1 files changed, 197 insertions, 0 deletions
diff --git a/third_party/rust/rkv/src/backend/traits.rs b/third_party/rust/rkv/src/backend/traits.rs
new file mode 100644
index 0000000000..d589a3c5fa
--- /dev/null
+++ b/third_party/rust/rkv/src/backend/traits.rs
@@ -0,0 +1,197 @@
+// Copyright 2018-2019 Mozilla
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+// this file except in compliance with the License. You may obtain a copy of the
+// License at http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software distributed
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+
+use std::{
+    fmt::{
+        Debug,
+        Display,
+    },
+    path::{
+        Path,
+        PathBuf,
+    },
+};
+
+use crate::{
+    backend::common::{
+        DatabaseFlags,
+        EnvironmentFlags,
+        WriteFlags,
+    },
+    error::StoreError,
+};
+
+pub trait BackendError: Debug + Display + Into<StoreError> {}
+
+pub trait BackendDatabase: Debug + Eq + PartialEq + Copy + Clone {}
+
+pub trait BackendFlags: Debug + Eq + PartialEq + Copy + Clone + Default {
+    fn empty() -> Self;
+}
+
+pub trait BackendEnvironmentFlags: BackendFlags {
+    fn set(&mut self, flag: EnvironmentFlags, value: bool);
+}
+
+pub trait BackendDatabaseFlags: BackendFlags {
+    fn set(&mut self, flag: DatabaseFlags, value: bool);
+}
+
+pub trait BackendWriteFlags: BackendFlags {
+    fn set(&mut self, flag: WriteFlags, value: bool);
+}
+
+pub trait BackendStat {
+    fn page_size(&self) -> usize;
+
+    fn depth(&self) -> usize;
+
+    fn branch_pages(&self) -> usize;
+
+    fn leaf_pages(&self) -> usize;
+
+    fn overflow_pages(&self) -> usize;
+
+    fn entries(&self) -> usize;
+}
+
+pub trait BackendInfo {
+    fn map_size(&self) -> usize;
+
+    fn last_pgno(&self) -> usize;
+
+    fn last_txnid(&self) -> usize;
+
+    fn max_readers(&self) -> usize;
+
+    fn num_readers(&self) -> usize;
+}
+
+pub trait BackendEnvironmentBuilder<'b>: Debug + Eq + PartialEq + Copy + Clone {
+    type Error: BackendError;
+    type Environment: BackendEnvironment<'b>;
+    type Flags: BackendEnvironmentFlags;
+
+    fn new() -> Self;
+
+    fn set_flags<T>(&mut self, flags: T) -> &mut Self
+    where
+        T: Into<Self::Flags>;
+
+    fn set_max_dbs(&mut self, max_dbs: u32) -> &mut Self;
+
+    fn set_max_readers(&mut self, max_readers: u32) -> &mut Self;
+
+    fn set_map_size(&mut self, size: usize) -> &mut Self;
+
+    fn set_make_dir_if_needed(&mut self, make_dir_if_needed: bool) -> &mut Self;
+
+    fn set_discard_if_corrupted(&mut self, discard_if_corrupted: bool) -> &mut Self;
+
+    fn open(&self, path: &Path) -> Result<Self::Environment, Self::Error>;
+}
+
+pub trait BackendEnvironment<'e>: Debug {
+    type Error: BackendError;
+    type Database: BackendDatabase;
+    type Flags: BackendDatabaseFlags;
+    type Stat: BackendStat;
+    type Info: BackendInfo;
+    type RoTransaction: BackendRoCursorTransaction<'e, Database = Self::Database>;
+    type RwTransaction: BackendRwCursorTransaction<'e, Database = Self::Database>;
+
+    fn get_dbs(&self) -> Result<Vec<Option<String>>, Self::Error>;
+
+    fn open_db(&self, name: Option<&str>) -> Result<Self::Database, Self::Error>;
+
+    fn create_db(&self, name: Option<&str>, flags: Self::Flags) -> Result<Self::Database, Self::Error>;
+
+    fn begin_ro_txn(&'e self) -> Result<Self::RoTransaction, Self::Error>;
+
+    fn begin_rw_txn(&'e self) -> Result<Self::RwTransaction, Self::Error>;
+
+    fn sync(&self, force: bool) -> Result<(), Self::Error>;
+
+    fn stat(&self) -> Result<Self::Stat, Self::Error>;
+
+    fn info(&self) -> Result<Self::Info, Self::Error>;
+
+    fn freelist(&self) -> Result<usize, Self::Error>;
+
+    fn load_ratio(&self) -> Result<Option<f32>, Self::Error>;
+
+    fn set_map_size(&self, size: usize) -> Result<(), Self::Error>;
+
+    fn get_files_on_disk(&self) -> Vec<PathBuf>;
+}
+
+pub trait BackendRoTransaction: Debug {
+    type Error: BackendError;
+    type Database: BackendDatabase;
+
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
+
+    fn abort(self);
+}
+
+pub trait BackendRwTransaction: Debug {
+    type Error: BackendError;
+    type Database: BackendDatabase;
+    type Flags: BackendWriteFlags;
+
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
+
+    fn put(&mut self, db: &Self::Database, key: &[u8], value: &[u8], flags: Self::Flags) -> Result<(), Self::Error>;
+
+    #[cfg(not(feature = "db-dup-sort"))]
+    fn del(&mut self, db: &Self::Database, key: &[u8]) -> Result<(), Self::Error>;
+
+    #[cfg(feature = "db-dup-sort")]
+    fn del(&mut self, db: &Self::Database, key: &[u8], value: Option<&[u8]>) -> Result<(), Self::Error>;
+
+    fn clear_db(&mut self, db: &Self::Database) -> Result<(), Self::Error>;
+
+    fn commit(self) -> Result<(), Self::Error>;
+
+    fn abort(self);
+}
+
+pub trait BackendRoCursorTransaction<'t>: BackendRoTransaction {
+    type RoCursor: BackendRoCursor<'t>;
+
+    fn open_ro_cursor(&'t self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error>;
+}
+
+pub trait BackendRwCursorTransaction<'t>: BackendRwTransaction {
+    type RoCursor: BackendRoCursor<'t>;
+
+    fn open_ro_cursor(&'t self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error>;
+}
+
+pub trait BackendRoCursor<'c>: Debug {
+    type Iter: BackendIter<'c>;
+
+    fn into_iter(self) -> Self::Iter;
+
+    fn into_iter_from<K>(self, key: K) -> Self::Iter
+    where
+        K: AsRef<[u8]> + 'c;
+
+    fn into_iter_dup_of<K>(self, key: K) -> Self::Iter
+    where
+        K: AsRef<[u8]> + 'c;
+}
+
+pub trait BackendIter<'i> {
+    type Error: BackendError;
+
+    #[allow(clippy::type_complexity)]
+    fn next(&mut self) -> Option<Result<(&'i [u8], &'i [u8]), Self::Error>>;
+}