 2023-11-26 + +### Added + +- Specialized `fold` implementation of iterators. (#480) + +### Fixed + +- Avoid using unstable `ptr::invalid_mut` on nightly. (#481) + +## [v0.14.2] - 2023-10-19 + +### Added + +- `HashTable` type which provides a low-level but safe API with explicit hashing. (#466) + +### Fixed + +- Disabled the use of NEON instructions on big-endian ARM. (#475) +- Disabled the use of NEON instructions on Miri. (#476) + +## [v0.14.1] - 2023-09-28 + +### Added + +- Allow serializing `HashMap`s that use a custom allocator. (#449) + +### Changed + +- Use the `Equivalent` trait from the `equivalent` crate. (#442) +- Slightly improved performance of table resizing. (#451) +- Relaxed MSRV to 1.63.0. (#457) +- Removed `Clone` requirement from custom allocators. (#468) + +### Fixed + +- Fixed custom allocators being leaked in some situations. (#439, #465) + +## [v0.14.0] - 2023-06-01 + +### Added + +- Support for `allocator-api2` crate + for interfacing with custom allocators on stable. (#417) +- Optimized implementation for ARM using NEON instructions. (#430) +- Support for rkyv serialization. (#432) +- `Equivalent` trait to look up values without `Borrow`. (#345) +- `Hash{Map,Set}::raw_table_mut` is added whic returns a mutable reference. (#404) +- Fast path for `clear` on empty tables. (#428) + +### Changed + +- Optimized insertion to only perform a single lookup. (#277) +- `DrainFilter` (`drain_filter`) has been renamed to `ExtractIf` and no longer drops remaining + elements when the iterator is dropped. #(374) +- Bumped MSRV to 1.64.0. (#431) +- `{Map,Set}::raw_table` now returns an immutable reference. (#404) +- `VacantEntry` and `OccupiedEntry` now use the default hasher if none is + specified in generics. (#389) +- `RawTable::data_start` now returns a `NonNull` to match `RawTable::data_end`. (#387) +- `RawIter::{reflect_insert, reflect_remove}` are now unsafe. (#429) +- `RawTable::find_potential` is renamed to `find_or_find_insert_slot` and returns an `InsertSlot`. (#429) +- `RawTable::remove` now also returns an `InsertSlot`. (#429) +- `InsertSlot` can be used to insert an element with `RawTable::insert_in_slot`. (#429) +- `RawIterHash` no longer has a lifetime tied to that of the `RawTable`. (#427) +- The trait bounds of `HashSet::raw_table` have been relaxed to not require `Eq + Hash`. (#423) +- `EntryRef::and_replace_entry_with` and `OccupiedEntryRef::replace_entry_with` + were changed to give a `&K` instead of a `&Q` to the closure. + +### Removed + +- Support for `bumpalo` as an allocator with custom wrapper. + Use `allocator-api2` feature in `bumpalo` to use it as an allocator + for `hashbrown` collections. (#417) + +## [v0.13.2] - 2023-01-12 + +### Fixed + +- Added `#[inline(always)]` to `find_inner`. (#375) +- Fixed `RawTable::allocation_info` for empty tables. (#376) + +## [v0.13.1] - 2022-11-10 + +### Added + +- Added `Equivalent` trait to customize key lookups. (#350) +- Added support for 16-bit targets. (#368) +- Added `RawTable::allocation_info` which provides information about the memory + usage of a table. (#371) + +### Changed + +- Bumped MSRV to 1.61.0. +- Upgraded to `ahash` 0.8. (#357) +- Make `with_hasher_in` const. (#355) +- The following methods have been removed from the `RawTable` API in favor of + safer alternatives: + - `RawTable::erase_no_drop` => Use `RawTable::erase` or `RawTable::remove` instead. + - `Bucket::read` => Use `RawTable::remove` instead. + - `Bucket::drop` => Use `RawTable::erase` instead. + - `Bucket::write` => Use `Bucket::as_mut` instead. + +### Fixed + +- Ensure that `HashMap` allocations don't exceed `isize::MAX`. (#362) +- Fixed issue with field retagging in scopeguard. (#359) + ## [v0.12.3] - 2022-07-17 -## Fixed +### Fixed - Fixed double-drop in `RawTable::clone_from`. (#348) ## [v0.12.2] - 2022-07-09 -## Added +### Added - Added `Entry` API for `HashSet`. (#342) - Added `Extend<&'a (K, V)> for HashMap<K, V, S, A>`. (#340) - Added length-based short-circuiting for hash table iteration. (#338) - Added a function to access the `RawTable` of a `HashMap`. (#335) -## Changed +### Changed - Edited `do_alloc` to reduce LLVM IR generated. (#341) ## [v0.12.1] - 2022-05-02 -## Fixed +### Fixed - Fixed underflow in `RawIterRange::size_hint`. (#325) - Fixed the implementation of `Debug` for `ValuesMut` and `IntoValues`. (#325) ## [v0.12.0] - 2022-01-17 -## Added +### Added - Added `From<[T; N]>` and `From<[(K, V); N]>` for `HashSet` and `HashMap` respectively. (#297) - Added an `allocator()` getter to HashMap and HashSet. (#257) @@ -44,7 +166,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/). - Implement `From<array>` on `HashSet` and `HashMap`. (#298) - Added `entry_ref` API to `HashMap`. (#201) -## Changed +### Changed - Bumped minimum Rust version to 1.56.1 and edition to 2021. - Use u64 for the GroupWord on WebAssembly. (#271) @@ -56,7 +178,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/). - Rename `get_each_mut` to `get_many_mut` and align API with the stdlib. (#291) - Don't hash the key when searching in an empty table. (#305) -## Fixed +### Fixed - Guard against allocations exceeding isize::MAX. (#268) - Made `RawTable::insert_no_grow` unsafe. (#254) @@ -65,19 +187,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/). ## [v0.11.2] - 2021-03-25 -## Fixed +### Fixed - Added missing allocator type parameter to `HashMap`'s and `HashSet`'s `Clone` impls. (#252) ## [v0.11.1] - 2021-03-20 -## Fixed +### Fixed - Added missing `pub` modifier to `BumpWrapper`. (#251) ## [v0.11.0] - 2021-03-14 -## Added +### Added - Added safe `try_insert_no_grow` method to `RawTable`. (#229) - Added support for `bumpalo` as an allocator without the `nightly` feature. (#231) - Implemented `Default` for `RawTable`. (#237) @@ -86,22 +208,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/). - Added `From<HashMap<T, ()>>` for `HashSet<T>`. (#235) - Added `try_insert` method to `HashMap`. (#247) -## Changed +### Changed - The minimum Rust version has been bumped to 1.49.0. (#230) - Significantly improved compilation times by reducing the amount of generated IR. (#205) -## Removed +### Removed - We no longer re-export the unstable allocator items from the standard library, nor the stable shims approximating the same. (#227) - Removed hasher specialization support from `aHash`, which was resulting in inconsistent hashes being generated for a key. (#248) -## Fixed +### Fixed - Fixed union length comparison. (#228) ## ~~[v0.10.0] - 2021-01-16~~ This release was _yanked_ due to inconsistent hashes being generated with the `nightly` feature. (#248) -## Changed +### Changed - Parametrized `RawTable`, `HashSet` and `HashMap` over an allocator. (#133) - Improved branch prediction hints on stable. (#209) - Optimized hashing of primitive types with AHash using specialization. (#207) @@ -109,7 +231,7 @@ This release was _yanked_ due to inconsistent hashes being generated with the `n ## [v0.9.1] - 2020-09-28 -## Added +### Added - Added safe methods to `RawTable` (#202): - `get`: `find` and `as_ref` - `get_mut`: `find` and `as_mut` @@ -117,7 +239,7 @@ This release was _yanked_ due to inconsistent hashes being generated with the `n - `remove_entry`: `find` and `remove` - `erase_entry`: `find` and `erase` -## Changed +### Changed - Removed `from_key_hashed_nocheck`'s `Q: Hash`. (#200) - Made `RawTable::drain` safe. (#201) @@ -215,7 +337,7 @@ This release was _yanked_ due to inconsistent hashes being generated with the `n ## [v0.6.2] - 2019-10-23 ### Added -- Added an `inline-more` feature (enabled by default) which allows choosing a tradeoff between +- Added an `inline-more` feature (enabled by default) which allows choosing a tradeoff between runtime performance and compilation time. (#119) ## [v0.6.1] - 2019-10-04 @@ -363,7 +485,15 @@ This release was _yanked_ due to a breaking change for users of `no-default-feat - Initial release -[Unreleased]: https://github.com/rust-lang/hashbrown/compare/v0.12.3...HEAD +[Unreleased]: https://github.com/rust-lang/hashbrown/compare/v0.14.5...HEAD +[v0.14.5]: https://github.com/rust-lang/hashbrown/compare/v0.14.4...v0.14.5 +[v0.14.4]: https://github.com/rust-lang/hashbrown/compare/v0.14.3...v0.14.4 +[v0.14.3]: https://github.com/rust-lang/hashbrown/compare/v0.14.2...v0.14.3 +[v0.14.2]: https://github.com/rust-lang/hashbrown/compare/v0.14.1...v0.14.2 +[v0.14.1]: https://github.com/rust-lang/hashbrown/compare/v0.14.0...v0.14.1 +[v0.14.0]: https://github.com/rust-lang/hashbrown/compare/v0.13.2...v0.14.0 +[v0.13.2]: https://github.com/rust-lang/hashbrown/compare/v0.13.1...v0.13.2 +[v0.13.1]: https://github.com/rust-lang/hashbrown/compare/v0.12.3...v0.13.1 [v0.12.3]: https://github.com/rust-lang/hashbrown/compare/v0.12.2...v0.12.3 [v0.12.2]: https://github.com/rust-lang/hashbrown/compare/v0.12.1...v0.12.2 [v0.12.1]: https://github.com/rust-lang/hashbrown/compare/v0.12.0...v0.12.1 diff --git a/third_party/rust/hashbrown/Cargo.toml b/third_party/rust/hashbrown/Cargo.toml index fb130d24d2..0a5434e494 100644 --- a/third_party/rust/hashbrown/Cargo.toml +++ b/third_party/rust/hashbrown/Cargo.toml @@ -11,9 +11,9 @@ [package] edition = "2021" -rust-version = "1.56.0" +rust-version = "1.63.0" name = "hashbrown" -version = "0.12.3" +version = "0.14.5" authors = ["Amanieu d'Antras <amanieu@gmail.com>"] exclude = [ ".github", @@ -33,7 +33,6 @@ categories = [ ] license = "MIT OR Apache-2.0" repository = "https://github.com/rust-lang/hashbrown" -resolver = "2" [package.metadata.docs.rs] features = [ @@ -42,9 +41,10 @@ features = [ "serde", "raw", ] +rustdoc-args = ["--generate-link-to-definition"] [dependencies.ahash] -version = "0.7.0" +version = "0.8.7" optional = true default-features = false @@ -53,9 +53,11 @@ version = "1.0.0" optional = true package = "rustc-std-workspace-alloc" -[dependencies.bumpalo] -version = "3.5.0" +[dependencies.allocator-api2] +version = "0.2.9" +features = ["alloc"] optional = true +default-features = false [dependencies.compiler_builtins] version = "0.1.2" @@ -66,15 +68,30 @@ version = "1.0.0" optional = true package = "rustc-std-workspace-core" +[dependencies.equivalent] +version = "1.0" +optional = true +default-features = false + [dependencies.rayon] version = "1.0" optional = true +[dependencies.rkyv] +version = "0.7.42" +features = ["alloc"] +optional = true +default-features = false + [dependencies.serde] version = "1.0.25" optional = true default-features = false +[dev-dependencies.bumpalo] +version = "3.13.0" +features = ["allocator-api2"] + [dev-dependencies.doc-comment] version = "0.3.1" @@ -91,17 +108,24 @@ features = ["small_rng"] [dev-dependencies.rayon] version = "1.0" +[dev-dependencies.rkyv] +version = "0.7.42" +features = ["validation"] + [dev-dependencies.serde_test] version = "1.0" [features] -ahash-compile-time-rng = ["ahash/compile-time-rng"] default = [ "ahash", "inline-more", + "allocator-api2", ] inline-more = [] -nightly = [] +nightly = [ + "allocator-api2?/nightly", + "bumpalo/allocator_api", +] raw = [] rustc-dep-of-std = [ "nightly", diff --git a/third_party/rust/hashbrown/README.md b/third_party/rust/hashbrown/README.md index 2eddcf3e29..5eaef8bd01 100644 --- a/third_party/rust/hashbrown/README.md +++ b/third_party/rust/hashbrown/README.md @@ -4,7 +4,7 @@ hashbrown [](https://github.com/rust-lang/hashbrown/actions) [](https://crates.io/crates/hashbrown) [](https://docs.rs/hashbrown) -[](https://github.com/rust-lang/hashbrown) +[](https://github.com/rust-lang/hashbrown) This crate is a Rust port of Google's high-performance [SwissTable] hash map, adapted to make it a drop-in replacement for Rust's standard `HashMap` @@ -40,44 +40,44 @@ Compared to the previous implementation of `std::collections::HashMap` (Rust 1.3 With the hashbrown default AHash hasher: -| name | oldstdhash ns/iter | hashbrown ns/iter | diff ns/iter | diff % | speedup | -|:------------------------|:-------------------:|------------------:|:------------:|---------:|---------| -| insert_ahash_highbits | 18,865 | 8,020 | -10,845 | -57.49% | x 2.35 | -| insert_ahash_random | 19,711 | 8,019 | -11,692 | -59.32% | x 2.46 | -| insert_ahash_serial | 19,365 | 6,463 | -12,902 | -66.63% | x 3.00 | -| insert_erase_ahash_highbits | 51,136 | 17,916 | -33,220 | -64.96% | x 2.85 | -| insert_erase_ahash_random | 51,157 | 17,688 | -33,469 | -65.42% | x 2.89 | -| insert_erase_ahash_serial | 45,479 | 14,895 | -30,584 | -67.25% | x 3.05 | -| iter_ahash_highbits | 1,399 | 1,092 | -307 | -21.94% | x 1.28 | -| iter_ahash_random | 1,586 | 1,059 | -527 | -33.23% | x 1.50 | -| iter_ahash_serial | 3,168 | 1,079 | -2,089 | -65.94% | x 2.94 | -| lookup_ahash_highbits | 32,351 | 4,792 | -27,559 | -85.19% | x 6.75 | -| lookup_ahash_random | 17,419 | 4,817 | -12,602 | -72.35% | x 3.62 | -| lookup_ahash_serial | 15,254 | 3,606 | -11,648 | -76.36% | x 4.23 | -| lookup_fail_ahash_highbits | 21,187 | 4,369 | -16,818 | -79.38% | x 4.85 | -| lookup_fail_ahash_random | 21,550 | 4,395 | -17,155 | -79.61% | x 4.90 | -| lookup_fail_ahash_serial | 19,450 | 3,176 | -16,274 | -83.67% | x 6.12 | +| name | oldstdhash ns/iter | hashbrown ns/iter | diff ns/iter | diff % | speedup | +| :-------------------------- | :----------------: | ----------------: | :----------: | ------: | ------- | +| insert_ahash_highbits | 18,865 | 8,020 | -10,845 | -57.49% | x 2.35 | +| insert_ahash_random | 19,711 | 8,019 | -11,692 | -59.32% | x 2.46 | +| insert_ahash_serial | 19,365 | 6,463 | -12,902 | -66.63% | x 3.00 | +| insert_erase_ahash_highbits | 51,136 | 17,916 | -33,220 | -64.96% | x 2.85 | +| insert_erase_ahash_random | 51,157 | 17,688 | -33,469 | -65.42% | x 2.89 | +| insert_erase_ahash_serial | 45,479 | 14,895 | -30,584 | -67.25% | x 3.05 | +| iter_ahash_highbits | 1,399 | 1,092 | -307 | -21.94% | x 1.28 | +| iter_ahash_random | 1,586 | 1,059 | -527 | -33.23% | x 1.50 | +| iter_ahash_serial | 3,168 | 1,079 | -2,089 | -65.94% | x 2.94 | +| lookup_ahash_highbits | 32,351 | 4,792 | -27,559 | -85.19% | x 6.75 | +| lookup_ahash_random | 17,419 | 4,817 | -12,602 | -72.35% | x 3.62 | +| lookup_ahash_serial | 15,254 | 3,606 | -11,648 | -76.36% | x 4.23 | +| lookup_fail_ahash_highbits | 21,187 | 4,369 | -16,818 | -79.38% | x 4.85 | +| lookup_fail_ahash_random | 21,550 | 4,395 | -17,155 | -79.61% | x 4.90 | +| lookup_fail_ahash_serial | 19,450 | 3,176 | -16,274 | -83.67% | x 6.12 | With the libstd default SipHash hasher: -|name | oldstdhash ns/iter | hashbrown ns/iter | diff ns/iter | diff % | speedup | -|:------------------------|:-------------------:|------------------:|:------------:|---------:|---------| -|insert_std_highbits |19,216 |16,885 | -2,331 | -12.13% | x 1.14 | -|insert_std_random |19,179 |17,034 | -2,145 | -11.18% | x 1.13 | -|insert_std_serial |19,462 |17,493 | -1,969 | -10.12% | x 1.11 | -|insert_erase_std_highbits |50,825 |35,847 | -14,978 | -29.47% | x 1.42 | -|insert_erase_std_random |51,448 |35,392 | -16,056 | -31.21% | x 1.45 | -|insert_erase_std_serial |87,711 |38,091 | -49,620 | -56.57% | x 2.30 | -|iter_std_highbits |1,378 |1,159 | -219 | -15.89% | x 1.19 | -|iter_std_random |1,395 |1,132 | -263 | -18.85% | x 1.23 | -|iter_std_serial |1,704 |1,105 | -599 | -35.15% | x 1.54 | -|lookup_std_highbits |17,195 |13,642 | -3,553 | -20.66% | x 1.26 | -|lookup_std_random |17,181 |13,773 | -3,408 | -19.84% | x 1.25 | -|lookup_std_serial |15,483 |13,651 | -1,832 | -11.83% | x 1.13 | -|lookup_fail_std_highbits |20,926 |13,474 | -7,452 | -35.61% | x 1.55 | -|lookup_fail_std_random |21,766 |13,505 | -8,261 | -37.95% | x 1.61 | -|lookup_fail_std_serial |19,336 |13,519 | -5,817 | -30.08% | x 1.43 | +| name | oldstdhash ns/iter | hashbrown ns/iter | diff ns/iter | diff % | speedup | +| :------------------------ | :----------------: | ----------------: | :----------: | ------: | ------- | +| insert_std_highbits | 19,216 | 16,885 | -2,331 | -12.13% | x 1.14 | +| insert_std_random | 19,179 | 17,034 | -2,145 | -11.18% | x 1.13 | +| insert_std_serial | 19,462 | 17,493 | -1,969 | -10.12% | x 1.11 | +| insert_erase_std_highbits | 50,825 | 35,847 | -14,978 | -29.47% | x 1.42 | +| insert_erase_std_random | 51,448 | 35,392 | -16,056 | -31.21% | x 1.45 | +| insert_erase_std_serial | 87,711 | 38,091 | -49,620 | -56.57% | x 2.30 | +| iter_std_highbits | 1,378 | 1,159 | -219 | -15.89% | x 1.19 | +| iter_std_random | 1,395 | 1,132 | -263 | -18.85% | x 1.23 | +| iter_std_serial | 1,704 | 1,105 | -599 | -35.15% | x 1.54 | +| lookup_std_highbits | 17,195 | 13,642 | -3,553 | -20.66% | x 1.26 | +| lookup_std_random | 17,181 | 13,773 | -3,408 | -19.84% | x 1.25 | +| lookup_std_serial | 15,483 | 13,651 | -1,832 | -11.83% | x 1.13 | +| lookup_fail_std_highbits | 20,926 | 13,474 | -7,452 | -35.61% | x 1.55 | +| lookup_fail_std_random | 21,766 | 13,505 | -8,261 | -37.95% | x 1.61 | +| lookup_fail_std_serial | 19,336 | 13,519 | -5,817 | -30.08% | x 1.43 | ## Usage @@ -85,7 +85,7 @@ Add this to your `Cargo.toml`: ```toml [dependencies] -hashbrown = "0.12" +hashbrown = "0.14" ``` Then: @@ -101,14 +101,13 @@ This crate has the following Cargo features: - `nightly`: Enables nightly-only features including: `#[may_dangle]`. - `serde`: Enables serde serialization support. +- `rkyv`: Enables rkyv serialization support. - `rayon`: Enables rayon parallel iterator support. - `raw`: Enables access to the experimental and unsafe `RawTable` API. - `inline-more`: Adds inline hints to most functions, improving run-time performance at the cost of compilation time. (enabled by default) -- `bumpalo`: Provides a `BumpWrapper` type which allows `bumpalo` to be used for memory allocation. - `ahash`: Compiles with ahash as default hasher. (enabled by default) -- `ahash-compile-time-rng`: Activates the `compile-time-rng` feature of ahash. For targets with no random number generator -this pre-generates seeds at compile time and embeds them as constants. See [aHash's documentation](https://github.com/tkaitchuck/aHash#flags) (disabled by default) +- `allocator-api2`: Enables support for allocators that support `allocator-api2`. (enabled by default) ## License diff --git a/third_party/rust/hashbrown/benches/bench.rs b/third_party/rust/hashbrown/benches/bench.rs index c393b9a706..346bd7ef89 100644 --- a/third_party/rust/hashbrown/benches/bench.rs +++ b/third_party/rust/hashbrown/benches/bench.rs @@ -311,7 +311,7 @@ fn rehash_in_place(b: &mut Bencher) { // Each loop triggers one rehash for _ in 0..10 { - for i in 0..224 { + for i in 0..223 { set.insert(i); } diff --git a/third_party/rust/hashbrown/src/external_trait_impls/mod.rs b/third_party/rust/hashbrown/src/external_trait_impls/mod.rs index ef497836cb..01d386b046 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/mod.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/mod.rs @@ -1,4 +1,6 @@ #[cfg(feature = "rayon")] pub(crate) mod rayon; +#[cfg(feature = "rkyv")] +mod rkyv; #[cfg(feature = "serde")] mod serde; diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/map.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/map.rs index 14d91c220c..2534dc9b2b 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/rayon/map.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/map.rs @@ -232,11 +232,11 @@ impl<K: Eq + Hash, V: fmt::Debug> fmt::Debug for ParValuesMut<'_, K, V> { /// [`into_par_iter`]: /hashbrown/struct.HashMap.html#method.into_par_iter /// [`HashMap`]: /hashbrown/struct.HashMap.html /// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html -pub struct IntoParIter<K, V, A: Allocator + Clone = Global> { +pub struct IntoParIter<K, V, A: Allocator = Global> { inner: RawIntoParIter<(K, V), A>, } -impl<K: Send, V: Send, A: Allocator + Clone + Send> ParallelIterator for IntoParIter<K, V, A> { +impl<K: Send, V: Send, A: Allocator + Send> ParallelIterator for IntoParIter<K, V, A> { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] @@ -248,9 +248,7 @@ impl<K: Send, V: Send, A: Allocator + Clone + Send> ParallelIterator for IntoPar } } -impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug - for IntoParIter<K, V, A> -{ +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator> fmt::Debug for IntoParIter<K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { ParIter { inner: unsafe { self.inner.par_iter() }, @@ -267,11 +265,11 @@ impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug /// /// [`par_drain`]: /hashbrown/struct.HashMap.html#method.par_drain /// [`HashMap`]: /hashbrown/struct.HashMap.html -pub struct ParDrain<'a, K, V, A: Allocator + Clone = Global> { +pub struct ParDrain<'a, K, V, A: Allocator = Global> { inner: RawParDrain<'a, (K, V), A>, } -impl<K: Send, V: Send, A: Allocator + Clone + Sync> ParallelIterator for ParDrain<'_, K, V, A> { +impl<K: Send, V: Send, A: Allocator + Sync> ParallelIterator for ParDrain<'_, K, V, A> { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] @@ -283,9 +281,7 @@ impl<K: Send, V: Send, A: Allocator + Clone + Sync> ParallelIterator for ParDrai } } -impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug - for ParDrain<'_, K, V, A> -{ +impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator> fmt::Debug for ParDrain<'_, K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { ParIter { inner: unsafe { self.inner.par_iter() }, @@ -295,7 +291,7 @@ impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, A: Allocator + Clone> fmt::Debug } } -impl<K: Sync, V: Sync, S, A: Allocator + Clone> HashMap<K, V, S, A> { +impl<K: Sync, V: Sync, S, A: Allocator> HashMap<K, V, S, A> { /// Visits (potentially in parallel) immutably borrowed keys in an arbitrary order. #[cfg_attr(feature = "inline-more", inline)] pub fn par_keys(&self) -> ParKeys<'_, K, V> { @@ -315,7 +311,7 @@ impl<K: Sync, V: Sync, S, A: Allocator + Clone> HashMap<K, V, S, A> { } } -impl<K: Send, V: Send, S, A: Allocator + Clone> HashMap<K, V, S, A> { +impl<K: Send, V: Send, S, A: Allocator> HashMap<K, V, S, A> { /// Visits (potentially in parallel) mutably borrowed values in an arbitrary order. #[cfg_attr(feature = "inline-more", inline)] pub fn par_values_mut(&mut self) -> ParValuesMut<'_, K, V> { @@ -340,7 +336,7 @@ where K: Eq + Hash + Sync, V: PartialEq + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { /// Returns `true` if the map is equal to another, /// i.e. both maps contain the same keys mapped to the same values. @@ -354,9 +350,7 @@ where } } -impl<K: Send, V: Send, S, A: Allocator + Clone + Send> IntoParallelIterator - for HashMap<K, V, S, A> -{ +impl<K: Send, V: Send, S, A: Allocator + Send> IntoParallelIterator for HashMap<K, V, S, A> { type Item = (K, V); type Iter = IntoParIter<K, V, A>; @@ -368,9 +362,7 @@ impl<K: Send, V: Send, S, A: Allocator + Clone + Send> IntoParallelIterator } } -impl<'a, K: Sync, V: Sync, S, A: Allocator + Clone> IntoParallelIterator - for &'a HashMap<K, V, S, A> -{ +impl<'a, K: Sync, V: Sync, S, A: Allocator> IntoParallelIterator for &'a HashMap<K, V, S, A> { type Item = (&'a K, &'a V); type Iter = ParIter<'a, K, V>; @@ -383,9 +375,7 @@ impl<'a, K: Sync, V: Sync, S, A: Allocator + Clone> IntoParallelIterator } } -impl<'a, K: Sync, V: Send, S, A: Allocator + Clone> IntoParallelIterator - for &'a mut HashMap<K, V, S, A> -{ +impl<'a, K: Sync, V: Send, S, A: Allocator> IntoParallelIterator for &'a mut HashMap<K, V, S, A> { type Item = (&'a K, &'a mut V); type Iter = ParIterMut<'a, K, V>; @@ -424,7 +414,7 @@ where K: Eq + Hash + Send, V: Send, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn par_extend<I>(&mut self, par_iter: I) where @@ -440,7 +430,7 @@ where K: Copy + Eq + Hash + Sync, V: Copy + Sync, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn par_extend<I>(&mut self, par_iter: I) where @@ -456,7 +446,7 @@ where K: Eq + Hash, S: BuildHasher, I: IntoParallelIterator, - A: Allocator + Clone, + A: Allocator, HashMap<K, V, S, A>: Extend<I::Item>, { let (list, len) = super::helpers::collect(par_iter); @@ -561,10 +551,7 @@ mod test_par_map { assert_eq!(value.load(Ordering::Relaxed), 100); // retain only half - let _v: Vec<_> = hm - .into_par_iter() - .filter(|&(ref key, _)| key.k < 50) - .collect(); + let _v: Vec<_> = hm.into_par_iter().filter(|(key, _)| key.k < 50).collect(); assert_eq!(key.load(Ordering::Relaxed), 50); assert_eq!(value.load(Ordering::Relaxed), 50); @@ -611,7 +598,7 @@ mod test_par_map { assert_eq!(value.load(Ordering::Relaxed), 100); // retain only half - let _v: Vec<_> = hm.drain().filter(|&(ref key, _)| key.k < 50).collect(); + let _v: Vec<_> = hm.drain().filter(|(key, _)| key.k < 50).collect(); assert!(hm.is_empty()); assert_eq!(key.load(Ordering::Relaxed), 50); diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/mod.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/mod.rs index 99337a1ce3..61ca69b61d 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/rayon/mod.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/mod.rs @@ -2,3 +2,4 @@ mod helpers; pub(crate) mod map; pub(crate) mod raw; pub(crate) mod set; +pub(crate) mod table; diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/raw.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/raw.rs index 883303e278..612be47a55 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/rayon/raw.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/raw.rs @@ -1,7 +1,6 @@ use crate::raw::Bucket; use crate::raw::{Allocator, Global, RawIter, RawIterRange, RawTable}; use crate::scopeguard::guard; -use alloc::alloc::dealloc; use core::marker::PhantomData; use core::mem; use core::ptr::NonNull; @@ -76,18 +75,18 @@ impl<T> UnindexedProducer for ParIterProducer<T> { } /// Parallel iterator which consumes a table and returns elements. -pub struct RawIntoParIter<T, A: Allocator + Clone = Global> { +pub struct RawIntoParIter<T, A: Allocator = Global> { table: RawTable<T, A>, } -impl<T, A: Allocator + Clone> RawIntoParIter<T, A> { +impl<T, A: Allocator> RawIntoParIter<T, A> { #[cfg_attr(feature = "inline-more", inline)] pub(super) unsafe fn par_iter(&self) -> RawParIter<T> { self.table.par_iter() } } -impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for RawIntoParIter<T, A> { +impl<T: Send, A: Allocator + Send> ParallelIterator for RawIntoParIter<T, A> { type Item = T; #[cfg_attr(feature = "inline-more", inline)] @@ -97,9 +96,9 @@ impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for RawIntoParIter<T { let iter = unsafe { self.table.iter().iter }; let _guard = guard(self.table.into_allocation(), |alloc| { - if let Some((ptr, layout)) = *alloc { + if let Some((ptr, layout, ref alloc)) = *alloc { unsafe { - dealloc(ptr.as_ptr(), layout); + alloc.deallocate(ptr, layout); } } }); @@ -109,23 +108,23 @@ impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for RawIntoParIter<T } /// Parallel iterator which consumes elements without freeing the table storage. -pub struct RawParDrain<'a, T, A: Allocator + Clone = Global> { +pub struct RawParDrain<'a, T, A: Allocator = Global> { // We don't use a &'a mut RawTable<T> because we want RawParDrain to be // covariant over T. table: NonNull<RawTable<T, A>>, marker: PhantomData<&'a RawTable<T, A>>, } -unsafe impl<T: Send, A: Allocator + Clone> Send for RawParDrain<'_, T, A> {} +unsafe impl<T: Send, A: Allocator> Send for RawParDrain<'_, T, A> {} -impl<T, A: Allocator + Clone> RawParDrain<'_, T, A> { +impl<T, A: Allocator> RawParDrain<'_, T, A> { #[cfg_attr(feature = "inline-more", inline)] pub(super) unsafe fn par_iter(&self) -> RawParIter<T> { self.table.as_ref().par_iter() } } -impl<T: Send, A: Allocator + Clone> ParallelIterator for RawParDrain<'_, T, A> { +impl<T: Send, A: Allocator> ParallelIterator for RawParDrain<'_, T, A> { type Item = T; #[cfg_attr(feature = "inline-more", inline)] @@ -143,7 +142,7 @@ impl<T: Send, A: Allocator + Clone> ParallelIterator for RawParDrain<'_, T, A> { } } -impl<T, A: Allocator + Clone> Drop for RawParDrain<'_, T, A> { +impl<T, A: Allocator> Drop for RawParDrain<'_, T, A> { fn drop(&mut self) { // If drive_unindexed is not called then simply clear the table. unsafe { @@ -204,7 +203,7 @@ impl<T> Drop for ParDrainProducer<T> { } } -impl<T, A: Allocator + Clone> RawTable<T, A> { +impl<T, A: Allocator> RawTable<T, A> { /// Returns a parallel iterator over the elements in a `RawTable`. #[cfg_attr(feature = "inline-more", inline)] pub unsafe fn par_iter(&self) -> RawParIter<T> { diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/set.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/set.rs index ee4f6e6693..3de98fccb8 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/rayon/set.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/set.rs @@ -16,11 +16,11 @@ use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, Pa /// [`into_par_iter`]: /hashbrown/struct.HashSet.html#method.into_par_iter /// [`HashSet`]: /hashbrown/struct.HashSet.html /// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html -pub struct IntoParIter<T, A: Allocator + Clone = Global> { +pub struct IntoParIter<T, A: Allocator = Global> { inner: map::IntoParIter<T, (), A>, } -impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for IntoParIter<T, A> { +impl<T: Send, A: Allocator + Send> ParallelIterator for IntoParIter<T, A> { type Item = T; fn drive_unindexed<C>(self, consumer: C) -> C::Result @@ -38,11 +38,11 @@ impl<T: Send, A: Allocator + Clone + Send> ParallelIterator for IntoParIter<T, A /// /// [`par_drain`]: /hashbrown/struct.HashSet.html#method.par_drain /// [`HashSet`]: /hashbrown/struct.HashSet.html -pub struct ParDrain<'a, T, A: Allocator + Clone = Global> { +pub struct ParDrain<'a, T, A: Allocator = Global> { inner: map::ParDrain<'a, T, (), A>, } -impl<T: Send, A: Allocator + Clone + Send + Sync> ParallelIterator for ParDrain<'_, T, A> { +impl<T: Send, A: Allocator + Send + Sync> ParallelIterator for ParDrain<'_, T, A> { type Item = T; fn drive_unindexed<C>(self, consumer: C) -> C::Result @@ -85,7 +85,7 @@ impl<'a, T: Sync> ParallelIterator for ParIter<'a, T> { /// /// [`par_difference`]: /hashbrown/struct.HashSet.html#method.par_difference /// [`HashSet`]: /hashbrown/struct.HashSet.html -pub struct ParDifference<'a, T, S, A: Allocator + Clone = Global> { +pub struct ParDifference<'a, T, S, A: Allocator = Global> { a: &'a HashSet<T, S, A>, b: &'a HashSet<T, S, A>, } @@ -94,7 +94,7 @@ impl<'a, T, S, A> ParallelIterator for ParDifference<'a, T, S, A> where T: Eq + Hash + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { type Item = &'a T; @@ -118,7 +118,7 @@ where /// /// [`par_symmetric_difference`]: /hashbrown/struct.HashSet.html#method.par_symmetric_difference /// [`HashSet`]: /hashbrown/struct.HashSet.html -pub struct ParSymmetricDifference<'a, T, S, A: Allocator + Clone = Global> { +pub struct ParSymmetricDifference<'a, T, S, A: Allocator = Global> { a: &'a HashSet<T, S, A>, b: &'a HashSet<T, S, A>, } @@ -127,7 +127,7 @@ impl<'a, T, S, A> ParallelIterator for ParSymmetricDifference<'a, T, S, A> where T: Eq + Hash + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { type Item = &'a T; @@ -150,7 +150,7 @@ where /// /// [`par_intersection`]: /hashbrown/struct.HashSet.html#method.par_intersection /// [`HashSet`]: /hashbrown/struct.HashSet.html -pub struct ParIntersection<'a, T, S, A: Allocator + Clone = Global> { +pub struct ParIntersection<'a, T, S, A: Allocator = Global> { a: &'a HashSet<T, S, A>, b: &'a HashSet<T, S, A>, } @@ -159,7 +159,7 @@ impl<'a, T, S, A> ParallelIterator for ParIntersection<'a, T, S, A> where T: Eq + Hash + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { type Item = &'a T; @@ -181,7 +181,7 @@ where /// /// [`par_union`]: /hashbrown/struct.HashSet.html#method.par_union /// [`HashSet`]: /hashbrown/struct.HashSet.html -pub struct ParUnion<'a, T, S, A: Allocator + Clone = Global> { +pub struct ParUnion<'a, T, S, A: Allocator = Global> { a: &'a HashSet<T, S, A>, b: &'a HashSet<T, S, A>, } @@ -190,7 +190,7 @@ impl<'a, T, S, A> ParallelIterator for ParUnion<'a, T, S, A> where T: Eq + Hash + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { type Item = &'a T; @@ -216,7 +216,7 @@ impl<T, S, A> HashSet<T, S, A> where T: Eq + Hash + Sync, S: BuildHasher + Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { /// Visits (potentially in parallel) the values representing the union, /// i.e. all the values in `self` or `other`, without duplicates. @@ -289,7 +289,7 @@ where impl<T, S, A> HashSet<T, S, A> where T: Eq + Hash + Send, - A: Allocator + Clone + Send, + A: Allocator + Send, { /// Consumes (potentially in parallel) all values in an arbitrary order, /// while preserving the set's allocated memory for reuse. @@ -301,7 +301,7 @@ where } } -impl<T: Send, S, A: Allocator + Clone + Send> IntoParallelIterator for HashSet<T, S, A> { +impl<T: Send, S, A: Allocator + Send> IntoParallelIterator for HashSet<T, S, A> { type Item = T; type Iter = IntoParIter<T, A>; @@ -313,7 +313,7 @@ impl<T: Send, S, A: Allocator + Clone + Send> IntoParallelIterator for HashSet<T } } -impl<'a, T: Sync, S, A: Allocator + Clone> IntoParallelIterator for &'a HashSet<T, S, A> { +impl<'a, T: Sync, S, A: Allocator> IntoParallelIterator for &'a HashSet<T, S, A> { type Item = &'a T; type Iter = ParIter<'a, T>; @@ -374,7 +374,7 @@ fn extend<T, S, I, A>(set: &mut HashSet<T, S, A>, par_iter: I) where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, I: IntoParallelIterator, HashSet<T, S, A>: Extend<I::Item>, { diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs new file mode 100644 index 0000000000..e8e50944ad --- /dev/null +++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs @@ -0,0 +1,252 @@ +//! Rayon extensions for `HashTable`. + +use super::raw::{RawIntoParIter, RawParDrain, RawParIter}; +use crate::hash_table::HashTable; +use crate::raw::{Allocator, Global}; +use core::fmt; +use core::marker::PhantomData; +use rayon::iter::plumbing::UnindexedConsumer; +use rayon::iter::{IntoParallelIterator, ParallelIterator}; + +/// Parallel iterator over shared references to entries in a map. +/// +/// This iterator is created by the [`par_iter`] method on [`HashTable`] +/// (provided by the [`IntoParallelRefIterator`] trait). +/// See its documentation for more. +/// +/// [`par_iter`]: /hashbrown/struct.HashTable.html#method.par_iter +/// [`HashTable`]: /hashbrown/struct.HashTable.html +/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html +pub struct ParIter<'a, T> { + inner: RawParIter<T>, + marker: PhantomData<&'a T>, +} + +impl<'a, T: Sync> ParallelIterator for ParIter<'a, T> { + type Item = &'a T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { x.as_ref() }) + .drive_unindexed(consumer) + } +} + +impl<T> Clone for ParIter<'_, T> { + #[cfg_attr(feature = "inline-more", inline)] + fn clone(&self) -> Self { + Self { + inner: self.inner.clone(), + marker: PhantomData, + } + } +} + +impl<T: fmt::Debug> fmt::Debug for ParIter<'_, T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let iter = unsafe { self.inner.iter() }.map(|x| unsafe { x.as_ref() }); + f.debug_list().entries(iter).finish() + } +} + +/// Parallel iterator over mutable references to entries in a map. +/// +/// This iterator is created by the [`par_iter_mut`] method on [`HashTable`] +/// (provided by the [`IntoParallelRefMutIterator`] trait). +/// See its documentation for more. +/// +/// [`par_iter_mut`]: /hashbrown/struct.HashTable.html#method.par_iter_mut +/// [`HashTable`]: /hashbrown/struct.HashTable.html +/// [`IntoParallelRefMutIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefMutIterator.html +pub struct ParIterMut<'a, T> { + inner: RawParIter<T>, + marker: PhantomData<&'a mut T>, +} + +impl<'a, T: Send> ParallelIterator for ParIterMut<'a, T> { + type Item = &'a mut T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner + .map(|x| unsafe { x.as_mut() }) + .drive_unindexed(consumer) + } +} + +impl<T: fmt::Debug> fmt::Debug for ParIterMut<'_, T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: self.inner.clone(), + marker: PhantomData, + } + .fmt(f) + } +} + +/// Parallel iterator over entries of a consumed map. +/// +/// This iterator is created by the [`into_par_iter`] method on [`HashTable`] +/// (provided by the [`IntoParallelIterator`] trait). +/// See its documentation for more. +/// +/// [`into_par_iter`]: /hashbrown/struct.HashTable.html#method.into_par_iter +/// [`HashTable`]: /hashbrown/struct.HashTable.html +/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html +pub struct IntoParIter<T, A: Allocator = Global> { + inner: RawIntoParIter<T, A>, +} + +impl<T: Send, A: Allocator + Send> ParallelIterator for IntoParIter<T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.drive_unindexed(consumer) + } +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for IntoParIter<T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: unsafe { self.inner.par_iter() }, + marker: PhantomData, + } + .fmt(f) + } +} + +/// Parallel draining iterator over entries of a map. +/// +/// This iterator is created by the [`par_drain`] method on [`HashTable`]. +/// See its documentation for more. +/// +/// [`par_drain`]: /hashbrown/struct.HashTable.html#method.par_drain +/// [`HashTable`]: /hashbrown/struct.HashTable.html +pub struct ParDrain<'a, T, A: Allocator = Global> { + inner: RawParDrain<'a, T, A>, +} + +impl<T: Send, A: Allocator + Sync> ParallelIterator for ParDrain<'_, T, A> { + type Item = T; + + #[cfg_attr(feature = "inline-more", inline)] + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.inner.drive_unindexed(consumer) + } +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for ParDrain<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + ParIter { + inner: unsafe { self.inner.par_iter() }, + marker: PhantomData, + } + .fmt(f) + } +} + +impl<T: Send, A: Allocator> HashTable<T, A> { + /// Consumes (potentially in parallel) all values in an arbitrary order, + /// while preserving the map's allocated memory for reuse. + #[cfg_attr(feature = "inline-more", inline)] + pub fn par_drain(&mut self) -> ParDrain<'_, T, A> { + ParDrain { + inner: self.raw.par_drain(), + } + } +} + +impl<T: Send, A: Allocator + Send> IntoParallelIterator for HashTable<T, A> { + type Item = T; + type Iter = IntoParIter<T, A>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + IntoParIter { + inner: self.raw.into_par_iter(), + } + } +} + +impl<'a, T: Sync, A: Allocator> IntoParallelIterator for &'a HashTable<T, A> { + type Item = &'a T; + type Iter = ParIter<'a, T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + ParIter { + inner: unsafe { self.raw.par_iter() }, + marker: PhantomData, + } + } +} + +impl<'a, T: Send, A: Allocator> IntoParallelIterator for &'a mut HashTable<T, A> { + type Item = &'a mut T; + type Iter = ParIterMut<'a, T>; + + #[cfg_attr(feature = "inline-more", inline)] + fn into_par_iter(self) -> Self::Iter { + ParIterMut { + inner: unsafe { self.raw.par_iter() }, + marker: PhantomData, + } + } +} + +#[cfg(test)] +mod test_par_table { + use alloc::vec::Vec; + use core::sync::atomic::{AtomicUsize, Ordering}; + + use rayon::prelude::*; + + use crate::{ + hash_map::{make_hash, DefaultHashBuilder}, + hash_table::HashTable, + }; + + #[test] + fn test_iterate() { + let hasher = DefaultHashBuilder::default(); + let mut a = HashTable::new(); + for i in 0..32 { + a.insert_unique(make_hash(&hasher, &i), i, |x| make_hash(&hasher, x)); + } + let observed = AtomicUsize::new(0); + a.par_iter().for_each(|k| { + observed.fetch_or(1 << *k, Ordering::Relaxed); + }); + assert_eq!(observed.into_inner(), 0xFFFF_FFFF); + } + + #[test] + fn test_move_iter() { + let hasher = DefaultHashBuilder::default(); + let hs = { + let mut hs = HashTable::new(); + + hs.insert_unique(make_hash(&hasher, &'a'), 'a', |x| make_hash(&hasher, x)); + hs.insert_unique(make_hash(&hasher, &'b'), 'b', |x| make_hash(&hasher, x)); + + hs + }; + + let v = hs.into_par_iter().collect::<Vec<char>>(); + assert!(v == ['a', 'b'] || v == ['b', 'a']); + } +} diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_map.rs b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_map.rs new file mode 100644 index 0000000000..fae7f76763 --- /dev/null +++ b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_map.rs @@ -0,0 +1,125 @@ +use crate::HashMap; +use core::{ + borrow::Borrow, + hash::{BuildHasher, Hash}, +}; +use rkyv::{ + collections::hash_map::{ArchivedHashMap, HashMapResolver}, + ser::{ScratchSpace, Serializer}, + Archive, Deserialize, Fallible, Serialize, +}; + +impl<K: Archive + Hash + Eq, V: Archive, S> Archive for HashMap<K, V, S> +where + K::Archived: Hash + Eq, +{ + type Archived = ArchivedHashMap<K::Archived, V::Archived>; + type Resolver = HashMapResolver; + + #[inline] + unsafe fn resolve(&self, pos: usize, resolver: Self::Resolver, out: *mut Self::Archived) { + ArchivedHashMap::resolve_from_len(self.len(), pos, resolver, out); + } +} + +impl<K, V, S, RandomState> Serialize<S> for HashMap<K, V, RandomState> +where + K: Serialize<S> + Hash + Eq, + K::Archived: Hash + Eq, + V: Serialize<S>, + S: Serializer + ScratchSpace + ?Sized, +{ + #[inline] + fn serialize(&self, serializer: &mut S) -> Result<Self::Resolver, S::Error> { + unsafe { ArchivedHashMap::serialize_from_iter(self.iter(), serializer) } + } +} + +impl<K: Archive + Hash + Eq, V: Archive, D: Fallible + ?Sized, S: Default + BuildHasher> + Deserialize<HashMap<K, V, S>, D> for ArchivedHashMap<K::Archived, V::Archived> +where + K::Archived: Deserialize<K, D> + Hash + Eq, + V::Archived: Deserialize<V, D>, +{ + #[inline] + fn deserialize(&self, deserializer: &mut D) -> Result<HashMap<K, V, S>, D::Error> { + let mut result = HashMap::with_capacity_and_hasher(self.len(), S::default()); + for (k, v) in self.iter() { + result.insert(k.deserialize(deserializer)?, v.deserialize(deserializer)?); + } + Ok(result) + } +} + +impl<K: Hash + Eq + Borrow<AK>, V, AK: Hash + Eq, AV: PartialEq<V>, S: BuildHasher> + PartialEq<HashMap<K, V, S>> for ArchivedHashMap<AK, AV> +{ + #[inline] + fn eq(&self, other: &HashMap<K, V, S>) -> bool { + if self.len() != other.len() { + false + } else { + self.iter() + .all(|(key, value)| other.get(key).map_or(false, |v| value.eq(v))) + } + } +} + +impl<K: Hash + Eq + Borrow<AK>, V, AK: Hash + Eq, AV: PartialEq<V>> + PartialEq<ArchivedHashMap<AK, AV>> for HashMap<K, V> +{ + #[inline] + fn eq(&self, other: &ArchivedHashMap<AK, AV>) -> bool { + other.eq(self) + } +} + +#[cfg(test)] +mod tests { + use crate::HashMap; + use alloc::string::String; + use rkyv::{ + archived_root, check_archived_root, + ser::{serializers::AllocSerializer, Serializer}, + Deserialize, Infallible, + }; + + #[test] + fn index_map() { + let mut value = HashMap::new(); + value.insert(String::from("foo"), 10); + value.insert(String::from("bar"), 20); + value.insert(String::from("baz"), 40); + value.insert(String::from("bat"), 80); + + let mut serializer = AllocSerializer::<4096>::default(); + serializer.serialize_value(&value).unwrap(); + let result = serializer.into_serializer().into_inner(); + let archived = unsafe { archived_root::<HashMap<String, i32>>(result.as_ref()) }; + + assert_eq!(value.len(), archived.len()); + for (k, v) in value.iter() { + let (ak, av) = archived.get_key_value(k.as_str()).unwrap(); + assert_eq!(k, ak); + assert_eq!(v, av); + } + + let deserialized: HashMap<String, i32> = archived.deserialize(&mut Infallible).unwrap(); + assert_eq!(value, deserialized); + } + + #[test] + fn validate_index_map() { + let mut value = HashMap::new(); + value.insert(String::from("foo"), 10); + value.insert(String::from("bar"), 20); + value.insert(String::from("baz"), 40); + value.insert(String::from("bat"), 80); + + let mut serializer = AllocSerializer::<4096>::default(); + serializer.serialize_value(&value).unwrap(); + let result = serializer.into_serializer().into_inner(); + check_archived_root::<HashMap<String, i32>>(result.as_ref()) + .expect("failed to validate archived index map"); + } +} diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_set.rs b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_set.rs new file mode 100644 index 0000000000..c8a69cf4fc --- /dev/null +++ b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/hash_set.rs @@ -0,0 +1,123 @@ +use crate::HashSet; +use core::{ + borrow::Borrow, + hash::{BuildHasher, Hash}, +}; +use rkyv::{ + collections::hash_set::{ArchivedHashSet, HashSetResolver}, + ser::{ScratchSpace, Serializer}, + Archive, Deserialize, Fallible, Serialize, +}; + +impl<K: Archive + Hash + Eq, S> Archive for HashSet<K, S> +where + K::Archived: Hash + Eq, +{ + type Archived = ArchivedHashSet<K::Archived>; + type Resolver = HashSetResolver; + + #[inline] + unsafe fn resolve(&self, pos: usize, resolver: Self::Resolver, out: *mut Self::Archived) { + ArchivedHashSet::<K::Archived>::resolve_from_len(self.len(), pos, resolver, out); + } +} + +impl<K, S, RS> Serialize<S> for HashSet<K, RS> +where + K::Archived: Hash + Eq, + K: Serialize<S> + Hash + Eq, + S: ScratchSpace + Serializer + ?Sized, +{ + #[inline] + fn serialize(&self, serializer: &mut S) -> Result<Self::Resolver, S::Error> { + unsafe { ArchivedHashSet::serialize_from_iter(self.iter(), serializer) } + } +} + +impl<K, D, S> Deserialize<HashSet<K, S>, D> for ArchivedHashSet<K::Archived> +where + K: Archive + Hash + Eq, + K::Archived: Deserialize<K, D> + Hash + Eq, + D: Fallible + ?Sized, + S: Default + BuildHasher, +{ + #[inline] + fn deserialize(&self, deserializer: &mut D) -> Result<HashSet<K, S>, D::Error> { + let mut result = HashSet::with_hasher(S::default()); + for k in self.iter() { + result.insert(k.deserialize(deserializer)?); + } + Ok(result) + } +} + +impl<K: Hash + Eq + Borrow<AK>, AK: Hash + Eq, S: BuildHasher> PartialEq<HashSet<K, S>> + for ArchivedHashSet<AK> +{ + #[inline] + fn eq(&self, other: &HashSet<K, S>) -> bool { + if self.len() != other.len() { + false + } else { + self.iter().all(|key| other.get(key).is_some()) + } + } +} + +impl<K: Hash + Eq + Borrow<AK>, AK: Hash + Eq, S: BuildHasher> PartialEq<ArchivedHashSet<AK>> + for HashSet<K, S> +{ + #[inline] + fn eq(&self, other: &ArchivedHashSet<AK>) -> bool { + other.eq(self) + } +} + +#[cfg(test)] +mod tests { + use crate::HashSet; + use alloc::string::String; + use rkyv::{ + archived_root, check_archived_root, + ser::{serializers::AllocSerializer, Serializer}, + Deserialize, Infallible, + }; + + #[test] + fn index_set() { + let mut value = HashSet::new(); + value.insert(String::from("foo")); + value.insert(String::from("bar")); + value.insert(String::from("baz")); + value.insert(String::from("bat")); + + let mut serializer = AllocSerializer::<4096>::default(); + serializer.serialize_value(&value).unwrap(); + let result = serializer.into_serializer().into_inner(); + let archived = unsafe { archived_root::<HashSet<String>>(result.as_ref()) }; + + assert_eq!(value.len(), archived.len()); + for k in value.iter() { + let ak = archived.get(k.as_str()).unwrap(); + assert_eq!(k, ak); + } + + let deserialized: HashSet<String> = archived.deserialize(&mut Infallible).unwrap(); + assert_eq!(value, deserialized); + } + + #[test] + fn validate_index_set() { + let mut value = HashSet::new(); + value.insert(String::from("foo")); + value.insert(String::from("bar")); + value.insert(String::from("baz")); + value.insert(String::from("bat")); + + let mut serializer = AllocSerializer::<4096>::default(); + serializer.serialize_value(&value).unwrap(); + let result = serializer.into_serializer().into_inner(); + check_archived_root::<HashSet<String>>(result.as_ref()) + .expect("failed to validate archived index set"); + } +} diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rkyv/mod.rs b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/mod.rs new file mode 100644 index 0000000000..2bde6a0653 --- /dev/null +++ b/third_party/rust/hashbrown/src/external_trait_impls/rkyv/mod.rs @@ -0,0 +1,2 @@ +mod hash_map; +mod hash_set; diff --git a/third_party/rust/hashbrown/src/external_trait_impls/serde.rs b/third_party/rust/hashbrown/src/external_trait_impls/serde.rs index 4d62deeb7a..0a76dbec25 100644 --- a/third_party/rust/hashbrown/src/external_trait_impls/serde.rs +++ b/third_party/rust/hashbrown/src/external_trait_impls/serde.rs @@ -11,6 +11,7 @@ mod size_hint { } mod map { + use crate::raw::Allocator; use core::fmt; use core::hash::{BuildHasher, Hash}; use core::marker::PhantomData; @@ -21,11 +22,12 @@ mod map { use super::size_hint; - impl<K, V, H> Serialize for HashMap<K, V, H> + impl<K, V, H, A> Serialize for HashMap<K, V, H, A> where K: Serialize + Eq + Hash, V: Serialize, H: BuildHasher, + A: Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> @@ -36,40 +38,46 @@ mod map { } } - impl<'de, K, V, S> Deserialize<'de> for HashMap<K, V, S> + impl<'de, K, V, S, A> Deserialize<'de> for HashMap<K, V, S, A> where K: Deserialize<'de> + Eq + Hash, V: Deserialize<'de>, S: BuildHasher + Default, + A: Allocator + Default, { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de>, { - struct MapVisitor<K, V, S> { - marker: PhantomData<HashMap<K, V, S>>, + struct MapVisitor<K, V, S, A> + where + A: Allocator, + { + marker: PhantomData<HashMap<K, V, S, A>>, } - impl<'de, K, V, S> Visitor<'de> for MapVisitor<K, V, S> + impl<'de, K, V, S, A> Visitor<'de> for MapVisitor<K, V, S, A> where K: Deserialize<'de> + Eq + Hash, V: Deserialize<'de>, S: BuildHasher + Default, + A: Allocator + Default, { - type Value = HashMap<K, V, S>; + type Value = HashMap<K, V, S, A>; fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { formatter.write_str("a map") } #[cfg_attr(feature = "inline-more", inline)] - fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + fn visit_map<M>(self, mut map: M) -> Result<Self::Value, M::Error> where - A: MapAccess<'de>, + M: MapAccess<'de>, { - let mut values = HashMap::with_capacity_and_hasher( + let mut values = HashMap::with_capacity_and_hasher_in( size_hint::cautious(map.size_hint()), S::default(), + A::default(), ); while let Some((key, value)) = map.next_entry()? { @@ -89,6 +97,7 @@ mod map { } mod set { + use crate::raw::Allocator; use core::fmt; use core::hash::{BuildHasher, Hash}; use core::marker::PhantomData; @@ -99,10 +108,11 @@ mod set { use super::size_hint; - impl<T, H> Serialize for HashSet<T, H> + impl<T, H, A> Serialize for HashSet<T, H, A> where T: Serialize + Eq + Hash, H: BuildHasher, + A: Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> @@ -113,38 +123,44 @@ mod set { } } - impl<'de, T, S> Deserialize<'de> for HashSet<T, S> + impl<'de, T, S, A> Deserialize<'de> for HashSet<T, S, A> where T: Deserialize<'de> + Eq + Hash, S: BuildHasher + Default, + A: Allocator + Default, { fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de>, { - struct SeqVisitor<T, S> { - marker: PhantomData<HashSet<T, S>>, + struct SeqVisitor<T, S, A> + where + A: Allocator, + { + marker: PhantomData<HashSet<T, S, A>>, } - impl<'de, T, S> Visitor<'de> for SeqVisitor<T, S> + impl<'de, T, S, A> Visitor<'de> for SeqVisitor<T, S, A> where T: Deserialize<'de> + Eq + Hash, S: BuildHasher + Default, + A: Allocator + Default, { - type Value = HashSet<T, S>; + type Value = HashSet<T, S, A>; fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { formatter.write_str("a sequence") } #[cfg_attr(feature = "inline-more", inline)] - fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + fn visit_seq<M>(self, mut seq: M) -> Result<Self::Value, M::Error> where - A: SeqAccess<'de>, + M: SeqAccess<'de>, { - let mut values = HashSet::with_capacity_and_hasher( + let mut values = HashSet::with_capacity_and_hasher_in( size_hint::cautious(seq.size_hint()), S::default(), + A::default(), ); while let Some(value) = seq.next_element()? { @@ -166,12 +182,15 @@ mod set { where D: Deserializer<'de>, { - struct SeqInPlaceVisitor<'a, T, S>(&'a mut HashSet<T, S>); + struct SeqInPlaceVisitor<'a, T, S, A>(&'a mut HashSet<T, S, A>) + where + A: Allocator; - impl<'a, 'de, T, S> Visitor<'de> for SeqInPlaceVisitor<'a, T, S> + impl<'a, 'de, T, S, A> Visitor<'de> for SeqInPlaceVisitor<'a, T, S, A> where T: Deserialize<'de> + Eq + Hash, S: BuildHasher + Default, + A: Allocator, { type Value = (); @@ -180,9 +199,9 @@ mod set { } #[cfg_attr(feature = "inline-more", inline)] - fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + fn visit_seq<M>(self, mut seq: M) -> Result<Self::Value, M::Error> where - A: SeqAccess<'de>, + M: SeqAccess<'de>, { self.0.clear(); self.0.reserve(size_hint::cautious(seq.size_hint())); diff --git a/third_party/rust/hashbrown/src/lib.rs b/third_party/rust/hashbrown/src/lib.rs index bc1c971303..f03ddb6ad9 100644 --- a/third_party/rust/hashbrown/src/lib.rs +++ b/third_party/rust/hashbrown/src/lib.rs @@ -20,9 +20,8 @@ extend_one, allocator_api, slice_ptr_get, - nonnull_slice_from_raw_parts, maybe_uninit_array_assume_init, - build_hasher_simple_hash_one + strict_provenance ) )] #![allow( @@ -37,6 +36,8 @@ )] #![warn(missing_docs)] #![warn(rust_2018_idioms)] +#![cfg_attr(feature = "nightly", warn(fuzzy_provenance_casts))] +#![cfg_attr(feature = "nightly", allow(internal_features))] #[cfg(test)] #[macro_use] @@ -81,6 +82,7 @@ mod map; mod rustc_entry; mod scopeguard; mod set; +mod table; pub mod hash_map { //! A hash map implemented with quadratic probing and SIMD lookup. @@ -113,9 +115,63 @@ pub mod hash_set { pub use crate::external_trait_impls::rayon::set::*; } } +pub mod hash_table { + //! A hash table implemented with quadratic probing and SIMD lookup. + pub use crate::table::*; + + #[cfg(feature = "rayon")] + /// [rayon]-based parallel iterator types for hash tables. + /// You will rarely need to interact with it directly unless you have need + /// to name one of the iterator types. + /// + /// [rayon]: https://docs.rs/rayon/1.0/rayon + pub mod rayon { + pub use crate::external_trait_impls::rayon::table::*; + } +} pub use crate::map::HashMap; pub use crate::set::HashSet; +pub use crate::table::HashTable; + +#[cfg(feature = "equivalent")] +pub use equivalent::Equivalent; + +// This is only used as a fallback when building as part of `std`. +#[cfg(not(feature = "equivalent"))] +/// Key equivalence trait. +/// +/// This trait defines the function used to compare the input value with the +/// map keys (or set values) during a lookup operation such as [`HashMap::get`] +/// or [`HashSet::contains`]. +/// It is provided with a blanket implementation based on the +/// [`Borrow`](core::borrow::Borrow) trait. +/// +/// # Correctness +/// +/// Equivalent values must hash to the same value. +pub trait Equivalent<K: ?Sized> { + /// Checks if this value is equivalent to the given key. + /// + /// Returns `true` if both values are equivalent, and `false` otherwise. + /// + /// # Correctness + /// + /// When this function returns `true`, both `self` and `key` must hash to + /// the same value. + fn equivalent(&self, key: &K) -> bool; +} + +#[cfg(not(feature = "equivalent"))] +impl<Q: ?Sized, K: ?Sized> Equivalent<K> for Q +where + Q: Eq, + K: core::borrow::Borrow<Q>, +{ + fn equivalent(&self, key: &K) -> bool { + self == key.borrow() + } +} /// The error type for `try_reserve` methods. #[derive(Clone, PartialEq, Eq, Debug)] @@ -130,21 +186,3 @@ pub enum TryReserveError { layout: alloc::alloc::Layout, }, } - -/// Wrapper around `Bump` which allows it to be used as an allocator for -/// `HashMap`, `HashSet` and `RawTable`. -/// -/// `Bump` can be used directly without this wrapper on nightly if you enable -/// the `allocator-api` feature of the `bumpalo` crate. -#[cfg(feature = "bumpalo")] -#[derive(Clone, Copy, Debug)] -pub struct BumpWrapper<'a>(pub &'a bumpalo::Bump); - -#[cfg(feature = "bumpalo")] -#[test] -fn test_bumpalo() { - use bumpalo::Bump; - let bump = Bump::new(); - let mut map = HashMap::new_in(BumpWrapper(&bump)); - map.insert(0, 1); -} diff --git a/third_party/rust/hashbrown/src/macros.rs b/third_party/rust/hashbrown/src/macros.rs index f8ef917b14..eaba6bed1f 100644 --- a/third_party/rust/hashbrown/src/macros.rs +++ b/third_party/rust/hashbrown/src/macros.rs @@ -37,7 +37,7 @@ macro_rules! cfg_if { // semicolon is all the remaining items (@__items ($($not:meta,)*) ; ) => {}; (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => { - // Emit all items within one block, applying an approprate #[cfg]. The + // Emit all items within one block, applying an appropriate #[cfg]. The // #[cfg] will require all `$m` matchers specified and must also negate // all previous matchers. cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* } diff --git a/third_party/rust/hashbrown/src/map.rs b/third_party/rust/hashbrown/src/map.rs index a5d3ccb97e..88a826582b 100644 --- a/third_party/rust/hashbrown/src/map.rs +++ b/third_party/rust/hashbrown/src/map.rs @@ -1,16 +1,18 @@ -use crate::raw::{Allocator, Bucket, Global, RawDrain, RawIntoIter, RawIter, RawTable}; -use crate::TryReserveError; +use crate::raw::{ + Allocator, Bucket, Global, RawDrain, RawExtractIf, RawIntoIter, RawIter, RawTable, +}; +use crate::{Equivalent, TryReserveError}; use core::borrow::Borrow; use core::fmt::{self, Debug}; use core::hash::{BuildHasher, Hash}; -use core::iter::{FromIterator, FusedIterator}; +use core::iter::FusedIterator; use core::marker::PhantomData; use core::mem; use core::ops::Index; /// Default hasher for `HashMap`. #[cfg(feature = "ahash")] -pub type DefaultHashBuilder = ahash::RandomState; +pub type DefaultHashBuilder = core::hash::BuildHasherDefault<ahash::AHasher>; /// Dummy default hasher for `HashMap`. #[cfg(not(feature = "ahash"))] @@ -182,10 +184,10 @@ pub enum DefaultHashBuilder {} /// use hashbrown::HashMap; /// /// let timber_resources: HashMap<&str, i32> = [("Norway", 100), ("Denmark", 50), ("Iceland", 10)] -/// .iter().cloned().collect(); +/// .into_iter().collect(); /// // use the values stored in map /// ``` -pub struct HashMap<K, V, S = DefaultHashBuilder, A: Allocator + Clone = Global> { +pub struct HashMap<K, V, S = DefaultHashBuilder, A: Allocator = Global> { pub(crate) hash_builder: S, pub(crate) table: RawTable<(K, V), A>, } @@ -209,13 +211,12 @@ impl<K: Clone, V: Clone, S: Clone, A: Allocator + Clone> Clone for HashMap<K, V, /// Ensures that a single closure type across uses of this which, in turn prevents multiple /// instances of any functions like RawTable::reserve from being generated #[cfg_attr(feature = "inline-more", inline)] -pub(crate) fn make_hasher<K, Q, V, S>(hash_builder: &S) -> impl Fn(&(Q, V)) -> u64 + '_ +pub(crate) fn make_hasher<Q, V, S>(hash_builder: &S) -> impl Fn(&(Q, V)) -> u64 + '_ where - K: Borrow<Q>, Q: Hash, S: BuildHasher, { - move |val| make_hash::<K, Q, S>(hash_builder, &val.0) + move |val| make_hash::<Q, S>(hash_builder, &val.0) } /// Ensures that a single closure type across uses of this which, in turn prevents multiple @@ -223,10 +224,9 @@ where #[cfg_attr(feature = "inline-more", inline)] fn equivalent_key<Q, K, V>(k: &Q) -> impl Fn(&(K, V)) -> bool + '_ where - K: Borrow<Q>, - Q: ?Sized + Eq, + Q: ?Sized + Equivalent<K>, { - move |x| k.eq(x.0.borrow()) + move |x| k.equivalent(&x.0) } /// Ensures that a single closure type across uses of this which, in turn prevents multiple @@ -234,17 +234,15 @@ where #[cfg_attr(feature = "inline-more", inline)] fn equivalent<Q, K>(k: &Q) -> impl Fn(&K) -> bool + '_ where - K: Borrow<Q>, - Q: ?Sized + Eq, + Q: ?Sized + Equivalent<K>, { - move |x| k.eq(x.borrow()) + move |x| k.equivalent(x) } #[cfg(not(feature = "nightly"))] #[cfg_attr(feature = "inline-more", inline)] -pub(crate) fn make_hash<K, Q, S>(hash_builder: &S, val: &Q) -> u64 +pub(crate) fn make_hash<Q, S>(hash_builder: &S, val: &Q) -> u64 where - K: Borrow<Q>, Q: Hash + ?Sized, S: BuildHasher, { @@ -256,38 +254,14 @@ where #[cfg(feature = "nightly")] #[cfg_attr(feature = "inline-more", inline)] -pub(crate) fn make_hash<K, Q, S>(hash_builder: &S, val: &Q) -> u64 +pub(crate) fn make_hash<Q, S>(hash_builder: &S, val: &Q) -> u64 where - K: Borrow<Q>, Q: Hash + ?Sized, S: BuildHasher, { hash_builder.hash_one(val) } -#[cfg(not(feature = "nightly"))] -#[cfg_attr(feature = "inline-more", inline)] -pub(crate) fn make_insert_hash<K, S>(hash_builder: &S, val: &K) -> u64 -where - K: Hash, - S: BuildHasher, -{ - use core::hash::Hasher; - let mut state = hash_builder.build_hasher(); - val.hash(&mut state); - state.finish() -} - -#[cfg(feature = "nightly")] -#[cfg_attr(feature = "inline-more", inline)] -pub(crate) fn make_insert_hash<K, S>(hash_builder: &S, val: &K) -> u64 -where - K: Hash, - S: BuildHasher, -{ - hash_builder.hash_one(val) -} - #[cfg(feature = "ahash")] impl<K, V> HashMap<K, V, DefaultHashBuilder> { /// Creates an empty `HashMap`. @@ -295,6 +269,18 @@ impl<K, V> HashMap<K, V, DefaultHashBuilder> { /// The hash map is initially created with a capacity of 0, so it will not allocate until it /// is first inserted into. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`], for example with + /// [`with_hasher`](HashMap::with_hasher) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -313,6 +299,18 @@ impl<K, V> HashMap<K, V, DefaultHashBuilder> { /// The hash map will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash map will not allocate. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`], for example with + /// [`with_capacity_and_hasher`](HashMap::with_capacity_and_hasher) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -328,11 +326,46 @@ impl<K, V> HashMap<K, V, DefaultHashBuilder> { } #[cfg(feature = "ahash")] -impl<K, V, A: Allocator + Clone> HashMap<K, V, DefaultHashBuilder, A> { +impl<K, V, A: Allocator> HashMap<K, V, DefaultHashBuilder, A> { /// Creates an empty `HashMap` using the given allocator. /// /// The hash map is initially created with a capacity of 0, so it will not allocate until it /// is first inserted into. + /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`], for example with + /// [`with_hasher_in`](HashMap::with_hasher_in) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use bumpalo::Bump; + /// + /// let bump = Bump::new(); + /// let mut map = HashMap::new_in(&bump); + /// + /// // The created HashMap holds none elements + /// assert_eq!(map.len(), 0); + /// + /// // The created HashMap also doesn't allocate memory + /// assert_eq!(map.capacity(), 0); + /// + /// // Now we insert element inside created HashMap + /// map.insert("One", 1); + /// // We can see that the HashMap holds 1 element + /// assert_eq!(map.len(), 1); + /// // And it also allocates some capacity + /// assert!(map.capacity() > 1); + /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn new_in(alloc: A) -> Self { Self::with_hasher_in(DefaultHashBuilder::default(), alloc) @@ -342,6 +375,46 @@ impl<K, V, A: Allocator + Clone> HashMap<K, V, DefaultHashBuilder, A> { /// /// The hash map will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash map will not allocate. + /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`], for example with + /// [`with_capacity_and_hasher_in`](HashMap::with_capacity_and_hasher_in) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashMap; + /// use bumpalo::Bump; + /// + /// let bump = Bump::new(); + /// let mut map = HashMap::with_capacity_in(5, &bump); + /// + /// // The created HashMap holds none elements + /// assert_eq!(map.len(), 0); + /// // But it can hold at least 5 elements without reallocating + /// let empty_map_capacity = map.capacity(); + /// assert!(empty_map_capacity >= 5); + /// + /// // Now we insert some 5 elements inside created HashMap + /// map.insert("One", 1); + /// map.insert("Two", 2); + /// map.insert("Three", 3); + /// map.insert("Four", 4); + /// map.insert("Five", 5); + /// + /// // We can see that the HashMap holds 5 elements + /// assert_eq!(map.len(), 5); + /// // But its capacity isn't changed + /// assert_eq!(map.capacity(), empty_map_capacity) + /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { Self::with_capacity_and_hasher_in(capacity, DefaultHashBuilder::default(), alloc) @@ -355,14 +428,21 @@ impl<K, V, S> HashMap<K, V, S> { /// The hash map is initially created with a capacity of 0, so it will not /// allocate until it is first inserted into. /// - /// Warning: `hash_builder` is normally randomly generated, and - /// is designed to allow HashMaps to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for /// the HashMap to be useful, see its documentation for details. /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + /// /// # Examples /// /// ``` @@ -376,8 +456,6 @@ impl<K, V, S> HashMap<K, V, S> { /// /// map.insert(1, 2); /// ``` - /// - /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html #[cfg_attr(feature = "inline-more", inline)] pub const fn with_hasher(hash_builder: S) -> Self { Self { @@ -392,14 +470,21 @@ impl<K, V, S> HashMap<K, V, S> { /// The hash map will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash map will not allocate. /// - /// Warning: `hash_builder` is normally randomly generated, and - /// is designed to allow HashMaps to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for /// the HashMap to be useful, see its documentation for details. /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html + /// /// # Examples /// /// ``` @@ -413,8 +498,6 @@ impl<K, V, S> HashMap<K, V, S> { /// /// map.insert(1, 2); /// ``` - /// - /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html #[cfg_attr(feature = "inline-more", inline)] pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self { Self { @@ -424,7 +507,7 @@ impl<K, V, S> HashMap<K, V, S> { } } -impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { +impl<K, V, S, A: Allocator> HashMap<K, V, S, A> { /// Returns a reference to the underlying allocator. #[inline] pub fn allocator(&self) -> &A { @@ -434,12 +517,19 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// Creates an empty `HashMap` which will use the given hash builder to hash /// keys. It will be allocated with the given allocator. /// - /// The created map has the default initial capacity. + /// The hash map is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`]. /// - /// Warning: `hash_builder` is normally randomly generated, and - /// is designed to allow HashMaps to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # Examples /// @@ -452,7 +542,7 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// map.insert(1, 2); /// ``` #[cfg_attr(feature = "inline-more", inline)] - pub fn with_hasher_in(hash_builder: S, alloc: A) -> Self { + pub const fn with_hasher_in(hash_builder: S, alloc: A) -> Self { Self { hash_builder, table: RawTable::new_in(alloc), @@ -465,10 +555,16 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// The hash map will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash map will not allocate. /// - /// Warning: `hash_builder` is normally randomly generated, and - /// is designed to allow HashMaps to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashMap` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashMap`]. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html /// /// # Examples /// @@ -810,14 +906,11 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// /// let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect(); /// assert_eq!(map.len(), 8); - /// let capacity_before_retain = map.capacity(); /// /// map.retain(|&k, _| k % 2 == 0); /// /// // We can see, that the number of elements inside map is changed. /// assert_eq!(map.len(), 4); - /// // But map capacity is equal to old one. - /// assert_eq!(map.capacity(), capacity_before_retain); /// /// let mut vec: Vec<(i32, i32)> = map.iter().map(|(&k, &v)| (k, v)).collect(); /// vec.sort_unstable(); @@ -844,26 +937,25 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// In other words, move all pairs `(k, v)` such that `f(&k, &mut v)` returns `true` out /// into another iterator. /// - /// Note that `drain_filter` lets you mutate every value in the filter closure, regardless of + /// Note that `extract_if` lets you mutate every value in the filter closure, regardless of /// whether you choose to keep or remove it. /// - /// When the returned DrainedFilter is dropped, any remaining elements that satisfy - /// the predicate are dropped from the table. - /// - /// It is unspecified how many more elements will be subjected to the closure - /// if a panic occurs in the closure, or a panic occurs while dropping an element, - /// or if the `DrainFilter` value is leaked. + /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating + /// or the iteration short-circuits, then the remaining elements will be retained. + /// Use [`retain()`] with a negated predicate if you do not need the returned iterator. /// /// Keeps the allocated memory for reuse. /// + /// [`retain()`]: HashMap::retain + /// /// # Examples /// /// ``` /// use hashbrown::HashMap; /// /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect(); - /// let capacity_before_drain_filter = map.capacity(); - /// let drained: HashMap<i32, i32> = map.drain_filter(|k, _v| k % 2 == 0).collect(); + /// + /// let drained: HashMap<i32, i32> = map.extract_if(|k, _v| k % 2 == 0).collect(); /// /// let mut evens = drained.keys().cloned().collect::<Vec<_>>(); /// let mut odds = map.keys().cloned().collect::<Vec<_>>(); @@ -872,27 +964,24 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// /// assert_eq!(evens, vec![0, 2, 4, 6]); /// assert_eq!(odds, vec![1, 3, 5, 7]); - /// // Map capacity is equal to old one. - /// assert_eq!(map.capacity(), capacity_before_drain_filter); /// /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect(); /// /// { // Iterator is dropped without being consumed. - /// let d = map.drain_filter(|k, _v| k % 2 != 0); + /// let d = map.extract_if(|k, _v| k % 2 != 0); /// } /// - /// // But the map lens have been reduced by half - /// // even if we do not use DrainFilter iterator. - /// assert_eq!(map.len(), 4); + /// // ExtractIf was not exhausted, therefore no elements were drained. + /// assert_eq!(map.len(), 8); /// ``` #[cfg_attr(feature = "inline-more", inline)] - pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, K, V, F, A> + pub fn extract_if<F>(&mut self, f: F) -> ExtractIf<'_, K, V, F, A> where F: FnMut(&K, &mut V) -> bool, { - DrainFilter { + ExtractIf { f, - inner: DrainFilterInner { + inner: RawExtractIf { iter: unsafe { self.table.iter() }, table: &mut self.table, }, @@ -984,7 +1073,7 @@ impl<K, V, S, A> HashMap<K, V, S, A> where K: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Reserves capacity for at least `additional` more elements to be inserted /// in the `HashMap`. The collection may reserve more space to avoid @@ -992,9 +1081,12 @@ where /// /// # Panics /// - /// Panics if the new allocation size overflows [`usize`]. + /// Panics if the new capacity exceeds [`isize::MAX`] bytes and [`abort`] the program + /// in case of allocation error. Use [`try_reserve`](HashMap::try_reserve) instead + /// if you want to handle memory allocation failure. /// - /// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html + /// [`isize::MAX`]: https://doc.rust-lang.org/std/primitive.isize.html + /// [`abort`]: https://doc.rust-lang.org/alloc/alloc/fn.handle_alloc_error.html /// /// # Examples /// @@ -1012,7 +1104,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn reserve(&mut self, additional: usize) { self.table - .reserve(additional, make_hasher::<K, _, V, S>(&self.hash_builder)); + .reserve(additional, make_hasher::<_, V, S>(&self.hash_builder)); } /// Tries to reserve capacity for at least `additional` more elements to be inserted @@ -1062,7 +1154,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> { self.table - .try_reserve(additional, make_hasher::<K, _, V, S>(&self.hash_builder)) + .try_reserve(additional, make_hasher::<_, V, S>(&self.hash_builder)) } /// Shrinks the capacity of the map as much as possible. It will drop @@ -1084,7 +1176,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn shrink_to_fit(&mut self) { self.table - .shrink_to(0, make_hasher::<K, _, V, S>(&self.hash_builder)); + .shrink_to(0, make_hasher::<_, V, S>(&self.hash_builder)); } /// Shrinks the capacity of the map with a lower limit. It will drop @@ -1113,7 +1205,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn shrink_to(&mut self, min_capacity: usize) { self.table - .shrink_to(min_capacity, make_hasher::<K, _, V, S>(&self.hash_builder)); + .shrink_to(min_capacity, make_hasher::<_, V, S>(&self.hash_builder)); } /// Gets the given key's corresponding entry in the map for in-place manipulation. @@ -1137,7 +1229,7 @@ where /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn entry(&mut self, key: K) -> Entry<'_, K, V, S, A> { - let hash = make_insert_hash::<K, S>(&self.hash_builder, &key); + let hash = make_hash::<K, S>(&self.hash_builder, &key); if let Some(elem) = self.table.find(hash, equivalent_key(&key)) { Entry::Occupied(OccupiedEntry { hash, @@ -1174,10 +1266,9 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn entry_ref<'a, 'b, Q: ?Sized>(&'a mut self, key: &'b Q) -> EntryRef<'a, 'b, K, Q, V, S, A> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { - let hash = make_hash::<K, Q, S>(&self.hash_builder, key); + let hash = make_hash::<Q, S>(&self.hash_builder, key); if let Some(elem) = self.table.find(hash, equivalent_key(key)) { EntryRef::Occupied(OccupiedEntryRef { hash, @@ -1216,12 +1307,11 @@ where #[inline] pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner(k) { - Some(&(_, ref v)) => Some(v), + Some((_, v)) => Some(v), None => None, } } @@ -1248,12 +1338,11 @@ where #[inline] pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner(k) { - Some(&(ref key, ref value)) => Some((key, value)), + Some((key, value)) => Some((key, value)), None => None, } } @@ -1261,13 +1350,12 @@ where #[inline] fn get_inner<Q: ?Sized>(&self, k: &Q) -> Option<&(K, V)> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { if self.table.is_empty() { None } else { - let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + let hash = make_hash::<Q, S>(&self.hash_builder, k); self.table.get(hash, equivalent_key(k)) } } @@ -1298,8 +1386,7 @@ where #[inline] pub fn get_key_value_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<(&K, &mut V)> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner_mut(k) { @@ -1330,8 +1417,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { self.get_inner(k).is_some() } @@ -1362,8 +1448,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { // Avoid `Option::map` because it bloats LLVM IR. match self.get_inner_mut(k) { @@ -1375,13 +1460,12 @@ where #[inline] fn get_inner_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut (K, V)> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { if self.table.is_empty() { None } else { - let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + let hash = make_hash::<Q, S>(&self.hash_builder, k); self.table.get_mut(hash, equivalent_key(k)) } } @@ -1431,8 +1515,7 @@ where /// ``` pub fn get_many_mut<Q: ?Sized, const N: usize>(&mut self, ks: [&Q; N]) -> Option<[&'_ mut V; N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { self.get_many_mut_inner(ks).map(|res| res.map(|(_, v)| v)) } @@ -1487,8 +1570,7 @@ where ks: [&Q; N], ) -> Option<[&'_ mut V; N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { self.get_many_unchecked_mut_inner(ks) .map(|res| res.map(|(_, v)| v)) @@ -1543,8 +1625,7 @@ where ks: [&Q; N], ) -> Option<[(&'_ K, &'_ mut V); N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { self.get_many_mut_inner(ks) .map(|res| res.map(|(k, v)| (&*k, v))) @@ -1599,8 +1680,7 @@ where ks: [&Q; N], ) -> Option<[(&'_ K, &'_ mut V); N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { self.get_many_unchecked_mut_inner(ks) .map(|res| res.map(|(k, v)| (&*k, v))) @@ -1611,12 +1691,11 @@ where ks: [&Q; N], ) -> Option<[&'_ mut (K, V); N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { let hashes = self.build_hashes_inner(ks); self.table - .get_many_mut(hashes, |i, (k, _)| ks[i].eq(k.borrow())) + .get_many_mut(hashes, |i, (k, _)| ks[i].equivalent(k)) } unsafe fn get_many_unchecked_mut_inner<Q: ?Sized, const N: usize>( @@ -1624,22 +1703,20 @@ where ks: [&Q; N], ) -> Option<[&'_ mut (K, V); N]> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { let hashes = self.build_hashes_inner(ks); self.table - .get_many_unchecked_mut(hashes, |i, (k, _)| ks[i].eq(k.borrow())) + .get_many_unchecked_mut(hashes, |i, (k, _)| ks[i].equivalent(k)) } fn build_hashes_inner<Q: ?Sized, const N: usize>(&self, ks: [&Q; N]) -> [u64; N] where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { let mut hashes = [0_u64; N]; for i in 0..N { - hashes[i] = make_hash::<K, Q, S>(&self.hash_builder, ks[i]); + hashes[i] = make_hash::<Q, S>(&self.hash_builder, ks[i]); } hashes } @@ -1672,13 +1749,19 @@ where /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn insert(&mut self, k: K, v: V) -> Option<V> { - let hash = make_insert_hash::<K, S>(&self.hash_builder, &k); - if let Some((_, item)) = self.table.get_mut(hash, equivalent_key(&k)) { - Some(mem::replace(item, v)) - } else { - self.table - .insert(hash, (k, v), make_hasher::<K, _, V, S>(&self.hash_builder)); - None + let hash = make_hash::<K, S>(&self.hash_builder, &k); + let hasher = make_hasher::<_, V, S>(&self.hash_builder); + match self + .table + .find_or_find_insert_slot(hash, equivalent_key(&k), hasher) + { + Ok(bucket) => Some(mem::replace(unsafe { &mut bucket.as_mut().1 }, v)), + Err(slot) => { + unsafe { + self.table.insert_in_slot(hash, slot, (k, v)); + } + None + } } } @@ -1733,10 +1816,10 @@ where /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn insert_unique_unchecked(&mut self, k: K, v: V) -> (&K, &mut V) { - let hash = make_insert_hash::<K, S>(&self.hash_builder, &k); + let hash = make_hash::<K, S>(&self.hash_builder, &k); let bucket = self .table - .insert(hash, (k, v), make_hasher::<K, _, V, S>(&self.hash_builder)); + .insert(hash, (k, v), make_hasher::<_, V, S>(&self.hash_builder)); let (k_ref, v_ref) = unsafe { bucket.as_mut() }; (k_ref, v_ref) } @@ -1801,19 +1884,17 @@ where /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.insert(1, "a"); - /// let capacity_before_remove = map.capacity(); /// /// assert_eq!(map.remove(&1), Some("a")); /// assert_eq!(map.remove(&1), None); /// - /// // Now map holds none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// // Now map holds none elements + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { // Avoid `Option::map` because it bloats LLVM IR. match self.remove_entry(k) { @@ -1842,26 +1923,24 @@ where /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.insert(1, "a"); - /// let capacity_before_remove = map.capacity(); /// /// assert_eq!(map.remove_entry(&1), Some((1, "a"))); /// assert_eq!(map.remove(&1), None); /// - /// // Now map hold none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// // Now map hold none elements + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)> where - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { - let hash = make_hash::<K, Q, S>(&self.hash_builder, k); + let hash = make_hash::<Q, S>(&self.hash_builder, k); self.table.remove_entry(hash, equivalent_key(k)) } } -impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { +impl<K, V, S, A: Allocator> HashMap<K, V, S, A> { /// Creates a raw entry builder for the HashMap. /// /// Raw entries provide the lowest level of control for searching and @@ -2013,19 +2092,31 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { RawEntryBuilder { map: self } } + /// Returns a reference to the [`RawTable`] used underneath [`HashMap`]. + /// This function is only available if the `raw` feature of the crate is enabled. + /// + /// See [`raw_table_mut`] for more. + /// + /// [`raw_table_mut`]: Self::raw_table_mut + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_table(&self) -> &RawTable<(K, V), A> { + &self.table + } + /// Returns a mutable reference to the [`RawTable`] used underneath [`HashMap`]. /// This function is only available if the `raw` feature of the crate is enabled. /// /// # Note /// - /// Calling the function safe, but using raw hash table API's may require + /// Calling this function is safe, but using the raw hash table API may require /// unsafe functions or blocks. /// /// `RawTable` API gives the lowest level of control under the map that can be useful /// for extending the HashMap's API, but may lead to *[undefined behavior]*. /// /// [`HashMap`]: struct.HashMap.html - /// [`RawTable`]: raw/struct.RawTable.html + /// [`RawTable`]: crate::raw::RawTable /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html /// /// # Examples @@ -2049,9 +2140,9 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// where /// F: Fn(&(K, V)) -> bool, /// { - /// let raw_table = map.raw_table(); + /// let raw_table = map.raw_table_mut(); /// match raw_table.find(hash, is_match) { - /// Some(bucket) => Some(unsafe { raw_table.remove(bucket) }), + /// Some(bucket) => Some(unsafe { raw_table.remove(bucket).0 }), /// None => None, /// } /// } @@ -2070,7 +2161,7 @@ impl<K, V, S, A: Allocator + Clone> HashMap<K, V, S, A> { /// ``` #[cfg(feature = "raw")] #[cfg_attr(feature = "inline-more", inline)] - pub fn raw_table(&mut self) -> &mut RawTable<(K, V), A> { + pub fn raw_table_mut(&mut self) -> &mut RawTable<(K, V), A> { &mut self.table } } @@ -2080,7 +2171,7 @@ where K: Eq + Hash, V: PartialEq, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn eq(&self, other: &Self) -> bool { if self.len() != other.len() { @@ -2097,7 +2188,7 @@ where K: Eq + Hash, V: Eq, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } @@ -2105,7 +2196,7 @@ impl<K, V, S, A> Debug for HashMap<K, V, S, A> where K: Debug, V: Debug, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_map().entries(self.iter()).finish() @@ -2115,7 +2206,7 @@ where impl<K, V, S, A> Default for HashMap<K, V, S, A> where S: Default, - A: Default + Allocator + Clone, + A: Default + Allocator, { /// Creates an empty `HashMap<K, V, S, A>`, with the `Default` value for the hasher and allocator. /// @@ -2140,10 +2231,10 @@ where impl<K, Q: ?Sized, V, S, A> Index<&Q> for HashMap<K, V, S, A> where - K: Eq + Hash + Borrow<Q>, - Q: Eq + Hash, + K: Eq + Hash, + Q: Hash + Equivalent<K>, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { type Output = V; @@ -2174,7 +2265,7 @@ where impl<K, V, A, const N: usize> From<[(K, V); N]> for HashMap<K, V, DefaultHashBuilder, A> where K: Eq + Hash, - A: Default + Allocator + Clone, + A: Default + Allocator, { /// # Examples /// @@ -2319,11 +2410,11 @@ impl<K, V> IterMut<'_, K, V> { /// assert_eq!(iter.next(), None); /// assert_eq!(iter.next(), None); /// ``` -pub struct IntoIter<K, V, A: Allocator + Clone = Global> { +pub struct IntoIter<K, V, A: Allocator = Global> { inner: RawIntoIter<(K, V), A>, } -impl<K, V, A: Allocator + Clone> IntoIter<K, V, A> { +impl<K, V, A: Allocator> IntoIter<K, V, A> { /// Returns a iterator of references over the remaining items. #[cfg_attr(feature = "inline-more", inline)] pub(super) fn iter(&self) -> Iter<'_, K, V> { @@ -2363,11 +2454,11 @@ impl<K, V, A: Allocator + Clone> IntoIter<K, V, A> { /// assert_eq!(keys.next(), None); /// assert_eq!(keys.next(), None); /// ``` -pub struct IntoKeys<K, V, A: Allocator + Clone = Global> { +pub struct IntoKeys<K, V, A: Allocator = Global> { inner: IntoIter<K, V, A>, } -impl<K, V, A: Allocator + Clone> Iterator for IntoKeys<K, V, A> { +impl<K, V, A: Allocator> Iterator for IntoKeys<K, V, A> { type Item = K; #[inline] @@ -2378,18 +2469,26 @@ impl<K, V, A: Allocator + Clone> Iterator for IntoKeys<K, V, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[inline] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, (k, _)| f(acc, k)) + } } -impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoKeys<K, V, A> { +impl<K, V, A: Allocator> ExactSizeIterator for IntoKeys<K, V, A> { #[inline] fn len(&self) -> usize { self.inner.len() } } -impl<K, V, A: Allocator + Clone> FusedIterator for IntoKeys<K, V, A> {} +impl<K, V, A: Allocator> FusedIterator for IntoKeys<K, V, A> {} -impl<K: Debug, V: Debug, A: Allocator + Clone> fmt::Debug for IntoKeys<K, V, A> { +impl<K: Debug, V: Debug, A: Allocator> fmt::Debug for IntoKeys<K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list() .entries(self.inner.iter().map(|(k, _)| k)) @@ -2425,11 +2524,11 @@ impl<K: Debug, V: Debug, A: Allocator + Clone> fmt::Debug for IntoKeys<K, V, A> /// assert_eq!(values.next(), None); /// assert_eq!(values.next(), None); /// ``` -pub struct IntoValues<K, V, A: Allocator + Clone = Global> { +pub struct IntoValues<K, V, A: Allocator = Global> { inner: IntoIter<K, V, A>, } -impl<K, V, A: Allocator + Clone> Iterator for IntoValues<K, V, A> { +impl<K, V, A: Allocator> Iterator for IntoValues<K, V, A> { type Item = V; #[inline] @@ -2440,18 +2539,26 @@ impl<K, V, A: Allocator + Clone> Iterator for IntoValues<K, V, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[inline] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, (_, v)| f(acc, v)) + } } -impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoValues<K, V, A> { +impl<K, V, A: Allocator> ExactSizeIterator for IntoValues<K, V, A> { #[inline] fn len(&self) -> usize { self.inner.len() } } -impl<K, V, A: Allocator + Clone> FusedIterator for IntoValues<K, V, A> {} +impl<K, V, A: Allocator> FusedIterator for IntoValues<K, V, A> {} -impl<K, V: Debug, A: Allocator + Clone> fmt::Debug for IntoValues<K, V, A> { +impl<K, V: Debug, A: Allocator> fmt::Debug for IntoValues<K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list() .entries(self.inner.iter().map(|(_, v)| v)) @@ -2583,11 +2690,11 @@ impl<K, V: Debug> fmt::Debug for Values<'_, K, V> { /// assert_eq!(drain_iter.next(), None); /// assert_eq!(drain_iter.next(), None); /// ``` -pub struct Drain<'a, K, V, A: Allocator + Clone = Global> { +pub struct Drain<'a, K, V, A: Allocator = Global> { inner: RawDrain<'a, (K, V), A>, } -impl<K, V, A: Allocator + Clone> Drain<'_, K, V, A> { +impl<K, V, A: Allocator> Drain<'_, K, V, A> { /// Returns a iterator of references over the remaining items. #[cfg_attr(feature = "inline-more", inline)] pub(super) fn iter(&self) -> Iter<'_, K, V> { @@ -2601,10 +2708,10 @@ impl<K, V, A: Allocator + Clone> Drain<'_, K, V, A> { /// A draining iterator over entries of a `HashMap` which don't satisfy the predicate /// `f(&k, &mut v)` in arbitrary order. The iterator element type is `(K, V)`. /// -/// This `struct` is created by the [`drain_filter`] method on [`HashMap`]. See its +/// This `struct` is created by the [`extract_if`] method on [`HashMap`]. See its /// documentation for more. /// -/// [`drain_filter`]: struct.HashMap.html#method.drain_filter +/// [`extract_if`]: struct.HashMap.html#method.extract_if /// [`HashMap`]: struct.HashMap.html /// /// # Examples @@ -2614,63 +2721,40 @@ impl<K, V, A: Allocator + Clone> Drain<'_, K, V, A> { /// /// let mut map: HashMap<i32, &str> = [(1, "a"), (2, "b"), (3, "c")].into(); /// -/// let mut drain_filter = map.drain_filter(|k, _v| k % 2 != 0); -/// let mut vec = vec![drain_filter.next(), drain_filter.next()]; +/// let mut extract_if = map.extract_if(|k, _v| k % 2 != 0); +/// let mut vec = vec![extract_if.next(), extract_if.next()]; /// -/// // The `DrainFilter` iterator produces items in arbitrary order, so the +/// // The `ExtractIf` iterator produces items in arbitrary order, so the /// // items must be sorted to test them against a sorted array. /// vec.sort_unstable(); /// assert_eq!(vec, [Some((1, "a")),Some((3, "c"))]); /// /// // It is fused iterator -/// assert_eq!(drain_filter.next(), None); -/// assert_eq!(drain_filter.next(), None); -/// drop(drain_filter); +/// assert_eq!(extract_if.next(), None); +/// assert_eq!(extract_if.next(), None); +/// drop(extract_if); /// /// assert_eq!(map.len(), 1); /// ``` -pub struct DrainFilter<'a, K, V, F, A: Allocator + Clone = Global> +#[must_use = "Iterators are lazy unless consumed"] +pub struct ExtractIf<'a, K, V, F, A: Allocator = Global> where F: FnMut(&K, &mut V) -> bool, { f: F, - inner: DrainFilterInner<'a, K, V, A>, -} - -impl<'a, K, V, F, A> Drop for DrainFilter<'a, K, V, F, A> -where - F: FnMut(&K, &mut V) -> bool, - A: Allocator + Clone, -{ - #[cfg_attr(feature = "inline-more", inline)] - fn drop(&mut self) { - while let Some(item) = self.next() { - let guard = ConsumeAllOnDrop(self); - drop(item); - mem::forget(guard); - } - } -} - -pub(super) struct ConsumeAllOnDrop<'a, T: Iterator>(pub &'a mut T); - -impl<T: Iterator> Drop for ConsumeAllOnDrop<'_, T> { - #[cfg_attr(feature = "inline-more", inline)] - fn drop(&mut self) { - self.0.for_each(drop); - } + inner: RawExtractIf<'a, (K, V), A>, } -impl<K, V, F, A> Iterator for DrainFilter<'_, K, V, F, A> +impl<K, V, F, A> Iterator for ExtractIf<'_, K, V, F, A> where F: FnMut(&K, &mut V) -> bool, - A: Allocator + Clone, + A: Allocator, { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] fn next(&mut self) -> Option<Self::Item> { - self.inner.next(&mut self.f) + self.inner.next(|&mut (ref k, ref mut v)| (self.f)(k, v)) } #[inline] @@ -2679,31 +2763,7 @@ where } } -impl<K, V, F> FusedIterator for DrainFilter<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {} - -/// Portions of `DrainFilter` shared with `set::DrainFilter` -pub(super) struct DrainFilterInner<'a, K, V, A: Allocator + Clone> { - pub iter: RawIter<(K, V)>, - pub table: &'a mut RawTable<(K, V), A>, -} - -impl<K, V, A: Allocator + Clone> DrainFilterInner<'_, K, V, A> { - #[cfg_attr(feature = "inline-more", inline)] - pub(super) fn next<F>(&mut self, f: &mut F) -> Option<(K, V)> - where - F: FnMut(&K, &mut V) -> bool, - { - unsafe { - for item in &mut self.iter { - let &mut (ref key, ref mut value) = item.as_mut(); - if f(key, value) { - return Some(self.table.remove(item)); - } - } - } - None - } -} +impl<K, V, F> FusedIterator for ExtractIf<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {} /// A mutable iterator over the values of a `HashMap` in arbitrary order. /// The iterator element type is `&'a mut V`. @@ -2791,7 +2851,7 @@ pub struct ValuesMut<'a, K, V> { /// /// assert_eq!(map.len(), 6); /// ``` -pub struct RawEntryBuilderMut<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct RawEntryBuilderMut<'a, K, V, S, A: Allocator = Global> { map: &'a mut HashMap<K, V, S, A>, } @@ -2879,7 +2939,7 @@ pub struct RawEntryBuilderMut<'a, K, V, S, A: Allocator + Clone = Global> { /// vec.sort_unstable(); /// assert_eq!(vec, [('a', 10), ('b', 20), ('c', 30), ('d', 40), ('e', 50), ('f', 60)]); /// ``` -pub enum RawEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { +pub enum RawEntryMut<'a, K, V, S, A: Allocator = Global> { /// An occupied entry. /// /// # Examples @@ -2970,7 +3030,7 @@ pub enum RawEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { /// assert_eq!(map.get(&"b"), None); /// assert_eq!(map.len(), 1); /// ``` -pub struct RawOccupiedEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct RawOccupiedEntryMut<'a, K, V, S, A: Allocator = Global> { elem: Bucket<(K, V)>, table: &'a mut RawTable<(K, V), A>, hash_builder: &'a S, @@ -2981,7 +3041,7 @@ where K: Send, V: Send, S: Send, - A: Send + Allocator + Clone, + A: Send + Allocator, { } unsafe impl<K, V, S, A> Sync for RawOccupiedEntryMut<'_, K, V, S, A> @@ -2989,7 +3049,7 @@ where K: Sync, V: Sync, S: Sync, - A: Sync + Allocator + Clone, + A: Sync + Allocator, { } @@ -3041,7 +3101,7 @@ where /// } /// assert!(map[&"c"] == 30 && map.len() == 3); /// ``` -pub struct RawVacantEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct RawVacantEntryMut<'a, K, V, S, A: Allocator = Global> { table: &'a mut RawTable<(K, V), A>, hash_builder: &'a S, } @@ -3080,11 +3140,11 @@ pub struct RawVacantEntryMut<'a, K, V, S, A: Allocator + Clone = Global> { /// assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv); /// } /// ``` -pub struct RawEntryBuilder<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct RawEntryBuilder<'a, K, V, S, A: Allocator = Global> { map: &'a HashMap<K, V, S, A>, } -impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawEntryBuilderMut<'a, K, V, S, A> { /// Creates a `RawEntryMut` from the given key. /// /// # Examples @@ -3103,10 +3163,9 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { pub fn from_key<Q: ?Sized>(self, k: &Q) -> RawEntryMut<'a, K, V, S, A> where S: BuildHasher, - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { - let hash = make_hash::<K, Q, S>(&self.map.hash_builder, k); + let hash = make_hash::<Q, S>(&self.map.hash_builder, k); self.from_key_hashed_nocheck(hash, k) } @@ -3136,14 +3195,13 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { #[allow(clippy::wrong_self_convention)] pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S, A> where - K: Borrow<Q>, - Q: Eq, + Q: Equivalent<K>, { self.from_hash(hash, equivalent(k)) } } -impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawEntryBuilderMut<'a, K, V, S, A> { /// Creates a `RawEntryMut` from the given hash and matching function. /// /// # Examples @@ -3194,7 +3252,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilderMut<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawEntryBuilder<'a, K, V, S, A> { /// Access an immutable entry by key. /// /// # Examples @@ -3211,10 +3269,9 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { pub fn from_key<Q: ?Sized>(self, k: &Q) -> Option<(&'a K, &'a V)> where S: BuildHasher, - K: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<K>, { - let hash = make_hash::<K, Q, S>(&self.map.hash_builder, k); + let hash = make_hash::<Q, S>(&self.map.hash_builder, k); self.from_key_hashed_nocheck(hash, k) } @@ -3242,8 +3299,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { #[allow(clippy::wrong_self_convention)] pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)> where - K: Borrow<Q>, - Q: Eq, + Q: Equivalent<K>, { self.from_hash(hash, equivalent(k)) } @@ -3254,7 +3310,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { F: FnMut(&K) -> bool, { match self.map.table.get(hash, |(k, _)| is_match(k)) { - Some(&(ref key, ref value)) => Some((key, value)), + Some((key, value)) => Some((key, value)), None => None, } } @@ -3289,7 +3345,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryBuilder<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> RawEntryMut<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawEntryMut<'a, K, V, S, A> { /// Sets the value of the entry, and returns a RawOccupiedEntryMut. /// /// # Examples @@ -3483,7 +3539,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawEntryMut<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> RawOccupiedEntryMut<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawOccupiedEntryMut<'a, K, V, S, A> { /// Gets a reference to the key in the entry. /// /// # Examples @@ -3650,7 +3706,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawOccupiedEntryMut<'a, K, V, S, A> { #[cfg_attr(feature = "inline-more", inline)] pub fn get_key_value(&self) -> (&K, &V) { unsafe { - let &(ref key, ref value) = self.elem.as_ref(); + let (key, value) = self.elem.as_ref(); (key, value) } } @@ -3822,7 +3878,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawOccupiedEntryMut<'a, K, V, S, A> { /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { - unsafe { self.table.remove(self.elem) } + unsafe { self.table.remove(self.elem).0 } } /// Provides shared access to the key and owned access to the value of @@ -3882,7 +3938,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawOccupiedEntryMut<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> RawVacantEntryMut<'a, K, V, S, A> { /// Sets the value of the entry with the VacantEntry's key, /// and returns a mutable reference to it. /// @@ -3906,7 +3962,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { K: Hash, S: BuildHasher, { - let hash = make_insert_hash::<K, S>(self.hash_builder, &key); + let hash = make_hash::<K, S>(self.hash_builder, &key); self.insert_hashed_nocheck(hash, key, value) } @@ -3950,7 +4006,7 @@ impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { let &mut (ref mut k, ref mut v) = self.table.insert_entry( hash, (key, value), - make_hasher::<K, _, V, S>(self.hash_builder), + make_hasher::<_, V, S>(self.hash_builder), ); (k, v) } @@ -4014,11 +4070,11 @@ impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { K: Hash, S: BuildHasher, { - let hash = make_insert_hash::<K, S>(self.hash_builder, &key); + let hash = make_hash::<K, S>(self.hash_builder, &key); let elem = self.table.insert( hash, (key, value), - make_hasher::<K, _, V, S>(self.hash_builder), + make_hasher::<_, V, S>(self.hash_builder), ); RawOccupiedEntryMut { elem, @@ -4028,13 +4084,13 @@ impl<'a, K, V, S, A: Allocator + Clone> RawVacantEntryMut<'a, K, V, S, A> { } } -impl<K, V, S, A: Allocator + Clone> Debug for RawEntryBuilderMut<'_, K, V, S, A> { +impl<K, V, S, A: Allocator> Debug for RawEntryBuilderMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawEntryBuilder").finish() } } -impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawEntryMut<'_, K, V, S, A> { +impl<K: Debug, V: Debug, S, A: Allocator> Debug for RawEntryMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { RawEntryMut::Vacant(ref v) => f.debug_tuple("RawEntry").field(v).finish(), @@ -4043,7 +4099,7 @@ impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawEntryMut<'_, K, V } } -impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawOccupiedEntryMut<'_, K, V, S, A> { +impl<K: Debug, V: Debug, S, A: Allocator> Debug for RawOccupiedEntryMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawOccupiedEntryMut") .field("key", self.key()) @@ -4052,13 +4108,13 @@ impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for RawOccupiedEntryMut< } } -impl<K, V, S, A: Allocator + Clone> Debug for RawVacantEntryMut<'_, K, V, S, A> { +impl<K, V, S, A: Allocator> Debug for RawVacantEntryMut<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawVacantEntryMut").finish() } } -impl<K, V, S, A: Allocator + Clone> Debug for RawEntryBuilder<'_, K, V, S, A> { +impl<K, V, S, A: Allocator> Debug for RawEntryBuilder<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("RawEntryBuilder").finish() } @@ -4109,7 +4165,7 @@ impl<K, V, S, A: Allocator + Clone> Debug for RawEntryBuilder<'_, K, V, S, A> { /// ``` pub enum Entry<'a, K, V, S, A = Global> where - A: Allocator + Clone, + A: Allocator, { /// An occupied entry. /// @@ -4142,7 +4198,7 @@ where Vacant(VacantEntry<'a, K, V, S, A>), } -impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for Entry<'_, K, V, S, A> { +impl<K: Debug, V: Debug, S, A: Allocator> Debug for Entry<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), @@ -4191,7 +4247,7 @@ impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for Entry<'_, K, V, S, A /// assert_eq!(map.get(&"c"), None); /// assert_eq!(map.len(), 2); /// ``` -pub struct OccupiedEntry<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct OccupiedEntry<'a, K, V, S = DefaultHashBuilder, A: Allocator = Global> { hash: u64, key: Option<K>, elem: Bucket<(K, V)>, @@ -4203,7 +4259,7 @@ where K: Send, V: Send, S: Send, - A: Send + Allocator + Clone, + A: Send + Allocator, { } unsafe impl<K, V, S, A> Sync for OccupiedEntry<'_, K, V, S, A> @@ -4211,11 +4267,11 @@ where K: Sync, V: Sync, S: Sync, - A: Sync + Allocator + Clone, + A: Sync + Allocator, { } -impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedEntry<'_, K, V, S, A> { +impl<K: Debug, V: Debug, S, A: Allocator> Debug for OccupiedEntry<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("OccupiedEntry") .field("key", self.key()) @@ -4254,13 +4310,13 @@ impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedEntry<'_, K, /// } /// assert!(map[&"b"] == 20 && map.len() == 2); /// ``` -pub struct VacantEntry<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct VacantEntry<'a, K, V, S = DefaultHashBuilder, A: Allocator = Global> { hash: u64, key: K, table: &'a mut HashMap<K, V, S, A>, } -impl<K: Debug, V, S, A: Allocator + Clone> Debug for VacantEntry<'_, K, V, S, A> { +impl<K: Debug, V, S, A: Allocator> Debug for VacantEntry<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_tuple("VacantEntry").field(self.key()).finish() } @@ -4320,7 +4376,7 @@ impl<K: Debug, V, S, A: Allocator + Clone> Debug for VacantEntry<'_, K, V, S, A> /// ``` pub enum EntryRef<'a, 'b, K, Q: ?Sized, V, S, A = Global> where - A: Allocator + Clone, + A: Allocator, { /// An occupied entry. /// @@ -4353,7 +4409,7 @@ where Vacant(VacantEntryRef<'a, 'b, K, Q, V, S, A>), } -impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator + Clone> Debug +impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator> Debug for EntryRef<'_, '_, K, Q, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { @@ -4431,7 +4487,7 @@ impl<'a, K: Borrow<Q>, Q: ?Sized> AsRef<Q> for KeyOrRef<'a, K, Q> { /// assert_eq!(map.get("c"), None); /// assert_eq!(map.len(), 2); /// ``` -pub struct OccupiedEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone = Global> { +pub struct OccupiedEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator = Global> { hash: u64, key: Option<KeyOrRef<'b, K, Q>>, elem: Bucket<(K, V)>, @@ -4444,7 +4500,7 @@ where Q: Sync + ?Sized, V: Send, S: Send, - A: Send + Allocator + Clone, + A: Send + Allocator, { } unsafe impl<'a, 'b, K, Q, V, S, A> Sync for OccupiedEntryRef<'a, 'b, K, Q, V, S, A> @@ -4453,16 +4509,16 @@ where Q: Sync + ?Sized, V: Sync, S: Sync, - A: Sync + Allocator + Clone, + A: Sync + Allocator, { } -impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator + Clone> Debug +impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator> Debug for OccupiedEntryRef<'_, '_, K, Q, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("OccupiedEntryRef") - .field("key", &self.key()) + .field("key", &self.key().borrow()) .field("value", &self.get()) .finish() } @@ -4498,13 +4554,13 @@ impl<K: Borrow<Q>, Q: ?Sized + Debug, V: Debug, S, A: Allocator + Clone> Debug /// } /// assert!(map["b"] == 20 && map.len() == 2); /// ``` -pub struct VacantEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone = Global> { +pub struct VacantEntryRef<'a, 'b, K, Q: ?Sized, V, S, A: Allocator = Global> { hash: u64, key: KeyOrRef<'b, K, Q>, table: &'a mut HashMap<K, V, S, A>, } -impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator + Clone> Debug +impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator> Debug for VacantEntryRef<'_, '_, K, Q, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { @@ -4536,14 +4592,14 @@ impl<K: Borrow<Q>, Q: ?Sized + Debug, V, S, A: Allocator + Clone> Debug /// } /// assert_eq!(map[&"a"], 100); /// ``` -pub struct OccupiedError<'a, K, V, S, A: Allocator + Clone = Global> { +pub struct OccupiedError<'a, K, V, S, A: Allocator = Global> { /// The entry in the map that was already occupied. pub entry: OccupiedEntry<'a, K, V, S, A>, /// The value which was not inserted, because the entry was already occupied. pub value: V, } -impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedError<'_, K, V, S, A> { +impl<K: Debug, V: Debug, S, A: Allocator> Debug for OccupiedError<'_, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("OccupiedError") .field("key", self.entry.key()) @@ -4553,9 +4609,7 @@ impl<K: Debug, V: Debug, S, A: Allocator + Clone> Debug for OccupiedError<'_, K, } } -impl<'a, K: Debug, V: Debug, S, A: Allocator + Clone> fmt::Display - for OccupiedError<'a, K, V, S, A> -{ +impl<'a, K: Debug, V: Debug, S, A: Allocator> fmt::Display for OccupiedError<'a, K, V, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!( f, @@ -4567,7 +4621,7 @@ impl<'a, K: Debug, V: Debug, S, A: Allocator + Clone> fmt::Display } } -impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a HashMap<K, V, S, A> { +impl<'a, K, V, S, A: Allocator> IntoIterator for &'a HashMap<K, V, S, A> { type Item = (&'a K, &'a V); type IntoIter = Iter<'a, K, V>; @@ -4599,7 +4653,7 @@ impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a HashMap<K, V, S, A> } } -impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a mut HashMap<K, V, S, A> { +impl<'a, K, V, S, A: Allocator> IntoIterator for &'a mut HashMap<K, V, S, A> { type Item = (&'a K, &'a mut V); type IntoIter = IterMut<'a, K, V>; @@ -4636,7 +4690,7 @@ impl<'a, K, V, S, A: Allocator + Clone> IntoIterator for &'a mut HashMap<K, V, S } } -impl<K, V, S, A: Allocator + Clone> IntoIterator for HashMap<K, V, S, A> { +impl<K, V, S, A: Allocator> IntoIterator for HashMap<K, V, S, A> { type Item = (K, V); type IntoIter = IntoIter<K, V, A>; @@ -4684,6 +4738,17 @@ impl<'a, K, V> Iterator for Iter<'a, K, V> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, x| unsafe { + let (k, v) = x.as_ref(); + f(acc, (k, v)) + }) + } } impl<K, V> ExactSizeIterator for Iter<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] @@ -4712,6 +4777,17 @@ impl<'a, K, V> Iterator for IterMut<'a, K, V> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, x| unsafe { + let (k, v) = x.as_mut(); + f(acc, (k, v)) + }) + } } impl<K, V> ExactSizeIterator for IterMut<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] @@ -4731,7 +4807,7 @@ where } } -impl<K, V, A: Allocator + Clone> Iterator for IntoIter<K, V, A> { +impl<K, V, A: Allocator> Iterator for IntoIter<K, V, A> { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] @@ -4742,16 +4818,24 @@ impl<K, V, A: Allocator + Clone> Iterator for IntoIter<K, V, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, f) + } } -impl<K, V, A: Allocator + Clone> ExactSizeIterator for IntoIter<K, V, A> { +impl<K, V, A: Allocator> ExactSizeIterator for IntoIter<K, V, A> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } -impl<K, V, A: Allocator + Clone> FusedIterator for IntoIter<K, V, A> {} +impl<K, V, A: Allocator> FusedIterator for IntoIter<K, V, A> {} -impl<K: Debug, V: Debug, A: Allocator + Clone> fmt::Debug for IntoIter<K, V, A> { +impl<K: Debug, V: Debug, A: Allocator> fmt::Debug for IntoIter<K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.iter()).finish() } @@ -4772,6 +4856,14 @@ impl<'a, K, V> Iterator for Keys<'a, K, V> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, (k, _)| f(acc, k)) + } } impl<K, V> ExactSizeIterator for Keys<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] @@ -4796,6 +4888,14 @@ impl<'a, K, V> Iterator for Values<'a, K, V> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, (_, v)| f(acc, v)) + } } impl<K, V> ExactSizeIterator for Values<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] @@ -4820,6 +4920,14 @@ impl<'a, K, V> Iterator for ValuesMut<'a, K, V> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, |acc, (_, v)| f(acc, v)) + } } impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> { #[cfg_attr(feature = "inline-more", inline)] @@ -4837,7 +4945,7 @@ impl<K, V: Debug> fmt::Debug for ValuesMut<'_, K, V> { } } -impl<'a, K, V, A: Allocator + Clone> Iterator for Drain<'a, K, V, A> { +impl<'a, K, V, A: Allocator> Iterator for Drain<'a, K, V, A> { type Item = (K, V); #[cfg_attr(feature = "inline-more", inline)] @@ -4848,27 +4956,35 @@ impl<'a, K, V, A: Allocator + Clone> Iterator for Drain<'a, K, V, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, f) + } } -impl<K, V, A: Allocator + Clone> ExactSizeIterator for Drain<'_, K, V, A> { +impl<K, V, A: Allocator> ExactSizeIterator for Drain<'_, K, V, A> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.inner.len() } } -impl<K, V, A: Allocator + Clone> FusedIterator for Drain<'_, K, V, A> {} +impl<K, V, A: Allocator> FusedIterator for Drain<'_, K, V, A> {} impl<K, V, A> fmt::Debug for Drain<'_, K, V, A> where K: fmt::Debug, V: fmt::Debug, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.iter()).finish() } } -impl<'a, K, V, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> Entry<'a, K, V, S, A> { /// Sets the value of the entry, and returns an OccupiedEntry. /// /// # Examples @@ -5115,7 +5231,7 @@ impl<'a, K, V, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { } } -impl<'a, K, V: Default, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { +impl<'a, K, V: Default, S, A: Allocator> Entry<'a, K, V, S, A> { /// Ensures a value is in the entry by inserting the default value if empty, /// and returns a mutable reference to the value in the entry. /// @@ -5148,7 +5264,7 @@ impl<'a, K, V: Default, S, A: Allocator + Clone> Entry<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> OccupiedEntry<'a, K, V, S, A> { /// Gets a reference to the key in the entry. /// /// # Examples @@ -5183,7 +5299,6 @@ impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry("poneyland").or_insert(12); - /// let capacity_before_remove = map.capacity(); /// /// if let Entry::Occupied(o) = map.entry("poneyland") { /// // We delete the entry from the map. @@ -5191,12 +5306,12 @@ impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { /// } /// /// assert_eq!(map.contains_key("poneyland"), false); - /// // Now map hold none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// // Now map hold none elements + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { - unsafe { self.table.table.remove(self.elem) } + unsafe { self.table.table.remove(self.elem).0 } } /// Gets a reference to the value in the entry. @@ -5319,15 +5434,14 @@ impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry("poneyland").or_insert(12); - /// let capacity_before_remove = map.capacity(); /// /// if let Entry::Occupied(o) = map.entry("poneyland") { /// assert_eq!(o.remove(), 12); /// } /// /// assert_eq!(map.contains_key("poneyland"), false); - /// // Now map hold none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// // Now map hold none elements + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove(self) -> V { @@ -5505,7 +5619,7 @@ impl<'a, K, V, S, A: Allocator + Clone> OccupiedEntry<'a, K, V, S, A> { } } -impl<'a, K, V, S, A: Allocator + Clone> VacantEntry<'a, K, V, S, A> { +impl<'a, K, V, S, A: Allocator> VacantEntry<'a, K, V, S, A> { /// Gets a reference to the key that would be used when inserting a value /// through the `VacantEntry`. /// @@ -5567,7 +5681,7 @@ impl<'a, K, V, S, A: Allocator + Clone> VacantEntry<'a, K, V, S, A> { let entry = table.insert_entry( self.hash, (self.key, value), - make_hasher::<K, _, V, S>(&self.table.hash_builder), + make_hasher::<_, V, S>(&self.table.hash_builder), ); &mut entry.1 } @@ -5581,7 +5695,7 @@ impl<'a, K, V, S, A: Allocator + Clone> VacantEntry<'a, K, V, S, A> { let elem = self.table.table.insert( self.hash, (self.key, value), - make_hasher::<K, _, V, S>(&self.table.hash_builder), + make_hasher::<_, V, S>(&self.table.hash_builder), ); OccupiedEntry { hash: self.hash, @@ -5592,7 +5706,7 @@ impl<'a, K, V, S, A: Allocator + Clone> VacantEntry<'a, K, V, S, A> { } } -impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, S, A> { +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator> EntryRef<'a, 'b, K, Q, V, S, A> { /// Sets the value of the entry, and returns an OccupiedEntryRef. /// /// # Examples @@ -5682,10 +5796,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, /// Ensures a value is in the entry by inserting, if empty, the result of the default function. /// This method allows for generating key-derived values for insertion by providing the default - /// function a reference to the key that was moved during the `.entry_ref(key)` method call. - /// - /// The reference to the moved key is provided so that cloning or copying the key is - /// unnecessary, unlike with `.or_insert_with(|| ... )`. + /// function an access to the borrower form of the key. /// /// # Examples /// @@ -5737,7 +5848,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, K: Borrow<Q>, { match *self { - EntryRef::Occupied(ref entry) => entry.key(), + EntryRef::Occupied(ref entry) => entry.key().borrow(), EntryRef::Vacant(ref entry) => entry.key(), } } @@ -5833,8 +5944,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, #[cfg_attr(feature = "inline-more", inline)] pub fn and_replace_entry_with<F>(self, f: F) -> Self where - F: FnOnce(&Q, V) -> Option<V>, - K: Borrow<Q>, + F: FnOnce(&K, V) -> Option<V>, { match self { EntryRef::Occupied(entry) => entry.replace_entry_with(f), @@ -5843,7 +5953,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, } } -impl<'a, 'b, K, Q: ?Sized, V: Default, S, A: Allocator + Clone> EntryRef<'a, 'b, K, Q, V, S, A> { +impl<'a, 'b, K, Q: ?Sized, V: Default, S, A: Allocator> EntryRef<'a, 'b, K, Q, V, S, A> { /// Ensures a value is in the entry by inserting the default value if empty, /// and returns a mutable reference to the value in the entry. /// @@ -5876,7 +5986,7 @@ impl<'a, 'b, K, Q: ?Sized, V: Default, S, A: Allocator + Clone> EntryRef<'a, 'b, } } -impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> { +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator> OccupiedEntryRef<'a, 'b, K, Q, V, S, A> { /// Gets a reference to the key in the entry. /// /// # Examples @@ -5893,11 +6003,8 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// } /// ``` #[cfg_attr(feature = "inline-more", inline)] - pub fn key(&self) -> &Q - where - K: Borrow<Q>, - { - unsafe { &self.elem.as_ref().0 }.borrow() + pub fn key(&self) -> &K { + unsafe { &self.elem.as_ref().0 } } /// Take the ownership of the key and value from the map. @@ -5914,7 +6021,6 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry_ref("poneyland").or_insert(12); - /// let capacity_before_remove = map.capacity(); /// /// if let EntryRef::Occupied(o) = map.entry_ref("poneyland") { /// // We delete the entry from the map. @@ -5923,11 +6029,11 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// /// assert_eq!(map.contains_key("poneyland"), false); /// // Now map hold none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { - unsafe { self.table.table.remove(self.elem) } + unsafe { self.table.table.remove(self.elem).0 } } /// Gets a reference to the value in the entry. @@ -6048,7 +6154,6 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// assert!(map.is_empty() && map.capacity() == 0); /// /// map.entry_ref("poneyland").or_insert(12); - /// let capacity_before_remove = map.capacity(); /// /// if let EntryRef::Occupied(o) = map.entry_ref("poneyland") { /// assert_eq!(o.remove(), 12); @@ -6056,7 +6161,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// /// assert_eq!(map.contains_key("poneyland"), false); /// // Now map hold none elements but capacity is equal to the old one - /// assert!(map.len() == 0 && map.capacity() == capacity_before_remove); + /// assert!(map.is_empty()); /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove(self) -> V { @@ -6068,7 +6173,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// /// # Panics /// - /// Will panic if this OccupiedEntry was created through [`EntryRef::insert`]. + /// Will panic if this OccupiedEntryRef was created through [`EntryRef::insert`]. /// /// # Examples /// @@ -6110,7 +6215,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// /// # Panics /// - /// Will panic if this OccupiedEntry was created through [`Entry::insert`]. + /// Will panic if this OccupiedEntryRef was created through [`EntryRef::insert`]. /// /// # Examples /// @@ -6138,7 +6243,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, /// fn reclaim_memory(map: &mut HashMap<Rc<str>, usize>, keys: &[Rc<str>]) { /// for key in keys { /// if let EntryRef::Occupied(entry) = map.entry_ref(key.as_ref()) { - /// /// Replaces the entry's key with our version of it in `keys`. + /// // Replaces the entry's key with our version of it in `keys`. /// entry.replace_key(); /// } /// } @@ -6204,8 +6309,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, #[cfg_attr(feature = "inline-more", inline)] pub fn replace_entry_with<F>(self, f: F) -> EntryRef<'a, 'b, K, Q, V, S, A> where - F: FnOnce(&Q, V) -> Option<V>, - K: Borrow<Q>, + F: FnOnce(&K, V) -> Option<V>, { unsafe { let mut spare_key = None; @@ -6213,7 +6317,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, self.table .table .replace_bucket_with(self.elem.clone(), |(key, value)| { - if let Some(new_value) = f(key.borrow(), value) { + if let Some(new_value) = f(&key, value) { Some((key, new_value)) } else { spare_key = Some(KeyOrRef::Owned(key)); @@ -6234,7 +6338,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> OccupiedEntryRef<'a, 'b, } } -impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> VacantEntryRef<'a, 'b, K, Q, V, S, A> { +impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator> VacantEntryRef<'a, 'b, K, Q, V, S, A> { /// Gets a reference to the key that would be used when inserting a value /// through the `VacantEntryRef`. /// @@ -6305,7 +6409,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> VacantEntryRef<'a, 'b, K, let entry = table.insert_entry( self.hash, (self.key.into_owned(), value), - make_hasher::<K, _, V, S>(&self.table.hash_builder), + make_hasher::<_, V, S>(&self.table.hash_builder), ); &mut entry.1 } @@ -6319,7 +6423,7 @@ impl<'a, 'b, K, Q: ?Sized, V, S, A: Allocator + Clone> VacantEntryRef<'a, 'b, K, let elem = self.table.table.insert( self.hash, (self.key.into_owned(), value), - make_hasher::<K, _, V, S>(&self.table.hash_builder), + make_hasher::<_, V, S>(&self.table.hash_builder), ); OccupiedEntryRef { hash: self.hash, @@ -6334,7 +6438,7 @@ impl<K, V, S, A> FromIterator<(K, V)> for HashMap<K, V, S, A> where K: Eq + Hash, S: BuildHasher + Default, - A: Default + Allocator + Clone, + A: Default + Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self { @@ -6354,7 +6458,7 @@ impl<K, V, S, A> Extend<(K, V)> for HashMap<K, V, S, A> where K: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. /// Replace values with existing keys with new values returned from the iterator. @@ -6438,7 +6542,7 @@ where K: Eq + Hash + Copy, V: Copy, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. /// Replace values with existing keys with new values returned from the iterator. @@ -6455,17 +6559,17 @@ where /// map.insert(1, 100); /// /// let arr = [(1, 1), (2, 2)]; - /// let some_iter = arr.iter().map(|&(k, v)| (k, v)); + /// let some_iter = arr.iter().map(|(k, v)| (k, v)); /// map.extend(some_iter); /// // Replace values with existing keys with new values returned from the iterator. /// // So that the map.get(&1) doesn't return Some(&100). /// assert_eq!(map.get(&1), Some(&1)); /// /// let some_vec: Vec<_> = vec![(3, 3), (4, 4)]; - /// map.extend(some_vec.iter().map(|&(k, v)| (k, v))); + /// map.extend(some_vec.iter().map(|(k, v)| (k, v))); /// /// let some_arr = [(5, 5), (6, 6)]; - /// map.extend(some_arr.iter().map(|&(k, v)| (k, v))); + /// map.extend(some_arr.iter().map(|(k, v)| (k, v))); /// /// // You can also extend from another HashMap /// let mut new_map = HashMap::new(); @@ -6503,7 +6607,7 @@ where K: Eq + Hash + Copy, V: Copy, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Inserts all new key-values from the iterator to existing `HashMap<K, V, S, A>`. /// Replace values with existing keys with new values returned from the iterator. @@ -6570,12 +6674,12 @@ fn assert_covariance() { fn iter_val<'a, 'new>(v: Iter<'a, u8, &'static str>) -> Iter<'a, u8, &'new str> { v } - fn into_iter_key<'new, A: Allocator + Clone>( + fn into_iter_key<'new, A: Allocator>( v: IntoIter<&'static str, u8, A>, ) -> IntoIter<&'new str, u8, A> { v } - fn into_iter_val<'new, A: Allocator + Clone>( + fn into_iter_val<'new, A: Allocator>( v: IntoIter<u8, &'static str, A>, ) -> IntoIter<u8, &'new str, A> { v @@ -6605,6 +6709,12 @@ mod test_map { use super::Entry::{Occupied, Vacant}; use super::EntryRef; use super::{HashMap, RawEntryMut}; + use alloc::string::{String, ToString}; + use alloc::sync::Arc; + use allocator_api2::alloc::{AllocError, Allocator, Global}; + use core::alloc::Layout; + use core::ptr::NonNull; + use core::sync::atomic::{AtomicI8, Ordering}; use rand::{rngs::SmallRng, Rng, SeedableRng}; use std::borrow::ToOwned; use std::cell::RefCell; @@ -6695,7 +6805,7 @@ mod test_map { assert_eq!(m2.len(), 2); } - thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = RefCell::new(Vec::new()) } + thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = const { RefCell::new(Vec::new()) } } #[derive(Hash, PartialEq, Eq)] struct Droppable { @@ -6827,7 +6937,6 @@ mod test_map { } }); - #[allow(clippy::let_underscore_drop)] // kind-of a false positive for _ in half.by_ref() {} DROP_VECTOR.with(|v| { @@ -7155,10 +7264,10 @@ mod test_map { map.insert(1, 2); map.insert(3, 4); - let map_str = format!("{:?}", map); + let map_str = format!("{map:?}"); assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}"); - assert_eq!(format!("{:?}", empty), "{}"); + assert_eq!(format!("{empty:?}"), "{}"); } #[test] @@ -7474,7 +7583,7 @@ mod test_map { // Test for #19292 fn check(m: &HashMap<i32, ()>) { for k in m.keys() { - assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } @@ -7510,7 +7619,7 @@ mod test_map { // Test for #19292 fn check(m: &HashMap<std::string::String, ()>) { for k in m.keys() { - assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } @@ -7559,6 +7668,7 @@ mod test_map { } #[test] + #[allow(clippy::needless_borrow)] fn test_extend_ref_kv_tuple() { use std::ops::AddAssign; let mut a = HashMap::new(); @@ -7580,7 +7690,7 @@ mod test_map { let vec: Vec<_> = (100..200).map(|i| (i, i)).collect(); a.extend(iter); a.extend(&vec); - a.extend(&create_arr::<i32, 100>(200, 1)); + a.extend(create_arr::<i32, 100>(200, 1)); assert_eq!(a.len(), 300); @@ -7981,7 +8091,7 @@ mod test_map { // Test for #19292 fn check(m: &HashMap<i32, ()>) { for k in m.keys() { - assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } @@ -8011,7 +8121,7 @@ mod test_map { // Test for #19292 fn check(m: &HashMap<std::string::String, ()>) { for k in m.keys() { - assert!(m.contains_key(k), "{} is in keys() but not in the map?", k); + assert!(m.contains_key(k), "{k} is in keys() but not in the map?"); } } @@ -8049,10 +8159,10 @@ mod test_map { } #[test] - fn test_drain_filter() { + fn test_extract_if() { { let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect(); - let drained = map.drain_filter(|&k, _| k % 2 == 0); + let drained = map.extract_if(|&k, _| k % 2 == 0); let mut out = drained.collect::<Vec<_>>(); out.sort_unstable(); assert_eq!(vec![(0, 0), (2, 20), (4, 40), (6, 60)], out); @@ -8060,7 +8170,7 @@ mod test_map { } { let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect(); - drop(map.drain_filter(|&k, _| k % 2 == 0)); + map.extract_if(|&k, _| k % 2 == 0).for_each(drop); assert_eq!(map.len(), 4); } } @@ -8070,27 +8180,32 @@ mod test_map { fn test_try_reserve() { use crate::TryReserveError::{AllocError, CapacityOverflow}; - const MAX_USIZE: usize = usize::MAX; + const MAX_ISIZE: usize = isize::MAX as usize; let mut empty_bytes: HashMap<u8, u8> = HashMap::new(); - if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_USIZE) { + if let Err(CapacityOverflow) = empty_bytes.try_reserve(usize::MAX) { } else { panic!("usize::MAX should trigger an overflow!"); } - if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_USIZE / 16) { + if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_ISIZE) { + } else { + panic!("isize::MAX should trigger an overflow!"); + } + + if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_ISIZE / 5) { } else { // This may succeed if there is enough free memory. Attempt to // allocate a few more hashmaps to ensure the allocation will fail. let mut empty_bytes2: HashMap<u8, u8> = HashMap::new(); - let _ = empty_bytes2.try_reserve(MAX_USIZE / 16); + let _ = empty_bytes2.try_reserve(MAX_ISIZE / 5); let mut empty_bytes3: HashMap<u8, u8> = HashMap::new(); - let _ = empty_bytes3.try_reserve(MAX_USIZE / 16); + let _ = empty_bytes3.try_reserve(MAX_ISIZE / 5); let mut empty_bytes4: HashMap<u8, u8> = HashMap::new(); - if let Err(AllocError { .. }) = empty_bytes4.try_reserve(MAX_USIZE / 16) { + if let Err(AllocError { .. }) = empty_bytes4.try_reserve(MAX_ISIZE / 5) { } else { - panic!("usize::MAX / 8 should trigger an OOM!"); + panic!("isize::MAX / 5 should trigger an OOM!"); } } } @@ -8104,7 +8219,7 @@ mod test_map { let mut map: HashMap<_, _> = xs.iter().copied().collect(); let compute_hash = |map: &HashMap<i32, i32>, k: i32| -> u64 { - super::make_insert_hash::<i32, _>(map.hasher(), &k) + super::make_hash::<i32, _>(map.hasher(), &k) }; // Existing key (insert) @@ -8266,21 +8381,21 @@ mod test_map { loop { // occasionally remove some elements if i < n && rng.gen_bool(0.1) { - let hash_value = super::make_insert_hash(&hash_builder, &i); + let hash_value = super::make_hash(&hash_builder, &i); unsafe { let e = map.table.find(hash_value, |q| q.0.eq(&i)); if let Some(e) = e { it.reflect_remove(&e); - let t = map.table.remove(e); + let t = map.table.remove(e).0; removed.push(t); left -= 1; } else { - assert!(removed.contains(&(i, 2 * i)), "{} not in {:?}", i, removed); + assert!(removed.contains(&(i, 2 * i)), "{i} not in {removed:?}"); let e = map.table.insert( hash_value, (i, 2 * i), - super::make_hasher::<usize, _, usize, _>(&hash_builder), + super::make_hasher::<_, usize, _>(&hash_builder), ); it.reflect_insert(&e); if let Some(p) = removed.iter().position(|e| e == &(i, 2 * i)) { @@ -8405,4 +8520,441 @@ mod test_map { map2.clone_from(&map1); } + + #[test] + #[should_panic = "panic in clone"] + fn test_clone_from_memory_leaks() { + use alloc::vec::Vec; + + struct CheckedClone { + panic_in_clone: bool, + need_drop: Vec<i32>, + } + impl Clone for CheckedClone { + fn clone(&self) -> Self { + if self.panic_in_clone { + panic!("panic in clone") + } + Self { + panic_in_clone: self.panic_in_clone, + need_drop: self.need_drop.clone(), + } + } + } + let mut map1 = HashMap::new(); + map1.insert( + 1, + CheckedClone { + panic_in_clone: false, + need_drop: vec![0, 1, 2], + }, + ); + map1.insert( + 2, + CheckedClone { + panic_in_clone: false, + need_drop: vec![3, 4, 5], + }, + ); + map1.insert( + 3, + CheckedClone { + panic_in_clone: true, + need_drop: vec![6, 7, 8], + }, + ); + let _map2 = map1.clone(); + } + + struct MyAllocInner { + drop_count: Arc<AtomicI8>, + } + + #[derive(Clone)] + struct MyAlloc { + _inner: Arc<MyAllocInner>, + } + + impl MyAlloc { + fn new(drop_count: Arc<AtomicI8>) -> Self { + MyAlloc { + _inner: Arc::new(MyAllocInner { drop_count }), + } + } + } + + impl Drop for MyAllocInner { + fn drop(&mut self) { + println!("MyAlloc freed."); + self.drop_count.fetch_sub(1, Ordering::SeqCst); + } + } + + unsafe impl Allocator for MyAlloc { + fn allocate(&self, layout: Layout) -> std::result::Result<NonNull<[u8]>, AllocError> { + let g = Global; + g.allocate(layout) + } + + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + let g = Global; + g.deallocate(ptr, layout) + } + } + + #[test] + fn test_hashmap_into_iter_bug() { + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(1)); + + { + let mut map = HashMap::with_capacity_in(10, MyAlloc::new(dropped.clone())); + for i in 0..10 { + map.entry(i).or_insert_with(|| "i".to_string()); + } + + for (k, v) in map { + println!("{}, {}", k, v); + } + } + + // All allocator clones should already be dropped. + assert_eq!(dropped.load(Ordering::SeqCst), 0); + } + + #[derive(Debug)] + struct CheckedCloneDrop<T> { + panic_in_clone: bool, + panic_in_drop: bool, + dropped: bool, + data: T, + } + + impl<T> CheckedCloneDrop<T> { + fn new(panic_in_clone: bool, panic_in_drop: bool, data: T) -> Self { + CheckedCloneDrop { + panic_in_clone, + panic_in_drop, + dropped: false, + data, + } + } + } + + impl<T: Clone> Clone for CheckedCloneDrop<T> { + fn clone(&self) -> Self { + if self.panic_in_clone { + panic!("panic in clone") + } + Self { + panic_in_clone: self.panic_in_clone, + panic_in_drop: self.panic_in_drop, + dropped: self.dropped, + data: self.data.clone(), + } + } + } + + impl<T> Drop for CheckedCloneDrop<T> { + fn drop(&mut self) { + if self.panic_in_drop { + self.dropped = true; + panic!("panic in drop"); + } + if self.dropped { + panic!("double drop"); + } + self.dropped = true; + } + } + + /// Return hashmap with predefined distribution of elements. + /// All elements will be located in the same order as elements + /// returned by iterator. + /// + /// This function does not panic, but returns an error as a `String` + /// to distinguish between a test panic and an error in the input data. + fn get_test_map<I, T, A>( + iter: I, + mut fun: impl FnMut(u64) -> T, + alloc: A, + ) -> Result<HashMap<u64, CheckedCloneDrop<T>, DefaultHashBuilder, A>, String> + where + I: Iterator<Item = (bool, bool)> + Clone + ExactSizeIterator, + A: Allocator, + T: PartialEq + core::fmt::Debug, + { + use crate::scopeguard::guard; + + let mut map: HashMap<u64, CheckedCloneDrop<T>, _, A> = + HashMap::with_capacity_in(iter.size_hint().0, alloc); + { + let mut guard = guard(&mut map, |map| { + for (_, value) in map.iter_mut() { + value.panic_in_drop = false + } + }); + + let mut count = 0; + // Hash and Key must be equal to each other for controlling the elements placement. + for (panic_in_clone, panic_in_drop) in iter.clone() { + if core::mem::needs_drop::<T>() && panic_in_drop { + return Err(String::from( + "panic_in_drop can be set with a type that doesn't need to be dropped", + )); + } + guard.table.insert( + count, + ( + count, + CheckedCloneDrop::new(panic_in_clone, panic_in_drop, fun(count)), + ), + |(k, _)| *k, + ); + count += 1; + } + + // Let's check that all elements are located as we wanted + let mut check_count = 0; + for ((key, value), (panic_in_clone, panic_in_drop)) in guard.iter().zip(iter) { + if *key != check_count { + return Err(format!( + "key != check_count,\nkey: `{}`,\ncheck_count: `{}`", + key, check_count + )); + } + if value.dropped + || value.panic_in_clone != panic_in_clone + || value.panic_in_drop != panic_in_drop + || value.data != fun(check_count) + { + return Err(format!( + "Value is not equal to expected,\nvalue: `{:?}`,\nexpected: \ + `CheckedCloneDrop {{ panic_in_clone: {}, panic_in_drop: {}, dropped: {}, data: {:?} }}`", + value, panic_in_clone, panic_in_drop, false, fun(check_count) + )); + } + check_count += 1; + } + + if guard.len() != check_count as usize { + return Err(format!( + "map.len() != check_count,\nmap.len(): `{}`,\ncheck_count: `{}`", + guard.len(), + check_count + )); + } + + if count != check_count { + return Err(format!( + "count != check_count,\ncount: `{}`,\ncheck_count: `{}`", + count, check_count + )); + } + core::mem::forget(guard); + } + Ok(map) + } + + const DISARMED: bool = false; + const ARMED: bool = true; + + const ARMED_FLAGS: [bool; 8] = [ + DISARMED, DISARMED, DISARMED, ARMED, DISARMED, DISARMED, DISARMED, DISARMED, + ]; + + const DISARMED_FLAGS: [bool; 8] = [ + DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, DISARMED, + ]; + + #[test] + #[should_panic = "panic in clone"] + fn test_clone_memory_leaks_and_double_drop_one() { + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(2)); + + { + assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); + + let map: HashMap<u64, CheckedCloneDrop<Vec<u64>>, DefaultHashBuilder, MyAlloc> = + match get_test_map( + ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), + |n| vec![n], + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => panic!("{msg}"), + }; + + // Clone should normally clone a few elements, and then (when the + // clone function panics), deallocate both its own memory, memory + // of `dropped: Arc<AtomicI8>` and the memory of already cloned + // elements (Vec<i32> memory inside CheckedCloneDrop). + let _map2 = map.clone(); + } + } + + #[test] + #[should_panic = "panic in drop"] + fn test_clone_memory_leaks_and_double_drop_two() { + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(2)); + + { + assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); + + let map: HashMap<u64, CheckedCloneDrop<u64>, DefaultHashBuilder, _> = match get_test_map( + DISARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), + |n| n, + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => panic!("{msg}"), + }; + + let mut map2 = match get_test_map( + DISARMED_FLAGS.into_iter().zip(ARMED_FLAGS), + |n| n, + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => panic!("{msg}"), + }; + + // The `clone_from` should try to drop the elements of `map2` without + // double drop and leaking the allocator. Elements that have not been + // dropped leak their memory. + map2.clone_from(&map); + } + } + + /// We check that we have a working table if the clone operation from another + /// thread ended in a panic (when buckets of maps are equal to each other). + #[test] + fn test_catch_panic_clone_from_when_len_is_equal() { + use std::thread; + + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(2)); + + { + assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); + + let mut map = match get_test_map( + DISARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), + |n| vec![n], + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => panic!("{msg}"), + }; + + thread::scope(|s| { + let result: thread::ScopedJoinHandle<'_, String> = s.spawn(|| { + let scope_map = + match get_test_map(ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), |n| vec![n * 2], MyAlloc::new(dropped.clone())) { + Ok(map) => map, + Err(msg) => return msg, + }; + if map.table.buckets() != scope_map.table.buckets() { + return format!( + "map.table.buckets() != scope_map.table.buckets(),\nleft: `{}`,\nright: `{}`", + map.table.buckets(), scope_map.table.buckets() + ); + } + map.clone_from(&scope_map); + "We must fail the cloning!!!".to_owned() + }); + if let Ok(msg) = result.join() { + panic!("{msg}") + } + }); + + // Let's check that all iterators work fine and do not return elements + // (especially `RawIterRange`, which does not depend on the number of + // elements in the table, but looks directly at the control bytes) + // + // SAFETY: We know for sure that `RawTable` will outlive + // the returned `RawIter / RawIterRange` iterator. + assert_eq!(map.len(), 0); + assert_eq!(map.iter().count(), 0); + assert_eq!(unsafe { map.table.iter().count() }, 0); + assert_eq!(unsafe { map.table.iter().iter.count() }, 0); + + for idx in 0..map.table.buckets() { + let idx = idx as u64; + assert!( + map.table.find(idx, |(k, _)| *k == idx).is_none(), + "Index: {idx}" + ); + } + } + + // All allocator clones should already be dropped. + assert_eq!(dropped.load(Ordering::SeqCst), 0); + } + + /// We check that we have a working table if the clone operation from another + /// thread ended in a panic (when buckets of maps are not equal to each other). + #[test] + fn test_catch_panic_clone_from_when_len_is_not_equal() { + use std::thread; + + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(2)); + + { + assert_eq!(ARMED_FLAGS.len(), DISARMED_FLAGS.len()); + + let mut map = match get_test_map( + [DISARMED].into_iter().zip([DISARMED]), + |n| vec![n], + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => panic!("{msg}"), + }; + + thread::scope(|s| { + let result: thread::ScopedJoinHandle<'_, String> = s.spawn(|| { + let scope_map = match get_test_map( + ARMED_FLAGS.into_iter().zip(DISARMED_FLAGS), + |n| vec![n * 2], + MyAlloc::new(dropped.clone()), + ) { + Ok(map) => map, + Err(msg) => return msg, + }; + if map.table.buckets() == scope_map.table.buckets() { + return format!( + "map.table.buckets() == scope_map.table.buckets(): `{}`", + map.table.buckets() + ); + } + map.clone_from(&scope_map); + "We must fail the cloning!!!".to_owned() + }); + if let Ok(msg) = result.join() { + panic!("{msg}") + } + }); + + // Let's check that all iterators work fine and do not return elements + // (especially `RawIterRange`, which does not depend on the number of + // elements in the table, but looks directly at the control bytes) + // + // SAFETY: We know for sure that `RawTable` will outlive + // the returned `RawIter / RawIterRange` iterator. + assert_eq!(map.len(), 0); + assert_eq!(map.iter().count(), 0); + assert_eq!(unsafe { map.table.iter().count() }, 0); + assert_eq!(unsafe { map.table.iter().iter.count() }, 0); + + for idx in 0..map.table.buckets() { + let idx = idx as u64; + assert!( + map.table.find(idx, |(k, _)| *k == idx).is_none(), + "Index: {idx}" + ); + } + } + + // All allocator clones should already be dropped. + assert_eq!(dropped.load(Ordering::SeqCst), 0); + } } diff --git a/third_party/rust/hashbrown/src/raw/alloc.rs b/third_party/rust/hashbrown/src/raw/alloc.rs index ba09ea9de7..15299e7b09 100644 --- a/third_party/rust/hashbrown/src/raw/alloc.rs +++ b/third_party/rust/hashbrown/src/raw/alloc.rs @@ -1,5 +1,9 @@ pub(crate) use self::inner::{do_alloc, Allocator, Global}; +// Nightly-case. +// Use unstable `allocator_api` feature. +// This is compatible with `allocator-api2` which can be enabled or not. +// This is used when building for `std`. #[cfg(feature = "nightly")] mod inner { use crate::alloc::alloc::Layout; @@ -7,28 +11,44 @@ mod inner { use core::ptr::NonNull; #[allow(clippy::map_err_ignore)] - pub fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { + pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { match alloc.allocate(layout) { Ok(ptr) => Ok(ptr.as_non_null_ptr()), Err(_) => Err(()), } } +} - #[cfg(feature = "bumpalo")] - unsafe impl Allocator for crate::BumpWrapper<'_> { - #[inline] - fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, core::alloc::AllocError> { - match self.0.try_alloc_layout(layout) { - Ok(ptr) => Ok(NonNull::slice_from_raw_parts(ptr, layout.size())), - Err(_) => Err(core::alloc::AllocError), - } +// Basic non-nightly case. +// This uses `allocator-api2` enabled by default. +// If any crate enables "nightly" in `allocator-api2`, +// this will be equivalent to the nightly case, +// since `allocator_api2::alloc::Allocator` would be re-export of +// `core::alloc::Allocator`. +#[cfg(all(not(feature = "nightly"), feature = "allocator-api2"))] +mod inner { + use crate::alloc::alloc::Layout; + pub use allocator_api2::alloc::{Allocator, Global}; + use core::ptr::NonNull; + + #[allow(clippy::map_err_ignore)] + pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { + match alloc.allocate(layout) { + Ok(ptr) => Ok(ptr.cast()), + Err(_) => Err(()), } - #[inline] - unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {} } } -#[cfg(not(feature = "nightly"))] +// No-defaults case. +// When building with default-features turned off and +// neither `nightly` nor `allocator-api2` is enabled, +// this will be used. +// Making it impossible to use any custom allocator with collections defined +// in this crate. +// Any crate in build-tree can enable `allocator-api2`, +// or `nightly` without disturbing users that don't want to use it. +#[cfg(not(any(feature = "nightly", feature = "allocator-api2")))] mod inner { use crate::alloc::alloc::{alloc, dealloc, Layout}; use core::ptr::NonNull; @@ -41,6 +61,7 @@ mod inner { #[derive(Copy, Clone)] pub struct Global; + unsafe impl Allocator for Global { #[inline] fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> { @@ -51,6 +72,7 @@ mod inner { dealloc(ptr.as_ptr(), layout); } } + impl Default for Global { #[inline] fn default() -> Self { @@ -58,16 +80,7 @@ mod inner { } } - pub fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { + pub(crate) fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> { alloc.allocate(layout) } - - #[cfg(feature = "bumpalo")] - unsafe impl Allocator for crate::BumpWrapper<'_> { - #[allow(clippy::map_err_ignore)] - fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> { - self.0.try_alloc_layout(layout).map_err(|_| ()) - } - unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {} - } } diff --git a/third_party/rust/hashbrown/src/raw/bitmask.rs b/third_party/rust/hashbrown/src/raw/bitmask.rs index 7d4f9fc387..6576b3c5c0 100644 --- a/third_party/rust/hashbrown/src/raw/bitmask.rs +++ b/third_party/rust/hashbrown/src/raw/bitmask.rs @@ -1,6 +1,6 @@ -use super::imp::{BitMaskWord, BITMASK_MASK, BITMASK_STRIDE}; -#[cfg(feature = "nightly")] -use core::intrinsics; +use super::imp::{ + BitMaskWord, NonZeroBitMaskWord, BITMASK_ITER_MASK, BITMASK_MASK, BITMASK_STRIDE, +}; /// A bit mask which contains the result of a `Match` operation on a `Group` and /// allows iterating through them. @@ -8,75 +8,55 @@ use core::intrinsics; /// The bit mask is arranged so that low-order bits represent lower memory /// addresses for group match results. /// -/// For implementation reasons, the bits in the set may be sparsely packed, so -/// that there is only one bit-per-byte used (the high bit, 7). If this is the +/// For implementation reasons, the bits in the set may be sparsely packed with +/// groups of 8 bits representing one element. If any of these bits are non-zero +/// then this element is considered to true in the mask. If this is the /// case, `BITMASK_STRIDE` will be 8 to indicate a divide-by-8 should be /// performed on counts/indices to normalize this difference. `BITMASK_MASK` is /// similarly a mask of all the actually-used bits. +/// +/// To iterate over a bit mask, it must be converted to a form where only 1 bit +/// is set per element. This is done by applying `BITMASK_ITER_MASK` on the +/// mask bits. #[derive(Copy, Clone)] -pub struct BitMask(pub BitMaskWord); +pub(crate) struct BitMask(pub(crate) BitMaskWord); #[allow(clippy::use_self)] impl BitMask { /// Returns a new `BitMask` with all bits inverted. #[inline] #[must_use] - pub fn invert(self) -> Self { + #[allow(dead_code)] + pub(crate) fn invert(self) -> Self { BitMask(self.0 ^ BITMASK_MASK) } - /// Flip the bit in the mask for the entry at the given index. - /// - /// Returns the bit's previous state. - #[inline] - #[allow(clippy::cast_ptr_alignment)] - #[cfg(feature = "raw")] - pub unsafe fn flip(&mut self, index: usize) -> bool { - // NOTE: The + BITMASK_STRIDE - 1 is to set the high bit. - let mask = 1 << (index * BITMASK_STRIDE + BITMASK_STRIDE - 1); - self.0 ^= mask; - // The bit was set if the bit is now 0. - self.0 & mask == 0 - } - /// Returns a new `BitMask` with the lowest bit removed. #[inline] #[must_use] - pub fn remove_lowest_bit(self) -> Self { + fn remove_lowest_bit(self) -> Self { BitMask(self.0 & (self.0 - 1)) } + /// Returns whether the `BitMask` has at least one set bit. #[inline] - pub fn any_bit_set(self) -> bool { + pub(crate) fn any_bit_set(self) -> bool { self.0 != 0 } /// Returns the first set bit in the `BitMask`, if there is one. #[inline] - pub fn lowest_set_bit(self) -> Option<usize> { - if self.0 == 0 { - None + pub(crate) fn lowest_set_bit(self) -> Option<usize> { + if let Some(nonzero) = NonZeroBitMaskWord::new(self.0) { + Some(Self::nonzero_trailing_zeros(nonzero)) } else { - Some(unsafe { self.lowest_set_bit_nonzero() }) + None } } - /// Returns the first set bit in the `BitMask`, if there is one. The - /// bitmask must not be empty. - #[inline] - #[cfg(feature = "nightly")] - pub unsafe fn lowest_set_bit_nonzero(self) -> usize { - intrinsics::cttz_nonzero(self.0) as usize / BITMASK_STRIDE - } - #[inline] - #[cfg(not(feature = "nightly"))] - pub unsafe fn lowest_set_bit_nonzero(self) -> usize { - self.trailing_zeros() - } - /// Returns the number of trailing zeroes in the `BitMask`. #[inline] - pub fn trailing_zeros(self) -> usize { + pub(crate) fn trailing_zeros(self) -> usize { // ARM doesn't have a trailing_zeroes instruction, and instead uses // reverse_bits (RBIT) + leading_zeroes (CLZ). However older ARM // versions (pre-ARMv7) don't have RBIT and need to emulate it @@ -89,9 +69,21 @@ impl BitMask { } } + /// Same as above but takes a `NonZeroBitMaskWord`. + #[inline] + fn nonzero_trailing_zeros(nonzero: NonZeroBitMaskWord) -> usize { + if cfg!(target_arch = "arm") && BITMASK_STRIDE % 8 == 0 { + // SAFETY: A byte-swapped non-zero value is still non-zero. + let swapped = unsafe { NonZeroBitMaskWord::new_unchecked(nonzero.get().swap_bytes()) }; + swapped.leading_zeros() as usize / BITMASK_STRIDE + } else { + nonzero.trailing_zeros() as usize / BITMASK_STRIDE + } + } + /// Returns the number of leading zeroes in the `BitMask`. #[inline] - pub fn leading_zeros(self) -> usize { + pub(crate) fn leading_zeros(self) -> usize { self.0.leading_zeros() as usize / BITMASK_STRIDE } } @@ -102,13 +94,32 @@ impl IntoIterator for BitMask { #[inline] fn into_iter(self) -> BitMaskIter { - BitMaskIter(self) + // A BitMask only requires each element (group of bits) to be non-zero. + // However for iteration we need each element to only contain 1 bit. + BitMaskIter(BitMask(self.0 & BITMASK_ITER_MASK)) } } /// Iterator over the contents of a `BitMask`, returning the indices of set /// bits. -pub struct BitMaskIter(BitMask); +#[derive(Copy, Clone)] +pub(crate) struct BitMaskIter(pub(crate) BitMask); + +impl BitMaskIter { + /// Flip the bit in the mask for the entry at the given index. + /// + /// Returns the bit's previous state. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + #[cfg(feature = "raw")] + pub(crate) unsafe fn flip(&mut self, index: usize) -> bool { + // NOTE: The + BITMASK_STRIDE - 1 is to set the high bit. + let mask = 1 << (index * BITMASK_STRIDE + BITMASK_STRIDE - 1); + self.0 .0 ^= mask; + // The bit was set if the bit is now 0. + self.0 .0 & mask == 0 + } +} impl Iterator for BitMaskIter { type Item = usize; diff --git a/third_party/rust/hashbrown/src/raw/generic.rs b/third_party/rust/hashbrown/src/raw/generic.rs index b4d31e62c2..c668b0642a 100644 --- a/third_party/rust/hashbrown/src/raw/generic.rs +++ b/third_party/rust/hashbrown/src/raw/generic.rs @@ -5,26 +5,29 @@ use core::{mem, ptr}; // Use the native word size as the group size. Using a 64-bit group size on // a 32-bit architecture will just end up being more expensive because // shifts and multiplies will need to be emulated. -#[cfg(any( - target_pointer_width = "64", - target_arch = "aarch64", - target_arch = "x86_64", - target_arch = "wasm32", -))] -type GroupWord = u64; -#[cfg(all( - target_pointer_width = "32", - not(target_arch = "aarch64"), - not(target_arch = "x86_64"), - not(target_arch = "wasm32"), -))] -type GroupWord = u32; -pub type BitMaskWord = GroupWord; -pub const BITMASK_STRIDE: usize = 8; +cfg_if! { + if #[cfg(any( + target_pointer_width = "64", + target_arch = "aarch64", + target_arch = "x86_64", + target_arch = "wasm32", + ))] { + type GroupWord = u64; + type NonZeroGroupWord = core::num::NonZeroU64; + } else { + type GroupWord = u32; + type NonZeroGroupWord = core::num::NonZeroU32; + } +} + +pub(crate) type BitMaskWord = GroupWord; +pub(crate) type NonZeroBitMaskWord = NonZeroGroupWord; +pub(crate) const BITMASK_STRIDE: usize = 8; // We only care about the highest bit of each byte for the mask. #[allow(clippy::cast_possible_truncation, clippy::unnecessary_cast)] -pub const BITMASK_MASK: BitMaskWord = 0x8080_8080_8080_8080_u64 as GroupWord; +pub(crate) const BITMASK_MASK: BitMaskWord = 0x8080_8080_8080_8080_u64 as GroupWord; +pub(crate) const BITMASK_ITER_MASK: BitMaskWord = !0; /// Helper function to replicate a byte across a `GroupWord`. #[inline] @@ -37,7 +40,7 @@ fn repeat(byte: u8) -> GroupWord { /// /// This implementation uses a word-sized integer. #[derive(Copy, Clone)] -pub struct Group(GroupWord); +pub(crate) struct Group(GroupWord); // We perform all operations in the native endianness, and convert to // little-endian just before creating a BitMask. The can potentially @@ -46,14 +49,14 @@ pub struct Group(GroupWord); #[allow(clippy::use_self)] impl Group { /// Number of bytes in the group. - pub const WIDTH: usize = mem::size_of::<Self>(); + pub(crate) const WIDTH: usize = mem::size_of::<Self>(); /// Returns a full group of empty bytes, suitable for use as the initial /// value for an empty hash table. /// /// This is guaranteed to be aligned to the group size. #[inline] - pub const fn static_empty() -> &'static [u8; Group::WIDTH] { + pub(crate) const fn static_empty() -> &'static [u8; Group::WIDTH] { #[repr(C)] struct AlignedBytes { _align: [Group; 0], @@ -69,7 +72,7 @@ impl Group { /// Loads a group of bytes starting at the given address. #[inline] #[allow(clippy::cast_ptr_alignment)] // unaligned load - pub unsafe fn load(ptr: *const u8) -> Self { + pub(crate) unsafe fn load(ptr: *const u8) -> Self { Group(ptr::read_unaligned(ptr.cast())) } @@ -77,7 +80,7 @@ impl Group { /// aligned to `mem::align_of::<Group>()`. #[inline] #[allow(clippy::cast_ptr_alignment)] - pub unsafe fn load_aligned(ptr: *const u8) -> Self { + pub(crate) unsafe fn load_aligned(ptr: *const u8) -> Self { // FIXME: use align_offset once it stabilizes debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); Group(ptr::read(ptr.cast())) @@ -87,7 +90,7 @@ impl Group { /// aligned to `mem::align_of::<Group>()`. #[inline] #[allow(clippy::cast_ptr_alignment)] - pub unsafe fn store_aligned(self, ptr: *mut u8) { + pub(crate) unsafe fn store_aligned(self, ptr: *mut u8) { // FIXME: use align_offset once it stabilizes debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); ptr::write(ptr.cast(), self.0); @@ -104,7 +107,7 @@ impl Group { /// - This only happens if there is at least 1 true match. /// - The chance of this happening is very low (< 1% chance per byte). #[inline] - pub fn match_byte(self, byte: u8) -> BitMask { + pub(crate) fn match_byte(self, byte: u8) -> BitMask { // This algorithm is derived from // https://graphics.stanford.edu/~seander/bithacks.html##ValueInWord let cmp = self.0 ^ repeat(byte); @@ -114,7 +117,7 @@ impl Group { /// Returns a `BitMask` indicating all bytes in the group which are /// `EMPTY`. #[inline] - pub fn match_empty(self) -> BitMask { + pub(crate) fn match_empty(self) -> BitMask { // If the high bit is set, then the byte must be either: // 1111_1111 (EMPTY) or 1000_0000 (DELETED). // So we can just check if the top two bits are 1 by ANDing them. @@ -124,14 +127,14 @@ impl Group { /// Returns a `BitMask` indicating all bytes in the group which are /// `EMPTY` or `DELETED`. #[inline] - pub fn match_empty_or_deleted(self) -> BitMask { + pub(crate) fn match_empty_or_deleted(self) -> BitMask { // A byte is EMPTY or DELETED iff the high bit is set BitMask((self.0 & repeat(0x80)).to_le()) } /// Returns a `BitMask` indicating all bytes in the group which are full. #[inline] - pub fn match_full(self) -> BitMask { + pub(crate) fn match_full(self) -> BitMask { self.match_empty_or_deleted().invert() } @@ -140,7 +143,7 @@ impl Group { /// - `DELETED => EMPTY` /// - `FULL => DELETED` #[inline] - pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self { + pub(crate) fn convert_special_to_empty_and_full_to_deleted(self) -> Self { // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111 // and high_bit = 0 (FULL) to 1000_0000 // diff --git a/third_party/rust/hashbrown/src/raw/mod.rs b/third_party/rust/hashbrown/src/raw/mod.rs index 211b818a5f..c8e8e29122 100644 --- a/third_party/rust/hashbrown/src/raw/mod.rs +++ b/third_party/rust/hashbrown/src/raw/mod.rs @@ -4,7 +4,6 @@ use crate::TryReserveError; use core::iter::FusedIterator; use core::marker::PhantomData; use core::mem; -use core::mem::ManuallyDrop; use core::mem::MaybeUninit; use core::ptr::NonNull; use core::{hint, ptr}; @@ -21,12 +20,21 @@ cfg_if! { if #[cfg(all( target_feature = "sse2", any(target_arch = "x86", target_arch = "x86_64"), - not(miri) + not(miri), ))] { mod sse2; use sse2 as imp; + } else if #[cfg(all( + target_arch = "aarch64", + target_feature = "neon", + // NEON intrinsics are currently broken on big-endian targets. + // See https://github.com/rust-lang/stdarch/issues/1484. + target_endian = "little", + not(miri), + ))] { + mod neon; + use neon as imp; } else { - #[path = "generic.rs"] mod generic; use generic as imp; } @@ -37,36 +45,24 @@ pub(crate) use self::alloc::{do_alloc, Allocator, Global}; mod bitmask; -use self::bitmask::{BitMask, BitMaskIter}; +use self::bitmask::BitMaskIter; use self::imp::Group; // Branch prediction hint. This is currently only available on nightly but it // consistently improves performance by 10-15%. +#[cfg(not(feature = "nightly"))] +use core::convert::identity as likely; +#[cfg(not(feature = "nightly"))] +use core::convert::identity as unlikely; #[cfg(feature = "nightly")] use core::intrinsics::{likely, unlikely}; -// On stable we can use #[cold] to get a equivalent effect: this attributes -// suggests that the function is unlikely to be called -#[cfg(not(feature = "nightly"))] -#[inline] -#[cold] -fn cold() {} - -#[cfg(not(feature = "nightly"))] -#[inline] -fn likely(b: bool) -> bool { - if !b { - cold(); - } - b -} -#[cfg(not(feature = "nightly"))] -#[inline] -fn unlikely(b: bool) -> bool { - if b { - cold(); - } - b +// FIXME: use strict provenance functions once they are stable. +// Implement it with a transmute for now. +#[inline(always)] +#[allow(clippy::useless_transmute)] // clippy is wrong, cast and transmute are different here +fn invalid_mut<T>(addr: usize) -> *mut T { + unsafe { core::mem::transmute(addr) } } #[inline] @@ -101,6 +97,13 @@ impl Fallibility { } } +trait SizedTypeProperties: Sized { + const IS_ZERO_SIZED: bool = mem::size_of::<Self>() == 0; + const NEEDS_DROP: bool = mem::needs_drop::<Self>(); +} + +impl<T> SizedTypeProperties for T {} + /// Control byte value for an empty bucket. const EMPTY: u8 = 0b1111_1111; @@ -134,6 +137,13 @@ fn h1(hash: u64) -> usize { hash as usize } +// Constant for h2 function that grabing the top 7 bits of the hash. +const MIN_HASH_LEN: usize = if mem::size_of::<usize>() < mem::size_of::<u64>() { + mem::size_of::<usize>() +} else { + mem::size_of::<u64>() +}; + /// Secondary hash function, saved in the low 7 bits of the control byte. #[inline] #[allow(clippy::cast_possible_truncation)] @@ -141,8 +151,8 @@ fn h2(hash: u64) -> u8 { // Grab the top 7 bits of the hash. While the hash is normally a full 64-bit // value, some hash functions (such as FxHash) produce a usize result // instead, which means that the top 32 bits are 0 on 32-bit platforms. - let hash_len = usize::min(mem::size_of::<usize>(), mem::size_of::<u64>()); - let top7 = hash >> (hash_len * 8 - 7); + // So we use MIN_HASH_LEN constant to handle this. + let top7 = hash >> (MIN_HASH_LEN * 8 - 7); (top7 & 0x7f) as u8 // truncation } @@ -230,11 +240,15 @@ struct TableLayout { impl TableLayout { #[inline] - fn new<T>() -> Self { + const fn new<T>() -> Self { let layout = Layout::new::<T>(); Self { size: layout.size(), - ctrl_align: usize::max(layout.align(), Group::WIDTH), + ctrl_align: if layout.align() > Group::WIDTH { + layout.align() + } else { + Group::WIDTH + }, } } @@ -248,6 +262,12 @@ impl TableLayout { size.checked_mul(buckets)?.checked_add(ctrl_align - 1)? & !(ctrl_align - 1); let len = ctrl_offset.checked_add(buckets + Group::WIDTH)?; + // We need an additional check to ensure that the allocation doesn't + // exceed `isize::MAX` (https://github.com/rust-lang/rust/pull/95295). + if len > isize::MAX as usize - (ctrl_align - 1) { + return None; + } + Some(( unsafe { Layout::from_size_align_unchecked(len, ctrl_align) }, ctrl_offset, @@ -255,14 +275,9 @@ impl TableLayout { } } -/// Returns a Layout which describes the allocation required for a hash table, -/// and the offset of the control bytes in the allocation. -/// (the offset is also one past last element of buckets) -/// -/// Returns `None` if an overflow occurs. -#[cfg_attr(feature = "inline-more", inline)] -fn calculate_layout<T>(buckets: usize) -> Option<(Layout, usize)> { - TableLayout::new::<T>().calculate_layout_for(buckets) +/// A reference to an empty bucket into which an can be inserted. +pub struct InsertSlot { + index: usize, } /// A reference to a hash table bucket containing a `T`. @@ -290,11 +305,79 @@ impl<T> Clone for Bucket<T> { } impl<T> Bucket<T> { + /// Creates a [`Bucket`] that contain pointer to the data. + /// The pointer calculation is performed by calculating the + /// offset from given `base` pointer (convenience for + /// `base.as_ptr().sub(index)`). + /// + /// `index` is in units of `T`; e.g., an `index` of 3 represents a pointer + /// offset of `3 * size_of::<T>()` bytes. + /// + /// If the `T` is a ZST, then we instead track the index of the element + /// in the table so that `erase` works properly (return + /// `NonNull::new_unchecked((index + 1) as *mut T)`) + /// + /// # Safety + /// + /// If `mem::size_of::<T>() != 0`, then the safety rules are directly derived + /// from the safety rules for [`<*mut T>::sub`] method of `*mut T` and the safety + /// rules of [`NonNull::new_unchecked`] function. + /// + /// Thus, in order to uphold the safety contracts for the [`<*mut T>::sub`] method + /// and [`NonNull::new_unchecked`] function, as well as for the correct + /// logic of the work of this crate, the following rules are necessary and + /// sufficient: + /// + /// * the `base` pointer must not be `dangling` and must points to the + /// end of the first `value element` from the `data part` of the table, i.e. + /// must be the pointer that returned by [`RawTable::data_end`] or by + /// [`RawTableInner::data_end<T>`]; + /// + /// * `index` must not be greater than `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` + /// must be no greater than the number returned by the function + /// [`RawTable::buckets`] or [`RawTableInner::buckets`]. + /// + /// If `mem::size_of::<T>() == 0`, then the only requirement is that the + /// `index` must not be greater than `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` + /// must be no greater than the number returned by the function + /// [`RawTable::buckets`] or [`RawTableInner::buckets`]. + /// + /// [`Bucket`]: crate::raw::Bucket + /// [`<*mut T>::sub`]: https://doc.rust-lang.org/core/primitive.pointer.html#method.sub-1 + /// [`NonNull::new_unchecked`]: https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.new_unchecked + /// [`RawTable::data_end`]: crate::raw::RawTable::data_end + /// [`RawTableInner::data_end<T>`]: RawTableInner::data_end<T> + /// [`RawTable::buckets`]: crate::raw::RawTable::buckets + /// [`RawTableInner::buckets`]: RawTableInner::buckets #[inline] unsafe fn from_base_index(base: NonNull<T>, index: usize) -> Self { - let ptr = if mem::size_of::<T>() == 0 { - // won't overflow because index must be less than length - (index + 1) as *mut T + // If mem::size_of::<T>() != 0 then return a pointer to an `element` in + // the data part of the table (we start counting from "0", so that + // in the expression T[last], the "last" index actually one less than the + // "buckets" number in the table, i.e. "last = RawTableInner.bucket_mask"): + // + // `from_base_index(base, 1).as_ptr()` returns a pointer that + // points here in the data part of the table + // (to the start of T1) + // | + // | `base: NonNull<T>` must point here + // | (to the end of T0 or to the start of C0) + // v v + // [Padding], Tlast, ..., |T1|, T0, |C0, C1, ..., Clast + // ^ + // `from_base_index(base, 1)` returns a pointer + // that points here in the data part of the table + // (to the end of T1) + // + // where: T0...Tlast - our stored data; C0...Clast - control bytes + // or metadata for data. + let ptr = if T::IS_ZERO_SIZED { + // won't overflow because index must be less than length (bucket_mask) + // and bucket_mask is guaranteed to be less than `isize::MAX` + // (see TableLayout::calculate_layout_for method) + invalid_mut(index + 1) } else { base.as_ptr().sub(index) }; @@ -302,27 +385,183 @@ impl<T> Bucket<T> { ptr: NonNull::new_unchecked(ptr), } } + + /// Calculates the index of a [`Bucket`] as distance between two pointers + /// (convenience for `base.as_ptr().offset_from(self.ptr.as_ptr()) as usize`). + /// The returned value is in units of T: the distance in bytes divided by + /// [`core::mem::size_of::<T>()`]. + /// + /// If the `T` is a ZST, then we return the index of the element in + /// the table so that `erase` works properly (return `self.ptr.as_ptr() as usize - 1`). + /// + /// This function is the inverse of [`from_base_index`]. + /// + /// # Safety + /// + /// If `mem::size_of::<T>() != 0`, then the safety rules are directly derived + /// from the safety rules for [`<*const T>::offset_from`] method of `*const T`. + /// + /// Thus, in order to uphold the safety contracts for [`<*const T>::offset_from`] + /// method, as well as for the correct logic of the work of this crate, the + /// following rules are necessary and sufficient: + /// + /// * `base` contained pointer must not be `dangling` and must point to the + /// end of the first `element` from the `data part` of the table, i.e. + /// must be a pointer that returns by [`RawTable::data_end`] or by + /// [`RawTableInner::data_end<T>`]; + /// + /// * `self` also must not contain dangling pointer; + /// + /// * both `self` and `base` must be created from the same [`RawTable`] + /// (or [`RawTableInner`]). + /// + /// If `mem::size_of::<T>() == 0`, this function is always safe. + /// + /// [`Bucket`]: crate::raw::Bucket + /// [`from_base_index`]: crate::raw::Bucket::from_base_index + /// [`RawTable::data_end`]: crate::raw::RawTable::data_end + /// [`RawTableInner::data_end<T>`]: RawTableInner::data_end<T> + /// [`RawTable`]: crate::raw::RawTable + /// [`RawTableInner`]: RawTableInner + /// [`<*const T>::offset_from`]: https://doc.rust-lang.org/nightly/core/primitive.pointer.html#method.offset_from #[inline] unsafe fn to_base_index(&self, base: NonNull<T>) -> usize { - if mem::size_of::<T>() == 0 { + // If mem::size_of::<T>() != 0 then return an index under which we used to store the + // `element` in the data part of the table (we start counting from "0", so + // that in the expression T[last], the "last" index actually is one less than the + // "buckets" number in the table, i.e. "last = RawTableInner.bucket_mask"). + // For example for 5th element in table calculation is performed like this: + // + // mem::size_of::<T>() + // | + // | `self = from_base_index(base, 5)` that returns pointer + // | that points here in tha data part of the table + // | (to the end of T5) + // | | `base: NonNull<T>` must point here + // v | (to the end of T0 or to the start of C0) + // /???\ v v + // [Padding], Tlast, ..., |T10|, ..., T5|, T4, T3, T2, T1, T0, |C0, C1, C2, C3, C4, C5, ..., C10, ..., Clast + // \__________ __________/ + // \/ + // `bucket.to_base_index(base)` = 5 + // (base.as_ptr() as usize - self.ptr.as_ptr() as usize) / mem::size_of::<T>() + // + // where: T0...Tlast - our stored data; C0...Clast - control bytes or metadata for data. + if T::IS_ZERO_SIZED { + // this can not be UB self.ptr.as_ptr() as usize - 1 } else { offset_from(base.as_ptr(), self.ptr.as_ptr()) } } + + /// Acquires the underlying raw pointer `*mut T` to `data`. + /// + /// # Note + /// + /// If `T` is not [`Copy`], do not use `*mut T` methods that can cause calling the + /// destructor of `T` (for example the [`<*mut T>::drop_in_place`] method), because + /// for properly dropping the data we also need to clear `data` control bytes. If we + /// drop data, but do not clear `data control byte` it leads to double drop when + /// [`RawTable`] goes out of scope. + /// + /// If you modify an already initialized `value`, so [`Hash`] and [`Eq`] on the new + /// `T` value and its borrowed form *must* match those for the old `T` value, as the map + /// will not re-evaluate where the new value should go, meaning the value may become + /// "lost" if their location does not reflect their state. + /// + /// [`RawTable`]: crate::raw::RawTable + /// [`<*mut T>::drop_in_place`]: https://doc.rust-lang.org/core/primitive.pointer.html#method.drop_in_place + /// [`Hash`]: https://doc.rust-lang.org/core/hash/trait.Hash.html + /// [`Eq`]: https://doc.rust-lang.org/core/cmp/trait.Eq.html + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "raw")] + /// # fn test() { + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::raw::{Bucket, RawTable}; + /// + /// type NewHashBuilder = core::hash::BuildHasherDefault<ahash::AHasher>; + /// + /// fn make_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let hash_builder = NewHashBuilder::default(); + /// let mut table = RawTable::new(); + /// + /// let value = ("a", 100); + /// let hash = make_hash(&hash_builder, &value.0); + /// + /// table.insert(hash, value.clone(), |val| make_hash(&hash_builder, &val.0)); + /// + /// let bucket: Bucket<(&str, i32)> = table.find(hash, |(k1, _)| k1 == &value.0).unwrap(); + /// + /// assert_eq!(unsafe { &*bucket.as_ptr() }, &("a", 100)); + /// # } + /// # fn main() { + /// # #[cfg(feature = "raw")] + /// # test() + /// # } + /// ``` #[inline] pub fn as_ptr(&self) -> *mut T { - if mem::size_of::<T>() == 0 { + if T::IS_ZERO_SIZED { // Just return an arbitrary ZST pointer which is properly aligned - mem::align_of::<T>() as *mut T + // invalid pointer is good enough for ZST + invalid_mut(mem::align_of::<T>()) } else { unsafe { self.ptr.as_ptr().sub(1) } } } + + /// Create a new [`Bucket`] that is offset from the `self` by the given + /// `offset`. The pointer calculation is performed by calculating the + /// offset from `self` pointer (convenience for `self.ptr.as_ptr().sub(offset)`). + /// This function is used for iterators. + /// + /// `offset` is in units of `T`; e.g., a `offset` of 3 represents a pointer + /// offset of `3 * size_of::<T>()` bytes. + /// + /// # Safety + /// + /// If `mem::size_of::<T>() != 0`, then the safety rules are directly derived + /// from the safety rules for [`<*mut T>::sub`] method of `*mut T` and safety + /// rules of [`NonNull::new_unchecked`] function. + /// + /// Thus, in order to uphold the safety contracts for [`<*mut T>::sub`] method + /// and [`NonNull::new_unchecked`] function, as well as for the correct + /// logic of the work of this crate, the following rules are necessary and + /// sufficient: + /// + /// * `self` contained pointer must not be `dangling`; + /// + /// * `self.to_base_index() + ofset` must not be greater than `RawTableInner.bucket_mask`, + /// i.e. `(self.to_base_index() + ofset) <= RawTableInner.bucket_mask` or, in other + /// words, `self.to_base_index() + ofset + 1` must be no greater than the number returned + /// by the function [`RawTable::buckets`] or [`RawTableInner::buckets`]. + /// + /// If `mem::size_of::<T>() == 0`, then the only requirement is that the + /// `self.to_base_index() + ofset` must not be greater than `RawTableInner.bucket_mask`, + /// i.e. `(self.to_base_index() + ofset) <= RawTableInner.bucket_mask` or, in other words, + /// `self.to_base_index() + ofset + 1` must be no greater than the number returned by the + /// function [`RawTable::buckets`] or [`RawTableInner::buckets`]. + /// + /// [`Bucket`]: crate::raw::Bucket + /// [`<*mut T>::sub`]: https://doc.rust-lang.org/core/primitive.pointer.html#method.sub-1 + /// [`NonNull::new_unchecked`]: https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.new_unchecked + /// [`RawTable::buckets`]: crate::raw::RawTable::buckets + /// [`RawTableInner::buckets`]: RawTableInner::buckets #[inline] unsafe fn next_n(&self, offset: usize) -> Self { - let ptr = if mem::size_of::<T>() == 0 { - (self.ptr.as_ptr() as usize + offset) as *mut T + let ptr = if T::IS_ZERO_SIZED { + // invalid pointer is good enough for ZST + invalid_mut(self.ptr.as_ptr() as usize + offset) } else { self.ptr.as_ptr().sub(offset) }; @@ -330,26 +569,212 @@ impl<T> Bucket<T> { ptr: NonNull::new_unchecked(ptr), } } + + /// Executes the destructor (if any) of the pointed-to `data`. + /// + /// # Safety + /// + /// See [`ptr::drop_in_place`] for safety concerns. + /// + /// You should use [`RawTable::erase`] instead of this function, + /// or be careful with calling this function directly, because for + /// properly dropping the data we need also clear `data` control bytes. + /// If we drop data, but do not erase `data control byte` it leads to + /// double drop when [`RawTable`] goes out of scope. + /// + /// [`ptr::drop_in_place`]: https://doc.rust-lang.org/core/ptr/fn.drop_in_place.html + /// [`RawTable`]: crate::raw::RawTable + /// [`RawTable::erase`]: crate::raw::RawTable::erase #[cfg_attr(feature = "inline-more", inline)] - pub unsafe fn drop(&self) { + pub(crate) unsafe fn drop(&self) { self.as_ptr().drop_in_place(); } + + /// Reads the `value` from `self` without moving it. This leaves the + /// memory in `self` unchanged. + /// + /// # Safety + /// + /// See [`ptr::read`] for safety concerns. + /// + /// You should use [`RawTable::remove`] instead of this function, + /// or be careful with calling this function directly, because compiler + /// calls its destructor when readed `value` goes out of scope. It + /// can cause double dropping when [`RawTable`] goes out of scope, + /// because of not erased `data control byte`. + /// + /// [`ptr::read`]: https://doc.rust-lang.org/core/ptr/fn.read.html + /// [`RawTable`]: crate::raw::RawTable + /// [`RawTable::remove`]: crate::raw::RawTable::remove #[inline] - pub unsafe fn read(&self) -> T { + pub(crate) unsafe fn read(&self) -> T { self.as_ptr().read() } + + /// Overwrites a memory location with the given `value` without reading + /// or dropping the old value (like [`ptr::write`] function). + /// + /// # Safety + /// + /// See [`ptr::write`] for safety concerns. + /// + /// # Note + /// + /// [`Hash`] and [`Eq`] on the new `T` value and its borrowed form *must* match + /// those for the old `T` value, as the map will not re-evaluate where the new + /// value should go, meaning the value may become "lost" if their location + /// does not reflect their state. + /// + /// [`ptr::write`]: https://doc.rust-lang.org/core/ptr/fn.write.html + /// [`Hash`]: https://doc.rust-lang.org/core/hash/trait.Hash.html + /// [`Eq`]: https://doc.rust-lang.org/core/cmp/trait.Eq.html #[inline] - pub unsafe fn write(&self, val: T) { + pub(crate) unsafe fn write(&self, val: T) { self.as_ptr().write(val); } + + /// Returns a shared immutable reference to the `value`. + /// + /// # Safety + /// + /// See [`NonNull::as_ref`] for safety concerns. + /// + /// [`NonNull::as_ref`]: https://doc.rust-lang.org/core/ptr/struct.NonNull.html#method.as_ref + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "raw")] + /// # fn test() { + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::raw::{Bucket, RawTable}; + /// + /// type NewHashBuilder = core::hash::BuildHasherDefault<ahash::AHasher>; + /// + /// fn make_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let hash_builder = NewHashBuilder::default(); + /// let mut table = RawTable::new(); + /// + /// let value: (&str, String) = ("A pony", "is a small horse".to_owned()); + /// let hash = make_hash(&hash_builder, &value.0); + /// + /// table.insert(hash, value.clone(), |val| make_hash(&hash_builder, &val.0)); + /// + /// let bucket: Bucket<(&str, String)> = table.find(hash, |(k, _)| k == &value.0).unwrap(); + /// + /// assert_eq!( + /// unsafe { bucket.as_ref() }, + /// &("A pony", "is a small horse".to_owned()) + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "raw")] + /// # test() + /// # } + /// ``` #[inline] pub unsafe fn as_ref<'a>(&self) -> &'a T { &*self.as_ptr() } + + /// Returns a unique mutable reference to the `value`. + /// + /// # Safety + /// + /// See [`NonNull::as_mut`] for safety concerns. + /// + /// # Note + /// + /// [`Hash`] and [`Eq`] on the new `T` value and its borrowed form *must* match + /// those for the old `T` value, as the map will not re-evaluate where the new + /// value should go, meaning the value may become "lost" if their location + /// does not reflect their state. + /// + /// [`NonNull::as_mut`]: https://doc.rust-lang.org/core/ptr/struct.NonNull.html#method.as_mut + /// [`Hash`]: https://doc.rust-lang.org/core/hash/trait.Hash.html + /// [`Eq`]: https://doc.rust-lang.org/core/cmp/trait.Eq.html + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "raw")] + /// # fn test() { + /// use core::hash::{BuildHasher, Hash}; + /// use hashbrown::raw::{Bucket, RawTable}; + /// + /// type NewHashBuilder = core::hash::BuildHasherDefault<ahash::AHasher>; + /// + /// fn make_hash<K: Hash + ?Sized, S: BuildHasher>(hash_builder: &S, key: &K) -> u64 { + /// use core::hash::Hasher; + /// let mut state = hash_builder.build_hasher(); + /// key.hash(&mut state); + /// state.finish() + /// } + /// + /// let hash_builder = NewHashBuilder::default(); + /// let mut table = RawTable::new(); + /// + /// let value: (&str, String) = ("A pony", "is a small horse".to_owned()); + /// let hash = make_hash(&hash_builder, &value.0); + /// + /// table.insert(hash, value.clone(), |val| make_hash(&hash_builder, &val.0)); + /// + /// let bucket: Bucket<(&str, String)> = table.find(hash, |(k, _)| k == &value.0).unwrap(); + /// + /// unsafe { + /// bucket + /// .as_mut() + /// .1 + /// .push_str(" less than 147 cm at the withers") + /// }; + /// assert_eq!( + /// unsafe { bucket.as_ref() }, + /// &( + /// "A pony", + /// "is a small horse less than 147 cm at the withers".to_owned() + /// ) + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "raw")] + /// # test() + /// # } + /// ``` #[inline] pub unsafe fn as_mut<'a>(&self) -> &'a mut T { &mut *self.as_ptr() } + + /// Copies `size_of<T>` bytes from `other` to `self`. The source + /// and destination may *not* overlap. + /// + /// # Safety + /// + /// See [`ptr::copy_nonoverlapping`] for safety concerns. + /// + /// Like [`read`], `copy_nonoverlapping` creates a bitwise copy of `T`, regardless of + /// whether `T` is [`Copy`]. If `T` is not [`Copy`], using *both* the values + /// in the region beginning at `*self` and the region beginning at `*other` can + /// [violate memory safety]. + /// + /// # Note + /// + /// [`Hash`] and [`Eq`] on the new `T` value and its borrowed form *must* match + /// those for the old `T` value, as the map will not re-evaluate where the new + /// value should go, meaning the value may become "lost" if their location + /// does not reflect their state. + /// + /// [`ptr::copy_nonoverlapping`]: https://doc.rust-lang.org/core/ptr/fn.copy_nonoverlapping.html + /// [`read`]: https://doc.rust-lang.org/core/ptr/fn.read.html + /// [violate memory safety]: https://doc.rust-lang.org/std/ptr/fn.read.html#ownership-of-the-returned-value + /// [`Hash`]: https://doc.rust-lang.org/core/hash/trait.Hash.html + /// [`Eq`]: https://doc.rust-lang.org/core/cmp/trait.Eq.html #[cfg(feature = "raw")] #[inline] pub unsafe fn copy_from_nonoverlapping(&self, other: &Self) { @@ -358,15 +783,16 @@ impl<T> Bucket<T> { } /// A raw hash table with an unsafe API. -pub struct RawTable<T, A: Allocator + Clone = Global> { - table: RawTableInner<A>, +pub struct RawTable<T, A: Allocator = Global> { + table: RawTableInner, + alloc: A, // Tell dropck that we own instances of T. marker: PhantomData<T>, } /// Non-generic part of `RawTable` which allows functions to be instantiated only once regardless /// of how many different key-value types are used. -struct RawTableInner<A> { +struct RawTableInner { // Mask to get an index from a hash value. The value is one less than the // number of buckets in the table. bucket_mask: usize, @@ -380,8 +806,6 @@ struct RawTableInner<A> { // Number of elements in the table, only really used by len() items: usize, - - alloc: A, } impl<T> RawTable<T, Global> { @@ -393,7 +817,8 @@ impl<T> RawTable<T, Global> { #[inline] pub const fn new() -> Self { Self { - table: RawTableInner::new_in(Global), + table: RawTableInner::NEW, + alloc: Global, marker: PhantomData, } } @@ -412,7 +837,9 @@ impl<T> RawTable<T, Global> { } } -impl<T, A: Allocator + Clone> RawTable<T, A> { +impl<T, A: Allocator> RawTable<T, A> { + const TABLE_LAYOUT: TableLayout = TableLayout::new::<T>(); + /// Creates a new empty hash table without allocating any memory, using the /// given allocator. /// @@ -420,9 +847,10 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// leave the data pointer dangling since that bucket is never written to /// due to our load factor forcing us to always have at least 1 free bucket. #[inline] - pub fn new_in(alloc: A) -> Self { + pub const fn new_in(alloc: A) -> Self { Self { - table: RawTableInner::new_in(alloc), + table: RawTableInner::NEW, + alloc, marker: PhantomData, } } @@ -440,73 +868,97 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { Ok(Self { table: RawTableInner::new_uninitialized( - alloc, - TableLayout::new::<T>(), + &alloc, + Self::TABLE_LAYOUT, buckets, fallibility, )?, + alloc, marker: PhantomData, }) } - /// Attempts to allocate a new hash table with at least enough capacity - /// for inserting the given number of elements without reallocating. - fn fallible_with_capacity( - alloc: A, - capacity: usize, - fallibility: Fallibility, - ) -> Result<Self, TryReserveError> { + /// Attempts to allocate a new hash table using the given allocator, with at least enough + /// capacity for inserting the given number of elements without reallocating. + #[cfg(feature = "raw")] + pub fn try_with_capacity_in(capacity: usize, alloc: A) -> Result<Self, TryReserveError> { Ok(Self { table: RawTableInner::fallible_with_capacity( - alloc, - TableLayout::new::<T>(), + &alloc, + Self::TABLE_LAYOUT, capacity, - fallibility, + Fallibility::Fallible, )?, + alloc, marker: PhantomData, }) } - /// Attempts to allocate a new hash table using the given allocator, with at least enough - /// capacity for inserting the given number of elements without reallocating. - #[cfg(feature = "raw")] - pub fn try_with_capacity_in(capacity: usize, alloc: A) -> Result<Self, TryReserveError> { - Self::fallible_with_capacity(alloc, capacity, Fallibility::Fallible) - } - /// Allocates a new hash table using the given allocator, with at least enough capacity for /// inserting the given number of elements without reallocating. pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { - // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. - match Self::fallible_with_capacity(alloc, capacity, Fallibility::Infallible) { - Ok(capacity) => capacity, - Err(_) => unsafe { hint::unreachable_unchecked() }, + Self { + table: RawTableInner::with_capacity(&alloc, Self::TABLE_LAYOUT, capacity), + alloc, + marker: PhantomData, } } /// Returns a reference to the underlying allocator. #[inline] pub fn allocator(&self) -> &A { - &self.table.alloc + &self.alloc } - /// Deallocates the table without dropping any entries. - #[cfg_attr(feature = "inline-more", inline)] - unsafe fn free_buckets(&mut self) { - self.table.free_buckets(TableLayout::new::<T>()); + /// Returns pointer to one past last `data` element in the table as viewed from + /// the start point of the allocation. + /// + /// The caller must ensure that the `RawTable` outlives the returned [`NonNull<T>`], + /// otherwise using it may result in [`undefined behavior`]. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[inline] + pub fn data_end(&self) -> NonNull<T> { + // `self.table.ctrl.cast()` returns pointer that + // points here (to the end of `T0`) + // ∨ + // [Pad], T_n, ..., T1, T0, |CT0, CT1, ..., CT_n|, CTa_0, CTa_1, ..., CTa_m + // \________ ________/ + // \/ + // `n = buckets - 1`, i.e. `RawTable::buckets() - 1` + // + // where: T0...T_n - our stored data; + // CT0...CT_n - control bytes or metadata for `data`. + // CTa_0...CTa_m - additional control bytes, where `m = Group::WIDTH - 1` (so that the search + // with loading `Group` bytes from the heap works properly, even if the result + // of `h1(hash) & self.bucket_mask` is equal to `self.bucket_mask`). See also + // `RawTableInner::set_ctrl` function. + // + // P.S. `h1(hash) & self.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + // of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + self.table.ctrl.cast() } - /// Returns pointer to one past last element of data table. + /// Returns pointer to start of data table. #[inline] - pub unsafe fn data_end(&self) -> NonNull<T> { - NonNull::new_unchecked(self.table.ctrl.as_ptr().cast()) + #[cfg(any(feature = "raw", feature = "nightly"))] + pub unsafe fn data_start(&self) -> NonNull<T> { + NonNull::new_unchecked(self.data_end().as_ptr().wrapping_sub(self.buckets())) } - /// Returns pointer to start of data table. + /// Return the information about memory allocated by the table. + /// + /// `RawTable` allocates single memory block to store both data and metadata. + /// This function returns allocation size and alignment and the beginning of the area. + /// These are the arguments which will be passed to `dealloc` when the table is dropped. + /// + /// This function might be useful for memory profiling. #[inline] - #[cfg(feature = "nightly")] - pub unsafe fn data_start(&self) -> *mut T { - self.data_end().as_ptr().wrapping_sub(self.buckets()) + #[cfg(feature = "raw")] + pub fn allocation_info(&self) -> (NonNull<u8>, Layout) { + // SAFETY: We use the same `table_layout` that was used to allocate + // this table. + unsafe { self.table.allocation_info_or_zero(Self::TABLE_LAYOUT) } } /// Returns the index of a bucket from a `Bucket`. @@ -516,8 +968,55 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { } /// Returns a pointer to an element in the table. + /// + /// The caller must ensure that the `RawTable` outlives the returned [`Bucket<T>`], + /// otherwise using it may result in [`undefined behavior`]. + /// + /// # Safety + /// + /// If `mem::size_of::<T>() != 0`, then the caller of this function must observe the + /// following safety rules: + /// + /// * The table must already be allocated; + /// + /// * The `index` must not be greater than the number returned by the [`RawTable::buckets`] + /// function, i.e. `(index + 1) <= self.buckets()`. + /// + /// It is safe to call this function with index of zero (`index == 0`) on a table that has + /// not been allocated, but using the returned [`Bucket`] results in [`undefined behavior`]. + /// + /// If `mem::size_of::<T>() == 0`, then the only requirement is that the `index` must + /// not be greater than the number returned by the [`RawTable::buckets`] function, i.e. + /// `(index + 1) <= self.buckets()`. + /// + /// [`RawTable::buckets`]: RawTable::buckets + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] pub unsafe fn bucket(&self, index: usize) -> Bucket<T> { + // If mem::size_of::<T>() != 0 then return a pointer to the `element` in the `data part` of the table + // (we start counting from "0", so that in the expression T[n], the "n" index actually one less than + // the "buckets" number of our `RawTable`, i.e. "n = RawTable::buckets() - 1"): + // + // `table.bucket(3).as_ptr()` returns a pointer that points here in the `data` + // part of the `RawTable`, i.e. to the start of T3 (see `Bucket::as_ptr`) + // | + // | `base = self.data_end()` points here + // | (to the start of CT0 or to the end of T0) + // v v + // [Pad], T_n, ..., |T3|, T2, T1, T0, |CT0, CT1, CT2, CT3, ..., CT_n, CTa_0, CTa_1, ..., CTa_m + // ^ \__________ __________/ + // `table.bucket(3)` returns a pointer that points \/ + // here in the `data` part of the `RawTable` (to additional control bytes + // the end of T3) `m = Group::WIDTH - 1` + // + // where: T0...T_n - our stored data; + // CT0...CT_n - control bytes or metadata for `data`; + // CTa_0...CTa_m - additional control bytes (so that the search with loading `Group` bytes from + // the heap works properly, even if the result of `h1(hash) & self.table.bucket_mask` + // is equal to `self.table.bucket_mask`). See also `RawTableInner::set_ctrl` function. + // + // P.S. `h1(hash) & self.table.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + // of buckets is a power of two, and `self.table.bucket_mask = self.buckets() - 1`. debug_assert_ne!(self.table.bucket_mask, 0); debug_assert!(index < self.buckets()); Bucket::from_base_index(self.data_end(), index) @@ -525,8 +1024,7 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// Erases an element from the table without dropping it. #[cfg_attr(feature = "inline-more", inline)] - #[deprecated(since = "0.8.1", note = "use erase or remove instead")] - pub unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) { + unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) { let index = self.bucket_index(item); self.table.erase(index); } @@ -534,7 +1032,6 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// Erases an element from the table, dropping it in place. #[cfg_attr(feature = "inline-more", inline)] #[allow(clippy::needless_pass_by_value)] - #[allow(deprecated)] pub unsafe fn erase(&mut self, item: Bucket<T>) { // Erase the element from the table first since drop might panic. self.erase_no_drop(&item); @@ -558,12 +1055,18 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { } /// Removes an element from the table, returning it. + /// + /// This also returns an `InsertSlot` pointing to the newly free bucket. #[cfg_attr(feature = "inline-more", inline)] #[allow(clippy::needless_pass_by_value)] - #[allow(deprecated)] - pub unsafe fn remove(&mut self, item: Bucket<T>) -> T { + pub unsafe fn remove(&mut self, item: Bucket<T>) -> (T, InsertSlot) { self.erase_no_drop(&item); - item.read() + ( + item.read(), + InsertSlot { + index: self.bucket_index(&item), + }, + ) } /// Finds and removes an element from the table, returning it. @@ -571,7 +1074,7 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { pub fn remove_entry(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<T> { // Avoid `Option::map` because it bloats LLVM IR. match self.find(hash, eq) { - Some(bucket) => Some(unsafe { self.remove(bucket) }), + Some(bucket) => Some(unsafe { self.remove(bucket).0 }), None => None, } } @@ -585,18 +1088,17 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// Removes all elements from the table without freeing the backing memory. #[cfg_attr(feature = "inline-more", inline)] pub fn clear(&mut self) { + if self.is_empty() { + // Special case empty table to avoid surprising O(capacity) time. + return; + } // Ensure that the table is reset even if one of the drops panic let mut self_ = guard(self, |self_| self_.clear_no_drop()); unsafe { - self_.drop_elements(); - } - } - - unsafe fn drop_elements(&mut self) { - if mem::needs_drop::<T>() && !self.is_empty() { - for item in self.iter() { - item.drop(); - } + // SAFETY: ScopeGuard sets to zero the `items` field of the table + // even in case of panic during the dropping of the elements so + // that there will be no double drop of the elements. + self_.table.drop_elements::<T>(); } } @@ -607,7 +1109,16 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { // space for. let min_size = usize::max(self.table.items, min_size); if min_size == 0 { - *self = Self::new_in(self.table.alloc.clone()); + let mut old_inner = mem::replace(&mut self.table, RawTableInner::NEW); + unsafe { + // SAFETY: + // 1. We call the function only once; + // 2. We know for sure that `alloc` and `table_layout` matches the [`Allocator`] + // and [`TableLayout`] that were used to allocate this table. + // 3. If any elements' drop function panics, then there will only be a memory leak, + // because we have replaced the inner table with a new one. + old_inner.drop_inner_table::<T, _>(&self.alloc, Self::TABLE_LAYOUT); + } return; } @@ -624,14 +1135,33 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { if min_buckets < self.buckets() { // Fast path if the table is empty if self.table.items == 0 { - *self = Self::with_capacity_in(min_size, self.table.alloc.clone()); + let new_inner = + RawTableInner::with_capacity(&self.alloc, Self::TABLE_LAYOUT, min_size); + let mut old_inner = mem::replace(&mut self.table, new_inner); + unsafe { + // SAFETY: + // 1. We call the function only once; + // 2. We know for sure that `alloc` and `table_layout` matches the [`Allocator`] + // and [`TableLayout`] that were used to allocate this table. + // 3. If any elements' drop function panics, then there will only be a memory leak, + // because we have replaced the inner table with a new one. + old_inner.drop_inner_table::<T, _>(&self.alloc, Self::TABLE_LAYOUT); + } } else { // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. - if self - .resize(min_size, hasher, Fallibility::Infallible) - .is_err() - { - unsafe { hint::unreachable_unchecked() } + unsafe { + // SAFETY: + // 1. We know for sure that `min_size >= self.table.items`. + // 2. The [`RawTableInner`] must already have properly initialized control bytes since + // we will never expose RawTable::new_uninitialized in a public API. + if self + .resize(min_size, hasher, Fallibility::Infallible) + .is_err() + { + // SAFETY: The result of calling the `resize` function cannot be an error + // because `fallibility == Fallibility::Infallible. + hint::unreachable_unchecked() + } } } } @@ -641,13 +1171,18 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// without reallocation. #[cfg_attr(feature = "inline-more", inline)] pub fn reserve(&mut self, additional: usize, hasher: impl Fn(&T) -> u64) { - if additional > self.table.growth_left { + if unlikely(additional > self.table.growth_left) { // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. - if self - .reserve_rehash(additional, hasher, Fallibility::Infallible) - .is_err() - { - unsafe { hint::unreachable_unchecked() } + unsafe { + // SAFETY: The [`RawTableInner`] must already have properly initialized control + // bytes since we will never expose RawTable::new_uninitialized in a public API. + if self + .reserve_rehash(additional, hasher, Fallibility::Infallible) + .is_err() + { + // SAFETY: All allocation errors will be caught inside `RawTableInner::reserve_rehash`. + hint::unreachable_unchecked() + } } } } @@ -661,28 +1196,45 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { hasher: impl Fn(&T) -> u64, ) -> Result<(), TryReserveError> { if additional > self.table.growth_left { - self.reserve_rehash(additional, hasher, Fallibility::Fallible) + // SAFETY: The [`RawTableInner`] must already have properly initialized control + // bytes since we will never expose RawTable::new_uninitialized in a public API. + unsafe { self.reserve_rehash(additional, hasher, Fallibility::Fallible) } } else { Ok(()) } } /// Out-of-line slow path for `reserve` and `try_reserve`. + /// + /// # Safety + /// + /// The [`RawTableInner`] must have properly initialized control bytes, + /// otherwise calling this function results in [`undefined behavior`] + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[cold] #[inline(never)] - fn reserve_rehash( + unsafe fn reserve_rehash( &mut self, additional: usize, hasher: impl Fn(&T) -> u64, fallibility: Fallibility, ) -> Result<(), TryReserveError> { unsafe { + // SAFETY: + // 1. We know for sure that `alloc` and `layout` matches the [`Allocator`] and + // [`TableLayout`] that were used to allocate this table. + // 2. The `drop` function is the actual drop function of the elements stored in + // the table. + // 3. The caller ensures that the control bytes of the `RawTableInner` + // are already initialized. self.table.reserve_rehash_inner( + &self.alloc, additional, &|table, index| hasher(table.bucket::<T>(index).as_ref()), fallibility, - TableLayout::new::<T>(), - if mem::needs_drop::<T>() { + Self::TABLE_LAYOUT, + if T::NEEDS_DROP { Some(mem::transmute(ptr::drop_in_place::<T> as unsafe fn(*mut T))) } else { None @@ -693,20 +1245,50 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// Allocates a new table of a different size and moves the contents of the /// current table into it. - fn resize( + /// + /// # Safety + /// + /// The [`RawTableInner`] must have properly initialized control bytes, + /// otherwise calling this function results in [`undefined behavior`] + /// + /// The caller of this function must ensure that `capacity >= self.table.items` + /// otherwise: + /// + /// * If `self.table.items != 0`, calling of this function with `capacity` + /// equal to 0 (`capacity == 0`) results in [`undefined behavior`]. + /// + /// * If `capacity_to_buckets(capacity) < Group::WIDTH` and + /// `self.table.items > capacity_to_buckets(capacity)` + /// calling this function results in [`undefined behavior`]. + /// + /// * If `capacity_to_buckets(capacity) >= Group::WIDTH` and + /// `self.table.items > capacity_to_buckets(capacity)` + /// calling this function are never return (will go into an + /// infinite loop). + /// + /// See [`RawTableInner::find_insert_slot`] for more information. + /// + /// [`RawTableInner::find_insert_slot`]: RawTableInner::find_insert_slot + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + unsafe fn resize( &mut self, capacity: usize, hasher: impl Fn(&T) -> u64, fallibility: Fallibility, ) -> Result<(), TryReserveError> { - unsafe { - self.table.resize_inner( - capacity, - &|table, index| hasher(table.bucket::<T>(index).as_ref()), - fallibility, - TableLayout::new::<T>(), - ) - } + // SAFETY: + // 1. The caller of this function guarantees that `capacity >= self.table.items`. + // 2. We know for sure that `alloc` and `layout` matches the [`Allocator`] and + // [`TableLayout`] that were used to allocate this table. + // 3. The caller ensures that the control bytes of the `RawTableInner` + // are already initialized. + self.table.resize_inner( + &self.alloc, + capacity, + &|table, index| hasher(table.bucket::<T>(index).as_ref()), + fallibility, + Self::TABLE_LAYOUT, + ) } /// Inserts a new element into the table, and returns its raw bucket. @@ -715,22 +1297,27 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { #[cfg_attr(feature = "inline-more", inline)] pub fn insert(&mut self, hash: u64, value: T, hasher: impl Fn(&T) -> u64) -> Bucket<T> { unsafe { - let mut index = self.table.find_insert_slot(hash); + // SAFETY: + // 1. The [`RawTableInner`] must already have properly initialized control bytes since + // we will never expose `RawTable::new_uninitialized` in a public API. + // + // 2. We reserve additional space (if necessary) right after calling this function. + let mut slot = self.table.find_insert_slot(hash); - // We can avoid growing the table once we have reached our load - // factor if we are replacing a tombstone. This works since the - // number of EMPTY slots does not change in this case. - let old_ctrl = *self.table.ctrl(index); + // We can avoid growing the table once we have reached our load factor if we are replacing + // a tombstone. This works since the number of EMPTY slots does not change in this case. + // + // SAFETY: The function is guaranteed to return [`InsertSlot`] that contains an index + // in the range `0..=self.buckets()`. + let old_ctrl = *self.table.ctrl(slot.index); if unlikely(self.table.growth_left == 0 && special_is_empty(old_ctrl)) { self.reserve(1, hasher); - index = self.table.find_insert_slot(hash); + // SAFETY: We know for sure that `RawTableInner` has control bytes + // initialized and that there is extra space in the table. + slot = self.table.find_insert_slot(hash); } - self.table.record_item_insert_at(index, old_ctrl, hash); - - let bucket = self.bucket(index); - bucket.write(value); - bucket + self.insert_in_slot(hash, slot, value) } } @@ -796,9 +1383,9 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { { let index = self.bucket_index(&bucket); let old_ctrl = *self.table.ctrl(index); - debug_assert!(is_full(old_ctrl)); + debug_assert!(self.is_bucket_full(index)); let old_growth_left = self.table.growth_left; - let item = self.remove(bucket); + let item = self.remove(bucket).0; if let Some(new_item) = f(item) { self.table.growth_left = old_growth_left; self.table.set_ctrl(index, old_ctrl); @@ -810,17 +1397,78 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { } } + /// Searches for an element in the table. If the element is not found, + /// returns `Err` with the position of a slot where an element with the + /// same hash could be inserted. + /// + /// This function may resize the table if additional space is required for + /// inserting an element. + #[inline] + pub fn find_or_find_insert_slot( + &mut self, + hash: u64, + mut eq: impl FnMut(&T) -> bool, + hasher: impl Fn(&T) -> u64, + ) -> Result<Bucket<T>, InsertSlot> { + self.reserve(1, hasher); + + unsafe { + // SAFETY: + // 1. We know for sure that there is at least one empty `bucket` in the table. + // 2. The [`RawTableInner`] must already have properly initialized control bytes since we will + // never expose `RawTable::new_uninitialized` in a public API. + // 3. The `find_or_find_insert_slot_inner` function returns the `index` of only the full bucket, + // which is in the range `0..self.buckets()` (since there is at least one empty `bucket` in + // the table), so calling `self.bucket(index)` and `Bucket::as_ref` is safe. + match self + .table + .find_or_find_insert_slot_inner(hash, &mut |index| eq(self.bucket(index).as_ref())) + { + // SAFETY: See explanation above. + Ok(index) => Ok(self.bucket(index)), + Err(slot) => Err(slot), + } + } + } + + /// Inserts a new element into the table in the given slot, and returns its + /// raw bucket. + /// + /// # Safety + /// + /// `slot` must point to a slot previously returned by + /// `find_or_find_insert_slot`, and no mutation of the table must have + /// occurred since that call. + #[inline] + pub unsafe fn insert_in_slot(&mut self, hash: u64, slot: InsertSlot, value: T) -> Bucket<T> { + let old_ctrl = *self.table.ctrl(slot.index); + self.table.record_item_insert_at(slot.index, old_ctrl, hash); + + let bucket = self.bucket(slot.index); + bucket.write(value); + bucket + } + /// Searches for an element in the table. #[inline] pub fn find(&self, hash: u64, mut eq: impl FnMut(&T) -> bool) -> Option<Bucket<T>> { - let result = self.table.find_inner(hash, &mut |index| unsafe { - eq(self.bucket(index).as_ref()) - }); - - // Avoid `Option::map` because it bloats LLVM IR. - match result { - Some(index) => Some(unsafe { self.bucket(index) }), - None => None, + unsafe { + // SAFETY: + // 1. The [`RawTableInner`] must already have properly initialized control bytes since we + // will never expose `RawTable::new_uninitialized` in a public API. + // 1. The `find_inner` function returns the `index` of only the full bucket, which is in + // the range `0..self.buckets()`, so calling `self.bucket(index)` and `Bucket::as_ref` + // is safe. + let result = self + .table + .find_inner(hash, &mut |index| eq(self.bucket(index).as_ref())); + + // Avoid `Option::map` because it bloats LLVM IR. + match result { + // SAFETY: See explanation above. + Some(index) => Some(self.bucket(index)), + None => None, + } } } @@ -928,17 +1576,27 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { self.table.bucket_mask + 1 } + /// Checks whether the bucket at `index` is full. + /// + /// # Safety + /// + /// The caller must ensure `index` is less than the number of buckets. + #[inline] + pub unsafe fn is_bucket_full(&self, index: usize) -> bool { + self.table.is_bucket_full(index) + } + /// Returns an iterator over every element in the table. It is up to /// the caller to ensure that the `RawTable` outlives the `RawIter`. /// Because we cannot make the `next` method unsafe on the `RawIter` /// struct, we have to make the `iter` method unsafe. #[inline] pub unsafe fn iter(&self) -> RawIter<T> { - let data = Bucket::from_base_index(self.data_end(), 0); - RawIter { - iter: RawIterRange::new(self.table.ctrl.as_ptr(), data, self.table.buckets()), - items: self.table.items, - } + // SAFETY: + // 1. The caller must uphold the safety contract for `iter` method. + // 2. The [`RawTableInner`] must already have properly initialized control bytes since + // we will never expose RawTable::new_uninitialized in a public API. + self.table.iter() } /// Returns an iterator over occupied buckets that could match a given hash. @@ -952,7 +1610,7 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { /// `RawIterHash` struct, we have to make the `iter_hash` method unsafe. #[cfg_attr(feature = "inline-more", inline)] #[cfg(feature = "raw")] - pub unsafe fn iter_hash(&self, hash: u64) -> RawIterHash<'_, T, A> { + pub unsafe fn iter_hash(&self, hash: u64) -> RawIterHash<T> { RawIterHash::new(self, hash) } @@ -978,8 +1636,8 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { debug_assert_eq!(iter.len(), self.len()); RawDrain { iter, - table: ManuallyDrop::new(mem::replace(self, Self::new_in(self.table.alloc.clone()))), - orig_table: NonNull::from(self), + table: mem::replace(&mut self.table, RawTableInner::NEW), + orig_table: NonNull::from(&mut self.table), marker: PhantomData, } } @@ -993,31 +1651,31 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { pub unsafe fn into_iter_from(self, iter: RawIter<T>) -> RawIntoIter<T, A> { debug_assert_eq!(iter.len(), self.len()); - let alloc = self.table.alloc.clone(); let allocation = self.into_allocation(); RawIntoIter { iter, allocation, marker: PhantomData, - alloc, } } /// Converts the table into a raw allocation. The contents of the table /// should be dropped using a `RawIter` before freeing the allocation. #[cfg_attr(feature = "inline-more", inline)] - pub(crate) fn into_allocation(self) -> Option<(NonNull<u8>, Layout)> { + pub(crate) fn into_allocation(self) -> Option<(NonNull<u8>, Layout, A)> { let alloc = if self.table.is_empty_singleton() { None } else { // Avoid `Option::unwrap_or_else` because it bloats LLVM IR. - let (layout, ctrl_offset) = match calculate_layout::<T>(self.table.buckets()) { - Some(lco) => lco, - None => unsafe { hint::unreachable_unchecked() }, - }; + let (layout, ctrl_offset) = + match Self::TABLE_LAYOUT.calculate_layout_for(self.table.buckets()) { + Some(lco) => lco, + None => unsafe { hint::unreachable_unchecked() }, + }; Some(( unsafe { NonNull::new_unchecked(self.table.ctrl.as_ptr().sub(ctrl_offset)) }, layout, + unsafe { ptr::read(&self.alloc) }, )) }; mem::forget(self); @@ -1025,41 +1683,62 @@ impl<T, A: Allocator + Clone> RawTable<T, A> { } } -unsafe impl<T, A: Allocator + Clone> Send for RawTable<T, A> +unsafe impl<T, A: Allocator> Send for RawTable<T, A> where T: Send, A: Send, { } -unsafe impl<T, A: Allocator + Clone> Sync for RawTable<T, A> +unsafe impl<T, A: Allocator> Sync for RawTable<T, A> where T: Sync, A: Sync, { } -impl<A> RawTableInner<A> { +impl RawTableInner { + const NEW: Self = RawTableInner::new(); + + /// Creates a new empty hash table without allocating any memory. + /// + /// In effect this returns a table with exactly 1 bucket. However we can + /// leave the data pointer dangling since that bucket is never accessed + /// due to our load factor forcing us to always have at least 1 free bucket. #[inline] - const fn new_in(alloc: A) -> Self { + const fn new() -> Self { Self { // Be careful to cast the entire slice to a raw pointer. ctrl: unsafe { NonNull::new_unchecked(Group::static_empty() as *const _ as *mut u8) }, bucket_mask: 0, items: 0, growth_left: 0, - alloc, } } } -impl<A: Allocator + Clone> RawTableInner<A> { +impl RawTableInner { + /// Allocates a new [`RawTableInner`] with the given number of buckets. + /// The control bytes and buckets are left uninitialized. + /// + /// # Safety + /// + /// The caller of this function must ensure that the `buckets` is power of two + /// and also initialize all control bytes of the length `self.bucket_mask + 1 + + /// Group::WIDTH` with the [`EMPTY`] bytes. + /// + /// See also [`Allocator`] API for other safety concerns. + /// + /// [`Allocator`]: https://doc.rust-lang.org/alloc/alloc/trait.Allocator.html #[cfg_attr(feature = "inline-more", inline)] - unsafe fn new_uninitialized( - alloc: A, + unsafe fn new_uninitialized<A>( + alloc: &A, table_layout: TableLayout, buckets: usize, fallibility: Fallibility, - ) -> Result<Self, TryReserveError> { + ) -> Result<Self, TryReserveError> + where + A: Allocator, + { debug_assert!(buckets.is_power_of_two()); // Avoid `Option::ok_or_else` because it bloats LLVM IR. @@ -1068,45 +1747,48 @@ impl<A: Allocator + Clone> RawTableInner<A> { None => return Err(fallibility.capacity_overflow()), }; - // We need an additional check to ensure that the allocation doesn't - // exceed `isize::MAX`. We can skip this check on 64-bit systems since - // such allocations will never succeed anyways. - // - // This mirrors what Vec does in the standard library. - if mem::size_of::<usize>() < 8 && layout.size() > isize::MAX as usize { - return Err(fallibility.capacity_overflow()); - } - - let ptr: NonNull<u8> = match do_alloc(&alloc, layout) { + let ptr: NonNull<u8> = match do_alloc(alloc, layout) { Ok(block) => block.cast(), Err(_) => return Err(fallibility.alloc_err(layout)), }; + // SAFETY: null pointer will be caught in above check let ctrl = NonNull::new_unchecked(ptr.as_ptr().add(ctrl_offset)); Ok(Self { ctrl, bucket_mask: buckets - 1, items: 0, growth_left: bucket_mask_to_capacity(buckets - 1), - alloc, }) } + /// Attempts to allocate a new [`RawTableInner`] with at least enough + /// capacity for inserting the given number of elements without reallocating. + /// + /// All the control bytes are initialized with the [`EMPTY`] bytes. #[inline] - fn fallible_with_capacity( - alloc: A, + fn fallible_with_capacity<A>( + alloc: &A, table_layout: TableLayout, capacity: usize, fallibility: Fallibility, - ) -> Result<Self, TryReserveError> { + ) -> Result<Self, TryReserveError> + where + A: Allocator, + { if capacity == 0 { - Ok(Self::new_in(alloc)) + Ok(Self::NEW) } else { + // SAFETY: We checked that we could successfully allocate the new table, and then + // initialized all control bytes with the constant `EMPTY` byte. unsafe { let buckets = capacity_to_buckets(capacity).ok_or_else(|| fallibility.capacity_overflow())?; let result = Self::new_uninitialized(alloc, table_layout, buckets, fallibility)?; + // SAFETY: We checked that the table is allocated and therefore the table already has + // `self.bucket_mask + 1 + Group::WIDTH` number of control bytes (see TableLayout::calculate_layout_for) + // so writing `self.num_ctrl_bytes() == bucket_mask + 1 + Group::WIDTH` bytes is safe. result.ctrl(0).write_bytes(EMPTY, result.num_ctrl_bytes()); Ok(result) @@ -1114,66 +1796,397 @@ impl<A: Allocator + Clone> RawTableInner<A> { } } - /// Searches for an empty or deleted bucket which is suitable for inserting - /// a new element and sets the hash for that slot. + /// Allocates a new [`RawTableInner`] with at least enough capacity for inserting + /// the given number of elements without reallocating. + /// + /// Panics if the new capacity exceeds [`isize::MAX`] bytes and [`abort`] the program + /// in case of allocation error. Use [`fallible_with_capacity`] instead if you want to + /// handle memory allocation failure. + /// + /// All the control bytes are initialized with the [`EMPTY`] bytes. + /// + /// [`fallible_with_capacity`]: RawTableInner::fallible_with_capacity + /// [`abort`]: https://doc.rust-lang.org/alloc/alloc/fn.handle_alloc_error.html + fn with_capacity<A>(alloc: &A, table_layout: TableLayout, capacity: usize) -> Self + where + A: Allocator, + { + // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. + match Self::fallible_with_capacity(alloc, table_layout, capacity, Fallibility::Infallible) { + Ok(table_inner) => table_inner, + // SAFETY: All allocation errors will be caught inside `RawTableInner::new_uninitialized`. + Err(_) => unsafe { hint::unreachable_unchecked() }, + } + } + + /// Fixes up an insertion slot returned by the [`RawTableInner::find_insert_slot_in_group`] method. + /// + /// In tables smaller than the group width (`self.buckets() < Group::WIDTH`), trailing control + /// bytes outside the range of the table are filled with [`EMPTY`] entries. These will unfortunately + /// trigger a match of [`RawTableInner::find_insert_slot_in_group`] function. This is because + /// the `Some(bit)` returned by `group.match_empty_or_deleted().lowest_set_bit()` after masking + /// (`(probe_seq.pos + bit) & self.bucket_mask`) may point to a full bucket that is already occupied. + /// We detect this situation here and perform a second scan starting at the beginning of the table. + /// This second scan is guaranteed to find an empty slot (due to the load factor) before hitting the + /// trailing control bytes (containing [`EMPTY`] bytes). + /// + /// If this function is called correctly, it is guaranteed to return [`InsertSlot`] with an + /// index of an empty or deleted bucket in the range `0..self.buckets()` (see `Warning` and + /// `Safety`). + /// + /// # Warning + /// + /// The table must have at least 1 empty or deleted `bucket`, otherwise if the table is less than + /// the group width (`self.buckets() < Group::WIDTH`) this function returns an index outside of the + /// table indices range `0..self.buckets()` (`0..=self.bucket_mask`). Attempt to write data at that + /// index will cause immediate [`undefined behavior`]. + /// + /// # Safety + /// + /// The safety rules are directly derived from the safety rules for [`RawTableInner::ctrl`] method. + /// Thus, in order to uphold those safety contracts, as well as for the correct logic of the work + /// of this crate, the following rules are necessary and sufficient: /// - /// There must be at least 1 empty bucket in the table. + /// * The [`RawTableInner`] must have properly initialized control bytes otherwise calling this + /// function results in [`undefined behavior`]. + /// + /// * This function must only be used on insertion slots found by [`RawTableInner::find_insert_slot_in_group`] + /// (after the `find_insert_slot_in_group` function, but before insertion into the table). + /// + /// * The `index` must not be greater than the `self.bucket_mask`, i.e. `(index + 1) <= self.buckets()` + /// (this one is provided by the [`RawTableInner::find_insert_slot_in_group`] function). + /// + /// Calling this function with an index not provided by [`RawTableInner::find_insert_slot_in_group`] + /// may result in [`undefined behavior`] even if the index satisfies the safety rules of the + /// [`RawTableInner::ctrl`] function (`index < self.bucket_mask + 1 + Group::WIDTH`). + /// + /// [`RawTableInner::ctrl`]: RawTableInner::ctrl + /// [`RawTableInner::find_insert_slot_in_group`]: RawTableInner::find_insert_slot_in_group + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - unsafe fn prepare_insert_slot(&self, hash: u64) -> (usize, u8) { - let index = self.find_insert_slot(hash); + unsafe fn fix_insert_slot(&self, mut index: usize) -> InsertSlot { + // SAFETY: The caller of this function ensures that `index` is in the range `0..=self.bucket_mask`. + if unlikely(self.is_bucket_full(index)) { + debug_assert!(self.bucket_mask < Group::WIDTH); + // SAFETY: + // + // * Since the caller of this function ensures that the control bytes are properly + // initialized and `ptr = self.ctrl(0)` points to the start of the array of control + // bytes, therefore: `ctrl` is valid for reads, properly aligned to `Group::WIDTH` + // and points to the properly initialized control bytes (see also + // `TableLayout::calculate_layout_for` and `ptr::read`); + // + // * Because the caller of this function ensures that the index was provided by the + // `self.find_insert_slot_in_group()` function, so for for tables larger than the + // group width (self.buckets() >= Group::WIDTH), we will never end up in the given + // branch, since `(probe_seq.pos + bit) & self.bucket_mask` in `find_insert_slot_in_group` + // cannot return a full bucket index. For tables smaller than the group width, calling + // the `unwrap_unchecked` function is also safe, as the trailing control bytes outside + // the range of the table are filled with EMPTY bytes (and we know for sure that there + // is at least one FULL bucket), so this second scan either finds an empty slot (due to + // the load factor) or hits the trailing control bytes (containing EMPTY). + index = Group::load_aligned(self.ctrl(0)) + .match_empty_or_deleted() + .lowest_set_bit() + .unwrap_unchecked(); + } + InsertSlot { index } + } + + /// Finds the position to insert something in a group. + /// + /// **This may have false positives and must be fixed up with `fix_insert_slot` + /// before it's used.** + /// + /// The function is guaranteed to return the index of an empty or deleted [`Bucket`] + /// in the range `0..self.buckets()` (`0..=self.bucket_mask`). + #[inline] + fn find_insert_slot_in_group(&self, group: &Group, probe_seq: &ProbeSeq) -> Option<usize> { + let bit = group.match_empty_or_deleted().lowest_set_bit(); + + if likely(bit.is_some()) { + // This is the same as `(probe_seq.pos + bit) % self.buckets()` because the number + // of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + Some((probe_seq.pos + bit.unwrap()) & self.bucket_mask) + } else { + None + } + } + + /// Searches for an element in the table, or a potential slot where that element could + /// be inserted (an empty or deleted [`Bucket`] index). + /// + /// This uses dynamic dispatch to reduce the amount of code generated, but that is + /// eliminated by LLVM optimizations. + /// + /// This function does not make any changes to the `data` part of the table, or any + /// changes to the `items` or `growth_left` field of the table. + /// + /// The table must have at least 1 empty or deleted `bucket`, otherwise, if the + /// `eq: &mut dyn FnMut(usize) -> bool` function does not return `true`, this function + /// will never return (will go into an infinite loop) for tables larger than the group + /// width, or return an index outside of the table indices range if the table is less + /// than the group width. + /// + /// This function is guaranteed to provide the `eq: &mut dyn FnMut(usize) -> bool` + /// function with only `FULL` buckets' indices and return the `index` of the found + /// element (as `Ok(index)`). If the element is not found and there is at least 1 + /// empty or deleted [`Bucket`] in the table, the function is guaranteed to return + /// [InsertSlot] with an index in the range `0..self.buckets()`, but in any case, + /// if this function returns [`InsertSlot`], it will contain an index in the range + /// `0..=self.buckets()`. + /// + /// # Safety + /// + /// The [`RawTableInner`] must have properly initialized control bytes otherwise calling + /// this function results in [`undefined behavior`]. + /// + /// Attempt to write data at the [`InsertSlot`] returned by this function when the table is + /// less than the group width and if there was not at least one empty or deleted bucket in + /// the table will cause immediate [`undefined behavior`]. This is because in this case the + /// function will return `self.bucket_mask + 1` as an index due to the trailing [`EMPTY] + /// control bytes outside the table range. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[inline] + unsafe fn find_or_find_insert_slot_inner( + &self, + hash: u64, + eq: &mut dyn FnMut(usize) -> bool, + ) -> Result<usize, InsertSlot> { + let mut insert_slot = None; + + let h2_hash = h2(hash); + let mut probe_seq = self.probe_seq(hash); + + loop { + // SAFETY: + // * Caller of this function ensures that the control bytes are properly initialized. + // + // * `ProbeSeq.pos` cannot be greater than `self.bucket_mask = self.buckets() - 1` + // of the table due to masking with `self.bucket_mask` and also because mumber of + // buckets is a power of two (see `self.probe_seq` function). + // + // * Even if `ProbeSeq.pos` returns `position == self.bucket_mask`, it is safe to + // call `Group::load` due to the extended control bytes range, which is + // `self.bucket_mask + 1 + Group::WIDTH` (in fact, this means that the last control + // byte will never be read for the allocated table); + // + // * Also, even if `RawTableInner` is not already allocated, `ProbeSeq.pos` will + // always return "0" (zero), so Group::load will read unaligned `Group::static_empty()` + // bytes, which is safe (see RawTableInner::new). + let group = unsafe { Group::load(self.ctrl(probe_seq.pos)) }; + + for bit in group.match_byte(h2_hash) { + let index = (probe_seq.pos + bit) & self.bucket_mask; + + if likely(eq(index)) { + return Ok(index); + } + } + + // We didn't find the element we were looking for in the group, try to get an + // insertion slot from the group if we don't have one yet. + if likely(insert_slot.is_none()) { + insert_slot = self.find_insert_slot_in_group(&group, &probe_seq); + } + + // Only stop the search if the group contains at least one empty element. + // Otherwise, the element that we are looking for might be in a following group. + if likely(group.match_empty().any_bit_set()) { + // We must have found a insert slot by now, since the current group contains at + // least one. For tables smaller than the group width, there will still be an + // empty element in the current (and only) group due to the load factor. + unsafe { + // SAFETY: + // * Caller of this function ensures that the control bytes are properly initialized. + // + // * We use this function with the slot / index found by `self.find_insert_slot_in_group` + return Err(self.fix_insert_slot(insert_slot.unwrap_unchecked())); + } + } + + probe_seq.move_next(self.bucket_mask); + } + } + + /// Searches for an empty or deleted bucket which is suitable for inserting a new + /// element and sets the hash for that slot. Returns an index of that slot and the + /// old control byte stored in the found index. + /// + /// This function does not check if the given element exists in the table. Also, + /// this function does not check if there is enough space in the table to insert + /// a new element. Caller of the funtion must make ensure that the table has at + /// least 1 empty or deleted `bucket`, otherwise this function will never return + /// (will go into an infinite loop) for tables larger than the group width, or + /// return an index outside of the table indices range if the table is less than + /// the group width. + /// + /// If there is at least 1 empty or deleted `bucket` in the table, the function is + /// guaranteed to return an `index` in the range `0..self.buckets()`, but in any case, + /// if this function returns an `index` it will be in the range `0..=self.buckets()`. + /// + /// This function does not make any changes to the `data` parts of the table, + /// or any changes to the `items` or `growth_left` field of the table. + /// + /// # Safety + /// + /// The safety rules are directly derived from the safety rules for the + /// [`RawTableInner::set_ctrl_h2`] and [`RawTableInner::find_insert_slot`] methods. + /// Thus, in order to uphold the safety contracts for that methods, as well as for + /// the correct logic of the work of this crate, you must observe the following rules + /// when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated and has properly initialized + /// control bytes otherwise calling this function results in [`undefined behavior`]. + /// + /// * The caller of this function must ensure that the "data" parts of the table + /// will have an entry in the returned index (matching the given hash) right + /// after calling this function. + /// + /// Attempt to write data at the `index` returned by this function when the table is + /// less than the group width and if there was not at least one empty or deleted bucket in + /// the table will cause immediate [`undefined behavior`]. This is because in this case the + /// function will return `self.bucket_mask + 1` as an index due to the trailing [`EMPTY] + /// control bytes outside the table range. + /// + /// The caller must independently increase the `items` field of the table, and also, + /// if the old control byte was [`EMPTY`], then decrease the table's `growth_left` + /// field, and do not change it if the old control byte was [`DELETED`]. + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// [`RawTableInner::ctrl`]: RawTableInner::ctrl + /// [`RawTableInner::set_ctrl_h2`]: RawTableInner::set_ctrl_h2 + /// [`RawTableInner::find_insert_slot`]: RawTableInner::find_insert_slot + #[inline] + unsafe fn prepare_insert_slot(&mut self, hash: u64) -> (usize, u8) { + // SAFETY: Caller of this function ensures that the control bytes are properly initialized. + let index: usize = self.find_insert_slot(hash).index; + // SAFETY: + // 1. The `find_insert_slot` function either returns an `index` less than or + // equal to `self.buckets() = self.bucket_mask + 1` of the table, or never + // returns if it cannot find an empty or deleted slot. + // 2. The caller of this function guarantees that the table has already been + // allocated let old_ctrl = *self.ctrl(index); self.set_ctrl_h2(index, hash); (index, old_ctrl) } /// Searches for an empty or deleted bucket which is suitable for inserting - /// a new element. + /// a new element, returning the `index` for the new [`Bucket`]. + /// + /// This function does not make any changes to the `data` part of the table, or any + /// changes to the `items` or `growth_left` field of the table. + /// + /// The table must have at least 1 empty or deleted `bucket`, otherwise this function + /// will never return (will go into an infinite loop) for tables larger than the group + /// width, or return an index outside of the table indices range if the table is less + /// than the group width. + /// + /// If there is at least 1 empty or deleted `bucket` in the table, the function is + /// guaranteed to return [`InsertSlot`] with an index in the range `0..self.buckets()`, + /// but in any case, if this function returns [`InsertSlot`], it will contain an index + /// in the range `0..=self.buckets()`. /// - /// There must be at least 1 empty bucket in the table. + /// # Safety + /// + /// The [`RawTableInner`] must have properly initialized control bytes otherwise calling + /// this function results in [`undefined behavior`]. + /// + /// Attempt to write data at the [`InsertSlot`] returned by this function when the table is + /// less than the group width and if there was not at least one empty or deleted bucket in + /// the table will cause immediate [`undefined behavior`]. This is because in this case the + /// function will return `self.bucket_mask + 1` as an index due to the trailing [`EMPTY] + /// control bytes outside the table range. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - fn find_insert_slot(&self, hash: u64) -> usize { + unsafe fn find_insert_slot(&self, hash: u64) -> InsertSlot { let mut probe_seq = self.probe_seq(hash); loop { - unsafe { - let group = Group::load(self.ctrl(probe_seq.pos)); - if let Some(bit) = group.match_empty_or_deleted().lowest_set_bit() { - let result = (probe_seq.pos + bit) & self.bucket_mask; - - // In tables smaller than the group width, trailing control - // bytes outside the range of the table are filled with - // EMPTY entries. These will unfortunately trigger a - // match, but once masked may point to a full bucket that - // is already occupied. We detect this situation here and - // perform a second scan starting at the beginning of the - // table. This second scan is guaranteed to find an empty - // slot (due to the load factor) before hitting the trailing - // control bytes (containing EMPTY). - if unlikely(is_full(*self.ctrl(result))) { - debug_assert!(self.bucket_mask < Group::WIDTH); - debug_assert_ne!(probe_seq.pos, 0); - return Group::load_aligned(self.ctrl(0)) - .match_empty_or_deleted() - .lowest_set_bit_nonzero(); - } + // SAFETY: + // * Caller of this function ensures that the control bytes are properly initialized. + // + // * `ProbeSeq.pos` cannot be greater than `self.bucket_mask = self.buckets() - 1` + // of the table due to masking with `self.bucket_mask` and also because mumber of + // buckets is a power of two (see `self.probe_seq` function). + // + // * Even if `ProbeSeq.pos` returns `position == self.bucket_mask`, it is safe to + // call `Group::load` due to the extended control bytes range, which is + // `self.bucket_mask + 1 + Group::WIDTH` (in fact, this means that the last control + // byte will never be read for the allocated table); + // + // * Also, even if `RawTableInner` is not already allocated, `ProbeSeq.pos` will + // always return "0" (zero), so Group::load will read unaligned `Group::static_empty()` + // bytes, which is safe (see RawTableInner::new). + let group = unsafe { Group::load(self.ctrl(probe_seq.pos)) }; - return result; + let index = self.find_insert_slot_in_group(&group, &probe_seq); + if likely(index.is_some()) { + // SAFETY: + // * Caller of this function ensures that the control bytes are properly initialized. + // + // * We use this function with the slot / index found by `self.find_insert_slot_in_group` + unsafe { + return self.fix_insert_slot(index.unwrap_unchecked()); } } probe_seq.move_next(self.bucket_mask); } } - /// Searches for an element in the table. This uses dynamic dispatch to reduce the amount of - /// code generated, but it is eliminated by LLVM optimizations. - #[inline] - fn find_inner(&self, hash: u64, eq: &mut dyn FnMut(usize) -> bool) -> Option<usize> { + /// Searches for an element in a table, returning the `index` of the found element. + /// This uses dynamic dispatch to reduce the amount of code generated, but it is + /// eliminated by LLVM optimizations. + /// + /// This function does not make any changes to the `data` part of the table, or any + /// changes to the `items` or `growth_left` field of the table. + /// + /// The table must have at least 1 empty `bucket`, otherwise, if the + /// `eq: &mut dyn FnMut(usize) -> bool` function does not return `true`, + /// this function will also never return (will go into an infinite loop). + /// + /// This function is guaranteed to provide the `eq: &mut dyn FnMut(usize) -> bool` + /// function with only `FULL` buckets' indices and return the `index` of the found + /// element as `Some(index)`, so the index will always be in the range + /// `0..self.buckets()`. + /// + /// # Safety + /// + /// The [`RawTableInner`] must have properly initialized control bytes otherwise calling + /// this function results in [`undefined behavior`]. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[inline(always)] + unsafe fn find_inner(&self, hash: u64, eq: &mut dyn FnMut(usize) -> bool) -> Option<usize> { let h2_hash = h2(hash); let mut probe_seq = self.probe_seq(hash); loop { + // SAFETY: + // * Caller of this function ensures that the control bytes are properly initialized. + // + // * `ProbeSeq.pos` cannot be greater than `self.bucket_mask = self.buckets() - 1` + // of the table due to masking with `self.bucket_mask`. + // + // * Even if `ProbeSeq.pos` returns `position == self.bucket_mask`, it is safe to + // call `Group::load` due to the extended control bytes range, which is + // `self.bucket_mask + 1 + Group::WIDTH` (in fact, this means that the last control + // byte will never be read for the allocated table); + // + // * Also, even if `RawTableInner` is not already allocated, `ProbeSeq.pos` will + // always return "0" (zero), so Group::load will read unaligned `Group::static_empty()` + // bytes, which is safe (see RawTableInner::new_in). let group = unsafe { Group::load(self.ctrl(probe_seq.pos)) }; for bit in group.match_byte(h2_hash) { + // This is the same as `(probe_seq.pos + bit) % self.buckets()` because the number + // of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. let index = (probe_seq.pos + bit) & self.bucket_mask; if likely(eq(index)) { @@ -1189,12 +2202,52 @@ impl<A: Allocator + Clone> RawTableInner<A> { } } + /// Prepares for rehashing data in place (that is, without allocating new memory). + /// Converts all full index `control bytes` to `DELETED` and all `DELETED` control + /// bytes to `EMPTY`, i.e. performs the following conversion: + /// + /// - `EMPTY` control bytes -> `EMPTY`; + /// - `DELETED` control bytes -> `EMPTY`; + /// - `FULL` control bytes -> `DELETED`. + /// + /// This function does not make any changes to the `data` parts of the table, + /// or any changes to the `items` or `growth_left` field of the table. + /// + /// # Safety + /// + /// You must observe the following safety rules when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The caller of this function must convert the `DELETED` bytes back to `FULL` + /// bytes when re-inserting them into their ideal position (which was impossible + /// to do during the first insert due to tombstones). If the caller does not do + /// this, then calling this function may result in a memory leak. + /// + /// * The [`RawTableInner`] must have properly initialized control bytes otherwise + /// calling this function results in [`undefined behavior`]. + /// + /// Calling this function on a table that has not been allocated results in + /// [`undefined behavior`]. + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[allow(clippy::mut_mut)] #[inline] unsafe fn prepare_rehash_in_place(&mut self) { - // Bulk convert all full control bytes to DELETED, and all DELETED - // control bytes to EMPTY. This effectively frees up all buckets - // containing a DELETED entry. + // Bulk convert all full control bytes to DELETED, and all DELETED control bytes to EMPTY. + // This effectively frees up all buckets containing a DELETED entry. + // + // SAFETY: + // 1. `i` is guaranteed to be within bounds since we are iterating from zero to `buckets - 1`; + // 2. Even if `i` will be `i == self.bucket_mask`, it is safe to call `Group::load_aligned` + // due to the extended control bytes range, which is `self.bucket_mask + 1 + Group::WIDTH`; + // 3. The caller of this function guarantees that [`RawTableInner`] has already been allocated; + // 4. We can use `Group::load_aligned` and `Group::store_aligned` here since we start from 0 + // and go to the end with a step equal to `Group::WIDTH` (see TableLayout::calculate_layout_for). for i in (0..self.buckets()).step_by(Group::WIDTH) { let group = Group::load_aligned(self.ctrl(i)); let group = group.convert_special_to_empty_and_full_to_deleted(); @@ -1203,15 +2256,245 @@ impl<A: Allocator + Clone> RawTableInner<A> { // Fix up the trailing control bytes. See the comments in set_ctrl // for the handling of tables smaller than the group width. - if self.buckets() < Group::WIDTH { + // + // SAFETY: The caller of this function guarantees that [`RawTableInner`] + // has already been allocated + if unlikely(self.buckets() < Group::WIDTH) { + // SAFETY: We have `self.bucket_mask + 1 + Group::WIDTH` number of control bytes, + // so copying `self.buckets() == self.bucket_mask + 1` bytes with offset equal to + // `Group::WIDTH` is safe self.ctrl(0) .copy_to(self.ctrl(Group::WIDTH), self.buckets()); } else { + // SAFETY: We have `self.bucket_mask + 1 + Group::WIDTH` number of + // control bytes,so copying `Group::WIDTH` bytes with offset equal + // to `self.buckets() == self.bucket_mask + 1` is safe self.ctrl(0) .copy_to(self.ctrl(self.buckets()), Group::WIDTH); } } + /// Returns an iterator over every element in the table. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result + /// is [`undefined behavior`]: + /// + /// * The caller has to ensure that the `RawTableInner` outlives the + /// `RawIter`. Because we cannot make the `next` method unsafe on + /// the `RawIter` struct, we have to make the `iter` method unsafe. + /// + /// * The [`RawTableInner`] must have properly initialized control bytes. + /// + /// The type `T` must be the actual type of the elements stored in the table, + /// otherwise using the returned [`RawIter`] results in [`undefined behavior`]. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[inline] + unsafe fn iter<T>(&self) -> RawIter<T> { + // SAFETY: + // 1. Since the caller of this function ensures that the control bytes + // are properly initialized and `self.data_end()` points to the start + // of the array of control bytes, therefore: `ctrl` is valid for reads, + // properly aligned to `Group::WIDTH` and points to the properly initialized + // control bytes. + // 2. `data` bucket index in the table is equal to the `ctrl` index (i.e. + // equal to zero). + // 3. We pass the exact value of buckets of the table to the function. + // + // `ctrl` points here (to the start + // of the first control byte `CT0`) + // ∨ + // [Pad], T_n, ..., T1, T0, |CT0, CT1, ..., CT_n|, CTa_0, CTa_1, ..., CTa_m + // \________ ________/ + // \/ + // `n = buckets - 1`, i.e. `RawTableInner::buckets() - 1` + // + // where: T0...T_n - our stored data; + // CT0...CT_n - control bytes or metadata for `data`. + // CTa_0...CTa_m - additional control bytes, where `m = Group::WIDTH - 1` (so that the search + // with loading `Group` bytes from the heap works properly, even if the result + // of `h1(hash) & self.bucket_mask` is equal to `self.bucket_mask`). See also + // `RawTableInner::set_ctrl` function. + // + // P.S. `h1(hash) & self.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + // of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + let data = Bucket::from_base_index(self.data_end(), 0); + RawIter { + // SAFETY: See explanation above + iter: RawIterRange::new(self.ctrl.as_ptr(), data, self.buckets()), + items: self.items, + } + } + + /// Executes the destructors (if any) of the values stored in the table. + /// + /// # Note + /// + /// This function does not erase the control bytes of the table and does + /// not make any changes to the `items` or `growth_left` fields of the + /// table. If necessary, the caller of this function must manually set + /// up these table fields, for example using the [`clear_no_drop`] function. + /// + /// Be careful during calling this function, because drop function of + /// the elements can panic, and this can leave table in an inconsistent + /// state. + /// + /// # Safety + /// + /// The type `T` must be the actual type of the elements stored in the table, + /// otherwise calling this function may result in [`undefined behavior`]. + /// + /// If `T` is a type that should be dropped and **the table is not empty**, + /// calling this function more than once results in [`undefined behavior`]. + /// + /// If `T` is not [`Copy`], attempting to use values stored in the table after + /// calling this function may result in [`undefined behavior`]. + /// + /// It is safe to call this function on a table that has not been allocated, + /// on a table with uninitialized control bytes, and on a table with no actual + /// data but with `Full` control bytes if `self.items == 0`. + /// + /// See also [`Bucket::drop`] / [`Bucket::as_ptr`] methods, for more information + /// about of properly removing or saving `element` from / into the [`RawTable`] / + /// [`RawTableInner`]. + /// + /// [`Bucket::drop`]: Bucket::drop + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`clear_no_drop`]: RawTableInner::clear_no_drop + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + unsafe fn drop_elements<T>(&mut self) { + // Check that `self.items != 0`. Protects against the possibility + // of creating an iterator on an table with uninitialized control bytes. + if T::NEEDS_DROP && self.items != 0 { + // SAFETY: We know for sure that RawTableInner will outlive the + // returned `RawIter` iterator, and the caller of this function + // must uphold the safety contract for `drop_elements` method. + for item in self.iter::<T>() { + // SAFETY: The caller must uphold the safety contract for + // `drop_elements` method. + item.drop(); + } + } + } + + /// Executes the destructors (if any) of the values stored in the table and than + /// deallocates the table. + /// + /// # Note + /// + /// Calling this function automatically makes invalid (dangling) all instances of + /// buckets ([`Bucket`]) and makes invalid (dangling) the `ctrl` field of the table. + /// + /// This function does not make any changes to the `bucket_mask`, `items` or `growth_left` + /// fields of the table. If necessary, the caller of this function must manually set + /// up these table fields. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is [`undefined behavior`]: + /// + /// * Calling this function more than once; + /// + /// * The type `T` must be the actual type of the elements stored in the table. + /// + /// * The `alloc` must be the same [`Allocator`] as the `Allocator` that was used + /// to allocate this table. + /// + /// * The `table_layout` must be the same [`TableLayout`] as the `TableLayout` that + /// was used to allocate this table. + /// + /// The caller of this function should pay attention to the possibility of the + /// elements' drop function panicking, because this: + /// + /// * May leave the table in an inconsistent state; + /// + /// * Memory is never deallocated, so a memory leak may occur. + /// + /// Attempt to use the `ctrl` field of the table (dereference) after calling this + /// function results in [`undefined behavior`]. + /// + /// It is safe to call this function on a table that has not been allocated, + /// on a table with uninitialized control bytes, and on a table with no actual + /// data but with `Full` control bytes if `self.items == 0`. + /// + /// See also [`RawTableInner::drop_elements`] or [`RawTableInner::free_buckets`] + /// for more information. + /// + /// [`RawTableInner::drop_elements`]: RawTableInner::drop_elements + /// [`RawTableInner::free_buckets`]: RawTableInner::free_buckets + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + unsafe fn drop_inner_table<T, A: Allocator>(&mut self, alloc: &A, table_layout: TableLayout) { + if !self.is_empty_singleton() { + unsafe { + // SAFETY: The caller must uphold the safety contract for `drop_inner_table` method. + self.drop_elements::<T>(); + // SAFETY: + // 1. We have checked that our table is allocated. + // 2. The caller must uphold the safety contract for `drop_inner_table` method. + self.free_buckets(alloc, table_layout); + } + } + } + + /// Returns a pointer to an element in the table (convenience for + /// `Bucket::from_base_index(self.data_end::<T>(), index)`). + /// + /// The caller must ensure that the `RawTableInner` outlives the returned [`Bucket<T>`], + /// otherwise using it may result in [`undefined behavior`]. + /// + /// # Safety + /// + /// If `mem::size_of::<T>() != 0`, then the safety rules are directly derived from the + /// safety rules of the [`Bucket::from_base_index`] function. Therefore, when calling + /// this function, the following safety rules must be observed: + /// + /// * The table must already be allocated; + /// + /// * The `index` must not be greater than the number returned by the [`RawTableInner::buckets`] + /// function, i.e. `(index + 1) <= self.buckets()`. + /// + /// * The type `T` must be the actual type of the elements stored in the table, otherwise + /// using the returned [`Bucket`] may result in [`undefined behavior`]. + /// + /// It is safe to call this function with index of zero (`index == 0`) on a table that has + /// not been allocated, but using the returned [`Bucket`] results in [`undefined behavior`]. + /// + /// If `mem::size_of::<T>() == 0`, then the only requirement is that the `index` must + /// not be greater than the number returned by the [`RawTable::buckets`] function, i.e. + /// `(index + 1) <= self.buckets()`. + /// + /// ```none + /// If mem::size_of::<T>() != 0 then return a pointer to the `element` in the `data part` of the table + /// (we start counting from "0", so that in the expression T[n], the "n" index actually one less than + /// the "buckets" number of our `RawTableInner`, i.e. "n = RawTableInner::buckets() - 1"): + /// + /// `table.bucket(3).as_ptr()` returns a pointer that points here in the `data` + /// part of the `RawTableInner`, i.e. to the start of T3 (see [`Bucket::as_ptr`]) + /// | + /// | `base = table.data_end::<T>()` points here + /// | (to the start of CT0 or to the end of T0) + /// v v + /// [Pad], T_n, ..., |T3|, T2, T1, T0, |CT0, CT1, CT2, CT3, ..., CT_n, CTa_0, CTa_1, ..., CTa_m + /// ^ \__________ __________/ + /// `table.bucket(3)` returns a pointer that points \/ + /// here in the `data` part of the `RawTableInner` additional control bytes + /// (to the end of T3) `m = Group::WIDTH - 1` + /// + /// where: T0...T_n - our stored data; + /// CT0...CT_n - control bytes or metadata for `data`; + /// CTa_0...CTa_m - additional control bytes (so that the search with loading `Group` bytes from + /// the heap works properly, even if the result of `h1(hash) & self.bucket_mask` + /// is equal to `self.bucket_mask`). See also `RawTableInner::set_ctrl` function. + /// + /// P.S. `h1(hash) & self.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + /// of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + /// ``` + /// + /// [`Bucket::from_base_index`]: Bucket::from_base_index + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] unsafe fn bucket<T>(&self, index: usize) -> Bucket<T> { debug_assert_ne!(self.bucket_mask, 0); @@ -1219,6 +2502,52 @@ impl<A: Allocator + Clone> RawTableInner<A> { Bucket::from_base_index(self.data_end(), index) } + /// Returns a raw `*mut u8` pointer to the start of the `data` element in the table + /// (convenience for `self.data_end::<u8>().as_ptr().sub((index + 1) * size_of)`). + /// + /// The caller must ensure that the `RawTableInner` outlives the returned `*mut u8`, + /// otherwise using it may result in [`undefined behavior`]. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is [`undefined behavior`]: + /// + /// * The table must already be allocated; + /// + /// * The `index` must not be greater than the number returned by the [`RawTableInner::buckets`] + /// function, i.e. `(index + 1) <= self.buckets()`; + /// + /// * The `size_of` must be equal to the size of the elements stored in the table; + /// + /// ```none + /// If mem::size_of::<T>() != 0 then return a pointer to the `element` in the `data part` of the table + /// (we start counting from "0", so that in the expression T[n], the "n" index actually one less than + /// the "buckets" number of our `RawTableInner`, i.e. "n = RawTableInner::buckets() - 1"): + /// + /// `table.bucket_ptr(3, mem::size_of::<T>())` returns a pointer that points here in the + /// `data` part of the `RawTableInner`, i.e. to the start of T3 + /// | + /// | `base = table.data_end::<u8>()` points here + /// | (to the start of CT0 or to the end of T0) + /// v v + /// [Pad], T_n, ..., |T3|, T2, T1, T0, |CT0, CT1, CT2, CT3, ..., CT_n, CTa_0, CTa_1, ..., CTa_m + /// \__________ __________/ + /// \/ + /// additional control bytes + /// `m = Group::WIDTH - 1` + /// + /// where: T0...T_n - our stored data; + /// CT0...CT_n - control bytes or metadata for `data`; + /// CTa_0...CTa_m - additional control bytes (so that the search with loading `Group` bytes from + /// the heap works properly, even if the result of `h1(hash) & self.bucket_mask` + /// is equal to `self.bucket_mask`). See also `RawTableInner::set_ctrl` function. + /// + /// P.S. `h1(hash) & self.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + /// of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + /// ``` + /// + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] unsafe fn bucket_ptr(&self, index: usize, size_of: usize) -> *mut u8 { debug_assert_ne!(self.bucket_mask, 0); @@ -1227,9 +2556,44 @@ impl<A: Allocator + Clone> RawTableInner<A> { base.sub((index + 1) * size_of) } + /// Returns pointer to one past last `data` element in the table as viewed from + /// the start point of the allocation (convenience for `self.ctrl.cast()`). + /// + /// This function actually returns a pointer to the end of the `data element` at + /// index "0" (zero). + /// + /// The caller must ensure that the `RawTableInner` outlives the returned [`NonNull<T>`], + /// otherwise using it may result in [`undefined behavior`]. + /// + /// # Note + /// + /// The type `T` must be the actual type of the elements stored in the table, otherwise + /// using the returned [`NonNull<T>`] may result in [`undefined behavior`]. + /// + /// ```none + /// `table.data_end::<T>()` returns pointer that points here + /// (to the end of `T0`) + /// ∨ + /// [Pad], T_n, ..., T1, T0, |CT0, CT1, ..., CT_n|, CTa_0, CTa_1, ..., CTa_m + /// \________ ________/ + /// \/ + /// `n = buckets - 1`, i.e. `RawTableInner::buckets() - 1` + /// + /// where: T0...T_n - our stored data; + /// CT0...CT_n - control bytes or metadata for `data`. + /// CTa_0...CTa_m - additional control bytes, where `m = Group::WIDTH - 1` (so that the search + /// with loading `Group` bytes from the heap works properly, even if the result + /// of `h1(hash) & self.bucket_mask` is equal to `self.bucket_mask`). See also + /// `RawTableInner::set_ctrl` function. + /// + /// P.S. `h1(hash) & self.bucket_mask` is the same as `hash as usize % self.buckets()` because the number + /// of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. + /// ``` + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - unsafe fn data_end<T>(&self) -> NonNull<T> { - NonNull::new_unchecked(self.ctrl.as_ptr().cast()) + fn data_end<T>(&self) -> NonNull<T> { + self.ctrl.cast() } /// Returns an iterator-like object for a probe sequence on the table. @@ -1240,6 +2604,8 @@ impl<A: Allocator + Clone> RawTableInner<A> { #[inline] fn probe_seq(&self, hash: u64) -> ProbeSeq { ProbeSeq { + // This is the same as `hash as usize % self.buckets()` because the number + // of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. pos: h1(hash) & self.bucket_mask, stride: 0, } @@ -1250,7 +2616,7 @@ impl<A: Allocator + Clone> RawTableInner<A> { #[cfg(feature = "raw")] #[inline] unsafe fn prepare_insert_no_grow(&mut self, hash: u64) -> Result<usize, ()> { - let index = self.find_insert_slot(hash); + let index = self.find_insert_slot(hash).index; let old_ctrl = *self.ctrl(index); if unlikely(self.growth_left == 0 && special_is_empty(old_ctrl)) { Err(()) @@ -1277,13 +2643,68 @@ impl<A: Allocator + Clone> RawTableInner<A> { /// Sets a control byte to the hash, and possibly also the replicated control byte at /// the end of the array. + /// + /// This function does not make any changes to the `data` parts of the table, + /// or any changes to the `items` or `growth_left` field of the table. + /// + /// # Safety + /// + /// The safety rules are directly derived from the safety rules for [`RawTableInner::set_ctrl`] + /// method. Thus, in order to uphold the safety contracts for the method, you must observe the + /// following rules when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The `index` must not be greater than the `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` must + /// be no greater than the number returned by the function [`RawTableInner::buckets`]. + /// + /// Calling this function on a table that has not been allocated results in [`undefined behavior`]. + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`RawTableInner::set_ctrl`]: RawTableInner::set_ctrl + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - unsafe fn set_ctrl_h2(&self, index: usize, hash: u64) { + unsafe fn set_ctrl_h2(&mut self, index: usize, hash: u64) { + // SAFETY: The caller must uphold the safety rules for the [`RawTableInner::set_ctrl_h2`] self.set_ctrl(index, h2(hash)); } + /// Replaces the hash in the control byte at the given index with the provided one, + /// and possibly also replicates the new control byte at the end of the array of control + /// bytes, returning the old control byte. + /// + /// This function does not make any changes to the `data` parts of the table, + /// or any changes to the `items` or `growth_left` field of the table. + /// + /// # Safety + /// + /// The safety rules are directly derived from the safety rules for [`RawTableInner::set_ctrl_h2`] + /// and [`RawTableInner::ctrl`] methods. Thus, in order to uphold the safety contracts for both + /// methods, you must observe the following rules when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The `index` must not be greater than the `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` must + /// be no greater than the number returned by the function [`RawTableInner::buckets`]. + /// + /// Calling this function on a table that has not been allocated results in [`undefined behavior`]. + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`RawTableInner::set_ctrl_h2`]: RawTableInner::set_ctrl_h2 + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - unsafe fn replace_ctrl_h2(&self, index: usize, hash: u64) -> u8 { + unsafe fn replace_ctrl_h2(&mut self, index: usize, hash: u64) -> u8 { + // SAFETY: The caller must uphold the safety rules for the [`RawTableInner::replace_ctrl_h2`] let prev_ctrl = *self.ctrl(index); self.set_ctrl_h2(index, hash); prev_ctrl @@ -1291,10 +2712,35 @@ impl<A: Allocator + Clone> RawTableInner<A> { /// Sets a control byte, and possibly also the replicated control byte at /// the end of the array. + /// + /// This function does not make any changes to the `data` parts of the table, + /// or any changes to the `items` or `growth_left` field of the table. + /// + /// # Safety + /// + /// You must observe the following safety rules when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The `index` must not be greater than the `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` must + /// be no greater than the number returned by the function [`RawTableInner::buckets`]. + /// + /// Calling this function on a table that has not been allocated results in [`undefined behavior`]. + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] - unsafe fn set_ctrl(&self, index: usize, ctrl: u8) { + unsafe fn set_ctrl(&mut self, index: usize, ctrl: u8) { // Replicate the first Group::WIDTH control bytes at the end of - // the array without using a branch: + // the array without using a branch. If the tables smaller than + // the group width (self.buckets() < Group::WIDTH), + // `index2 = Group::WIDTH + index`, otherwise `index2` is: + // // - If index >= Group::WIDTH then index == index2. // - Otherwise index2 == self.bucket_mask + 1 + index. // @@ -1311,16 +2757,43 @@ impl<A: Allocator + Clone> RawTableInner<A> { // --------------------------------------------- // | [A] | [B] | [EMPTY] | [EMPTY] | [A] | [B] | // --------------------------------------------- + + // This is the same as `(index.wrapping_sub(Group::WIDTH)) % self.buckets() + Group::WIDTH` + // because the number of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. let index2 = ((index.wrapping_sub(Group::WIDTH)) & self.bucket_mask) + Group::WIDTH; + // SAFETY: The caller must uphold the safety rules for the [`RawTableInner::set_ctrl`] *self.ctrl(index) = ctrl; *self.ctrl(index2) = ctrl; } /// Returns a pointer to a control byte. + /// + /// # Safety + /// + /// For the allocated [`RawTableInner`], the result is [`Undefined Behavior`], + /// if the `index` is greater than the `self.bucket_mask + 1 + Group::WIDTH`. + /// In that case, calling this function with `index == self.bucket_mask + 1 + Group::WIDTH` + /// will return a pointer to the end of the allocated table and it is useless on its own. + /// + /// Calling this function with `index >= self.bucket_mask + 1 + Group::WIDTH` on a + /// table that has not been allocated results in [`Undefined Behavior`]. + /// + /// So to satisfy both requirements you should always follow the rule that + /// `index < self.bucket_mask + 1 + Group::WIDTH` + /// + /// Calling this function on [`RawTableInner`] that are not already allocated is safe + /// for read-only purpose. + /// + /// See also [`Bucket::as_ptr()`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`Bucket::as_ptr()`]: Bucket::as_ptr() + /// [`Undefined Behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] unsafe fn ctrl(&self, index: usize) -> *mut u8 { debug_assert!(index < self.num_ctrl_bytes()); + // SAFETY: The caller must uphold the safety rules for the [`RawTableInner::ctrl`] self.ctrl.as_ptr().add(index) } @@ -1329,6 +2802,17 @@ impl<A: Allocator + Clone> RawTableInner<A> { self.bucket_mask + 1 } + /// Checks whether the bucket at `index` is full. + /// + /// # Safety + /// + /// The caller must ensure `index` is less than the number of buckets. + #[inline] + unsafe fn is_bucket_full(&self, index: usize) -> bool { + debug_assert!(index < self.buckets()); + is_full(*self.ctrl(index)) + } + #[inline] fn num_ctrl_bytes(&self) -> usize { self.bucket_mask + 1 + Group::WIDTH @@ -1339,25 +2823,45 @@ impl<A: Allocator + Clone> RawTableInner<A> { self.bucket_mask == 0 } + /// Attempts to allocate a new hash table with at least enough capacity + /// for inserting the given number of elements without reallocating, + /// and return it inside ScopeGuard to protect against panic in the hash + /// function. + /// + /// # Note + /// + /// It is recommended (but not required): + /// + /// * That the new table's `capacity` be greater than or equal to `self.items`. + /// + /// * The `alloc` is the same [`Allocator`] as the `Allocator` used + /// to allocate this table. + /// + /// * The `table_layout` is the same [`TableLayout`] as the `TableLayout` used + /// to allocate this table. + /// + /// If `table_layout` does not match the `TableLayout` that was used to allocate + /// this table, then using `mem::swap` with the `self` and the new table returned + /// by this function results in [`undefined behavior`]. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[allow(clippy::mut_mut)] #[inline] - unsafe fn prepare_resize( + fn prepare_resize<'a, A>( &self, + alloc: &'a A, table_layout: TableLayout, capacity: usize, fallibility: Fallibility, - ) -> Result<crate::scopeguard::ScopeGuard<Self, impl FnMut(&mut Self)>, TryReserveError> { + ) -> Result<crate::scopeguard::ScopeGuard<Self, impl FnMut(&mut Self) + 'a>, TryReserveError> + where + A: Allocator, + { debug_assert!(self.items <= capacity); // Allocate and initialize the new table. - let mut new_table = RawTableInner::fallible_with_capacity( - self.alloc.clone(), - table_layout, - capacity, - fallibility, - )?; - new_table.growth_left -= self.items; - new_table.items = self.items; + let new_table = + RawTableInner::fallible_with_capacity(alloc, table_layout, capacity, fallibility)?; // The hash function may panic, in which case we simply free the new // table without dropping any elements that may have been copied into @@ -1367,7 +2871,11 @@ impl<A: Allocator + Clone> RawTableInner<A> { // the comment at the bottom of this function. Ok(guard(new_table, move |self_| { if !self_.is_empty_singleton() { - self_.free_buckets(table_layout); + // SAFETY: + // 1. We have checked that our table is allocated. + // 2. We know for sure that the `alloc` and `table_layout` matches the + // [`Allocator`] and [`TableLayout`] used to allocate this table. + unsafe { self_.free_buckets(alloc, table_layout) }; } })) } @@ -1376,16 +2884,38 @@ impl<A: Allocator + Clone> RawTableInner<A> { /// /// This uses dynamic dispatch to reduce the amount of /// code generated, but it is eliminated by LLVM optimizations when inlined. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is + /// [`undefined behavior`]: + /// + /// * The `alloc` must be the same [`Allocator`] as the `Allocator` used + /// to allocate this table. + /// + /// * The `layout` must be the same [`TableLayout`] as the `TableLayout` + /// used to allocate this table. + /// + /// * The `drop` function (`fn(*mut u8)`) must be the actual drop function of + /// the elements stored in the table. + /// + /// * The [`RawTableInner`] must have properly initialized control bytes. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[allow(clippy::inline_always)] #[inline(always)] - unsafe fn reserve_rehash_inner( + unsafe fn reserve_rehash_inner<A>( &mut self, + alloc: &A, additional: usize, hasher: &dyn Fn(&mut Self, usize) -> u64, fallibility: Fallibility, layout: TableLayout, drop: Option<fn(*mut u8)>, - ) -> Result<(), TryReserveError> { + ) -> Result<(), TryReserveError> + where + A: Allocator, + { // Avoid `Option::ok_or_else` because it bloats LLVM IR. let new_items = match self.items.checked_add(additional) { Some(new_items) => new_items, @@ -1395,12 +2925,30 @@ impl<A: Allocator + Clone> RawTableInner<A> { if new_items <= full_capacity / 2 { // Rehash in-place without re-allocating if we have plenty of spare // capacity that is locked up due to DELETED entries. + + // SAFETY: + // 1. We know for sure that `[`RawTableInner`]` has already been allocated + // (since new_items <= full_capacity / 2); + // 2. The caller ensures that `drop` function is the actual drop function of + // the elements stored in the table. + // 3. The caller ensures that `layout` matches the [`TableLayout`] that was + // used to allocate this table. + // 4. The caller ensures that the control bytes of the `RawTableInner` + // are already initialized. self.rehash_in_place(hasher, layout.size, drop); Ok(()) } else { // Otherwise, conservatively resize to at least the next size up // to avoid churning deletes into frequent rehashes. + // + // SAFETY: + // 1. We know for sure that `capacity >= self.items`. + // 2. The caller ensures that `alloc` and `layout` matches the [`Allocator`] and + // [`TableLayout`] that were used to allocate this table. + // 3. The caller ensures that the control bytes of the `RawTableInner` + // are already initialized. self.resize_inner( + alloc, usize::max(new_items, full_capacity + 1), hasher, fallibility, @@ -1409,48 +2957,160 @@ impl<A: Allocator + Clone> RawTableInner<A> { } } + /// Returns an iterator over full buckets indices in the table. + /// + /// # Safety + /// + /// Behavior is undefined if any of the following conditions are violated: + /// + /// * The caller has to ensure that the `RawTableInner` outlives the + /// `FullBucketsIndices`. Because we cannot make the `next` method + /// unsafe on the `FullBucketsIndices` struct, we have to make the + /// `full_buckets_indices` method unsafe. + /// + /// * The [`RawTableInner`] must have properly initialized control bytes. + #[inline(always)] + unsafe fn full_buckets_indices(&self) -> FullBucketsIndices { + // SAFETY: + // 1. Since the caller of this function ensures that the control bytes + // are properly initialized and `self.ctrl(0)` points to the start + // of the array of control bytes, therefore: `ctrl` is valid for reads, + // properly aligned to `Group::WIDTH` and points to the properly initialized + // control bytes. + // 2. The value of `items` is equal to the amount of data (values) added + // to the table. + // + // `ctrl` points here (to the start + // of the first control byte `CT0`) + // ∨ + // [Pad], T_n, ..., T1, T0, |CT0, CT1, ..., CT_n|, Group::WIDTH + // \________ ________/ + // \/ + // `n = buckets - 1`, i.e. `RawTableInner::buckets() - 1` + // + // where: T0...T_n - our stored data; + // CT0...CT_n - control bytes or metadata for `data`. + let ctrl = NonNull::new_unchecked(self.ctrl(0)); + + FullBucketsIndices { + // Load the first group + // SAFETY: See explanation above. + current_group: Group::load_aligned(ctrl.as_ptr()).match_full().into_iter(), + group_first_index: 0, + ctrl, + items: self.items, + } + } + /// Allocates a new table of a different size and moves the contents of the /// current table into it. /// /// This uses dynamic dispatch to reduce the amount of /// code generated, but it is eliminated by LLVM optimizations when inlined. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is + /// [`undefined behavior`]: + /// + /// * The `alloc` must be the same [`Allocator`] as the `Allocator` used + /// to allocate this table; + /// + /// * The `layout` must be the same [`TableLayout`] as the `TableLayout` + /// used to allocate this table; + /// + /// * The [`RawTableInner`] must have properly initialized control bytes. + /// + /// The caller of this function must ensure that `capacity >= self.items` + /// otherwise: + /// + /// * If `self.items != 0`, calling of this function with `capacity == 0` + /// results in [`undefined behavior`]. + /// + /// * If `capacity_to_buckets(capacity) < Group::WIDTH` and + /// `self.items > capacity_to_buckets(capacity)` calling this function + /// results in [`undefined behavior`]. + /// + /// * If `capacity_to_buckets(capacity) >= Group::WIDTH` and + /// `self.items > capacity_to_buckets(capacity)` calling this function + /// are never return (will go into an infinite loop). + /// + /// Note: It is recommended (but not required) that the new table's `capacity` + /// be greater than or equal to `self.items`. In case if `capacity <= self.items` + /// this function can never return. See [`RawTableInner::find_insert_slot`] for + /// more information. + /// + /// [`RawTableInner::find_insert_slot`]: RawTableInner::find_insert_slot + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[allow(clippy::inline_always)] #[inline(always)] - unsafe fn resize_inner( + unsafe fn resize_inner<A>( &mut self, + alloc: &A, capacity: usize, hasher: &dyn Fn(&mut Self, usize) -> u64, fallibility: Fallibility, layout: TableLayout, - ) -> Result<(), TryReserveError> { - let mut new_table = self.prepare_resize(layout, capacity, fallibility)?; - - // Copy all elements to the new table. - for i in 0..self.buckets() { - if !is_full(*self.ctrl(i)) { - continue; - } - + ) -> Result<(), TryReserveError> + where + A: Allocator, + { + // SAFETY: We know for sure that `alloc` and `layout` matches the [`Allocator`] and [`TableLayout`] + // that were used to allocate this table. + let mut new_table = self.prepare_resize(alloc, layout, capacity, fallibility)?; + + // SAFETY: We know for sure that RawTableInner will outlive the + // returned `FullBucketsIndices` iterator, and the caller of this + // function ensures that the control bytes are properly initialized. + for full_byte_index in self.full_buckets_indices() { // This may panic. - let hash = hasher(self, i); + let hash = hasher(self, full_byte_index); + // SAFETY: // We can use a simpler version of insert() here since: - // - there are no DELETED entries. - // - we know there is enough space in the table. - // - all elements are unique. - let (index, _) = new_table.prepare_insert_slot(hash); - + // 1. There are no DELETED entries. + // 2. We know there is enough space in the table. + // 3. All elements are unique. + // 4. The caller of this function guarantees that `capacity > 0` + // so `new_table` must already have some allocated memory. + // 5. We set `growth_left` and `items` fields of the new table + // after the loop. + // 6. We insert into the table, at the returned index, the data + // matching the given hash immediately after calling this function. + let (new_index, _) = new_table.prepare_insert_slot(hash); + + // SAFETY: + // + // * `src` is valid for reads of `layout.size` bytes, since the + // table is alive and the `full_byte_index` is guaranteed to be + // within bounds (see `FullBucketsIndices::next_impl`); + // + // * `dst` is valid for writes of `layout.size` bytes, since the + // caller ensures that `table_layout` matches the [`TableLayout`] + // that was used to allocate old table and we have the `new_index` + // returned by `prepare_insert_slot`. + // + // * Both `src` and `dst` are properly aligned. + // + // * Both `src` and `dst` point to different region of memory. ptr::copy_nonoverlapping( - self.bucket_ptr(i, layout.size), - new_table.bucket_ptr(index, layout.size), + self.bucket_ptr(full_byte_index, layout.size), + new_table.bucket_ptr(new_index, layout.size), layout.size, ); } + // The hash function didn't panic, so we can safely set the + // `growth_left` and `items` fields of the new table. + new_table.growth_left -= self.items; + new_table.items = self.items; + // We successfully copied all elements without panicking. Now replace // self with the new table. The old table will have its memory freed but // the items will not be dropped (since they have been moved into the // new table). + // SAFETY: The caller ensures that `table_layout` matches the [`TableLayout`] + // that was used to allocate this table. mem::swap(self, &mut new_table); Ok(()) @@ -1463,6 +3123,21 @@ impl<A: Allocator + Clone> RawTableInner<A> { /// /// This uses dynamic dispatch to reduce the amount of /// code generated, but it is eliminated by LLVM optimizations when inlined. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is [`undefined behavior`]: + /// + /// * The `size_of` must be equal to the size of the elements stored in the table; + /// + /// * The `drop` function (`fn(*mut u8)`) must be the actual drop function of + /// the elements stored in the table. + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The [`RawTableInner`] must have properly initialized control bytes. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[allow(clippy::inline_always)] #[cfg_attr(feature = "inline-more", inline(always))] #[cfg_attr(not(feature = "inline-more"), inline)] @@ -1506,8 +3181,10 @@ impl<A: Allocator + Clone> RawTableInner<A> { let hash = hasher(*guard, i); // Search for a suitable place to put it - let new_i = guard.find_insert_slot(hash); - let new_i_p = guard.bucket_ptr(new_i, size_of); + // + // SAFETY: Caller of this function ensures that the control bytes + // are properly initialized. + let new_i = guard.find_insert_slot(hash).index; // Probing works by scanning through all of the control // bytes in groups, which may not be aligned to the group @@ -1519,6 +3196,8 @@ impl<A: Allocator + Clone> RawTableInner<A> { continue 'outer; } + let new_i_p = guard.bucket_ptr(new_i, size_of); + // We are moving the current item to a new position. Write // our H2 to the control byte of the new position. let prev_ctrl = guard.replace_ctrl_h2(new_i, hash); @@ -1545,17 +3224,107 @@ impl<A: Allocator + Clone> RawTableInner<A> { mem::forget(guard); } + /// Deallocates the table without dropping any entries. + /// + /// # Note + /// + /// This function must be called only after [`drop_elements`](RawTableInner::drop_elements), + /// else it can lead to leaking of memory. Also calling this function automatically + /// makes invalid (dangling) all instances of buckets ([`Bucket`]) and makes invalid + /// (dangling) the `ctrl` field of the table. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is [`Undefined Behavior`]: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * The `alloc` must be the same [`Allocator`] as the `Allocator` that was used + /// to allocate this table. + /// + /// * The `table_layout` must be the same [`TableLayout`] as the `TableLayout` that was used + /// to allocate this table. + /// + /// See also [`GlobalAlloc::dealloc`] or [`Allocator::deallocate`] for more information. + /// + /// [`Undefined Behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// [`GlobalAlloc::dealloc`]: https://doc.rust-lang.org/alloc/alloc/trait.GlobalAlloc.html#tymethod.dealloc + /// [`Allocator::deallocate`]: https://doc.rust-lang.org/alloc/alloc/trait.Allocator.html#tymethod.deallocate + #[inline] + unsafe fn free_buckets<A>(&mut self, alloc: &A, table_layout: TableLayout) + where + A: Allocator, + { + // SAFETY: The caller must uphold the safety contract for `free_buckets` + // method. + let (ptr, layout) = self.allocation_info(table_layout); + alloc.deallocate(ptr, layout); + } + + /// Returns a pointer to the allocated memory and the layout that was used to + /// allocate the table. + /// + /// # Safety + /// + /// Caller of this function must observe the following safety rules: + /// + /// * The [`RawTableInner`] has already been allocated, otherwise + /// calling this function results in [`undefined behavior`] + /// + /// * The `table_layout` must be the same [`TableLayout`] as the `TableLayout` + /// that was used to allocate this table. Failure to comply with this condition + /// may result in [`undefined behavior`]. + /// + /// See also [`GlobalAlloc::dealloc`] or [`Allocator::deallocate`] for more information. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// [`GlobalAlloc::dealloc`]: https://doc.rust-lang.org/alloc/alloc/trait.GlobalAlloc.html#tymethod.dealloc + /// [`Allocator::deallocate`]: https://doc.rust-lang.org/alloc/alloc/trait.Allocator.html#tymethod.deallocate #[inline] - unsafe fn free_buckets(&mut self, table_layout: TableLayout) { + unsafe fn allocation_info(&self, table_layout: TableLayout) -> (NonNull<u8>, Layout) { + debug_assert!( + !self.is_empty_singleton(), + "this function can only be called on non-empty tables" + ); + // Avoid `Option::unwrap_or_else` because it bloats LLVM IR. let (layout, ctrl_offset) = match table_layout.calculate_layout_for(self.buckets()) { Some(lco) => lco, - None => hint::unreachable_unchecked(), + None => unsafe { hint::unreachable_unchecked() }, }; - self.alloc.deallocate( - NonNull::new_unchecked(self.ctrl.as_ptr().sub(ctrl_offset)), + ( + // SAFETY: The caller must uphold the safety contract for `allocation_info` method. + unsafe { NonNull::new_unchecked(self.ctrl.as_ptr().sub(ctrl_offset)) }, layout, - ); + ) + } + + /// Returns a pointer to the allocated memory and the layout that was used to + /// allocate the table. If [`RawTableInner`] has not been allocated, this + /// function return `dangling` pointer and `()` (unit) layout. + /// + /// # Safety + /// + /// The `table_layout` must be the same [`TableLayout`] as the `TableLayout` + /// that was used to allocate this table. Failure to comply with this condition + /// may result in [`undefined behavior`]. + /// + /// See also [`GlobalAlloc::dealloc`] or [`Allocator::deallocate`] for more information. + /// + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// [`GlobalAlloc::dealloc`]: https://doc.rust-lang.org/alloc/alloc/trait.GlobalAlloc.html#tymethod.dealloc + /// [`Allocator::deallocate`]: https://doc.rust-lang.org/alloc/alloc/trait.Allocator.html#tymethod.deallocate + #[cfg(feature = "raw")] + unsafe fn allocation_info_or_zero(&self, table_layout: TableLayout) -> (NonNull<u8>, Layout) { + if self.is_empty_singleton() { + (NonNull::dangling(), Layout::new::<()>()) + } else { + // SAFETY: + // 1. We have checked that our table is allocated. + // 2. The caller ensures that `table_layout` matches the [`TableLayout`] + // that was used to allocate this table. + unsafe { self.allocation_info(table_layout) } + } } /// Marks all table buckets as empty without dropping their contents. @@ -1570,27 +3339,95 @@ impl<A: Allocator + Clone> RawTableInner<A> { self.growth_left = bucket_mask_to_capacity(self.bucket_mask); } + /// Erases the [`Bucket`]'s control byte at the given index so that it does not + /// triggered as full, decreases the `items` of the table and, if it can be done, + /// increases `self.growth_left`. + /// + /// This function does not actually erase / drop the [`Bucket`] itself, i.e. it + /// does not make any changes to the `data` parts of the table. The caller of this + /// function must take care to properly drop the `data`, otherwise calling this + /// function may result in a memory leak. + /// + /// # Safety + /// + /// You must observe the following safety rules when calling this function: + /// + /// * The [`RawTableInner`] has already been allocated; + /// + /// * It must be the full control byte at the given position; + /// + /// * The `index` must not be greater than the `RawTableInner.bucket_mask`, i.e. + /// `index <= RawTableInner.bucket_mask` or, in other words, `(index + 1)` must + /// be no greater than the number returned by the function [`RawTableInner::buckets`]. + /// + /// Calling this function on a table that has not been allocated results in [`undefined behavior`]. + /// + /// Calling this function on a table with no elements is unspecified, but calling subsequent + /// functions is likely to result in [`undefined behavior`] due to overflow subtraction + /// (`self.items -= 1 cause overflow when self.items == 0`). + /// + /// See also [`Bucket::as_ptr`] method, for more information about of properly removing + /// or saving `data element` from / into the [`RawTable`] / [`RawTableInner`]. + /// + /// [`RawTableInner::buckets`]: RawTableInner::buckets + /// [`Bucket::as_ptr`]: Bucket::as_ptr + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[inline] unsafe fn erase(&mut self, index: usize) { - debug_assert!(is_full(*self.ctrl(index))); + debug_assert!(self.is_bucket_full(index)); + + // This is the same as `index.wrapping_sub(Group::WIDTH) % self.buckets()` because + // the number of buckets is a power of two, and `self.bucket_mask = self.buckets() - 1`. let index_before = index.wrapping_sub(Group::WIDTH) & self.bucket_mask; + // SAFETY: + // - The caller must uphold the safety contract for `erase` method; + // - `index_before` is guaranteed to be in range due to masking with `self.bucket_mask` let empty_before = Group::load(self.ctrl(index_before)).match_empty(); let empty_after = Group::load(self.ctrl(index)).match_empty(); - // If we are inside a continuous block of Group::WIDTH full or deleted - // cells then a probe window may have seen a full block when trying to - // insert. We therefore need to keep that block non-empty so that - // lookups will continue searching to the next probe window. + // Inserting and searching in the map is performed by two key functions: + // + // - The `find_insert_slot` function that looks up the index of any `EMPTY` or `DELETED` + // slot in a group to be able to insert. If it doesn't find an `EMPTY` or `DELETED` + // slot immediately in the first group, it jumps to the next `Group` looking for it, + // and so on until it has gone through all the groups in the control bytes. + // + // - The `find_inner` function that looks for the index of the desired element by looking + // at all the `FULL` bytes in the group. If it did not find the element right away, and + // there is no `EMPTY` byte in the group, then this means that the `find_insert_slot` + // function may have found a suitable slot in the next group. Therefore, `find_inner` + // jumps further, and if it does not find the desired element and again there is no `EMPTY` + // byte, then it jumps further, and so on. The search stops only if `find_inner` function + // finds the desired element or hits an `EMPTY` slot/byte. + // + // Accordingly, this leads to two consequences: // - // Note that in this context `leading_zeros` refers to the bytes at the - // end of a group, while `trailing_zeros` refers to the bytes at the - // beginning of a group. + // - The map must have `EMPTY` slots (bytes); + // + // - You can't just mark the byte to be erased as `EMPTY`, because otherwise the `find_inner` + // function may stumble upon an `EMPTY` byte before finding the desired element and stop + // searching. + // + // Thus it is necessary to check all bytes after and before the erased element. If we are in + // a contiguous `Group` of `FULL` or `DELETED` bytes (the number of `FULL` or `DELETED` bytes + // before and after is greater than or equal to `Group::WIDTH`), then we must mark our byte as + // `DELETED` in order for the `find_inner` function to go further. On the other hand, if there + // is at least one `EMPTY` slot in the `Group`, then the `find_inner` function will still stumble + // upon an `EMPTY` byte, so we can safely mark our erased byte as `EMPTY` as well. + // + // Finally, since `index_before == (index.wrapping_sub(Group::WIDTH) & self.bucket_mask) == index` + // and given all of the above, tables smaller than the group width (self.buckets() < Group::WIDTH) + // cannot have `DELETED` bytes. + // + // Note that in this context `leading_zeros` refers to the bytes at the end of a group, while + // `trailing_zeros` refers to the bytes at the beginning of a group. let ctrl = if empty_before.leading_zeros() + empty_after.trailing_zeros() >= Group::WIDTH { DELETED } else { self.growth_left += 1; EMPTY }; + // SAFETY: the caller must uphold the safety contract for `erase` method. self.set_ctrl(index, ctrl); self.items -= 1; } @@ -1599,12 +3436,16 @@ impl<A: Allocator + Clone> RawTableInner<A> { impl<T: Clone, A: Allocator + Clone> Clone for RawTable<T, A> { fn clone(&self) -> Self { if self.table.is_empty_singleton() { - Self::new_in(self.table.alloc.clone()) + Self::new_in(self.alloc.clone()) } else { unsafe { // Avoid `Result::ok_or_else` because it bloats LLVM IR. - let new_table = match Self::new_uninitialized( - self.table.alloc.clone(), + // + // SAFETY: This is safe as we are taking the size of an already allocated table + // and therefore сapacity overflow cannot occur, `self.table.buckets()` is power + // of two and all allocator errors will be caught inside `RawTableInner::new_uninitialized`. + let mut new_table = match Self::new_uninitialized( + self.alloc.clone(), self.table.buckets(), Fallibility::Infallible, ) { @@ -1612,24 +3453,32 @@ impl<T: Clone, A: Allocator + Clone> Clone for RawTable<T, A> { Err(_) => hint::unreachable_unchecked(), }; - // If cloning fails then we need to free the allocation for the - // new table. However we don't run its drop since its control - // bytes are not initialized yet. - let mut guard = guard(ManuallyDrop::new(new_table), |new_table| { - new_table.free_buckets(); - }); - - guard.clone_from_spec(self); - - // Disarm the scope guard and return the newly created table. - ManuallyDrop::into_inner(ScopeGuard::into_inner(guard)) + // Cloning elements may fail (the clone function may panic). But we don't + // need to worry about uninitialized control bits, since: + // 1. The number of items (elements) in the table is zero, which means that + // the control bits will not be readed by Drop function. + // 2. The `clone_from_spec` method will first copy all control bits from + // `self` (thus initializing them). But this will not affect the `Drop` + // function, since the `clone_from_spec` function sets `items` only after + // successfully clonning all elements. + new_table.clone_from_spec(self); + new_table } } } fn clone_from(&mut self, source: &Self) { if source.table.is_empty_singleton() { - *self = Self::new_in(self.table.alloc.clone()); + let mut old_inner = mem::replace(&mut self.table, RawTableInner::NEW); + unsafe { + // SAFETY: + // 1. We call the function only once; + // 2. We know for sure that `alloc` and `table_layout` matches the [`Allocator`] + // and [`TableLayout`] that were used to allocate this table. + // 3. If any elements' drop function panics, then there will only be a memory leak, + // because we have replaced the inner table with a new one. + old_inner.drop_inner_table::<T, _>(&self.alloc, Self::TABLE_LAYOUT); + } } else { unsafe { // Make sure that if any panics occurs, we clear the table and @@ -1644,27 +3493,38 @@ impl<T: Clone, A: Allocator + Clone> Clone for RawTable<T, A> { // // This leak is unavoidable: we can't try dropping more elements // since this could lead to another panic and abort the process. - self_.drop_elements(); + // + // SAFETY: If something gets wrong we clear our table right after + // dropping the elements, so there is no double drop, since `items` + // will be equal to zero. + self_.table.drop_elements::<T>(); // If necessary, resize our table to match the source. if self_.buckets() != source.buckets() { - // Skip our drop by using ptr::write. - if !self_.table.is_empty_singleton() { - self_.free_buckets(); + let new_inner = match RawTableInner::new_uninitialized( + &self_.alloc, + Self::TABLE_LAYOUT, + source.buckets(), + Fallibility::Infallible, + ) { + Ok(table) => table, + Err(_) => hint::unreachable_unchecked(), + }; + // Replace the old inner with new uninitialized one. It's ok, since if something gets + // wrong `ScopeGuard` will initialize all control bytes and leave empty table. + let mut old_inner = mem::replace(&mut self_.table, new_inner); + if !old_inner.is_empty_singleton() { + // SAFETY: + // 1. We have checked that our table is allocated. + // 2. We know for sure that `alloc` and `table_layout` matches + // the [`Allocator`] and [`TableLayout`] that were used to allocate this table. + old_inner.free_buckets(&self_.alloc, Self::TABLE_LAYOUT); } - (&mut **self_ as *mut Self).write( - // Avoid `Result::unwrap_or_else` because it bloats LLVM IR. - match Self::new_uninitialized( - self_.table.alloc.clone(), - source.buckets(), - Fallibility::Infallible, - ) { - Ok(table) => table, - Err(_) => hint::unreachable_unchecked(), - }, - ); } + // Cloning elements may fail (the clone function may panic), but the `ScopeGuard` + // inside the `clone_from_impl` function will take care of that, dropping all + // cloned elements if necessary. Our `ScopeGuard` will clear the table. self_.clone_from_spec(source); // Disarm the scope guard if cloning was successful. @@ -1696,7 +3556,8 @@ impl<T: Copy, A: Allocator + Clone> RawTableClone for RawTable<T, A> { .copy_to_nonoverlapping(self.table.ctrl(0), self.table.num_ctrl_bytes()); source .data_start() - .copy_to_nonoverlapping(self.data_start(), self.table.buckets()); + .as_ptr() + .copy_to_nonoverlapping(self.data_start().as_ptr(), self.table.buckets()); self.table.items = source.table.items; self.table.growth_left = source.table.growth_left; @@ -1720,9 +3581,9 @@ impl<T: Clone, A: Allocator + Clone> RawTable<T, A> { // to make sure we drop only the elements that have been // cloned so far. let mut guard = guard((0, &mut *self), |(index, self_)| { - if mem::needs_drop::<T>() && !self_.is_empty() { - for i in 0..=*index { - if is_full(*self_.table.ctrl(i)) { + if T::NEEDS_DROP { + for i in 0..*index { + if self_.is_bucket_full(i) { self_.bucket(i).drop(); } } @@ -1735,7 +3596,7 @@ impl<T: Clone, A: Allocator + Clone> RawTable<T, A> { to.write(from.as_ref().clone()); // Update the index in case we need to unwind. - guard.0 = index; + guard.0 = index + 1; } // Successfully cloned all items, no need to clean up. @@ -1757,7 +3618,7 @@ impl<T: Clone, A: Allocator + Clone> RawTable<T, A> { { self.clear(); - let guard_self = guard(&mut *self, |self_| { + let mut guard_self = guard(&mut *self, |self_| { // Clear the partially copied table if a panic occurs, otherwise // items and growth_left will be out of sync with the contents // of the table. @@ -1790,7 +3651,7 @@ impl<T: Clone, A: Allocator + Clone> RawTable<T, A> { } } -impl<T, A: Allocator + Clone + Default> Default for RawTable<T, A> { +impl<T, A: Allocator + Default> Default for RawTable<T, A> { #[inline] fn default() -> Self { Self::new_in(Default::default()) @@ -1798,31 +3659,41 @@ impl<T, A: Allocator + Clone + Default> Default for RawTable<T, A> { } #[cfg(feature = "nightly")] -unsafe impl<#[may_dangle] T, A: Allocator + Clone> Drop for RawTable<T, A> { +unsafe impl<#[may_dangle] T, A: Allocator> Drop for RawTable<T, A> { #[cfg_attr(feature = "inline-more", inline)] fn drop(&mut self) { - if !self.table.is_empty_singleton() { - unsafe { - self.drop_elements(); - self.free_buckets(); - } + unsafe { + // SAFETY: + // 1. We call the function only once; + // 2. We know for sure that `alloc` and `table_layout` matches the [`Allocator`] + // and [`TableLayout`] that were used to allocate this table. + // 3. If the drop function of any elements fails, then only a memory leak will occur, + // and we don't care because we are inside the `Drop` function of the `RawTable`, + // so there won't be any table left in an inconsistent state. + self.table + .drop_inner_table::<T, _>(&self.alloc, Self::TABLE_LAYOUT); } } } #[cfg(not(feature = "nightly"))] -impl<T, A: Allocator + Clone> Drop for RawTable<T, A> { +impl<T, A: Allocator> Drop for RawTable<T, A> { #[cfg_attr(feature = "inline-more", inline)] fn drop(&mut self) { - if !self.table.is_empty_singleton() { - unsafe { - self.drop_elements(); - self.free_buckets(); - } + unsafe { + // SAFETY: + // 1. We call the function only once; + // 2. We know for sure that `alloc` and `table_layout` matches the [`Allocator`] + // and [`TableLayout`] that were used to allocate this table. + // 3. If the drop function of any elements fails, then only a memory leak will occur, + // and we don't care because we are inside the `Drop` function of the `RawTable`, + // so there won't be any table left in an inconsistent state. + self.table + .drop_inner_table::<T, _>(&self.alloc, Self::TABLE_LAYOUT); } } } -impl<T, A: Allocator + Clone> IntoIterator for RawTable<T, A> { +impl<T, A: Allocator> IntoIterator for RawTable<T, A> { type Item = T; type IntoIter = RawIntoIter<T, A>; @@ -1840,7 +3711,7 @@ impl<T, A: Allocator + Clone> IntoIterator for RawTable<T, A> { pub(crate) struct RawIterRange<T> { // Mask of full buckets in the current group. Bits are cleared from this // mask as each element is processed. - current_group: BitMask, + current_group: BitMaskIter, // Pointer to the buckets for the current group. data: Bucket<T>, @@ -1856,19 +3727,44 @@ pub(crate) struct RawIterRange<T> { impl<T> RawIterRange<T> { /// Returns a `RawIterRange` covering a subset of a table. /// - /// The control byte address must be aligned to the group size. + /// # Safety + /// + /// If any of the following conditions are violated, the result is + /// [`undefined behavior`]: + /// + /// * `ctrl` must be [valid] for reads, i.e. table outlives the `RawIterRange`; + /// + /// * `ctrl` must be properly aligned to the group size (Group::WIDTH); + /// + /// * `ctrl` must point to the array of properly initialized control bytes; + /// + /// * `data` must be the [`Bucket`] at the `ctrl` index in the table; + /// + /// * the value of `len` must be less than or equal to the number of table buckets, + /// and the returned value of `ctrl.as_ptr().add(len).offset_from(ctrl.as_ptr())` + /// must be positive. + /// + /// * The `ctrl.add(len)` pointer must be either in bounds or one + /// byte past the end of the same [allocated table]. + /// + /// * The `len` must be a power of two. + /// + /// [valid]: https://doc.rust-lang.org/std/ptr/index.html#safety + /// [`undefined behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html #[cfg_attr(feature = "inline-more", inline)] unsafe fn new(ctrl: *const u8, data: Bucket<T>, len: usize) -> Self { debug_assert_ne!(len, 0); debug_assert_eq!(ctrl as usize % Group::WIDTH, 0); + // SAFETY: The caller must uphold the safety rules for the [`RawIterRange::new`] let end = ctrl.add(len); // Load the first group and advance ctrl to point to the next group + // SAFETY: The caller must uphold the safety rules for the [`RawIterRange::new`] let current_group = Group::load_aligned(ctrl).match_full(); let next_ctrl = ctrl.add(Group::WIDTH); Self { - current_group, + current_group: current_group.into_iter(), data, next_ctrl, end, @@ -1925,8 +3821,7 @@ impl<T> RawIterRange<T> { #[cfg_attr(feature = "inline-more", inline)] unsafe fn next_impl<const DO_CHECK_PTR_RANGE: bool>(&mut self) -> Option<Bucket<T>> { loop { - if let Some(index) = self.current_group.lowest_set_bit() { - self.current_group = self.current_group.remove_lowest_bit(); + if let Some(index) = self.current_group.next() { return Some(self.data.next_n(index)); } @@ -1939,7 +3834,86 @@ impl<T> RawIterRange<T> { // than the group size where the trailing control bytes are all // EMPTY. On larger tables self.end is guaranteed to be aligned // to the group size (since tables are power-of-two sized). - self.current_group = Group::load_aligned(self.next_ctrl).match_full(); + self.current_group = Group::load_aligned(self.next_ctrl).match_full().into_iter(); + self.data = self.data.next_n(Group::WIDTH); + self.next_ctrl = self.next_ctrl.add(Group::WIDTH); + } + } + + /// Folds every element into an accumulator by applying an operation, + /// returning the final result. + /// + /// `fold_impl()` takes three arguments: the number of items remaining in + /// the iterator, an initial value, and a closure with two arguments: an + /// 'accumulator', and an element. The closure returns the value that the + /// accumulator should have for the next iteration. + /// + /// The initial value is the value the accumulator will have on the first call. + /// + /// After applying this closure to every element of the iterator, `fold_impl()` + /// returns the accumulator. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is + /// [`Undefined Behavior`]: + /// + /// * The [`RawTableInner`] / [`RawTable`] must be alive and not moved, + /// i.e. table outlives the `RawIterRange`; + /// + /// * The provided `n` value must match the actual number of items + /// in the table. + /// + /// [`Undefined Behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[allow(clippy::while_let_on_iterator)] + #[cfg_attr(feature = "inline-more", inline)] + unsafe fn fold_impl<F, B>(mut self, mut n: usize, mut acc: B, mut f: F) -> B + where + F: FnMut(B, Bucket<T>) -> B, + { + loop { + while let Some(index) = self.current_group.next() { + // The returned `index` will always be in the range `0..Group::WIDTH`, + // so that calling `self.data.next_n(index)` is safe (see detailed explanation below). + debug_assert!(n != 0); + let bucket = self.data.next_n(index); + acc = f(acc, bucket); + n -= 1; + } + + if n == 0 { + return acc; + } + + // SAFETY: The caller of this function ensures that: + // + // 1. The provided `n` value matches the actual number of items in the table; + // 2. The table is alive and did not moved. + // + // Taking the above into account, we always stay within the bounds, because: + // + // 1. For tables smaller than the group width (self.buckets() <= Group::WIDTH), + // we will never end up in the given branch, since we should have already + // yielded all the elements of the table. + // + // 2. For tables larger than the group width. The number of buckets is a + // power of two (2 ^ n), Group::WIDTH is also power of two (2 ^ k). Since + // `(2 ^ n) > (2 ^ k)`, than `(2 ^ n) % (2 ^ k) = 0`. As we start from the + // start of the array of control bytes, and never try to iterate after + // getting all the elements, the last `self.current_group` will read bytes + // from the `self.buckets() - Group::WIDTH` index. We know also that + // `self.current_group.next()` will always retun indices within the range + // `0..Group::WIDTH`. + // + // Knowing all of the above and taking into account that we are synchronizing + // the `self.data` index with the index we used to read the `self.current_group`, + // the subsequent `self.data.next_n(index)` will always return a bucket with + // an index number less than `self.buckets()`. + // + // The last `self.next_ctrl`, whose index would be `self.buckets()`, will never + // actually be read, since we should have already yielded all the elements of + // the table. + self.current_group = Group::load_aligned(self.next_ctrl).match_full().into_iter(); self.data = self.data.next_n(Group::WIDTH); self.next_ctrl = self.next_ctrl.add(Group::WIDTH); } @@ -2016,7 +3990,7 @@ impl<T> RawIter<T> { /// This method should be called _before_ the removal is made. It is not necessary to call this /// method if you are removing an item that this iterator yielded in the past. #[cfg(feature = "raw")] - pub fn reflect_remove(&mut self, b: &Bucket<T>) { + pub unsafe fn reflect_remove(&mut self, b: &Bucket<T>) { self.reflect_toggle_full(b, false); } @@ -2030,36 +4004,76 @@ impl<T> RawIter<T> { /// /// This method should be called _after_ the given insert is made. #[cfg(feature = "raw")] - pub fn reflect_insert(&mut self, b: &Bucket<T>) { + pub unsafe fn reflect_insert(&mut self, b: &Bucket<T>) { self.reflect_toggle_full(b, true); } /// Refresh the iterator so that it reflects a change to the state of the given bucket. #[cfg(feature = "raw")] - fn reflect_toggle_full(&mut self, b: &Bucket<T>, is_insert: bool) { - unsafe { - if b.as_ptr() > self.iter.data.as_ptr() { - // The iterator has already passed the bucket's group. - // So the toggle isn't relevant to this iterator. - return; + unsafe fn reflect_toggle_full(&mut self, b: &Bucket<T>, is_insert: bool) { + if b.as_ptr() > self.iter.data.as_ptr() { + // The iterator has already passed the bucket's group. + // So the toggle isn't relevant to this iterator. + return; + } + + if self.iter.next_ctrl < self.iter.end + && b.as_ptr() <= self.iter.data.next_n(Group::WIDTH).as_ptr() + { + // The iterator has not yet reached the bucket's group. + // We don't need to reload anything, but we do need to adjust the item count. + + if cfg!(debug_assertions) { + // Double-check that the user isn't lying to us by checking the bucket state. + // To do that, we need to find its control byte. We know that self.iter.data is + // at self.iter.next_ctrl - Group::WIDTH, so we work from there: + let offset = offset_from(self.iter.data.as_ptr(), b.as_ptr()); + let ctrl = self.iter.next_ctrl.sub(Group::WIDTH).add(offset); + // This method should be called _before_ a removal, or _after_ an insert, + // so in both cases the ctrl byte should indicate that the bucket is full. + assert!(is_full(*ctrl)); } - if self.iter.next_ctrl < self.iter.end - && b.as_ptr() <= self.iter.data.next_n(Group::WIDTH).as_ptr() - { - // The iterator has not yet reached the bucket's group. - // We don't need to reload anything, but we do need to adjust the item count. + if is_insert { + self.items += 1; + } else { + self.items -= 1; + } - if cfg!(debug_assertions) { - // Double-check that the user isn't lying to us by checking the bucket state. - // To do that, we need to find its control byte. We know that self.iter.data is - // at self.iter.next_ctrl - Group::WIDTH, so we work from there: - let offset = offset_from(self.iter.data.as_ptr(), b.as_ptr()); - let ctrl = self.iter.next_ctrl.sub(Group::WIDTH).add(offset); - // This method should be called _before_ a removal, or _after_ an insert, - // so in both cases the ctrl byte should indicate that the bucket is full. - assert!(is_full(*ctrl)); - } + return; + } + + // The iterator is at the bucket group that the toggled bucket is in. + // We need to do two things: + // + // - Determine if the iterator already yielded the toggled bucket. + // If it did, we're done. + // - Otherwise, update the iterator cached group so that it won't + // yield a to-be-removed bucket, or _will_ yield a to-be-added bucket. + // We'll also need to update the item count accordingly. + if let Some(index) = self.iter.current_group.0.lowest_set_bit() { + let next_bucket = self.iter.data.next_n(index); + if b.as_ptr() > next_bucket.as_ptr() { + // The toggled bucket is "before" the bucket the iterator would yield next. We + // therefore don't need to do anything --- the iterator has already passed the + // bucket in question. + // + // The item count must already be correct, since a removal or insert "prior" to + // the iterator's position wouldn't affect the item count. + } else { + // The removed bucket is an upcoming bucket. We need to make sure it does _not_ + // get yielded, and also that it's no longer included in the item count. + // + // NOTE: We can't just reload the group here, both since that might reflect + // inserts we've already passed, and because that might inadvertently unset the + // bits for _other_ removals. If we do that, we'd have to also decrement the + // item count for those other bits that we unset. But the presumably subsequent + // call to reflect for those buckets might _also_ decrement the item count. + // Instead, we _just_ flip the bit for the particular bucket the caller asked + // us to reflect. + let our_bit = offset_from(self.iter.data.as_ptr(), b.as_ptr()); + let was_full = self.iter.current_group.flip(our_bit); + debug_assert_ne!(was_full, is_insert); if is_insert { self.items += 1; @@ -2067,65 +4081,23 @@ impl<T> RawIter<T> { self.items -= 1; } - return; - } - - // The iterator is at the bucket group that the toggled bucket is in. - // We need to do two things: - // - // - Determine if the iterator already yielded the toggled bucket. - // If it did, we're done. - // - Otherwise, update the iterator cached group so that it won't - // yield a to-be-removed bucket, or _will_ yield a to-be-added bucket. - // We'll also need to update the item count accordingly. - if let Some(index) = self.iter.current_group.lowest_set_bit() { - let next_bucket = self.iter.data.next_n(index); - if b.as_ptr() > next_bucket.as_ptr() { - // The toggled bucket is "before" the bucket the iterator would yield next. We - // therefore don't need to do anything --- the iterator has already passed the - // bucket in question. - // - // The item count must already be correct, since a removal or insert "prior" to - // the iterator's position wouldn't affect the item count. - } else { - // The removed bucket is an upcoming bucket. We need to make sure it does _not_ - // get yielded, and also that it's no longer included in the item count. - // - // NOTE: We can't just reload the group here, both since that might reflect - // inserts we've already passed, and because that might inadvertently unset the - // bits for _other_ removals. If we do that, we'd have to also decrement the - // item count for those other bits that we unset. But the presumably subsequent - // call to reflect for those buckets might _also_ decrement the item count. - // Instead, we _just_ flip the bit for the particular bucket the caller asked - // us to reflect. - let our_bit = offset_from(self.iter.data.as_ptr(), b.as_ptr()); - let was_full = self.iter.current_group.flip(our_bit); - debug_assert_ne!(was_full, is_insert); - - if is_insert { - self.items += 1; + if cfg!(debug_assertions) { + if b.as_ptr() == next_bucket.as_ptr() { + // The removed bucket should no longer be next + debug_assert_ne!(self.iter.current_group.0.lowest_set_bit(), Some(index)); } else { - self.items -= 1; - } - - if cfg!(debug_assertions) { - if b.as_ptr() == next_bucket.as_ptr() { - // The removed bucket should no longer be next - debug_assert_ne!(self.iter.current_group.lowest_set_bit(), Some(index)); - } else { - // We should not have changed what bucket comes next. - debug_assert_eq!(self.iter.current_group.lowest_set_bit(), Some(index)); - } + // We should not have changed what bucket comes next. + debug_assert_eq!(self.iter.current_group.0.lowest_set_bit(), Some(index)); } } - } else { - // We must have already iterated past the removed item. } + } else { + // We must have already iterated past the removed item. } } unsafe fn drop_elements(&mut self) { - if mem::needs_drop::<T>() && self.len() != 0 { + if T::NEEDS_DROP && self.items != 0 { for item in self { item.drop(); } @@ -2159,9 +4131,8 @@ impl<T> Iterator for RawIter<T> { self.iter.next_impl::<false>() }; - if nxt.is_some() { - self.items -= 1; - } + debug_assert!(nxt.is_some()); + self.items -= 1; nxt } @@ -2170,33 +4141,160 @@ impl<T> Iterator for RawIter<T> { fn size_hint(&self) -> (usize, Option<usize>) { (self.items, Some(self.items)) } + + #[inline] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + unsafe { self.iter.fold_impl(self.items, init, f) } + } } impl<T> ExactSizeIterator for RawIter<T> {} impl<T> FusedIterator for RawIter<T> {} +/// Iterator which returns an index of every full bucket in the table. +/// +/// For maximum flexibility this iterator is not bound by a lifetime, but you +/// must observe several rules when using it: +/// - You must not free the hash table while iterating (including via growing/shrinking). +/// - It is fine to erase a bucket that has been yielded by the iterator. +/// - Erasing a bucket that has not yet been yielded by the iterator may still +/// result in the iterator yielding index of that bucket. +/// - It is unspecified whether an element inserted after the iterator was +/// created will be yielded by that iterator. +/// - The order in which the iterator yields indices of the buckets is unspecified +/// and may change in the future. +pub(crate) struct FullBucketsIndices { + // Mask of full buckets in the current group. Bits are cleared from this + // mask as each element is processed. + current_group: BitMaskIter, + + // Initial value of the bytes' indices of the current group (relative + // to the start of the control bytes). + group_first_index: usize, + + // Pointer to the current group of control bytes, + // Must be aligned to the group size (Group::WIDTH). + ctrl: NonNull<u8>, + + // Number of elements in the table. + items: usize, +} + +impl FullBucketsIndices { + /// Advances the iterator and returns the next value. + /// + /// # Safety + /// + /// If any of the following conditions are violated, the result is + /// [`Undefined Behavior`]: + /// + /// * The [`RawTableInner`] / [`RawTable`] must be alive and not moved, + /// i.e. table outlives the `FullBucketsIndices`; + /// + /// * It never tries to iterate after getting all elements. + /// + /// [`Undefined Behavior`]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[inline(always)] + unsafe fn next_impl(&mut self) -> Option<usize> { + loop { + if let Some(index) = self.current_group.next() { + // The returned `self.group_first_index + index` will always + // be in the range `0..self.buckets()`. See explanation below. + return Some(self.group_first_index + index); + } + + // SAFETY: The caller of this function ensures that: + // + // 1. It never tries to iterate after getting all the elements; + // 2. The table is alive and did not moved; + // 3. The first `self.ctrl` pointed to the start of the array of control bytes. + // + // Taking the above into account, we always stay within the bounds, because: + // + // 1. For tables smaller than the group width (self.buckets() <= Group::WIDTH), + // we will never end up in the given branch, since we should have already + // yielded all the elements of the table. + // + // 2. For tables larger than the group width. The number of buckets is a + // power of two (2 ^ n), Group::WIDTH is also power of two (2 ^ k). Since + // `(2 ^ n) > (2 ^ k)`, than `(2 ^ n) % (2 ^ k) = 0`. As we start from the + // the start of the array of control bytes, and never try to iterate after + // getting all the elements, the last `self.ctrl` will be equal to + // the `self.buckets() - Group::WIDTH`, so `self.current_group.next()` + // will always contains indices within the range `0..Group::WIDTH`, + // and subsequent `self.group_first_index + index` will always return a + // number less than `self.buckets()`. + self.ctrl = NonNull::new_unchecked(self.ctrl.as_ptr().add(Group::WIDTH)); + + // SAFETY: See explanation above. + self.current_group = Group::load_aligned(self.ctrl.as_ptr()) + .match_full() + .into_iter(); + self.group_first_index += Group::WIDTH; + } + } +} + +impl Iterator for FullBucketsIndices { + type Item = usize; + + /// Advances the iterator and returns the next value. It is up to + /// the caller to ensure that the `RawTable` outlives the `FullBucketsIndices`, + /// because we cannot make the `next` method unsafe. + #[inline(always)] + fn next(&mut self) -> Option<usize> { + // Return if we already yielded all items. + if self.items == 0 { + return None; + } + + let nxt = unsafe { + // SAFETY: + // 1. We check number of items to yield using `items` field. + // 2. The caller ensures that the table is alive and has not moved. + self.next_impl() + }; + + debug_assert!(nxt.is_some()); + self.items -= 1; + + nxt + } + + #[inline(always)] + fn size_hint(&self) -> (usize, Option<usize>) { + (self.items, Some(self.items)) + } +} + +impl ExactSizeIterator for FullBucketsIndices {} +impl FusedIterator for FullBucketsIndices {} + /// Iterator which consumes a table and returns elements. -pub struct RawIntoIter<T, A: Allocator + Clone = Global> { +pub struct RawIntoIter<T, A: Allocator = Global> { iter: RawIter<T>, - allocation: Option<(NonNull<u8>, Layout)>, + allocation: Option<(NonNull<u8>, Layout, A)>, marker: PhantomData<T>, - alloc: A, } -impl<T, A: Allocator + Clone> RawIntoIter<T, A> { +impl<T, A: Allocator> RawIntoIter<T, A> { #[cfg_attr(feature = "inline-more", inline)] pub fn iter(&self) -> RawIter<T> { self.iter.clone() } } -unsafe impl<T, A: Allocator + Clone> Send for RawIntoIter<T, A> +unsafe impl<T, A: Allocator> Send for RawIntoIter<T, A> where T: Send, A: Send, { } -unsafe impl<T, A: Allocator + Clone> Sync for RawIntoIter<T, A> +unsafe impl<T, A: Allocator> Sync for RawIntoIter<T, A> where T: Sync, A: Sync, @@ -2204,7 +4302,7 @@ where } #[cfg(feature = "nightly")] -unsafe impl<#[may_dangle] T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { +unsafe impl<#[may_dangle] T, A: Allocator> Drop for RawIntoIter<T, A> { #[cfg_attr(feature = "inline-more", inline)] fn drop(&mut self) { unsafe { @@ -2212,14 +4310,14 @@ unsafe impl<#[may_dangle] T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { self.iter.drop_elements(); // Free the table - if let Some((ptr, layout)) = self.allocation { - self.alloc.deallocate(ptr, layout); + if let Some((ptr, layout, ref alloc)) = self.allocation { + alloc.deallocate(ptr, layout); } } } } #[cfg(not(feature = "nightly"))] -impl<T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { +impl<T, A: Allocator> Drop for RawIntoIter<T, A> { #[cfg_attr(feature = "inline-more", inline)] fn drop(&mut self) { unsafe { @@ -2227,14 +4325,14 @@ impl<T, A: Allocator + Clone> Drop for RawIntoIter<T, A> { self.iter.drop_elements(); // Free the table - if let Some((ptr, layout)) = self.allocation { - self.alloc.deallocate(ptr, layout); + if let Some((ptr, layout, ref alloc)) = self.allocation { + alloc.deallocate(ptr, layout); } } } } -impl<T, A: Allocator + Clone> Iterator for RawIntoIter<T, A> { +impl<T, A: Allocator> Iterator for RawIntoIter<T, A> { type Item = T; #[cfg_attr(feature = "inline-more", inline)] @@ -2248,45 +4346,45 @@ impl<T, A: Allocator + Clone> Iterator for RawIntoIter<T, A> { } } -impl<T, A: Allocator + Clone> ExactSizeIterator for RawIntoIter<T, A> {} -impl<T, A: Allocator + Clone> FusedIterator for RawIntoIter<T, A> {} +impl<T, A: Allocator> ExactSizeIterator for RawIntoIter<T, A> {} +impl<T, A: Allocator> FusedIterator for RawIntoIter<T, A> {} /// Iterator which consumes elements without freeing the table storage. -pub struct RawDrain<'a, T, A: Allocator + Clone = Global> { +pub struct RawDrain<'a, T, A: Allocator = Global> { iter: RawIter<T>, // The table is moved into the iterator for the duration of the drain. This // ensures that an empty table is left if the drain iterator is leaked // without dropping. - table: ManuallyDrop<RawTable<T, A>>, - orig_table: NonNull<RawTable<T, A>>, + table: RawTableInner, + orig_table: NonNull<RawTableInner>, // We don't use a &'a mut RawTable<T> because we want RawDrain to be // covariant over T. marker: PhantomData<&'a RawTable<T, A>>, } -impl<T, A: Allocator + Clone> RawDrain<'_, T, A> { +impl<T, A: Allocator> RawDrain<'_, T, A> { #[cfg_attr(feature = "inline-more", inline)] pub fn iter(&self) -> RawIter<T> { self.iter.clone() } } -unsafe impl<T, A: Allocator + Copy> Send for RawDrain<'_, T, A> +unsafe impl<T, A: Allocator> Send for RawDrain<'_, T, A> where T: Send, A: Send, { } -unsafe impl<T, A: Allocator + Copy> Sync for RawDrain<'_, T, A> +unsafe impl<T, A: Allocator> Sync for RawDrain<'_, T, A> where T: Sync, A: Sync, { } -impl<T, A: Allocator + Clone> Drop for RawDrain<'_, T, A> { +impl<T, A: Allocator> Drop for RawDrain<'_, T, A> { #[cfg_attr(feature = "inline-more", inline)] fn drop(&mut self) { unsafe { @@ -2300,12 +4398,12 @@ impl<T, A: Allocator + Clone> Drop for RawDrain<'_, T, A> { // Move the now empty table back to its original location. self.orig_table .as_ptr() - .copy_from_nonoverlapping(&*self.table, 1); + .copy_from_nonoverlapping(&self.table, 1); } } } -impl<T, A: Allocator + Clone> Iterator for RawDrain<'_, T, A> { +impl<T, A: Allocator> Iterator for RawDrain<'_, T, A> { type Item = T; #[cfg_attr(feature = "inline-more", inline)] @@ -2322,21 +4420,36 @@ impl<T, A: Allocator + Clone> Iterator for RawDrain<'_, T, A> { } } -impl<T, A: Allocator + Clone> ExactSizeIterator for RawDrain<'_, T, A> {} -impl<T, A: Allocator + Clone> FusedIterator for RawDrain<'_, T, A> {} +impl<T, A: Allocator> ExactSizeIterator for RawDrain<'_, T, A> {} +impl<T, A: Allocator> FusedIterator for RawDrain<'_, T, A> {} /// Iterator over occupied buckets that could match a given hash. /// /// `RawTable` only stores 7 bits of the hash value, so this iterator may return /// items that have a hash value different than the one provided. You should /// always validate the returned values before using them. -pub struct RawIterHash<'a, T, A: Allocator + Clone = Global> { - inner: RawIterHashInner<'a, A>, +/// +/// For maximum flexibility this iterator is not bound by a lifetime, but you +/// must observe several rules when using it: +/// - You must not free the hash table while iterating (including via growing/shrinking). +/// - It is fine to erase a bucket that has been yielded by the iterator. +/// - Erasing a bucket that has not yet been yielded by the iterator may still +/// result in the iterator yielding that bucket. +/// - It is unspecified whether an element inserted after the iterator was +/// created will be yielded by that iterator. +/// - The order in which the iterator yields buckets is unspecified and may +/// change in the future. +pub struct RawIterHash<T> { + inner: RawIterHashInner, _marker: PhantomData<T>, } -struct RawIterHashInner<'a, A: Allocator + Clone> { - table: &'a RawTableInner<A>, +struct RawIterHashInner { + // See `RawTableInner`'s corresponding fields for details. + // We can't store a `*const RawTableInner` as it would get + // invalidated by the user calling `&mut` methods on `RawTable`. + bucket_mask: usize, + ctrl: NonNull<u8>, // The top 7 bits of the hash. h2_hash: u8, @@ -2350,71 +4463,105 @@ struct RawIterHashInner<'a, A: Allocator + Clone> { bitmask: BitMaskIter, } -impl<'a, T, A: Allocator + Clone> RawIterHash<'a, T, A> { +impl<T> RawIterHash<T> { #[cfg_attr(feature = "inline-more", inline)] #[cfg(feature = "raw")] - fn new(table: &'a RawTable<T, A>, hash: u64) -> Self { + unsafe fn new<A: Allocator>(table: &RawTable<T, A>, hash: u64) -> Self { RawIterHash { inner: RawIterHashInner::new(&table.table, hash), _marker: PhantomData, } } } -impl<'a, A: Allocator + Clone> RawIterHashInner<'a, A> { +impl RawIterHashInner { #[cfg_attr(feature = "inline-more", inline)] #[cfg(feature = "raw")] - fn new(table: &'a RawTableInner<A>, hash: u64) -> Self { - unsafe { - let h2_hash = h2(hash); - let probe_seq = table.probe_seq(hash); - let group = Group::load(table.ctrl(probe_seq.pos)); - let bitmask = group.match_byte(h2_hash).into_iter(); - - RawIterHashInner { - table, - h2_hash, - probe_seq, - group, - bitmask, - } + unsafe fn new(table: &RawTableInner, hash: u64) -> Self { + let h2_hash = h2(hash); + let probe_seq = table.probe_seq(hash); + let group = Group::load(table.ctrl(probe_seq.pos)); + let bitmask = group.match_byte(h2_hash).into_iter(); + + RawIterHashInner { + bucket_mask: table.bucket_mask, + ctrl: table.ctrl, + h2_hash, + probe_seq, + group, + bitmask, } } } -impl<'a, T, A: Allocator + Clone> Iterator for RawIterHash<'a, T, A> { +impl<T> Iterator for RawIterHash<T> { type Item = Bucket<T>; fn next(&mut self) -> Option<Bucket<T>> { unsafe { match self.inner.next() { - Some(index) => Some(self.inner.table.bucket(index)), + Some(index) => { + // Can't use `RawTable::bucket` here as we don't have + // an actual `RawTable` reference to use. + debug_assert!(index <= self.inner.bucket_mask); + let bucket = Bucket::from_base_index(self.inner.ctrl.cast(), index); + Some(bucket) + } None => None, } } } } -impl<'a, A: Allocator + Clone> Iterator for RawIterHashInner<'a, A> { +impl Iterator for RawIterHashInner { type Item = usize; fn next(&mut self) -> Option<Self::Item> { unsafe { loop { if let Some(bit) = self.bitmask.next() { - let index = (self.probe_seq.pos + bit) & self.table.bucket_mask; + let index = (self.probe_seq.pos + bit) & self.bucket_mask; return Some(index); } if likely(self.group.match_empty().any_bit_set()) { return None; } - self.probe_seq.move_next(self.table.bucket_mask); - self.group = Group::load(self.table.ctrl(self.probe_seq.pos)); + self.probe_seq.move_next(self.bucket_mask); + + // Can't use `RawTableInner::ctrl` here as we don't have + // an actual `RawTableInner` reference to use. + let index = self.probe_seq.pos; + debug_assert!(index < self.bucket_mask + 1 + Group::WIDTH); + let group_ctrl = self.ctrl.as_ptr().add(index); + + self.group = Group::load(group_ctrl); self.bitmask = self.group.match_byte(self.h2_hash).into_iter(); } } } } +pub(crate) struct RawExtractIf<'a, T, A: Allocator> { + pub iter: RawIter<T>, + pub table: &'a mut RawTable<T, A>, +} + +impl<T, A: Allocator> RawExtractIf<'_, T, A> { + #[cfg_attr(feature = "inline-more", inline)] + pub(crate) fn next<F>(&mut self, mut f: F) -> Option<T> + where + F: FnMut(&mut T) -> bool, + { + unsafe { + for item in &mut self.iter { + if f(item.as_mut()) { + return Some(self.table.remove(item).0); + } + } + } + None + } +} + #[cfg(test)] mod test_map { use super::*; @@ -2457,4 +4604,214 @@ mod test_map { assert!(table.find(i + 100, |x| *x == i + 100).is_none()); } } + + /// CHECKING THAT WE ARE NOT TRYING TO READ THE MEMORY OF + /// AN UNINITIALIZED TABLE DURING THE DROP + #[test] + fn test_drop_uninitialized() { + use ::alloc::vec::Vec; + + let table = unsafe { + // SAFETY: The `buckets` is power of two and we're not + // trying to actually use the returned RawTable. + RawTable::<(u64, Vec<i32>)>::new_uninitialized(Global, 8, Fallibility::Infallible) + .unwrap() + }; + drop(table); + } + + /// CHECKING THAT WE DON'T TRY TO DROP DATA IF THE `ITEMS` + /// ARE ZERO, EVEN IF WE HAVE `FULL` CONTROL BYTES. + #[test] + fn test_drop_zero_items() { + use ::alloc::vec::Vec; + unsafe { + // SAFETY: The `buckets` is power of two and we're not + // trying to actually use the returned RawTable. + let table = + RawTable::<(u64, Vec<i32>)>::new_uninitialized(Global, 8, Fallibility::Infallible) + .unwrap(); + + // WE SIMULATE, AS IT WERE, A FULL TABLE. + + // SAFETY: We checked that the table is allocated and therefore the table already has + // `self.bucket_mask + 1 + Group::WIDTH` number of control bytes (see TableLayout::calculate_layout_for) + // so writing `table.table.num_ctrl_bytes() == bucket_mask + 1 + Group::WIDTH` bytes is safe. + table + .table + .ctrl(0) + .write_bytes(EMPTY, table.table.num_ctrl_bytes()); + + // SAFETY: table.capacity() is guaranteed to be smaller than table.buckets() + table.table.ctrl(0).write_bytes(0, table.capacity()); + + // Fix up the trailing control bytes. See the comments in set_ctrl + // for the handling of tables smaller than the group width. + if table.buckets() < Group::WIDTH { + // SAFETY: We have `self.bucket_mask + 1 + Group::WIDTH` number of control bytes, + // so copying `self.buckets() == self.bucket_mask + 1` bytes with offset equal to + // `Group::WIDTH` is safe + table + .table + .ctrl(0) + .copy_to(table.table.ctrl(Group::WIDTH), table.table.buckets()); + } else { + // SAFETY: We have `self.bucket_mask + 1 + Group::WIDTH` number of + // control bytes,so copying `Group::WIDTH` bytes with offset equal + // to `self.buckets() == self.bucket_mask + 1` is safe + table + .table + .ctrl(0) + .copy_to(table.table.ctrl(table.table.buckets()), Group::WIDTH); + } + drop(table); + } + } + + /// CHECKING THAT WE DON'T TRY TO DROP DATA IF THE `ITEMS` + /// ARE ZERO, EVEN IF WE HAVE `FULL` CONTROL BYTES. + #[test] + fn test_catch_panic_clone_from() { + use ::alloc::sync::Arc; + use ::alloc::vec::Vec; + use allocator_api2::alloc::{AllocError, Allocator, Global}; + use core::sync::atomic::{AtomicI8, Ordering}; + use std::thread; + + struct MyAllocInner { + drop_count: Arc<AtomicI8>, + } + + #[derive(Clone)] + struct MyAlloc { + _inner: Arc<MyAllocInner>, + } + + impl Drop for MyAllocInner { + fn drop(&mut self) { + println!("MyAlloc freed."); + self.drop_count.fetch_sub(1, Ordering::SeqCst); + } + } + + unsafe impl Allocator for MyAlloc { + fn allocate(&self, layout: Layout) -> std::result::Result<NonNull<[u8]>, AllocError> { + let g = Global; + g.allocate(layout) + } + + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + let g = Global; + g.deallocate(ptr, layout) + } + } + + const DISARMED: bool = false; + const ARMED: bool = true; + + struct CheckedCloneDrop { + panic_in_clone: bool, + dropped: bool, + need_drop: Vec<u64>, + } + + impl Clone for CheckedCloneDrop { + fn clone(&self) -> Self { + if self.panic_in_clone { + panic!("panic in clone") + } + Self { + panic_in_clone: self.panic_in_clone, + dropped: self.dropped, + need_drop: self.need_drop.clone(), + } + } + } + + impl Drop for CheckedCloneDrop { + fn drop(&mut self) { + if self.dropped { + panic!("double drop"); + } + self.dropped = true; + } + } + + let dropped: Arc<AtomicI8> = Arc::new(AtomicI8::new(2)); + + let mut table = RawTable::new_in(MyAlloc { + _inner: Arc::new(MyAllocInner { + drop_count: dropped.clone(), + }), + }); + + for (idx, panic_in_clone) in core::iter::repeat(DISARMED).take(7).enumerate() { + let idx = idx as u64; + table.insert( + idx, + ( + idx, + CheckedCloneDrop { + panic_in_clone, + dropped: false, + need_drop: vec![idx], + }, + ), + |(k, _)| *k, + ); + } + + assert_eq!(table.len(), 7); + + thread::scope(|s| { + let result = s.spawn(|| { + let armed_flags = [ + DISARMED, DISARMED, ARMED, DISARMED, DISARMED, DISARMED, DISARMED, + ]; + let mut scope_table = RawTable::new_in(MyAlloc { + _inner: Arc::new(MyAllocInner { + drop_count: dropped.clone(), + }), + }); + for (idx, &panic_in_clone) in armed_flags.iter().enumerate() { + let idx = idx as u64; + scope_table.insert( + idx, + ( + idx, + CheckedCloneDrop { + panic_in_clone, + dropped: false, + need_drop: vec![idx + 100], + }, + ), + |(k, _)| *k, + ); + } + table.clone_from(&scope_table); + }); + assert!(result.join().is_err()); + }); + + // Let's check that all iterators work fine and do not return elements + // (especially `RawIterRange`, which does not depend on the number of + // elements in the table, but looks directly at the control bytes) + // + // SAFETY: We know for sure that `RawTable` will outlive + // the returned `RawIter / RawIterRange` iterator. + assert_eq!(table.len(), 0); + assert_eq!(unsafe { table.iter().count() }, 0); + assert_eq!(unsafe { table.iter().iter.count() }, 0); + + for idx in 0..table.buckets() { + let idx = idx as u64; + assert!( + table.find(idx, |(k, _)| *k == idx).is_none(), + "Index: {idx}" + ); + } + + // All allocator clones should already be dropped. + assert_eq!(dropped.load(Ordering::SeqCst), 1); + } } diff --git a/third_party/rust/hashbrown/src/raw/neon.rs b/third_party/rust/hashbrown/src/raw/neon.rs new file mode 100644 index 0000000000..44e82d57d5 --- /dev/null +++ b/third_party/rust/hashbrown/src/raw/neon.rs @@ -0,0 +1,124 @@ +use super::bitmask::BitMask; +use super::EMPTY; +use core::arch::aarch64 as neon; +use core::mem; +use core::num::NonZeroU64; + +pub(crate) type BitMaskWord = u64; +pub(crate) type NonZeroBitMaskWord = NonZeroU64; +pub(crate) const BITMASK_STRIDE: usize = 8; +pub(crate) const BITMASK_MASK: BitMaskWord = !0; +pub(crate) const BITMASK_ITER_MASK: BitMaskWord = 0x8080_8080_8080_8080; + +/// Abstraction over a group of control bytes which can be scanned in +/// parallel. +/// +/// This implementation uses a 64-bit NEON value. +#[derive(Copy, Clone)] +pub(crate) struct Group(neon::uint8x8_t); + +#[allow(clippy::use_self)] +impl Group { + /// Number of bytes in the group. + pub(crate) const WIDTH: usize = mem::size_of::<Self>(); + + /// Returns a full group of empty bytes, suitable for use as the initial + /// value for an empty hash table. + /// + /// This is guaranteed to be aligned to the group size. + #[inline] + pub(crate) const fn static_empty() -> &'static [u8; Group::WIDTH] { + #[repr(C)] + struct AlignedBytes { + _align: [Group; 0], + bytes: [u8; Group::WIDTH], + } + const ALIGNED_BYTES: AlignedBytes = AlignedBytes { + _align: [], + bytes: [EMPTY; Group::WIDTH], + }; + &ALIGNED_BYTES.bytes + } + + /// Loads a group of bytes starting at the given address. + #[inline] + #[allow(clippy::cast_ptr_alignment)] // unaligned load + pub(crate) unsafe fn load(ptr: *const u8) -> Self { + Group(neon::vld1_u8(ptr)) + } + + /// Loads a group of bytes starting at the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub(crate) unsafe fn load_aligned(ptr: *const u8) -> Self { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + Group(neon::vld1_u8(ptr)) + } + + /// Stores the group of bytes to the given address, which must be + /// aligned to `mem::align_of::<Group>()`. + #[inline] + #[allow(clippy::cast_ptr_alignment)] + pub(crate) unsafe fn store_aligned(self, ptr: *mut u8) { + // FIXME: use align_offset once it stabilizes + debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); + neon::vst1_u8(ptr, self.0); + } + + /// Returns a `BitMask` indicating all bytes in the group which *may* + /// have the given value. + #[inline] + pub(crate) fn match_byte(self, byte: u8) -> BitMask { + unsafe { + let cmp = neon::vceq_u8(self.0, neon::vdup_n_u8(byte)); + BitMask(neon::vget_lane_u64(neon::vreinterpret_u64_u8(cmp), 0)) + } + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY`. + #[inline] + pub(crate) fn match_empty(self) -> BitMask { + self.match_byte(EMPTY) + } + + /// Returns a `BitMask` indicating all bytes in the group which are + /// `EMPTY` or `DELETED`. + #[inline] + pub(crate) fn match_empty_or_deleted(self) -> BitMask { + unsafe { + let cmp = neon::vcltz_s8(neon::vreinterpret_s8_u8(self.0)); + BitMask(neon::vget_lane_u64(neon::vreinterpret_u64_u8(cmp), 0)) + } + } + + /// Returns a `BitMask` indicating all bytes in the group which are full. + #[inline] + pub(crate) fn match_full(self) -> BitMask { + unsafe { + let cmp = neon::vcgez_s8(neon::vreinterpret_s8_u8(self.0)); + BitMask(neon::vget_lane_u64(neon::vreinterpret_u64_u8(cmp), 0)) + } + } + + /// Performs the following transformation on all bytes in the group: + /// - `EMPTY => EMPTY` + /// - `DELETED => EMPTY` + /// - `FULL => DELETED` + #[inline] + pub(crate) fn convert_special_to_empty_and_full_to_deleted(self) -> Self { + // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111 + // and high_bit = 0 (FULL) to 1000_0000 + // + // Here's this logic expanded to concrete values: + // let special = 0 > byte = 1111_1111 (true) or 0000_0000 (false) + // 1111_1111 | 1000_0000 = 1111_1111 + // 0000_0000 | 1000_0000 = 1000_0000 + unsafe { + let special = neon::vcltz_s8(neon::vreinterpret_s8_u8(self.0)); + Group(neon::vorr_u8(special, neon::vdup_n_u8(0x80))) + } + } +} diff --git a/third_party/rust/hashbrown/src/raw/sse2.rs b/third_party/rust/hashbrown/src/raw/sse2.rs index a0bf6da804..956ba5d265 100644 --- a/third_party/rust/hashbrown/src/raw/sse2.rs +++ b/third_party/rust/hashbrown/src/raw/sse2.rs @@ -1,28 +1,31 @@ use super::bitmask::BitMask; use super::EMPTY; use core::mem; +use core::num::NonZeroU16; #[cfg(target_arch = "x86")] use core::arch::x86; #[cfg(target_arch = "x86_64")] use core::arch::x86_64 as x86; -pub type BitMaskWord = u16; -pub const BITMASK_STRIDE: usize = 1; -pub const BITMASK_MASK: BitMaskWord = 0xffff; +pub(crate) type BitMaskWord = u16; +pub(crate) type NonZeroBitMaskWord = NonZeroU16; +pub(crate) const BITMASK_STRIDE: usize = 1; +pub(crate) const BITMASK_MASK: BitMaskWord = 0xffff; +pub(crate) const BITMASK_ITER_MASK: BitMaskWord = !0; /// Abstraction over a group of control bytes which can be scanned in /// parallel. /// /// This implementation uses a 128-bit SSE value. #[derive(Copy, Clone)] -pub struct Group(x86::__m128i); +pub(crate) struct Group(x86::__m128i); // FIXME: https://github.com/rust-lang/rust-clippy/issues/3859 #[allow(clippy::use_self)] impl Group { /// Number of bytes in the group. - pub const WIDTH: usize = mem::size_of::<Self>(); + pub(crate) const WIDTH: usize = mem::size_of::<Self>(); /// Returns a full group of empty bytes, suitable for use as the initial /// value for an empty hash table. @@ -30,7 +33,7 @@ impl Group { /// This is guaranteed to be aligned to the group size. #[inline] #[allow(clippy::items_after_statements)] - pub const fn static_empty() -> &'static [u8; Group::WIDTH] { + pub(crate) const fn static_empty() -> &'static [u8; Group::WIDTH] { #[repr(C)] struct AlignedBytes { _align: [Group; 0], @@ -46,7 +49,7 @@ impl Group { /// Loads a group of bytes starting at the given address. #[inline] #[allow(clippy::cast_ptr_alignment)] // unaligned load - pub unsafe fn load(ptr: *const u8) -> Self { + pub(crate) unsafe fn load(ptr: *const u8) -> Self { Group(x86::_mm_loadu_si128(ptr.cast())) } @@ -54,7 +57,7 @@ impl Group { /// aligned to `mem::align_of::<Group>()`. #[inline] #[allow(clippy::cast_ptr_alignment)] - pub unsafe fn load_aligned(ptr: *const u8) -> Self { + pub(crate) unsafe fn load_aligned(ptr: *const u8) -> Self { // FIXME: use align_offset once it stabilizes debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); Group(x86::_mm_load_si128(ptr.cast())) @@ -64,7 +67,7 @@ impl Group { /// aligned to `mem::align_of::<Group>()`. #[inline] #[allow(clippy::cast_ptr_alignment)] - pub unsafe fn store_aligned(self, ptr: *mut u8) { + pub(crate) unsafe fn store_aligned(self, ptr: *mut u8) { // FIXME: use align_offset once it stabilizes debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0); x86::_mm_store_si128(ptr.cast(), self.0); @@ -73,7 +76,7 @@ impl Group { /// Returns a `BitMask` indicating all bytes in the group which have /// the given value. #[inline] - pub fn match_byte(self, byte: u8) -> BitMask { + pub(crate) fn match_byte(self, byte: u8) -> BitMask { #[allow( clippy::cast_possible_wrap, // byte: u8 as i8 // byte: i32 as u16 @@ -91,14 +94,14 @@ impl Group { /// Returns a `BitMask` indicating all bytes in the group which are /// `EMPTY`. #[inline] - pub fn match_empty(self) -> BitMask { + pub(crate) fn match_empty(self) -> BitMask { self.match_byte(EMPTY) } /// Returns a `BitMask` indicating all bytes in the group which are /// `EMPTY` or `DELETED`. #[inline] - pub fn match_empty_or_deleted(self) -> BitMask { + pub(crate) fn match_empty_or_deleted(self) -> BitMask { #[allow( // byte: i32 as u16 // note: _mm_movemask_epi8 returns a 16-bit mask in a i32, the @@ -114,7 +117,7 @@ impl Group { /// Returns a `BitMask` indicating all bytes in the group which are full. #[inline] - pub fn match_full(&self) -> BitMask { + pub(crate) fn match_full(&self) -> BitMask { self.match_empty_or_deleted().invert() } @@ -123,7 +126,7 @@ impl Group { /// - `DELETED => EMPTY` /// - `FULL => DELETED` #[inline] - pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self { + pub(crate) fn convert_special_to_empty_and_full_to_deleted(self) -> Self { // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111 // and high_bit = 0 (FULL) to 1000_0000 // diff --git a/third_party/rust/hashbrown/src/rustc_entry.rs b/third_party/rust/hashbrown/src/rustc_entry.rs index 2e84595269..defbd4bb88 100644 --- a/third_party/rust/hashbrown/src/rustc_entry.rs +++ b/third_party/rust/hashbrown/src/rustc_entry.rs @@ -1,5 +1,5 @@ use self::RustcEntry::*; -use crate::map::{make_insert_hash, Drain, HashMap, IntoIter, Iter, IterMut}; +use crate::map::{make_hash, Drain, HashMap, IntoIter, Iter, IterMut}; use crate::raw::{Allocator, Bucket, Global, RawTable}; use core::fmt::{self, Debug}; use core::hash::{BuildHasher, Hash}; @@ -9,7 +9,7 @@ impl<K, V, S, A> HashMap<K, V, S, A> where K: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Gets the given key's corresponding entry in the map for in-place manipulation. /// @@ -32,7 +32,7 @@ where /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn rustc_entry(&mut self, key: K) -> RustcEntry<'_, K, V, A> { - let hash = make_insert_hash(&self.hash_builder, &key); + let hash = make_hash(&self.hash_builder, &key); if let Some(elem) = self.table.find(hash, |q| q.0.eq(&key)) { RustcEntry::Occupied(RustcOccupiedEntry { key: Some(key), @@ -62,7 +62,7 @@ where /// [`rustc_entry`]: struct.HashMap.html#method.rustc_entry pub enum RustcEntry<'a, K, V, A = Global> where - A: Allocator + Clone, + A: Allocator, { /// An occupied entry. Occupied(RustcOccupiedEntry<'a, K, V, A>), @@ -71,7 +71,7 @@ where Vacant(RustcVacantEntry<'a, K, V, A>), } -impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcEntry<'_, K, V, A> { +impl<K: Debug, V: Debug, A: Allocator> Debug for RustcEntry<'_, K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), @@ -86,7 +86,7 @@ impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcEntry<'_, K, V, A> /// [`RustcEntry`]: enum.RustcEntry.html pub struct RustcOccupiedEntry<'a, K, V, A = Global> where - A: Allocator + Clone, + A: Allocator, { key: Option<K>, elem: Bucket<(K, V)>, @@ -97,18 +97,18 @@ unsafe impl<K, V, A> Send for RustcOccupiedEntry<'_, K, V, A> where K: Send, V: Send, - A: Allocator + Clone + Send, + A: Allocator + Send, { } unsafe impl<K, V, A> Sync for RustcOccupiedEntry<'_, K, V, A> where K: Sync, V: Sync, - A: Allocator + Clone + Sync, + A: Allocator + Sync, { } -impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcOccupiedEntry<'_, K, V, A> { +impl<K: Debug, V: Debug, A: Allocator> Debug for RustcOccupiedEntry<'_, K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("OccupiedEntry") .field("key", self.key()) @@ -123,20 +123,20 @@ impl<K: Debug, V: Debug, A: Allocator + Clone> Debug for RustcOccupiedEntry<'_, /// [`RustcEntry`]: enum.RustcEntry.html pub struct RustcVacantEntry<'a, K, V, A = Global> where - A: Allocator + Clone, + A: Allocator, { hash: u64, key: K, table: &'a mut RawTable<(K, V), A>, } -impl<K: Debug, V, A: Allocator + Clone> Debug for RustcVacantEntry<'_, K, V, A> { +impl<K: Debug, V, A: Allocator> Debug for RustcVacantEntry<'_, K, V, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_tuple("VacantEntry").field(self.key()).finish() } } -impl<'a, K, V, A: Allocator + Clone> RustcEntry<'a, K, V, A> { +impl<'a, K, V, A: Allocator> RustcEntry<'a, K, V, A> { /// Sets the value of the entry, and returns a RustcOccupiedEntry. /// /// # Examples @@ -265,7 +265,7 @@ impl<'a, K, V, A: Allocator + Clone> RustcEntry<'a, K, V, A> { } } -impl<'a, K, V: Default, A: Allocator + Clone> RustcEntry<'a, K, V, A> { +impl<'a, K, V: Default, A: Allocator> RustcEntry<'a, K, V, A> { /// Ensures a value is in the entry by inserting the default value if empty, /// and returns a mutable reference to the value in the entry. /// @@ -293,7 +293,7 @@ impl<'a, K, V: Default, A: Allocator + Clone> RustcEntry<'a, K, V, A> { } } -impl<'a, K, V, A: Allocator + Clone> RustcOccupiedEntry<'a, K, V, A> { +impl<'a, K, V, A: Allocator> RustcOccupiedEntry<'a, K, V, A> { /// Gets a reference to the key in the entry. /// /// # Examples @@ -330,7 +330,7 @@ impl<'a, K, V, A: Allocator + Clone> RustcOccupiedEntry<'a, K, V, A> { /// ``` #[cfg_attr(feature = "inline-more", inline)] pub fn remove_entry(self) -> (K, V) { - unsafe { self.table.remove(self.elem) } + unsafe { self.table.remove(self.elem).0 } } /// Gets a reference to the value in the entry. @@ -518,7 +518,7 @@ impl<'a, K, V, A: Allocator + Clone> RustcOccupiedEntry<'a, K, V, A> { } } -impl<'a, K, V, A: Allocator + Clone> RustcVacantEntry<'a, K, V, A> { +impl<'a, K, V, A: Allocator> RustcVacantEntry<'a, K, V, A> { /// Gets a reference to the key that would be used when inserting a value /// through the `RustcVacantEntry`. /// diff --git a/third_party/rust/hashbrown/src/scopeguard.rs b/third_party/rust/hashbrown/src/scopeguard.rs index f85e6ab0ed..382d06043e 100644 --- a/third_party/rust/hashbrown/src/scopeguard.rs +++ b/third_party/rust/hashbrown/src/scopeguard.rs @@ -1,6 +1,6 @@ // Extracted from the scopeguard crate use core::{ - mem, + mem::ManuallyDrop, ops::{Deref, DerefMut}, ptr, }; @@ -28,15 +28,13 @@ where #[inline] pub fn into_inner(guard: Self) -> T { // Cannot move out of Drop-implementing types, so - // ptr::read the value and forget the guard. + // ptr::read the value out of a ManuallyDrop<Self> + // Don't use mem::forget as that might invalidate value + let guard = ManuallyDrop::new(guard); unsafe { let value = ptr::read(&guard.value); - // read the closure so that it is dropped, and assign it to a local - // variable to ensure that it is only dropped after the guard has - // been forgotten. (In case the Drop impl of the closure, or that - // of any consumed captured variable, panics). - let _dropfn = ptr::read(&guard.dropfn); - mem::forget(guard); + // read the closure so that it is dropped + let _ = ptr::read(&guard.dropfn); value } } diff --git a/third_party/rust/hashbrown/src/set.rs b/third_party/rust/hashbrown/src/set.rs index 2a4dcea52c..2125a7ac81 100644 --- a/third_party/rust/hashbrown/src/set.rs +++ b/third_party/rust/hashbrown/src/set.rs @@ -1,14 +1,14 @@ -use crate::TryReserveError; +#[cfg(feature = "raw")] +use crate::raw::RawTable; +use crate::{Equivalent, TryReserveError}; use alloc::borrow::ToOwned; -use core::borrow::Borrow; use core::fmt; use core::hash::{BuildHasher, Hash}; -use core::iter::{Chain, FromIterator, FusedIterator}; -use core::mem; +use core::iter::{Chain, FusedIterator}; use core::ops::{BitAnd, BitOr, BitXor, Sub}; -use super::map::{self, ConsumeAllOnDrop, DefaultHashBuilder, DrainFilterInner, HashMap, Keys}; -use crate::raw::{Allocator, Global}; +use super::map::{self, DefaultHashBuilder, HashMap, Keys}; +use crate::raw::{Allocator, Global, RawExtractIf}; // Future Optimization (FIXME!) // ============================= @@ -102,7 +102,7 @@ use crate::raw::{Allocator, Global}; /// use hashbrown::HashSet; /// /// let viking_names: HashSet<&'static str> = -/// [ "Einar", "Olaf", "Harald" ].iter().cloned().collect(); +/// [ "Einar", "Olaf", "Harald" ].into_iter().collect(); /// // use the values stored in the set /// ``` /// @@ -112,7 +112,7 @@ use crate::raw::{Allocator, Global}; /// [`HashMap`]: struct.HashMap.html /// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html /// [`RefCell`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html -pub struct HashSet<T, S = DefaultHashBuilder, A: Allocator + Clone = Global> { +pub struct HashSet<T, S = DefaultHashBuilder, A: Allocator = Global> { pub(crate) map: HashMap<T, (), S, A>, } @@ -135,6 +135,18 @@ impl<T> HashSet<T, DefaultHashBuilder> { /// The hash set is initially created with a capacity of 0, so it will not allocate until it /// is first inserted into. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`], for example with + /// [`with_hasher`](HashSet::with_hasher) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -153,6 +165,18 @@ impl<T> HashSet<T, DefaultHashBuilder> { /// The hash set will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash set will not allocate. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`], for example with + /// [`with_capacity_and_hasher`](HashSet::with_capacity_and_hasher) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -169,12 +193,24 @@ impl<T> HashSet<T, DefaultHashBuilder> { } #[cfg(feature = "ahash")] -impl<T: Hash + Eq, A: Allocator + Clone> HashSet<T, DefaultHashBuilder, A> { +impl<T: Hash + Eq, A: Allocator> HashSet<T, DefaultHashBuilder, A> { /// Creates an empty `HashSet`. /// /// The hash set is initially created with a capacity of 0, so it will not allocate until it /// is first inserted into. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`], for example with + /// [`with_hasher_in`](HashSet::with_hasher_in) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -193,6 +229,18 @@ impl<T: Hash + Eq, A: Allocator + Clone> HashSet<T, DefaultHashBuilder, A> { /// The hash set will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash set will not allocate. /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`], for example with + /// [`with_capacity_and_hasher_in`](HashSet::with_capacity_and_hasher_in) method. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// /// # Examples /// /// ``` @@ -208,7 +256,7 @@ impl<T: Hash + Eq, A: Allocator + Clone> HashSet<T, DefaultHashBuilder, A> { } } -impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { +impl<T, S, A: Allocator> HashSet<T, S, A> { /// Returns the number of elements the set can hold without reallocating. /// /// # Examples @@ -287,7 +335,7 @@ impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { /// ``` /// use hashbrown::HashSet; /// - /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let mut set: HashSet<_> = [1, 2, 3].into_iter().collect(); /// assert!(!set.is_empty()); /// /// // print 1, 2, 3 in an arbitrary order @@ -314,7 +362,7 @@ impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { /// use hashbrown::HashSet; /// /// let xs = [1,2,3,4,5,6]; - /// let mut set: HashSet<i32> = xs.iter().cloned().collect(); + /// let mut set: HashSet<i32> = xs.into_iter().collect(); /// set.retain(|&k| k % 2 == 0); /// assert_eq!(set.len(), 3); /// ``` @@ -331,8 +379,11 @@ impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { /// In other words, move all elements `e` such that `f(&e)` returns `true` out /// into another iterator. /// - /// When the returned DrainedFilter is dropped, any remaining elements that satisfy - /// the predicate are dropped from the set. + /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating + /// or the iteration short-circuits, then the remaining elements will be retained. + /// Use [`retain()`] with a negated predicate if you do not need the returned iterator. + /// + /// [`retain()`]: HashSet::retain /// /// # Examples /// @@ -340,7 +391,7 @@ impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { /// use hashbrown::HashSet; /// /// let mut set: HashSet<i32> = (0..8).collect(); - /// let drained: HashSet<i32> = set.drain_filter(|v| v % 2 == 0).collect(); + /// let drained: HashSet<i32> = set.extract_if(|v| v % 2 == 0).collect(); /// /// let mut evens = drained.into_iter().collect::<Vec<_>>(); /// let mut odds = set.into_iter().collect::<Vec<_>>(); @@ -351,13 +402,13 @@ impl<T, S, A: Allocator + Clone> HashSet<T, S, A> { /// assert_eq!(odds, vec![1, 3, 5, 7]); /// ``` #[cfg_attr(feature = "inline-more", inline)] - pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, T, F, A> + pub fn extract_if<F>(&mut self, f: F) -> ExtractIf<'_, T, F, A> where F: FnMut(&T) -> bool, { - DrainFilter { + ExtractIf { f, - inner: DrainFilterInner { + inner: RawExtractIf { iter: unsafe { self.map.table.iter() }, table: &mut self.map.table, }, @@ -386,16 +437,23 @@ impl<T, S> HashSet<T, S, Global> { /// Creates a new empty hash set which will use the given hasher to hash /// keys. /// - /// The hash set is also created with the default initial capacity. + /// The hash set is initially created with a capacity of 0, so it will not + /// allocate until it is first inserted into. + /// + /// # HashDoS resistance /// - /// Warning: `hasher` is normally randomly generated, and - /// is designed to allow `HashSet`s to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for - /// the HashMap to be useful, see its documentation for details. + /// the HashSet to be useful, see its documentation for details. /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # Examples /// @@ -407,8 +465,6 @@ impl<T, S> HashSet<T, S, Global> { /// let mut set = HashSet::with_hasher(s); /// set.insert(2); /// ``` - /// - /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html #[cfg_attr(feature = "inline-more", inline)] pub const fn with_hasher(hasher: S) -> Self { Self { @@ -422,13 +478,20 @@ impl<T, S> HashSet<T, S, Global> { /// The hash set will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash set will not allocate. /// - /// Warning: `hasher` is normally randomly generated, and - /// is designed to allow `HashSet`s to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`]. /// /// The `hash_builder` passed should implement the [`BuildHasher`] trait for - /// the HashMap to be useful, see its documentation for details. + /// the HashSet to be useful, see its documentation for details. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # Examples /// @@ -440,8 +503,6 @@ impl<T, S> HashSet<T, S, Global> { /// let mut set = HashSet::with_capacity_and_hasher(10, s); /// set.insert(1); /// ``` - /// - /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html #[cfg_attr(feature = "inline-more", inline)] pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> Self { Self { @@ -452,7 +513,7 @@ impl<T, S> HashSet<T, S, Global> { impl<T, S, A> HashSet<T, S, A> where - A: Allocator + Clone, + A: Allocator, { /// Returns a reference to the underlying allocator. #[inline] @@ -463,12 +524,23 @@ where /// Creates a new empty hash set which will use the given hasher to hash /// keys. /// - /// The hash set is also created with the default initial capacity. + /// The hash set is initially created with a capacity of 0, so it will not + /// allocate until it is first inserted into. + /// + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`]. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashSet to be useful, see its documentation for details. /// - /// Warning: `hasher` is normally randomly generated, and - /// is designed to allow `HashSet`s to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # Examples /// @@ -481,7 +553,7 @@ where /// set.insert(2); /// ``` #[cfg_attr(feature = "inline-more", inline)] - pub fn with_hasher_in(hasher: S, alloc: A) -> Self { + pub const fn with_hasher_in(hasher: S, alloc: A) -> Self { Self { map: HashMap::with_hasher_in(hasher, alloc), } @@ -493,10 +565,20 @@ where /// The hash set will be able to hold at least `capacity` elements without /// reallocating. If `capacity` is 0, the hash set will not allocate. /// - /// Warning: `hasher` is normally randomly generated, and - /// is designed to allow `HashSet`s to be resistant to attacks that - /// cause many collisions and very poor performance. Setting it - /// manually using this function can expose a DoS attack vector. + /// # HashDoS resistance + /// + /// The `hash_builder` normally use a fixed key by default and that does + /// not allow the `HashSet` to be protected against attacks such as [`HashDoS`]. + /// Users who require HashDoS resistance should explicitly use + /// [`ahash::RandomState`] or [`std::collections::hash_map::RandomState`] + /// as the hasher when creating a [`HashSet`]. + /// + /// The `hash_builder` passed should implement the [`BuildHasher`] trait for + /// the HashSet to be useful, see its documentation for details. + /// + /// [`HashDoS`]: https://en.wikipedia.org/wiki/Collision_attack + /// [`std::collections::hash_map::RandomState`]: https://doc.rust-lang.org/std/collections/hash_map/struct.RandomState.html + /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html /// /// # Examples /// @@ -539,7 +621,7 @@ impl<T, S, A> HashSet<T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { /// Reserves capacity for at least `additional` more elements to be inserted /// in the `HashSet`. The collection may reserve more space to avoid @@ -547,7 +629,12 @@ where /// /// # Panics /// - /// Panics if the new allocation size overflows `usize`. + /// Panics if the new capacity exceeds [`isize::MAX`] bytes and [`abort`] the program + /// in case of allocation error. Use [`try_reserve`](HashSet::try_reserve) instead + /// if you want to handle memory allocation failure. + /// + /// [`isize::MAX`]: https://doc.rust-lang.org/std/primitive.isize.html + /// [`abort`]: https://doc.rust-lang.org/alloc/alloc/fn.handle_alloc_error.html /// /// # Examples /// @@ -637,8 +724,8 @@ where /// /// ``` /// use hashbrown::HashSet; - /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); - /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// let a: HashSet<_> = [1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].into_iter().collect(); /// /// // Can be seen as `a - b`. /// for x in a.difference(&b) { @@ -668,8 +755,8 @@ where /// /// ``` /// use hashbrown::HashSet; - /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); - /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// let a: HashSet<_> = [1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].into_iter().collect(); /// /// // Print 1, 4 in arbitrary order. /// for x in a.symmetric_difference(&b) { @@ -696,8 +783,8 @@ where /// /// ``` /// use hashbrown::HashSet; - /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); - /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// let a: HashSet<_> = [1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].into_iter().collect(); /// /// // Print 2, 3 in arbitrary order. /// for x in a.intersection(&b) { @@ -727,8 +814,8 @@ where /// /// ``` /// use hashbrown::HashSet; - /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); - /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); + /// let a: HashSet<_> = [1, 2, 3].into_iter().collect(); + /// let b: HashSet<_> = [4, 2, 3, 4].into_iter().collect(); /// /// // Print 1, 2, 3, 4 in arbitrary order. /// for x in a.union(&b) { @@ -763,7 +850,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let set: HashSet<_> = [1, 2, 3].into_iter().collect(); /// assert_eq!(set.contains(&1), true); /// assert_eq!(set.contains(&4), false); /// ``` @@ -773,8 +860,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool where - T: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<T>, { self.map.contains_key(value) } @@ -790,7 +876,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let set: HashSet<_> = [1, 2, 3].into_iter().collect(); /// assert_eq!(set.get(&2), Some(&2)); /// assert_eq!(set.get(&4), None); /// ``` @@ -800,8 +886,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> where - T: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<T>, { // Avoid `Option::map` because it bloats LLVM IR. match self.map.get_key_value(value) { @@ -818,7 +903,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let mut set: HashSet<_> = [1, 2, 3].into_iter().collect(); /// assert_eq!(set.len(), 3); /// assert_eq!(set.get_or_insert(2), &2); /// assert_eq!(set.get_or_insert(100), &100); @@ -856,8 +941,7 @@ where #[inline] pub fn get_or_insert_owned<Q: ?Sized>(&mut self, value: &Q) -> &T where - T: Borrow<Q>, - Q: Hash + Eq + ToOwned<Owned = T>, + Q: Hash + Equivalent<T> + ToOwned<Owned = T>, { // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. @@ -889,8 +973,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn get_or_insert_with<Q: ?Sized, F>(&mut self, value: &Q, f: F) -> &T where - T: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<T>, F: FnOnce(&Q) -> T, { // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with @@ -951,7 +1034,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let a: HashSet<_> = [1, 2, 3].into_iter().collect(); /// let mut b = HashSet::new(); /// /// assert_eq!(a.is_disjoint(&b), true); @@ -972,7 +1055,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let sup: HashSet<_> = [1, 2, 3].into_iter().collect(); /// let mut set = HashSet::new(); /// /// assert_eq!(set.is_subset(&sup), true); @@ -993,7 +1076,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let sub: HashSet<_> = [1, 2].iter().cloned().collect(); + /// let sub: HashSet<_> = [1, 2].into_iter().collect(); /// let mut set = HashSet::new(); /// /// assert_eq!(set.is_superset(&sub), false); @@ -1106,8 +1189,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool where - T: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<T>, { self.map.remove(value).is_some() } @@ -1123,7 +1205,7 @@ where /// ``` /// use hashbrown::HashSet; /// - /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); + /// let mut set: HashSet<_> = [1, 2, 3].into_iter().collect(); /// assert_eq!(set.take(&2), Some(2)); /// assert_eq!(set.take(&2), None); /// ``` @@ -1133,8 +1215,7 @@ where #[cfg_attr(feature = "inline-more", inline)] pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> where - T: Borrow<Q>, - Q: Hash + Eq, + Q: Hash + Equivalent<T>, { // Avoid `Option::map` because it bloats LLVM IR. match self.map.remove_entry(value) { @@ -1144,11 +1225,53 @@ where } } +impl<T, S, A: Allocator> HashSet<T, S, A> { + /// Returns a reference to the [`RawTable`] used underneath [`HashSet`]. + /// This function is only available if the `raw` feature of the crate is enabled. + /// + /// # Note + /// + /// Calling this function is safe, but using the raw hash table API may require + /// unsafe functions or blocks. + /// + /// `RawTable` API gives the lowest level of control under the set that can be useful + /// for extending the HashSet's API, but may lead to *[undefined behavior]*. + /// + /// [`HashSet`]: struct.HashSet.html + /// [`RawTable`]: crate::raw::RawTable + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_table(&self) -> &RawTable<(T, ()), A> { + self.map.raw_table() + } + + /// Returns a mutable reference to the [`RawTable`] used underneath [`HashSet`]. + /// This function is only available if the `raw` feature of the crate is enabled. + /// + /// # Note + /// + /// Calling this function is safe, but using the raw hash table API may require + /// unsafe functions or blocks. + /// + /// `RawTable` API gives the lowest level of control under the set that can be useful + /// for extending the HashSet's API, but may lead to *[undefined behavior]*. + /// + /// [`HashSet`]: struct.HashSet.html + /// [`RawTable`]: crate::raw::RawTable + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + #[cfg(feature = "raw")] + #[cfg_attr(feature = "inline-more", inline)] + pub fn raw_table_mut(&mut self) -> &mut RawTable<(T, ()), A> { + self.map.raw_table_mut() + } +} + impl<T, S, A> PartialEq for HashSet<T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn eq(&self, other: &Self) -> bool { if self.len() != other.len() { @@ -1163,14 +1286,14 @@ impl<T, S, A> Eq for HashSet<T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } impl<T, S, A> fmt::Debug for HashSet<T, S, A> where T: fmt::Debug, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_set().entries(self.iter()).finish() @@ -1179,7 +1302,7 @@ where impl<T, S, A> From<HashMap<T, (), S, A>> for HashSet<T, S, A> where - A: Allocator + Clone, + A: Allocator, { fn from(map: HashMap<T, (), S, A>) -> Self { Self { map } @@ -1190,7 +1313,7 @@ impl<T, S, A> FromIterator<T> for HashSet<T, S, A> where T: Eq + Hash, S: BuildHasher + Default, - A: Default + Allocator + Clone, + A: Default + Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self { @@ -1205,7 +1328,7 @@ where impl<T, A, const N: usize> From<[T; N]> for HashSet<T, DefaultHashBuilder, A> where T: Eq + Hash, - A: Default + Allocator + Clone, + A: Default + Allocator, { /// # Examples /// @@ -1225,7 +1348,7 @@ impl<T, S, A> Extend<T> for HashSet<T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) { @@ -1249,7 +1372,7 @@ impl<'a, T, S, A> Extend<&'a T> for HashSet<T, S, A> where T: 'a + Eq + Hash + Copy, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { #[cfg_attr(feature = "inline-more", inline)] fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { @@ -1272,7 +1395,7 @@ where impl<T, S, A> Default for HashSet<T, S, A> where S: Default, - A: Default + Allocator + Clone, + A: Default + Allocator, { /// Creates an empty `HashSet<T, S>` with the `Default` value for the hasher. #[cfg_attr(feature = "inline-more", inline)] @@ -1287,7 +1410,7 @@ impl<T, S, A> BitOr<&HashSet<T, S, A>> for &HashSet<T, S, A> where T: Eq + Hash + Clone, S: BuildHasher + Default, - A: Allocator + Clone, + A: Allocator, { type Output = HashSet<T, S>; @@ -1320,7 +1443,7 @@ impl<T, S, A> BitAnd<&HashSet<T, S, A>> for &HashSet<T, S, A> where T: Eq + Hash + Clone, S: BuildHasher + Default, - A: Allocator + Clone, + A: Allocator, { type Output = HashSet<T, S>; @@ -1431,7 +1554,7 @@ pub struct Iter<'a, K> { /// /// [`HashSet`]: struct.HashSet.html /// [`into_iter`]: struct.HashSet.html#method.into_iter -pub struct IntoIter<K, A: Allocator + Clone = Global> { +pub struct IntoIter<K, A: Allocator = Global> { iter: map::IntoIter<K, (), A>, } @@ -1442,23 +1565,24 @@ pub struct IntoIter<K, A: Allocator + Clone = Global> { /// /// [`HashSet`]: struct.HashSet.html /// [`drain`]: struct.HashSet.html#method.drain -pub struct Drain<'a, K, A: Allocator + Clone = Global> { +pub struct Drain<'a, K, A: Allocator = Global> { iter: map::Drain<'a, K, (), A>, } /// A draining iterator over entries of a `HashSet` which don't satisfy the predicate `f`. /// -/// This `struct` is created by the [`drain_filter`] method on [`HashSet`]. See its +/// This `struct` is created by the [`extract_if`] method on [`HashSet`]. See its /// documentation for more. /// -/// [`drain_filter`]: struct.HashSet.html#method.drain_filter +/// [`extract_if`]: struct.HashSet.html#method.extract_if /// [`HashSet`]: struct.HashSet.html -pub struct DrainFilter<'a, K, F, A: Allocator + Clone = Global> +#[must_use = "Iterators are lazy unless consumed"] +pub struct ExtractIf<'a, K, F, A: Allocator = Global> where F: FnMut(&K) -> bool, { f: F, - inner: DrainFilterInner<'a, K, (), A>, + inner: RawExtractIf<'a, (K, ()), A>, } /// A lazy iterator producing elements in the intersection of `HashSet`s. @@ -1468,7 +1592,7 @@ where /// /// [`HashSet`]: struct.HashSet.html /// [`intersection`]: struct.HashSet.html#method.intersection -pub struct Intersection<'a, T, S, A: Allocator + Clone = Global> { +pub struct Intersection<'a, T, S, A: Allocator = Global> { // iterator of the first set iter: Iter<'a, T>, // the second set @@ -1482,7 +1606,7 @@ pub struct Intersection<'a, T, S, A: Allocator + Clone = Global> { /// /// [`HashSet`]: struct.HashSet.html /// [`difference`]: struct.HashSet.html#method.difference -pub struct Difference<'a, T, S, A: Allocator + Clone = Global> { +pub struct Difference<'a, T, S, A: Allocator = Global> { // iterator of the first set iter: Iter<'a, T>, // the second set @@ -1496,7 +1620,7 @@ pub struct Difference<'a, T, S, A: Allocator + Clone = Global> { /// /// [`HashSet`]: struct.HashSet.html /// [`symmetric_difference`]: struct.HashSet.html#method.symmetric_difference -pub struct SymmetricDifference<'a, T, S, A: Allocator + Clone = Global> { +pub struct SymmetricDifference<'a, T, S, A: Allocator = Global> { iter: Chain<Difference<'a, T, S, A>, Difference<'a, T, S, A>>, } @@ -1507,11 +1631,11 @@ pub struct SymmetricDifference<'a, T, S, A: Allocator + Clone = Global> { /// /// [`HashSet`]: struct.HashSet.html /// [`union`]: struct.HashSet.html#method.union -pub struct Union<'a, T, S, A: Allocator + Clone = Global> { +pub struct Union<'a, T, S, A: Allocator = Global> { iter: Chain<Iter<'a, T>, Difference<'a, T, S, A>>, } -impl<'a, T, S, A: Allocator + Clone> IntoIterator for &'a HashSet<T, S, A> { +impl<'a, T, S, A: Allocator> IntoIterator for &'a HashSet<T, S, A> { type Item = &'a T; type IntoIter = Iter<'a, T>; @@ -1521,7 +1645,7 @@ impl<'a, T, S, A: Allocator + Clone> IntoIterator for &'a HashSet<T, S, A> { } } -impl<T, S, A: Allocator + Clone> IntoIterator for HashSet<T, S, A> { +impl<T, S, A: Allocator> IntoIterator for HashSet<T, S, A> { type Item = T; type IntoIter = IntoIter<T, A>; @@ -1572,6 +1696,14 @@ impl<'a, K> Iterator for Iter<'a, K> { fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, f) + } } impl<'a, K> ExactSizeIterator for Iter<'a, K> { #[cfg_attr(feature = "inline-more", inline)] @@ -1587,7 +1719,7 @@ impl<K: fmt::Debug> fmt::Debug for Iter<'_, K> { } } -impl<K, A: Allocator + Clone> Iterator for IntoIter<K, A> { +impl<K, A: Allocator> Iterator for IntoIter<K, A> { type Item = K; #[cfg_attr(feature = "inline-more", inline)] @@ -1602,23 +1734,31 @@ impl<K, A: Allocator + Clone> Iterator for IntoIter<K, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, |acc, (k, ())| f(acc, k)) + } } -impl<K, A: Allocator + Clone> ExactSizeIterator for IntoIter<K, A> { +impl<K, A: Allocator> ExactSizeIterator for IntoIter<K, A> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.iter.len() } } -impl<K, A: Allocator + Clone> FusedIterator for IntoIter<K, A> {} +impl<K, A: Allocator> FusedIterator for IntoIter<K, A> {} -impl<K: fmt::Debug, A: Allocator + Clone> fmt::Debug for IntoIter<K, A> { +impl<K: fmt::Debug, A: Allocator> fmt::Debug for IntoIter<K, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let entries_iter = self.iter.iter().map(|(k, _)| k); f.debug_list().entries(entries_iter).finish() } } -impl<K, A: Allocator + Clone> Iterator for Drain<'_, K, A> { +impl<K, A: Allocator> Iterator for Drain<'_, K, A> { type Item = K; #[cfg_attr(feature = "inline-more", inline)] @@ -1633,37 +1773,31 @@ impl<K, A: Allocator + Clone> Iterator for Drain<'_, K, A> { fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, |acc, (k, ())| f(acc, k)) + } } -impl<K, A: Allocator + Clone> ExactSizeIterator for Drain<'_, K, A> { +impl<K, A: Allocator> ExactSizeIterator for Drain<'_, K, A> { #[cfg_attr(feature = "inline-more", inline)] fn len(&self) -> usize { self.iter.len() } } -impl<K, A: Allocator + Clone> FusedIterator for Drain<'_, K, A> {} +impl<K, A: Allocator> FusedIterator for Drain<'_, K, A> {} -impl<K: fmt::Debug, A: Allocator + Clone> fmt::Debug for Drain<'_, K, A> { +impl<K: fmt::Debug, A: Allocator> fmt::Debug for Drain<'_, K, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let entries_iter = self.iter.iter().map(|(k, _)| k); f.debug_list().entries(entries_iter).finish() } } -impl<'a, K, F, A: Allocator + Clone> Drop for DrainFilter<'a, K, F, A> -where - F: FnMut(&K) -> bool, -{ - #[cfg_attr(feature = "inline-more", inline)] - fn drop(&mut self) { - while let Some(item) = self.next() { - let guard = ConsumeAllOnDrop(self); - drop(item); - mem::forget(guard); - } - } -} - -impl<K, F, A: Allocator + Clone> Iterator for DrainFilter<'_, K, F, A> +impl<K, F, A: Allocator> Iterator for ExtractIf<'_, K, F, A> where F: FnMut(&K) -> bool, { @@ -1671,9 +1805,9 @@ where #[cfg_attr(feature = "inline-more", inline)] fn next(&mut self) -> Option<Self::Item> { - let f = &mut self.f; - let (k, _) = self.inner.next(&mut |k, _| f(k))?; - Some(k) + self.inner + .next(|&mut (ref k, ())| (self.f)(k)) + .map(|(k, ())| k) } #[inline] @@ -1682,12 +1816,9 @@ where } } -impl<K, F, A: Allocator + Clone> FusedIterator for DrainFilter<'_, K, F, A> where - F: FnMut(&K) -> bool -{ -} +impl<K, F, A: Allocator> FusedIterator for ExtractIf<'_, K, F, A> where F: FnMut(&K) -> bool {} -impl<T, S, A: Allocator + Clone> Clone for Intersection<'_, T, S, A> { +impl<T, S, A: Allocator> Clone for Intersection<'_, T, S, A> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Intersection { @@ -1701,7 +1832,7 @@ impl<'a, T, S, A> Iterator for Intersection<'a, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { type Item = &'a T; @@ -1720,13 +1851,27 @@ where let (_, upper) = self.iter.size_hint(); (0, upper) } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, |acc, elt| { + if self.other.contains(elt) { + f(acc, elt) + } else { + acc + } + }) + } } impl<T, S, A> fmt::Debug for Intersection<'_, T, S, A> where T: fmt::Debug + Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.clone()).finish() @@ -1737,11 +1882,11 @@ impl<T, S, A> FusedIterator for Intersection<'_, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } -impl<T, S, A: Allocator + Clone> Clone for Difference<'_, T, S, A> { +impl<T, S, A: Allocator> Clone for Difference<'_, T, S, A> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Difference { @@ -1755,7 +1900,7 @@ impl<'a, T, S, A> Iterator for Difference<'a, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { type Item = &'a T; @@ -1774,13 +1919,27 @@ where let (_, upper) = self.iter.size_hint(); (0, upper) } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, |acc, elt| { + if self.other.contains(elt) { + acc + } else { + f(acc, elt) + } + }) + } } impl<T, S, A> FusedIterator for Difference<'_, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } @@ -1788,14 +1947,14 @@ impl<T, S, A> fmt::Debug for Difference<'_, T, S, A> where T: fmt::Debug + Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.clone()).finish() } } -impl<T, S, A: Allocator + Clone> Clone for SymmetricDifference<'_, T, S, A> { +impl<T, S, A: Allocator> Clone for SymmetricDifference<'_, T, S, A> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { SymmetricDifference { @@ -1808,7 +1967,7 @@ impl<'a, T, S, A> Iterator for SymmetricDifference<'a, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { type Item = &'a T; @@ -1820,13 +1979,21 @@ where fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, f) + } } impl<T, S, A> FusedIterator for SymmetricDifference<'_, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } @@ -1834,14 +2001,14 @@ impl<T, S, A> fmt::Debug for SymmetricDifference<'_, T, S, A> where T: fmt::Debug + Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.clone()).finish() } } -impl<T, S, A: Allocator + Clone> Clone for Union<'_, T, S, A> { +impl<T, S, A: Allocator> Clone for Union<'_, T, S, A> { #[cfg_attr(feature = "inline-more", inline)] fn clone(&self) -> Self { Union { @@ -1854,7 +2021,7 @@ impl<T, S, A> FusedIterator for Union<'_, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { } @@ -1862,7 +2029,7 @@ impl<T, S, A> fmt::Debug for Union<'_, T, S, A> where T: fmt::Debug + Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_list().entries(self.clone()).finish() @@ -1873,7 +2040,7 @@ impl<'a, T, S, A> Iterator for Union<'a, T, S, A> where T: Eq + Hash, S: BuildHasher, - A: Allocator + Clone, + A: Allocator, { type Item = &'a T; @@ -1885,6 +2052,14 @@ where fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } + #[cfg_attr(feature = "inline-more", inline)] + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.iter.fold(init, f) + } } /// A view into a single entry in a set, which may either be vacant or occupied. @@ -1925,7 +2100,7 @@ where /// ``` pub enum Entry<'a, T, S, A = Global> where - A: Allocator + Clone, + A: Allocator, { /// An occupied entry. /// @@ -1958,7 +2133,7 @@ where Vacant(VacantEntry<'a, T, S, A>), } -impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for Entry<'_, T, S, A> { +impl<T: fmt::Debug, S, A: Allocator> fmt::Debug for Entry<'_, T, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), @@ -2003,11 +2178,11 @@ impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for Entry<'_, T, S, A> { /// assert_eq!(set.get(&"c"), None); /// assert_eq!(set.len(), 2); /// ``` -pub struct OccupiedEntry<'a, T, S, A: Allocator + Clone = Global> { +pub struct OccupiedEntry<'a, T, S, A: Allocator = Global> { inner: map::OccupiedEntry<'a, T, (), S, A>, } -impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for OccupiedEntry<'_, T, S, A> { +impl<T: fmt::Debug, S, A: Allocator> fmt::Debug for OccupiedEntry<'_, T, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("OccupiedEntry") .field("value", self.get()) @@ -2041,17 +2216,17 @@ impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for OccupiedEntry<'_, T, /// } /// assert!(set.contains("b") && set.len() == 2); /// ``` -pub struct VacantEntry<'a, T, S, A: Allocator + Clone = Global> { +pub struct VacantEntry<'a, T, S, A: Allocator = Global> { inner: map::VacantEntry<'a, T, (), S, A>, } -impl<T: fmt::Debug, S, A: Allocator + Clone> fmt::Debug for VacantEntry<'_, T, S, A> { +impl<T: fmt::Debug, S, A: Allocator> fmt::Debug for VacantEntry<'_, T, S, A> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_tuple("VacantEntry").field(self.get()).finish() } } -impl<'a, T, S, A: Allocator + Clone> Entry<'a, T, S, A> { +impl<'a, T, S, A: Allocator> Entry<'a, T, S, A> { /// Sets the value of the entry, and returns an OccupiedEntry. /// /// # Examples @@ -2128,7 +2303,7 @@ impl<'a, T, S, A: Allocator + Clone> Entry<'a, T, S, A> { } } -impl<T, S, A: Allocator + Clone> OccupiedEntry<'_, T, S, A> { +impl<T, S, A: Allocator> OccupiedEntry<'_, T, S, A> { /// Gets a reference to the value in the entry. /// /// # Examples @@ -2215,7 +2390,7 @@ impl<T, S, A: Allocator + Clone> OccupiedEntry<'_, T, S, A> { } } -impl<'a, T, S, A: Allocator + Clone> VacantEntry<'a, T, S, A> { +impl<'a, T, S, A: Allocator> VacantEntry<'a, T, S, A> { /// Gets a reference to the value that would be used when inserting /// through the `VacantEntry`. /// @@ -2295,34 +2470,30 @@ fn assert_covariance() { fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> { v } - fn into_iter<'new, A: Allocator + Clone>( - v: IntoIter<&'static str, A>, - ) -> IntoIter<&'new str, A> { + fn into_iter<'new, A: Allocator>(v: IntoIter<&'static str, A>) -> IntoIter<&'new str, A> { v } - fn difference<'a, 'new, A: Allocator + Clone>( + fn difference<'a, 'new, A: Allocator>( v: Difference<'a, &'static str, DefaultHashBuilder, A>, ) -> Difference<'a, &'new str, DefaultHashBuilder, A> { v } - fn symmetric_difference<'a, 'new, A: Allocator + Clone>( + fn symmetric_difference<'a, 'new, A: Allocator>( v: SymmetricDifference<'a, &'static str, DefaultHashBuilder, A>, ) -> SymmetricDifference<'a, &'new str, DefaultHashBuilder, A> { v } - fn intersection<'a, 'new, A: Allocator + Clone>( + fn intersection<'a, 'new, A: Allocator>( v: Intersection<'a, &'static str, DefaultHashBuilder, A>, ) -> Intersection<'a, &'new str, DefaultHashBuilder, A> { v } - fn union<'a, 'new, A: Allocator + Clone>( + fn union<'a, 'new, A: Allocator>( v: Union<'a, &'static str, DefaultHashBuilder, A>, ) -> Union<'a, &'new str, DefaultHashBuilder, A> { v } - fn drain<'new, A: Allocator + Clone>( - d: Drain<'static, &'static str, A>, - ) -> Drain<'new, &'new str, A> { + fn drain<'new, A: Allocator>(d: Drain<'static, &'static str, A>) -> Drain<'new, &'new str, A> { d } } @@ -2613,10 +2784,10 @@ mod test_set { set.insert(1); set.insert(2); - let set_str = format!("{:?}", set); + let set_str = format!("{set:?}"); assert!(set_str == "{1, 2}" || set_str == "{2, 1}"); - assert_eq!(format!("{:?}", empty), "{}"); + assert_eq!(format!("{empty:?}"), "{}"); } #[test] @@ -2649,7 +2820,7 @@ mod test_set { assert_eq!(last_i, 49); } - for _ in &s { + if !s.is_empty() { panic!("s should be empty!"); } @@ -2663,6 +2834,7 @@ mod test_set { use core::hash; #[derive(Debug)] + #[allow(dead_code)] struct Foo(&'static str, i32); impl PartialEq for Foo { @@ -2691,11 +2863,12 @@ mod test_set { } #[test] + #[allow(clippy::needless_borrow)] fn test_extend_ref() { let mut a = HashSet::new(); a.insert(1); - a.extend(&[2, 3, 4]); + a.extend([2, 3, 4]); assert_eq!(a.len(), 4); assert!(a.contains(&1)); @@ -2730,10 +2903,10 @@ mod test_set { } #[test] - fn test_drain_filter() { + fn test_extract_if() { { let mut set: HashSet<i32> = (0..8).collect(); - let drained = set.drain_filter(|&k| k % 2 == 0); + let drained = set.extract_if(|&k| k % 2 == 0); let mut out = drained.collect::<Vec<_>>(); out.sort_unstable(); assert_eq!(vec![0, 2, 4, 6], out); @@ -2741,7 +2914,7 @@ mod test_set { } { let mut set: HashSet<i32> = (0..8).collect(); - drop(set.drain_filter(|&k| k % 2 == 0)); + set.extract_if(|&k| k % 2 == 0).for_each(drop); assert_eq!(set.len(), 4, "Removes non-matching items on drop"); } } @@ -2787,4 +2960,11 @@ mod test_set { set.insert(i); } } + + #[test] + fn collect() { + // At the time of writing, this hits the ZST case in from_base_index + // (and without the `map`, it does not). + let mut _set: HashSet<_> = (0..3).map(|_| ()).collect(); + } } diff --git a/third_party/rust/hashbrown/src/table.rs b/third_party/rust/hashbrown/src/table.rs new file mode 100644 index 0000000000..faf8a6330f --- /dev/null +++ b/third_party/rust/hashbrown/src/table.rs @@ -0,0 +1,2070 @@ +use core::{fmt, iter::FusedIterator, marker::PhantomData}; + +use crate::{ + raw::{ + Allocator, Bucket, Global, InsertSlot, RawDrain, RawExtractIf, RawIntoIter, RawIter, + RawTable, + }, + TryReserveError, +}; + +/// Low-level hash table with explicit hashing. +/// +/// The primary use case for this type over [`HashMap`] or [`HashSet`] is to +/// support types that do not implement the [`Hash`] and [`Eq`] traits, but +/// instead require additional data not contained in the key itself to compute a +/// hash and compare two elements for equality. +/// +/// Examples of when this can be useful include: +/// - An `IndexMap` implementation where indices into a `Vec` are stored as +/// elements in a `HashTable<usize>`. Hashing and comparing the elements +/// requires indexing the associated `Vec` to get the actual value referred to +/// by the index. +/// - Avoiding re-computing a hash when it is already known. +/// - Mutating the key of an element in a way that doesn't affect its hash. +/// +/// To achieve this, `HashTable` methods that search for an element in the table +/// require a hash value and equality function to be explicitly passed in as +/// arguments. The method will then iterate over the elements with the given +/// hash and call the equality function on each of them, until a match is found. +/// +/// In most cases, a `HashTable` will not be exposed directly in an API. It will +/// instead be wrapped in a helper type which handles the work of calculating +/// hash values and comparing elements. +/// +/// Due to its low-level nature, this type provides fewer guarantees than +/// [`HashMap`] and [`HashSet`]. Specifically, the API allows you to shoot +/// yourself in the foot by having multiple elements with identical keys in the +/// table. The table itself will still function correctly and lookups will +/// arbitrarily return one of the matching elements. However you should avoid +/// doing this because it changes the runtime of hash table operations from +/// `O(1)` to `O(k)` where `k` is the number of duplicate entries. +/// +/// [`HashMap`]: super::HashMap +/// [`HashSet`]: super::HashSet +pub struct HashTable<T, A = Global> +where + A: Allocator, +{ + pub(crate) raw: RawTable<T, A>, +} + +impl<T> HashTable<T, Global> { + /// Creates an empty `HashTable`. + /// + /// The hash table is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashTable; + /// let mut table: HashTable<&str> = HashTable::new(); + /// assert_eq!(table.len(), 0); + /// assert_eq!(table.capacity(), 0); + /// ``` + pub const fn new() -> Self { + Self { + raw: RawTable::new(), + } + } + + /// Creates an empty `HashTable` with the specified capacity. + /// + /// The hash table will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash table will not allocate. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashTable; + /// let mut table: HashTable<&str> = HashTable::with_capacity(10); + /// assert_eq!(table.len(), 0); + /// assert!(table.capacity() >= 10); + /// ``` + pub fn with_capacity(capacity: usize) -> Self { + Self { + raw: RawTable::with_capacity(capacity), + } + } +} + +impl<T, A> HashTable<T, A> +where + A: Allocator, +{ + /// Creates an empty `HashTable` using the given allocator. + /// + /// The hash table is initially created with a capacity of 0, so it will not allocate until it + /// is first inserted into. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use bumpalo::Bump; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let bump = Bump::new(); + /// let mut table = HashTable::new_in(&bump); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// // The created HashTable holds none elements + /// assert_eq!(table.len(), 0); + /// + /// // The created HashTable also doesn't allocate memory + /// assert_eq!(table.capacity(), 0); + /// + /// // Now we insert element inside created HashTable + /// table.insert_unique(hasher(&"One"), "One", hasher); + /// // We can see that the HashTable holds 1 element + /// assert_eq!(table.len(), 1); + /// // And it also allocates some capacity + /// assert!(table.capacity() > 1); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub const fn new_in(alloc: A) -> Self { + Self { + raw: RawTable::new_in(alloc), + } + } + + /// Creates an empty `HashTable` with the specified capacity using the given allocator. + /// + /// The hash table will be able to hold at least `capacity` elements without + /// reallocating. If `capacity` is 0, the hash table will not allocate. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use bumpalo::Bump; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let bump = Bump::new(); + /// let mut table = HashTable::with_capacity_in(5, &bump); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// // The created HashTable holds none elements + /// assert_eq!(table.len(), 0); + /// // But it can hold at least 5 elements without reallocating + /// let empty_map_capacity = table.capacity(); + /// assert!(empty_map_capacity >= 5); + /// + /// // Now we insert some 5 elements inside created HashTable + /// table.insert_unique(hasher(&"One"), "One", hasher); + /// table.insert_unique(hasher(&"Two"), "Two", hasher); + /// table.insert_unique(hasher(&"Three"), "Three", hasher); + /// table.insert_unique(hasher(&"Four"), "Four", hasher); + /// table.insert_unique(hasher(&"Five"), "Five", hasher); + /// + /// // We can see that the HashTable holds 5 elements + /// assert_eq!(table.len(), 5); + /// // But its capacity isn't changed + /// assert_eq!(table.capacity(), empty_map_capacity) + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn with_capacity_in(capacity: usize, alloc: A) -> Self { + Self { + raw: RawTable::with_capacity_in(capacity, alloc), + } + } + + /// Returns a reference to the underlying allocator. + pub fn allocator(&self) -> &A { + self.raw.allocator() + } + + /// Returns a reference to an entry in the table with the given hash and + /// which satisfies the equality function passed. + /// + /// This method will call `eq` for all entries with the given hash, but may + /// also call it for entries with a different hash. `eq` should only return + /// true for the desired entry, at which point the search is stopped. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), 1, hasher); + /// table.insert_unique(hasher(&2), 2, hasher); + /// table.insert_unique(hasher(&3), 3, hasher); + /// assert_eq!(table.find(hasher(&2), |&val| val == 2), Some(&2)); + /// assert_eq!(table.find(hasher(&4), |&val| val == 4), None); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn find(&self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&T> { + self.raw.get(hash, eq) + } + + /// Returns a mutable reference to an entry in the table with the given hash + /// and which satisfies the equality function passed. + /// + /// This method will call `eq` for all entries with the given hash, but may + /// also call it for entries with a different hash. `eq` should only return + /// true for the desired entry, at which point the search is stopped. + /// + /// When mutating an entry, you should ensure that it still retains the same + /// hash value as when it was inserted, otherwise lookups of that entry may + /// fail to find it. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), (1, "a"), |val| hasher(&val.0)); + /// if let Some(val) = table.find_mut(hasher(&1), |val| val.0 == 1) { + /// val.1 = "b"; + /// } + /// assert_eq!(table.find(hasher(&1), |val| val.0 == 1), Some(&(1, "b"))); + /// assert_eq!(table.find(hasher(&2), |val| val.0 == 2), None); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn find_mut(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&mut T> { + self.raw.get_mut(hash, eq) + } + + /// Returns an `OccupiedEntry` for an entry in the table with the given hash + /// and which satisfies the equality function passed. + /// + /// This can be used to remove the entry from the table. Call + /// [`HashTable::entry`] instead if you wish to insert an entry if the + /// lookup fails. + /// + /// This method will call `eq` for all entries with the given hash, but may + /// also call it for entries with a different hash. `eq` should only return + /// true for the desired entry, at which point the search is stopped. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), (1, "a"), |val| hasher(&val.0)); + /// if let Ok(entry) = table.find_entry(hasher(&1), |val| val.0 == 1) { + /// entry.remove(); + /// } + /// assert_eq!(table.find(hasher(&1), |val| val.0 == 1), None); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn find_entry( + &mut self, + hash: u64, + eq: impl FnMut(&T) -> bool, + ) -> Result<OccupiedEntry<'_, T, A>, AbsentEntry<'_, T, A>> { + match self.raw.find(hash, eq) { + Some(bucket) => Ok(OccupiedEntry { + hash, + bucket, + table: self, + }), + None => Err(AbsentEntry { table: self }), + } + } + + /// Returns an `Entry` for an entry in the table with the given hash + /// and which satisfies the equality function passed. + /// + /// This can be used to remove the entry from the table, or insert a new + /// entry with the given hash if one doesn't already exist. + /// + /// This method will call `eq` for all entries with the given hash, but may + /// also call it for entries with a different hash. `eq` should only return + /// true for the desired entry, at which point the search is stopped. + /// + /// This method may grow the table in preparation for an insertion. Call + /// [`HashTable::find_entry`] if this is undesirable. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), (1, "a"), |val| hasher(&val.0)); + /// if let Entry::Occupied(entry) = table.entry(hasher(&1), |val| val.0 == 1, |val| hasher(&val.0)) + /// { + /// entry.remove(); + /// } + /// if let Entry::Vacant(entry) = table.entry(hasher(&2), |val| val.0 == 2, |val| hasher(&val.0)) { + /// entry.insert((2, "b")); + /// } + /// assert_eq!(table.find(hasher(&1), |val| val.0 == 1), None); + /// assert_eq!(table.find(hasher(&2), |val| val.0 == 2), Some(&(2, "b"))); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn entry( + &mut self, + hash: u64, + eq: impl FnMut(&T) -> bool, + hasher: impl Fn(&T) -> u64, + ) -> Entry<'_, T, A> { + match self.raw.find_or_find_insert_slot(hash, eq, hasher) { + Ok(bucket) => Entry::Occupied(OccupiedEntry { + hash, + bucket, + table: self, + }), + Err(insert_slot) => Entry::Vacant(VacantEntry { + hash, + insert_slot, + table: self, + }), + } + } + + /// Inserts an element into the `HashTable` with the given hash value, but + /// without checking whether an equivalent element already exists within the + /// table. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut v = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// v.insert_unique(hasher(&1), 1, hasher); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn insert_unique( + &mut self, + hash: u64, + value: T, + hasher: impl Fn(&T) -> u64, + ) -> OccupiedEntry<'_, T, A> { + let bucket = self.raw.insert(hash, value, hasher); + OccupiedEntry { + hash, + bucket, + table: self, + } + } + + /// Clears the table, removing all values. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut v = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// v.insert_unique(hasher(&1), 1, hasher); + /// v.clear(); + /// assert!(v.is_empty()); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn clear(&mut self) { + self.raw.clear(); + } + + /// Shrinks the capacity of the table as much as possible. It will drop + /// down as much as possible while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::with_capacity(100); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), 1, hasher); + /// table.insert_unique(hasher(&2), 2, hasher); + /// assert!(table.capacity() >= 100); + /// table.shrink_to_fit(hasher); + /// assert!(table.capacity() >= 2); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn shrink_to_fit(&mut self, hasher: impl Fn(&T) -> u64) { + self.raw.shrink_to(self.len(), hasher) + } + + /// Shrinks the capacity of the table with a lower limit. It will drop + /// down no lower than the supplied limit while maintaining the internal rules + /// and possibly leaving some space in accordance with the resize policy. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// Panics if the current capacity is smaller than the supplied + /// minimum capacity. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::with_capacity(100); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), 1, hasher); + /// table.insert_unique(hasher(&2), 2, hasher); + /// assert!(table.capacity() >= 100); + /// table.shrink_to(10, hasher); + /// assert!(table.capacity() >= 10); + /// table.shrink_to(0, hasher); + /// assert!(table.capacity() >= 2); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn shrink_to(&mut self, min_capacity: usize, hasher: impl Fn(&T) -> u64) { + self.raw.shrink_to(min_capacity, hasher); + } + + /// Reserves capacity for at least `additional` more elements to be inserted + /// in the `HashTable`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// # Panics + /// + /// Panics if the new capacity exceeds [`isize::MAX`] bytes and [`abort`] the program + /// in case of allocation error. Use [`try_reserve`](HashTable::try_reserve) instead + /// if you want to handle memory allocation failure. + /// + /// [`isize::MAX`]: https://doc.rust-lang.org/std/primitive.isize.html + /// [`abort`]: https://doc.rust-lang.org/alloc/alloc/fn.handle_alloc_error.html + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<i32> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.reserve(10, hasher); + /// assert!(table.capacity() >= 10); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn reserve(&mut self, additional: usize, hasher: impl Fn(&T) -> u64) { + self.raw.reserve(additional, hasher) + } + + /// Tries to reserve capacity for at least `additional` more elements to be inserted + /// in the given `HashTable`. The collection may reserve more space to avoid + /// frequent reallocations. + /// + /// `hasher` is called if entries need to be moved or copied to a new table. + /// This must return the same hash value that each entry was inserted with. + /// + /// # Errors + /// + /// If the capacity overflows, or the allocator reports a failure, then an error + /// is returned. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<i32> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table + /// .try_reserve(10, hasher) + /// .expect("why is the test harness OOMing on 10 bytes?"); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn try_reserve( + &mut self, + additional: usize, + hasher: impl Fn(&T) -> u64, + ) -> Result<(), TryReserveError> { + self.raw.try_reserve(additional, hasher) + } + + /// Returns the number of elements the table can hold without reallocating. + /// + /// # Examples + /// + /// ``` + /// use hashbrown::HashTable; + /// let table: HashTable<i32> = HashTable::with_capacity(100); + /// assert!(table.capacity() >= 100); + /// ``` + pub fn capacity(&self) -> usize { + self.raw.capacity() + } + + /// Returns the number of elements in the table. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// let mut v = HashTable::new(); + /// assert_eq!(v.len(), 0); + /// v.insert_unique(hasher(&1), 1, hasher); + /// assert_eq!(v.len(), 1); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn len(&self) -> usize { + self.raw.len() + } + + /// Returns `true` if the set contains no elements. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// let mut v = HashTable::new(); + /// assert!(v.is_empty()); + /// v.insert_unique(hasher(&1), 1, hasher); + /// assert!(!v.is_empty()); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn is_empty(&self) -> bool { + self.raw.is_empty() + } + + /// An iterator visiting all elements in arbitrary order. + /// The iterator element type is `&'a T`. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&"a"), "b", hasher); + /// table.insert_unique(hasher(&"b"), "b", hasher); + /// + /// // Will print in an arbitrary order. + /// for x in table.iter() { + /// println!("{}", x); + /// } + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn iter(&self) -> Iter<'_, T> { + Iter { + inner: unsafe { self.raw.iter() }, + marker: PhantomData, + } + } + + /// An iterator visiting all elements in arbitrary order, + /// with mutable references to the elements. + /// The iterator element type is `&'a mut T`. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&1), 1, hasher); + /// table.insert_unique(hasher(&2), 2, hasher); + /// table.insert_unique(hasher(&3), 3, hasher); + /// + /// // Update all values + /// for val in table.iter_mut() { + /// *val *= 2; + /// } + /// + /// assert_eq!(table.len(), 3); + /// let mut vec: Vec<i32> = Vec::new(); + /// + /// for val in &table { + /// println!("val: {}", val); + /// vec.push(*val); + /// } + /// + /// // The `Iter` iterator produces items in arbitrary order, so the + /// // items must be sorted to test them against a sorted array. + /// vec.sort_unstable(); + /// assert_eq!(vec, [2, 4, 6]); + /// + /// assert_eq!(table.len(), 3); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn iter_mut(&mut self) -> IterMut<'_, T> { + IterMut { + inner: unsafe { self.raw.iter() }, + marker: PhantomData, + } + } + + /// Retains only the elements specified by the predicate. + /// + /// In other words, remove all elements `e` such that `f(&e)` returns `false`. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for x in 1..=6 { + /// table.insert_unique(hasher(&x), x, hasher); + /// } + /// table.retain(|&mut x| x % 2 == 0); + /// assert_eq!(table.len(), 3); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn retain(&mut self, mut f: impl FnMut(&mut T) -> bool) { + // Here we only use `iter` as a temporary, preventing use-after-free + unsafe { + for item in self.raw.iter() { + if !f(item.as_mut()) { + self.raw.erase(item); + } + } + } + } + + /// Clears the set, returning all elements in an iterator. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for x in 1..=3 { + /// table.insert_unique(hasher(&x), x, hasher); + /// } + /// assert!(!table.is_empty()); + /// + /// // print 1, 2, 3 in an arbitrary order + /// for i in table.drain() { + /// println!("{}", i); + /// } + /// + /// assert!(table.is_empty()); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn drain(&mut self) -> Drain<'_, T, A> { + Drain { + inner: self.raw.drain(), + } + } + + /// Drains elements which are true under the given predicate, + /// and returns an iterator over the removed items. + /// + /// In other words, move all elements `e` such that `f(&e)` returns `true` out + /// into another iterator. + /// + /// If the returned `ExtractIf` is not exhausted, e.g. because it is dropped without iterating + /// or the iteration short-circuits, then the remaining elements will be retained. + /// Use [`retain()`] with a negated predicate if you do not need the returned iterator. + /// + /// [`retain()`]: HashTable::retain + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for x in 0..8 { + /// table.insert_unique(hasher(&x), x, hasher); + /// } + /// let drained: Vec<i32> = table.extract_if(|&mut v| v % 2 == 0).collect(); + /// + /// let mut evens = drained.into_iter().collect::<Vec<_>>(); + /// let mut odds = table.into_iter().collect::<Vec<_>>(); + /// evens.sort(); + /// odds.sort(); + /// + /// assert_eq!(evens, vec![0, 2, 4, 6]); + /// assert_eq!(odds, vec![1, 3, 5, 7]); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn extract_if<F>(&mut self, f: F) -> ExtractIf<'_, T, F, A> + where + F: FnMut(&mut T) -> bool, + { + ExtractIf { + f, + inner: RawExtractIf { + iter: unsafe { self.raw.iter() }, + table: &mut self.raw, + }, + } + } + + /// Attempts to get mutable references to `N` values in the map at once. + /// + /// The `eq` argument should be a closure such that `eq(i, k)` returns true if `k` is equal to + /// the `i`th key to be looked up. + /// + /// Returns an array of length `N` with the results of each query. For soundness, at most one + /// mutable reference will be returned to any value. `None` will be returned if any of the + /// keys are duplicates or missing. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut libraries: HashTable<(&str, u32)> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for (k, v) in [ + /// ("Bodleian Library", 1602), + /// ("Athenæum", 1807), + /// ("Herzogin-Anna-Amalia-Bibliothek", 1691), + /// ("Library of Congress", 1800), + /// ] { + /// libraries.insert_unique(hasher(&k), (k, v), |(k, _)| hasher(&k)); + /// } + /// + /// let keys = ["Athenæum", "Library of Congress"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!( + /// got, + /// Some([&mut ("Athenæum", 1807), &mut ("Library of Congress", 1800),]), + /// ); + /// + /// // Missing keys result in None + /// let keys = ["Athenæum", "New York Public Library"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!(got, None); + /// + /// // Duplicate keys result in None + /// let keys = ["Athenæum", "Athenæum"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!(got, None); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn get_many_mut<const N: usize>( + &mut self, + hashes: [u64; N], + eq: impl FnMut(usize, &T) -> bool, + ) -> Option<[&'_ mut T; N]> { + self.raw.get_many_mut(hashes, eq) + } + + /// Attempts to get mutable references to `N` values in the map at once, without validating that + /// the values are unique. + /// + /// The `eq` argument should be a closure such that `eq(i, k)` returns true if `k` is equal to + /// the `i`th key to be looked up. + /// + /// Returns an array of length `N` with the results of each query. `None` will be returned if + /// any of the keys are missing. + /// + /// For a safe alternative see [`get_many_mut`](`HashTable::get_many_mut`). + /// + /// # Safety + /// + /// Calling this method with overlapping keys is *[undefined behavior]* even if the resulting + /// references are not used. + /// + /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut libraries: HashTable<(&str, u32)> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for (k, v) in [ + /// ("Bodleian Library", 1602), + /// ("Athenæum", 1807), + /// ("Herzogin-Anna-Amalia-Bibliothek", 1691), + /// ("Library of Congress", 1800), + /// ] { + /// libraries.insert_unique(hasher(&k), (k, v), |(k, _)| hasher(&k)); + /// } + /// + /// let keys = ["Athenæum", "Library of Congress"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!( + /// got, + /// Some([&mut ("Athenæum", 1807), &mut ("Library of Congress", 1800),]), + /// ); + /// + /// // Missing keys result in None + /// let keys = ["Athenæum", "New York Public Library"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!(got, None); + /// + /// // Duplicate keys result in None + /// let keys = ["Athenæum", "Athenæum"]; + /// let got = libraries.get_many_mut(keys.map(|k| hasher(&k)), |i, val| keys[i] == val.0); + /// assert_eq!(got, None); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub unsafe fn get_many_unchecked_mut<const N: usize>( + &mut self, + hashes: [u64; N], + eq: impl FnMut(usize, &T) -> bool, + ) -> Option<[&'_ mut T; N]> { + self.raw.get_many_unchecked_mut(hashes, eq) + } +} + +impl<T, A> IntoIterator for HashTable<T, A> +where + A: Allocator, +{ + type Item = T; + type IntoIter = IntoIter<T, A>; + + fn into_iter(self) -> IntoIter<T, A> { + IntoIter { + inner: self.raw.into_iter(), + } + } +} + +impl<'a, T, A> IntoIterator for &'a HashTable<T, A> +where + A: Allocator, +{ + type Item = &'a T; + type IntoIter = Iter<'a, T>; + + fn into_iter(self) -> Iter<'a, T> { + self.iter() + } +} + +impl<'a, T, A> IntoIterator for &'a mut HashTable<T, A> +where + A: Allocator, +{ + type Item = &'a mut T; + type IntoIter = IterMut<'a, T>; + + fn into_iter(self) -> IterMut<'a, T> { + self.iter_mut() + } +} + +impl<T, A> Default for HashTable<T, A> +where + A: Allocator + Default, +{ + fn default() -> Self { + Self { + raw: Default::default(), + } + } +} + +impl<T, A> Clone for HashTable<T, A> +where + T: Clone, + A: Allocator + Clone, +{ + fn clone(&self) -> Self { + Self { + raw: self.raw.clone(), + } + } +} + +impl<T, A> fmt::Debug for HashTable<T, A> +where + T: fmt::Debug, + A: Allocator, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_set().entries(self.iter()).finish() + } +} + +/// A view into a single entry in a table, which may either be vacant or occupied. +/// +/// This `enum` is constructed from the [`entry`] method on [`HashTable`]. +/// +/// [`HashTable`]: struct.HashTable.html +/// [`entry`]: struct.HashTable.html#method.entry +/// +/// # Examples +/// +/// ``` +/// # #[cfg(feature = "nightly")] +/// # fn test() { +/// use ahash::AHasher; +/// use hashbrown::hash_table::{Entry, HashTable, OccupiedEntry}; +/// use std::hash::{BuildHasher, BuildHasherDefault}; +/// +/// let mut table = HashTable::new(); +/// let hasher = BuildHasherDefault::<AHasher>::default(); +/// let hasher = |val: &_| hasher.hash_one(val); +/// for x in ["a", "b", "c"] { +/// table.insert_unique(hasher(&x), x, hasher); +/// } +/// assert_eq!(table.len(), 3); +/// +/// // Existing value (insert) +/// let entry: Entry<_> = table.entry(hasher(&"a"), |&x| x == "a", hasher); +/// let _raw_o: OccupiedEntry<_, _> = entry.insert("a"); +/// assert_eq!(table.len(), 3); +/// // Nonexistent value (insert) +/// table.entry(hasher(&"d"), |&x| x == "d", hasher).insert("d"); +/// +/// // Existing value (or_insert) +/// table +/// .entry(hasher(&"b"), |&x| x == "b", hasher) +/// .or_insert("b"); +/// // Nonexistent value (or_insert) +/// table +/// .entry(hasher(&"e"), |&x| x == "e", hasher) +/// .or_insert("e"); +/// +/// println!("Our HashTable: {:?}", table); +/// +/// let mut vec: Vec<_> = table.iter().copied().collect(); +/// // The `Iter` iterator produces items in arbitrary order, so the +/// // items must be sorted to test them against a sorted array. +/// vec.sort_unstable(); +/// assert_eq!(vec, ["a", "b", "c", "d", "e"]); +/// # } +/// # fn main() { +/// # #[cfg(feature = "nightly")] +/// # test() +/// # } +/// ``` +pub enum Entry<'a, T, A = Global> +where + A: Allocator, +{ + /// An occupied entry. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::{Entry, HashTable, OccupiedEntry}; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// for x in ["a", "b"] { + /// table.insert_unique(hasher(&x), x, hasher); + /// } + /// + /// match table.entry(hasher(&"a"), |&x| x == "a", hasher) { + /// Entry::Vacant(_) => unreachable!(), + /// Entry::Occupied(_) => {} + /// } + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + Occupied(OccupiedEntry<'a, T, A>), + + /// A vacant entry. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::{Entry, HashTable, OccupiedEntry}; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table = HashTable::<&str>::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// match table.entry(hasher(&"a"), |&x| x == "a", hasher) { + /// Entry::Vacant(_) => {} + /// Entry::Occupied(_) => unreachable!(), + /// } + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + Vacant(VacantEntry<'a, T, A>), +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for Entry<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(), + Entry::Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(), + } + } +} + +impl<'a, T, A> Entry<'a, T, A> +where + A: Allocator, +{ + /// Sets the value of the entry, replacing any existing value if there is + /// one, and returns an [`OccupiedEntry`]. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<&str> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// let entry = table + /// .entry(hasher(&"horseyland"), |&x| x == "horseyland", hasher) + /// .insert("horseyland"); + /// + /// assert_eq!(entry.get(), &"horseyland"); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn insert(self, value: T) -> OccupiedEntry<'a, T, A> { + match self { + Entry::Occupied(mut entry) => { + *entry.get_mut() = value; + entry + } + Entry::Vacant(entry) => entry.insert(value), + } + } + + /// Ensures a value is in the entry by inserting if it was vacant. + /// + /// Returns an [`OccupiedEntry`] pointing to the now-occupied entry. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<&str> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// // nonexistent key + /// table + /// .entry(hasher(&"poneyland"), |&x| x == "poneyland", hasher) + /// .or_insert("poneyland"); + /// assert!(table + /// .find(hasher(&"poneyland"), |&x| x == "poneyland") + /// .is_some()); + /// + /// // existing key + /// table + /// .entry(hasher(&"poneyland"), |&x| x == "poneyland", hasher) + /// .or_insert("poneyland"); + /// assert!(table + /// .find(hasher(&"poneyland"), |&x| x == "poneyland") + /// .is_some()); + /// assert_eq!(table.len(), 1); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn or_insert(self, default: T) -> OccupiedEntry<'a, T, A> { + match self { + Entry::Occupied(entry) => entry, + Entry::Vacant(entry) => entry.insert(default), + } + } + + /// Ensures a value is in the entry by inserting the result of the default function if empty.. + /// + /// Returns an [`OccupiedEntry`] pointing to the now-occupied entry. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<String> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// table + /// .entry(hasher("poneyland"), |x| x == "poneyland", |val| hasher(val)) + /// .or_insert_with(|| "poneyland".to_string()); + /// + /// assert!(table + /// .find(hasher(&"poneyland"), |x| x == "poneyland") + /// .is_some()); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn or_insert_with(self, default: impl FnOnce() -> T) -> OccupiedEntry<'a, T, A> { + match self { + Entry::Occupied(entry) => entry, + Entry::Vacant(entry) => entry.insert(default()), + } + } + + /// Provides in-place mutable access to an occupied entry before any + /// potential inserts into the table. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<(&str, u32)> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// table + /// .entry( + /// hasher(&"poneyland"), + /// |&(x, _)| x == "poneyland", + /// |(k, _)| hasher(&k), + /// ) + /// .and_modify(|(_, v)| *v += 1) + /// .or_insert(("poneyland", 42)); + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(k, _)| k == "poneyland"), + /// Some(&("poneyland", 42)) + /// ); + /// + /// table + /// .entry( + /// hasher(&"poneyland"), + /// |&(x, _)| x == "poneyland", + /// |(k, _)| hasher(&k), + /// ) + /// .and_modify(|(_, v)| *v += 1) + /// .or_insert(("poneyland", 42)); + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(k, _)| k == "poneyland"), + /// Some(&("poneyland", 43)) + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn and_modify(self, f: impl FnOnce(&mut T)) -> Self { + match self { + Entry::Occupied(mut entry) => { + f(entry.get_mut()); + Entry::Occupied(entry) + } + Entry::Vacant(entry) => Entry::Vacant(entry), + } + } +} + +/// A view into an occupied entry in a `HashTable`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// # #[cfg(feature = "nightly")] +/// # fn test() { +/// use ahash::AHasher; +/// use hashbrown::hash_table::{Entry, HashTable, OccupiedEntry}; +/// use std::hash::{BuildHasher, BuildHasherDefault}; +/// +/// let mut table = HashTable::new(); +/// let hasher = BuildHasherDefault::<AHasher>::default(); +/// let hasher = |val: &_| hasher.hash_one(val); +/// for x in ["a", "b", "c"] { +/// table.insert_unique(hasher(&x), x, hasher); +/// } +/// assert_eq!(table.len(), 3); +/// +/// let _entry_o: OccupiedEntry<_, _> = table.find_entry(hasher(&"a"), |&x| x == "a").unwrap(); +/// assert_eq!(table.len(), 3); +/// +/// // Existing key +/// match table.entry(hasher(&"a"), |&x| x == "a", hasher) { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(view) => { +/// assert_eq!(view.get(), &"a"); +/// } +/// } +/// +/// assert_eq!(table.len(), 3); +/// +/// // Existing key (take) +/// match table.entry(hasher(&"c"), |&x| x == "c", hasher) { +/// Entry::Vacant(_) => unreachable!(), +/// Entry::Occupied(view) => { +/// assert_eq!(view.remove().0, "c"); +/// } +/// } +/// assert_eq!(table.find(hasher(&"c"), |&x| x == "c"), None); +/// assert_eq!(table.len(), 2); +/// # } +/// # fn main() { +/// # #[cfg(feature = "nightly")] +/// # test() +/// # } +/// ``` +pub struct OccupiedEntry<'a, T, A = Global> +where + A: Allocator, +{ + hash: u64, + bucket: Bucket<T>, + table: &'a mut HashTable<T, A>, +} + +unsafe impl<T, A> Send for OccupiedEntry<'_, T, A> +where + T: Send, + A: Send + Allocator, +{ +} +unsafe impl<T, A> Sync for OccupiedEntry<'_, T, A> +where + T: Sync, + A: Sync + Allocator, +{ +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for OccupiedEntry<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("OccupiedEntry") + .field("value", self.get()) + .finish() + } +} + +impl<'a, T, A> OccupiedEntry<'a, T, A> +where + A: Allocator, +{ + /// Takes the value out of the entry, and returns it along with a + /// `VacantEntry` that can be used to insert another value with the same + /// hash as the one that was just removed. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<&str> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// // The table is empty + /// assert!(table.is_empty() && table.capacity() == 0); + /// + /// table.insert_unique(hasher(&"poneyland"), "poneyland", hasher); + /// let capacity_before_remove = table.capacity(); + /// + /// if let Entry::Occupied(o) = table.entry(hasher(&"poneyland"), |&x| x == "poneyland", hasher) { + /// assert_eq!(o.remove().0, "poneyland"); + /// } + /// + /// assert!(table + /// .find(hasher(&"poneyland"), |&x| x == "poneyland") + /// .is_none()); + /// // Now table hold none elements but capacity is equal to the old one + /// assert!(table.len() == 0 && table.capacity() == capacity_before_remove); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[cfg_attr(feature = "inline-more", inline)] + pub fn remove(self) -> (T, VacantEntry<'a, T, A>) { + let (val, slot) = unsafe { self.table.raw.remove(self.bucket) }; + ( + val, + VacantEntry { + hash: self.hash, + insert_slot: slot, + table: self.table, + }, + ) + } + + /// Gets a reference to the value in the entry. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<&str> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&"poneyland"), "poneyland", hasher); + /// + /// match table.entry(hasher(&"poneyland"), |&x| x == "poneyland", hasher) { + /// Entry::Vacant(_) => panic!(), + /// Entry::Occupied(entry) => assert_eq!(entry.get(), &"poneyland"), + /// } + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[inline] + pub fn get(&self) -> &T { + unsafe { self.bucket.as_ref() } + } + + /// Gets a mutable reference to the value in the entry. + /// + /// If you need a reference to the `OccupiedEntry` which may outlive the + /// destruction of the `Entry` value, see [`into_mut`]. + /// + /// [`into_mut`]: #method.into_mut + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<(&str, u32)> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&"poneyland"), ("poneyland", 12), |(k, _)| hasher(&k)); + /// + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(x, _)| x == "poneyland",), + /// Some(&("poneyland", 12)) + /// ); + /// + /// if let Entry::Occupied(mut o) = table.entry( + /// hasher(&"poneyland"), + /// |&(x, _)| x == "poneyland", + /// |(k, _)| hasher(&k), + /// ) { + /// o.get_mut().1 += 10; + /// assert_eq!(o.get().1, 22); + /// + /// // We can use the same Entry multiple times. + /// o.get_mut().1 += 2; + /// } + /// + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(x, _)| x == "poneyland",), + /// Some(&("poneyland", 24)) + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[inline] + pub fn get_mut(&mut self) -> &mut T { + unsafe { self.bucket.as_mut() } + } + + /// Converts the OccupiedEntry into a mutable reference to the value in the entry + /// with a lifetime bound to the table itself. + /// + /// If you need multiple references to the `OccupiedEntry`, see [`get_mut`]. + /// + /// [`get_mut`]: #method.get_mut + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<(&str, u32)> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// table.insert_unique(hasher(&"poneyland"), ("poneyland", 12), |(k, _)| hasher(&k)); + /// + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(x, _)| x == "poneyland",), + /// Some(&("poneyland", 12)) + /// ); + /// + /// let value: &mut (&str, u32); + /// match table.entry( + /// hasher(&"poneyland"), + /// |&(x, _)| x == "poneyland", + /// |(k, _)| hasher(&k), + /// ) { + /// Entry::Occupied(entry) => value = entry.into_mut(), + /// Entry::Vacant(_) => panic!(), + /// } + /// value.1 += 10; + /// + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&(x, _)| x == "poneyland",), + /// Some(&("poneyland", 22)) + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + pub fn into_mut(self) -> &'a mut T { + unsafe { self.bucket.as_mut() } + } + + /// Converts the OccupiedEntry into a mutable reference to the underlying + /// table. + pub fn into_table(self) -> &'a mut HashTable<T, A> { + self.table + } +} + +/// A view into a vacant entry in a `HashTable`. +/// It is part of the [`Entry`] enum. +/// +/// [`Entry`]: enum.Entry.html +/// +/// # Examples +/// +/// ``` +/// # #[cfg(feature = "nightly")] +/// # fn test() { +/// use ahash::AHasher; +/// use hashbrown::hash_table::{Entry, HashTable, VacantEntry}; +/// use std::hash::{BuildHasher, BuildHasherDefault}; +/// +/// let mut table: HashTable<&str> = HashTable::new(); +/// let hasher = BuildHasherDefault::<AHasher>::default(); +/// let hasher = |val: &_| hasher.hash_one(val); +/// +/// let entry_v: VacantEntry<_, _> = match table.entry(hasher(&"a"), |&x| x == "a", hasher) { +/// Entry::Vacant(view) => view, +/// Entry::Occupied(_) => unreachable!(), +/// }; +/// entry_v.insert("a"); +/// assert!(table.find(hasher(&"a"), |&x| x == "a").is_some() && table.len() == 1); +/// +/// // Nonexistent key (insert) +/// match table.entry(hasher(&"b"), |&x| x == "b", hasher) { +/// Entry::Vacant(view) => { +/// view.insert("b"); +/// } +/// Entry::Occupied(_) => unreachable!(), +/// } +/// assert!(table.find(hasher(&"b"), |&x| x == "b").is_some() && table.len() == 2); +/// # } +/// # fn main() { +/// # #[cfg(feature = "nightly")] +/// # test() +/// # } +/// ``` +pub struct VacantEntry<'a, T, A = Global> +where + A: Allocator, +{ + hash: u64, + insert_slot: InsertSlot, + table: &'a mut HashTable<T, A>, +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for VacantEntry<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("VacantEntry") + } +} + +impl<'a, T, A> VacantEntry<'a, T, A> +where + A: Allocator, +{ + /// Inserts a new element into the table with the hash that was used to + /// obtain the `VacantEntry`. + /// + /// An `OccupiedEntry` is returned for the newly inserted element. + /// + /// # Examples + /// + /// ``` + /// # #[cfg(feature = "nightly")] + /// # fn test() { + /// use ahash::AHasher; + /// use hashbrown::hash_table::Entry; + /// use hashbrown::HashTable; + /// use std::hash::{BuildHasher, BuildHasherDefault}; + /// + /// let mut table: HashTable<&str> = HashTable::new(); + /// let hasher = BuildHasherDefault::<AHasher>::default(); + /// let hasher = |val: &_| hasher.hash_one(val); + /// + /// if let Entry::Vacant(o) = table.entry(hasher(&"poneyland"), |&x| x == "poneyland", hasher) { + /// o.insert("poneyland"); + /// } + /// assert_eq!( + /// table.find(hasher(&"poneyland"), |&x| x == "poneyland"), + /// Some(&"poneyland") + /// ); + /// # } + /// # fn main() { + /// # #[cfg(feature = "nightly")] + /// # test() + /// # } + /// ``` + #[inline] + pub fn insert(self, value: T) -> OccupiedEntry<'a, T, A> { + let bucket = unsafe { + self.table + .raw + .insert_in_slot(self.hash, self.insert_slot, value) + }; + OccupiedEntry { + hash: self.hash, + bucket, + table: self.table, + } + } + + /// Converts the VacantEntry into a mutable reference to the underlying + /// table. + pub fn into_table(self) -> &'a mut HashTable<T, A> { + self.table + } +} + +/// Type representing the absence of an entry, as returned by [`HashTable::find_entry`]. +/// +/// This type only exists due to [limitations] in Rust's NLL borrow checker. In +/// the future, `find_entry` will return an `Option<OccupiedEntry>` and this +/// type will be removed. +/// +/// [limitations]: https://smallcultfollowing.com/babysteps/blog/2018/06/15/mir-based-borrow-check-nll-status-update/#polonius +/// +/// # Examples +/// +/// ``` +/// # #[cfg(feature = "nightly")] +/// # fn test() { +/// use ahash::AHasher; +/// use hashbrown::hash_table::{AbsentEntry, Entry, HashTable}; +/// use std::hash::{BuildHasher, BuildHasherDefault}; +/// +/// let mut table: HashTable<&str> = HashTable::new(); +/// let hasher = BuildHasherDefault::<AHasher>::default(); +/// let hasher = |val: &_| hasher.hash_one(val); +/// +/// let entry_v: AbsentEntry<_, _> = table.find_entry(hasher(&"a"), |&x| x == "a").unwrap_err(); +/// entry_v +/// .into_table() +/// .insert_unique(hasher(&"a"), "a", hasher); +/// assert!(table.find(hasher(&"a"), |&x| x == "a").is_some() && table.len() == 1); +/// +/// // Nonexistent key (insert) +/// match table.entry(hasher(&"b"), |&x| x == "b", hasher) { +/// Entry::Vacant(view) => { +/// view.insert("b"); +/// } +/// Entry::Occupied(_) => unreachable!(), +/// } +/// assert!(table.find(hasher(&"b"), |&x| x == "b").is_some() && table.len() == 2); +/// # } +/// # fn main() { +/// # #[cfg(feature = "nightly")] +/// # test() +/// # } +/// ``` +pub struct AbsentEntry<'a, T, A = Global> +where + A: Allocator, +{ + table: &'a mut HashTable<T, A>, +} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for AbsentEntry<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("AbsentEntry") + } +} + +impl<'a, T, A> AbsentEntry<'a, T, A> +where + A: Allocator, +{ + /// Converts the AbsentEntry into a mutable reference to the underlying + /// table. + pub fn into_table(self) -> &'a mut HashTable<T, A> { + self.table + } +} + +/// An iterator over the entries of a `HashTable` in arbitrary order. +/// The iterator element type is `&'a T`. +/// +/// This `struct` is created by the [`iter`] method on [`HashTable`]. See its +/// documentation for more. +/// +/// [`iter`]: struct.HashTable.html#method.iter +/// [`HashTable`]: struct.HashTable.html +pub struct Iter<'a, T> { + inner: RawIter<T>, + marker: PhantomData<&'a T>, +} + +impl<'a, T> Iterator for Iter<'a, T> { + type Item = &'a T; + + fn next(&mut self) -> Option<Self::Item> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some(bucket) => Some(unsafe { bucket.as_ref() }), + None => None, + } + } + + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } + + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner + .fold(init, |acc, bucket| unsafe { f(acc, bucket.as_ref()) }) + } +} + +impl<T> ExactSizeIterator for Iter<'_, T> { + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<T> FusedIterator for Iter<'_, T> {} + +/// A mutable iterator over the entries of a `HashTable` in arbitrary order. +/// The iterator element type is `&'a mut T`. +/// +/// This `struct` is created by the [`iter_mut`] method on [`HashTable`]. See its +/// documentation for more. +/// +/// [`iter_mut`]: struct.HashTable.html#method.iter_mut +/// [`HashTable`]: struct.HashTable.html +pub struct IterMut<'a, T> { + inner: RawIter<T>, + marker: PhantomData<&'a mut T>, +} + +impl<'a, T> Iterator for IterMut<'a, T> { + type Item = &'a mut T; + + fn next(&mut self) -> Option<Self::Item> { + // Avoid `Option::map` because it bloats LLVM IR. + match self.inner.next() { + Some(bucket) => Some(unsafe { bucket.as_mut() }), + None => None, + } + } + + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } + + fn fold<B, F>(self, init: B, mut f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner + .fold(init, |acc, bucket| unsafe { f(acc, bucket.as_mut()) }) + } +} + +impl<T> ExactSizeIterator for IterMut<'_, T> { + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<T> FusedIterator for IterMut<'_, T> {} + +/// An owning iterator over the entries of a `HashTable` in arbitrary order. +/// The iterator element type is `T`. +/// +/// This `struct` is created by the [`into_iter`] method on [`HashTable`] +/// (provided by the [`IntoIterator`] trait). See its documentation for more. +/// The table cannot be used after calling that method. +/// +/// [`into_iter`]: struct.HashTable.html#method.into_iter +/// [`HashTable`]: struct.HashTable.html +/// [`IntoIterator`]: https://doc.rust-lang.org/core/iter/trait.IntoIterator.html +pub struct IntoIter<T, A = Global> +where + A: Allocator, +{ + inner: RawIntoIter<T, A>, +} + +impl<T, A> Iterator for IntoIter<T, A> +where + A: Allocator, +{ + type Item = T; + + fn next(&mut self) -> Option<Self::Item> { + self.inner.next() + } + + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } + + fn fold<B, F>(self, init: B, f: F) -> B + where + Self: Sized, + F: FnMut(B, Self::Item) -> B, + { + self.inner.fold(init, f) + } +} + +impl<T, A> ExactSizeIterator for IntoIter<T, A> +where + A: Allocator, +{ + fn len(&self) -> usize { + self.inner.len() + } +} + +impl<T, A> FusedIterator for IntoIter<T, A> where A: Allocator {} + +/// A draining iterator over the items of a `HashTable`. +/// +/// This `struct` is created by the [`drain`] method on [`HashTable`]. +/// See its documentation for more. +/// +/// [`HashTable`]: struct.HashTable.html +/// [`drain`]: struct.HashTable.html#method.drain +pub struct Drain<'a, T, A: Allocator = Global> { + inner: RawDrain<'a, T, A>, +} + +impl<T, A: Allocator> Drain<'_, T, A> { + /// Returns a iterator of references over the remaining items. + fn iter(&self) -> Iter<'_, T> { + Iter { + inner: self.inner.iter(), + marker: PhantomData, + } + } +} + +impl<T, A: Allocator> Iterator for Drain<'_, T, A> { + type Item = T; + + fn next(&mut self) -> Option<T> { + self.inner.next() + } + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } +} +impl<T, A: Allocator> ExactSizeIterator for Drain<'_, T, A> { + fn len(&self) -> usize { + self.inner.len() + } +} +impl<T, A: Allocator> FusedIterator for Drain<'_, T, A> {} + +impl<T: fmt::Debug, A: Allocator> fmt::Debug for Drain<'_, T, A> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self.iter()).finish() + } +} + +/// A draining iterator over entries of a `HashTable` which don't satisfy the predicate `f`. +/// +/// This `struct` is created by [`HashTable::extract_if`]. See its +/// documentation for more. +#[must_use = "Iterators are lazy unless consumed"] +pub struct ExtractIf<'a, T, F, A: Allocator = Global> +where + F: FnMut(&mut T) -> bool, +{ + f: F, + inner: RawExtractIf<'a, T, A>, +} + +impl<T, F, A: Allocator> Iterator for ExtractIf<'_, T, F, A> +where + F: FnMut(&mut T) -> bool, +{ + type Item = T; + + #[inline] + fn next(&mut self) -> Option<Self::Item> { + self.inner.next(|val| (self.f)(val)) + } + + #[inline] + fn size_hint(&self) -> (usize, Option<usize>) { + (0, self.inner.iter.size_hint().1) + } +} + +impl<T, F, A: Allocator> FusedIterator for ExtractIf<'_, T, F, A> where F: FnMut(&mut T) -> bool {} diff --git a/third_party/rust/hashbrown/tests/equivalent_trait.rs b/third_party/rust/hashbrown/tests/equivalent_trait.rs new file mode 100644 index 0000000000..713dddd53c --- /dev/null +++ b/third_party/rust/hashbrown/tests/equivalent_trait.rs @@ -0,0 +1,53 @@ +use hashbrown::Equivalent; +use hashbrown::HashMap; + +use std::hash::Hash; + +#[derive(Debug, Hash)] +pub struct Pair<A, B>(pub A, pub B); + +impl<A, B, C, D> PartialEq<(A, B)> for Pair<C, D> +where + C: PartialEq<A>, + D: PartialEq<B>, +{ + fn eq(&self, rhs: &(A, B)) -> bool { + self.0 == rhs.0 && self.1 == rhs.1 + } +} + +impl<A, B, X> Equivalent<X> for Pair<A, B> +where + Pair<A, B>: PartialEq<X>, + A: Hash + Eq, + B: Hash + Eq, +{ + fn equivalent(&self, other: &X) -> bool { + *self == *other + } +} + +#[test] +fn test_lookup() { + let s = String::from; + let mut map = HashMap::new(); + map.insert((s("a"), s("b")), 1); + map.insert((s("a"), s("x")), 2); + + assert!(map.contains_key(&Pair("a", "b"))); + assert!(!map.contains_key(&Pair("b", "a"))); +} + +#[test] +fn test_string_str() { + let s = String::from; + let mut map = HashMap::new(); + map.insert(s("a"), 1); + map.insert(s("b"), 2); + map.insert(s("x"), 3); + map.insert(s("y"), 4); + + assert!(map.contains_key("a")); + assert!(!map.contains_key("z")); + assert_eq!(map.remove("b"), Some(2)); +} diff --git a/third_party/rust/hashbrown/tests/raw.rs b/third_party/rust/hashbrown/tests/raw.rs new file mode 100644 index 0000000000..858836e63b --- /dev/null +++ b/third_party/rust/hashbrown/tests/raw.rs @@ -0,0 +1,11 @@ +#![cfg(feature = "raw")] + +use hashbrown::raw::RawTable; +use std::mem; + +#[test] +fn test_allocation_info() { + assert_eq!(RawTable::<()>::new().allocation_info().1.size(), 0); + assert_eq!(RawTable::<u32>::new().allocation_info().1.size(), 0); + assert!(RawTable::<u32>::with_capacity(1).allocation_info().1.size() > mem::size_of::<u32>()); +} diff --git a/third_party/rust/hashbrown/tests/rayon.rs b/third_party/rust/hashbrown/tests/rayon.rs index 8c603c5c41..d55e5a9804 100644 --- a/third_party/rust/hashbrown/tests/rayon.rs +++ b/third_party/rust/hashbrown/tests/rayon.rs @@ -356,7 +356,9 @@ fn set_seq_par_equivalence_into_iter_empty() { let vec_seq = SET_EMPTY.clone().into_iter().collect::<Vec<_>>(); let vec_par = SET_EMPTY.clone().into_par_iter().collect::<Vec<_>>(); - assert_eq3!(vec_seq, vec_par, []); + // Work around type inference failure introduced by rend dev-dependency. + let empty: [char; 0] = []; + assert_eq3!(vec_seq, vec_par, empty); } #[test] diff --git a/third_party/rust/hashbrown/tests/set.rs b/third_party/rust/hashbrown/tests/set.rs index 5ae1ec98ec..86ec964766 100644 --- a/third_party/rust/hashbrown/tests/set.rs +++ b/third_party/rust/hashbrown/tests/set.rs @@ -27,7 +27,7 @@ fn test_hashset_insert_remove() { assert_eq!(m.insert(x.clone()), true); } for (i, x) in tx.iter().enumerate() { - println!("removing {} {:?}", i, x); + println!("removing {i} {x:?}"); assert_eq!(m.remove(x), true); } } |