Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

13 files changed, 2474 insertions, 0 deletions

diff --git a/vendor/tracing-log/.cargo-checksum.json b/vendor/tracing-log/.cargo-checksum.json
new file mode 100644
index 000000000..9d068bc0e
--- /dev/null
+++ b/vendor/tracing-log/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGELOG.md":"d7cc8e83d800946b622f3392cbb5245d57dde70ef1b544fe82260371a90b39ec","Cargo.toml":"3e7cfde6270347998b817355e0b9bb7a59cfb458477f8a91045a15b5081900c7","LICENSE":"898b1ae9821e98daf8964c8d6c7f61641f5f5aa78ad500020771c0939ee0dea1","README.md":"f69a91df2fb2eb0b8a381acf6dc7d4fe611aece9a2ce9389743a00c6b1ca9dc9","benches/logging.rs":"d4d0ceb4bf0fcf0c139c48bece64cad22c04b0c83fa2754983b5d4f141c817b5","src/env_logger.rs":"853d961ef431fcad924d07b90e4fc9f73413ed45e7bd7b9aaba95a1fdc28349a","src/interest_cache.rs":"590437659a6f10f2ba53b640dbe2eb090c3fc7b364c2b7d8b6178d1a849454c2","src/lib.rs":"7f1b89dc2fbd8f4d8bc81fe5818fb175f44b4d91d789e5bf67f3463f46864d8d","src/log_tracer.rs":"679c0a84896598439bcb8a01bc49ae58148039df642f43c70fd665b9c687a05a","src/trace_logger.rs":"b1d58046a76bdad604072c7f969e19e02f90324d6881504403b7debc965845a6","tests/log_tracer.rs":"2d4725822b19c47c0cbcfaf2f9af3f939f55b4b0d9b3a2c5584af2b77453854b","tests/reexport_log_crate.rs":"1eb4672784ecda75743494b0662d90fd48b1252b44b68afa898fa0bec3699683"},"package":"78ddad33d2d10b1ed7eb9d1f518a5674713876e97e5bb9b7345a7984fbb4f922"}
\ No newline at end of file
diff --git a/vendor/tracing-log/CHANGELOG.md b/vendor/tracing-log/CHANGELOG.md
new file mode 100644
index 000000000..2ae9f0e6d
--- /dev/null
+++ b/vendor/tracing-log/CHANGELOG.md
@@ -0,0 +1,66 @@
+# 0.1.3 (April 21st, 2022)
+
+### Added
+
+- **log-tracer**: Added `LogTracer::with_interest_cache` to enable a limited
+ form of per-record `Interest` caching for `log` records ([#1636])
+
+### Changed
+
+- Updated minimum supported Rust version (MSRV) to Rust 1.49.0 ([#1913])
+
+### Fixed
+
+- **log-tracer**: Fixed `LogTracer` not honoring `tracing` max level filters
+  ([#1543])
+- Broken links in documentation ([#2068], [#2077])
+
+Thanks to @Millione, @teozkr, @koute, @Folyd, and @ben0x539 for contributing to
+this release!
+
+[#1636]: https://github.com/tokio-rs/tracing/pulls/1636
+[#1913]: https://github.com/tokio-rs/tracing/pulls/1913
+[#1543]: https://github.com/tokio-rs/tracing/pulls/1543
+[#2068]: https://github.com/tokio-rs/tracing/pulls/2068
+[#2077]: https://github.com/tokio-rs/tracing/pulls/2077
+
+# 0.1.2 (February 19th, 2020)
+
+### Added
+
+- Re-export the `log` crate so that users can ensure consistent versions ([#602])
+- `AsLog` implementation for `tracing::LevelFilter` ([#1248])
+- `AsTrace` implementation for `log::LevelFilter` ([#1248])
+
+### Fixed
+
+- **log-tracer**: Fixed `Log::enabled` implementation for `LogTracer` not
+  calling `Subscriber::enabled` ([#1254])
+- **log-tracer**: Fixed `Log::enabled` implementation for `LogTracer` not
+  checking the max level hint ([#1247])
+- Several documentation fixes ([#483], [#485], [#537], [#595], [#941], [#981])
+
+[#483]: https://github.com/tokio-rs/tracing/pulls/483
+[#485]: https://github.com/tokio-rs/tracing/pulls/485
+[#537]: https://github.com/tokio-rs/tracing/pulls/537
+[#595]: https://github.com/tokio-rs/tracing/pulls/595
+[#605]: https://github.com/tokio-rs/tracing/pulls/604
+[#941]: https://github.com/tokio-rs/tracing/pulls/941
+[#1247]: https://github.com/tokio-rs/tracing/pulls/1247
+[#1248]: https://github.com/tokio-rs/tracing/pulls/1248
+[#1254]: https://github.com/tokio-rs/tracing/pulls/1254
+
+# 0.1.1 (October 29, 2019)
+
+### Deprecated
+
+- `TraceLogger` (use `tracing`'s "log" and "log-always" feature flags instead)
+
+### Fixed
+
+- Issues with `log/std` feature flag (#406)
+- Minor documentation issues (#405, #408)
+
+# 0.1.0 (September 3, 2019)
+
+- Initial release
diff --git a/vendor/tracing-log/Cargo.toml b/vendor/tracing-log/Cargo.toml
new file mode 100644
index 000000000..4243c3413
--- /dev/null
+++ b/vendor/tracing-log/Cargo.toml
@@ -0,0 +1,89 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+rust-version = "1.49.0"
+name = "tracing-log"
+version = "0.1.3"
+authors = ["Tokio Contributors <team@tokio.rs>"]
+description = """
+Provides compatibility between `tracing` and the `log` crate.
+"""
+homepage = "https://tokio.rs"
+readme = "README.md"
+keywords = [
+    "logging",
+    "tracing",
+    "log",
+]
+categories = [
+    "development-tools::debugging",
+    "asynchronous",
+]
+license = "MIT"
+repository = "https://github.com/tokio-rs/tracing"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = [
+    "--cfg",
+    "docsrs",
+]
+
+[[bench]]
+name = "logging"
+harness = false
+
+[dependencies.ahash]
+version = "0.7.4"
+optional = true
+
+[dependencies.env_logger]
+version = "0.7"
+optional = true
+
+[dependencies.lazy_static]
+version = "1.3.0"
+
+[dependencies.log]
+version = "0.4"
+
+[dependencies.lru]
+version = "0.7.0"
+optional = true
+
+[dependencies.tracing-core]
+version = "0.1.17"
+
+[dev-dependencies.criterion]
+version = "0.3"
+default_features = false
+
+[dev-dependencies.tracing]
+version = "0.1"
+
+[features]
+default = [
+    "log-tracer",
+    "trace-logger",
+    "std",
+]
+interest-cache = [
+    "lru",
+    "ahash",
+]
+log-tracer = []
+std = ["log/std"]
+trace-logger = []
+
+[badges.maintenance]
+status = "actively-maintained"
diff --git a/vendor/tracing-log/LICENSE b/vendor/tracing-log/LICENSE
new file mode 100644
index 000000000..cdb28b4b5
--- /dev/null
+++ b/vendor/tracing-log/LICENSE
@@ -0,0 +1,25 @@
+Copyright (c) 2019 Tokio Contributors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/vendor/tracing-log/README.md b/vendor/tracing-log/README.md
new file mode 100644
index 000000000..1cfee3681
--- /dev/null
+++ b/vendor/tracing-log/README.md
@@ -0,0 +1,85 @@
+![Tracing — Structured, application-level diagnostics][splash]
+
+[splash]: https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/splash.svg
+
+# tracing-log
+
+[`log`] compatibility for [`tracing`].
+
+[![Crates.io][crates-badge]][crates-url]
+[![Documentation][docs-badge]][docs-url]
+[![Documentation (master)][docs-master-badge]][docs-master-url]
+[![MIT licensed][mit-badge]][mit-url]
+[![Build Status][actions-badge]][actions-url]
+[![Discord chat][discord-badge]][discord-url]
+![maintenance status][maint-badge]
+
+[Documentation][docs-url] | [Chat (discord)][discord-url]
+
+
+[crates-badge]: https://img.shields.io/crates/v/tracing-log.svg
+[crates-url]: https://crates.io/crates/tracing-log
+[docs-badge]: https://docs.rs/tracing-log/badge.svg
+[docs-url]: https://docs.rs/tracing-log
+[docs-master-badge]: https://img.shields.io/badge/docs-master-blue
+[docs-master-url]: https://tracing-rs.netlify.com/tracing_log
+[mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg
+[mit-url]: LICENSE
+[actions-badge]: https://github.com/tokio-rs/tracing/workflows/CI/badge.svg
+[actions-url]:https://github.com/tokio-rs/tracing/actions?query=workflow%3ACI
+[discord-badge]: https://img.shields.io/discord/500028886025895936?logo=discord&label=discord&logoColor=white
+[discord-url]: https://discord.gg/EeF3cQw
+[maint-badge]: https://img.shields.io/badge/maintenance-experimental-blue.svg
+
+## Overview
+
+[`tracing`] is a framework for instrumenting Rust programs with context-aware,
+structured, event-based diagnostic information. This crate provides
+compatibility layers for using `tracing` alongside the logging facade provided
+by the [`log`] crate.
+
+This crate provides:
+
+- [`AsTrace`] and [`AsLog`] traits for converting between `tracing` and `log` types.
+- [`LogTracer`], a [`log::Log`] implementation that consumes [`log::Record`]s
+  and outputs them as [`tracing::Event`]s.
+- An [`env_logger`] module, with helpers for using the [`env_logger` crate]
+  with `tracing` (optional, enabled by the `env_logger` feature).
+
+[`tracing`]: https://crates.io/crates/tracing
+[`log`]: https://crates.io/crates/log
+[`AsTrace`]: https://docs.rs/tracing-log/latest/tracing_log/trait.AsTrace.html
+[`AsLog`]: https://docs.rs/tracing-log/latest/tracing_log/trait.AsLog.html
+[`LogTracer`]: https://docs.rs/tracing-log/latest/tracing_log/struct.LogTracer.html
+[`log::Log`]: https://docs.rs/log/latest/log/trait.Log.html
+[`log::Record`]: https://docs.rs/log/latest/log/struct.Record.html
+[`tracing::Subscriber`]: https://docs.rs/tracing/latest/tracing/trait.Subscriber.html
+[`tracing::Event`]: https://docs.rs/tracing/latest/tracing/struct.Event.html
+
+*Compiler support: [requires `rustc` 1.49+][msrv]*
+
+[msrv]: #supported-rust-versions
+
+## Supported Rust Versions
+
+Tracing is built against the latest stable release. The minimum supported
+version is 1.49. The current Tracing version is not guaranteed to build on Rust
+versions earlier than the minimum supported version.
+
+Tracing follows the same compiler support policies as the rest of the Tokio
+project. The current stable Rust compiler and the three most recent minor
+versions before it will always be supported. For example, if the current stable
+compiler version is 1.45, the minimum supported version will not be increased
+past 1.42, three minor versions prior. Increasing the minimum supported compiler
+version is not considered a semver breaking change as long as doing so complies
+with this policy.
+
+## License
+
+This project is licensed under the [MIT license](LICENSE).
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in Tracing by you, shall be licensed as MIT, without any additional
+terms or conditions.
diff --git a/vendor/tracing-log/benches/logging.rs b/vendor/tracing-log/benches/logging.rs
new file mode 100644
index 000000000..c72e3edf0
--- /dev/null
+++ b/vendor/tracing-log/benches/logging.rs
@@ -0,0 +1,91 @@
+use criterion::{criterion_group, criterion_main, Criterion};
+use log::trace;
+use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use tracing_subscriber::{EnvFilter, FmtSubscriber};
+
+// This creates a bunch of threads and makes sure they start executing
+// a given callback almost exactly at the same time.
+fn run_on_many_threads<F, R>(thread_count: usize, callback: F) -> Vec<R>
+where
+    F: Fn() -> R + 'static + Send + Clone,
+    R: Send + 'static,
+{
+    let started_count = Arc::new(AtomicUsize::new(0));
+    let barrier = Arc::new(AtomicBool::new(false));
+    #[allow(clippy::needless_collect)]
+    let threads: Vec<_> = (0..thread_count)
+        .map(|_| {
+            let started_count = started_count.clone();
+            let barrier = barrier.clone();
+            let callback = callback.clone();
+
+            std::thread::spawn(move || {
+                started_count.fetch_add(1, Ordering::SeqCst);
+                while !barrier.load(Ordering::SeqCst) {
+                    std::thread::yield_now();
+                }
+
+                callback()
+            })
+        })
+        .collect();
+
+    while started_count.load(Ordering::SeqCst) != thread_count {
+        std::thread::yield_now();
+    }
+    barrier.store(true, Ordering::SeqCst);
+
+    threads
+        .into_iter()
+        .map(|handle| handle.join())
+        .collect::<Result<Vec<R>, _>>()
+        .unwrap()
+}
+
+fn bench_logger(c: &mut Criterion) {
+    let env_filter = EnvFilter::default()
+        .add_directive("info".parse().unwrap())
+        .add_directive("ws=off".parse().unwrap())
+        .add_directive("yamux=off".parse().unwrap())
+        .add_directive("regalloc=off".parse().unwrap())
+        .add_directive("cranelift_codegen=off".parse().unwrap())
+        .add_directive("cranelift_wasm=warn".parse().unwrap())
+        .add_directive("hyper=warn".parse().unwrap())
+        .add_directive("dummy=trace".parse().unwrap());
+
+    let builder = tracing_log::LogTracer::builder().with_max_level(log::LevelFilter::Trace);
+
+    #[cfg(feature = "interest-cache")]
+    let builder = builder.with_interest_cache(tracing_log::InterestCacheConfig::default());
+
+    builder.init().unwrap();
+
+    let builder = FmtSubscriber::builder()
+        .with_env_filter(env_filter)
+        .with_filter_reloading();
+
+    let subscriber = builder.finish();
+    tracing::subscriber::set_global_default(subscriber).unwrap();
+
+    const THREAD_COUNT: usize = 8;
+
+    c.bench_function("log_from_multiple_threads", |b| {
+        b.iter_custom(|count| {
+            let durations = run_on_many_threads(THREAD_COUNT, move || {
+                let start = Instant::now();
+                for _ in 0..count {
+                    trace!("A dummy log!");
+                }
+                start.elapsed()
+            });
+
+            let total_time: Duration = durations.into_iter().sum();
+            Duration::from_nanos((total_time.as_nanos() / THREAD_COUNT as u128) as u64)
+        })
+    });
+}
+
+criterion_group!(benches, bench_logger);
+criterion_main!(benches);
diff --git a/vendor/tracing-log/src/env_logger.rs b/vendor/tracing-log/src/env_logger.rs
new file mode 100644
index 000000000..74922d1dc
--- /dev/null
+++ b/vendor/tracing-log/src/env_logger.rs
@@ -0,0 +1,49 @@
+//! Utilities for configuring the `env_logger` crate to emit `tracing` events.
+
+/// Extension trait to configure an `env_logger::Builder` to emit traces.
+pub trait BuilderExt: crate::sealed::Sealed {
+    /// Configure the built `env_logger::Logger` to emit `tracing` events for
+    /// all consumed `log` records, rather than printing them to standard out.
+    ///
+    /// Note that this replaces any previously configured formatting.
+    fn emit_traces(&mut self) -> &mut Self;
+}
+
+impl crate::sealed::Sealed for env_logger::Builder {}
+
+impl BuilderExt for env_logger::Builder {
+    fn emit_traces(&mut self) -> &mut Self {
+        self.format(|_, record| super::format_trace(record))
+    }
+}
+
+/// Attempts to initialize the global logger with an env logger configured to
+/// emit `tracing` events.
+///
+/// This should be called early in the execution of a Rust program. Any log
+/// events that occur before initialization will be ignored.
+///
+/// # Errors
+///
+/// This function will fail if it is called more than once, or if another
+/// library has already initialized a global logger.
+pub fn try_init() -> Result<(), log::SetLoggerError> {
+    env_logger::Builder::from_default_env()
+        .emit_traces()
+        .try_init()
+}
+
+/// Initializes the global logger with an env logger configured to
+/// emit `tracing` events.
+///
+/// This should be called early in the execution of a Rust program. Any log
+/// events that occur before initialization will be ignored.
+///
+/// # Panics
+///
+/// This function will panic if it is called more than once, or if another
+/// library has already initialized a global logger.
+pub fn init() {
+    try_init()
+        .expect("tracing_log::env_logger::init should not be called after logger initialized");
+}
diff --git a/vendor/tracing-log/src/interest_cache.rs b/vendor/tracing-log/src/interest_cache.rs
new file mode 100644
index 000000000..fb3da875e
--- /dev/null
+++ b/vendor/tracing-log/src/interest_cache.rs
@@ -0,0 +1,542 @@
+use ahash::AHasher;
+use log::{Level, Metadata};
+use lru::LruCache;
+use std::cell::RefCell;
+use std::hash::Hasher;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Mutex;
+
+/// The interest cache configuration.
+#[derive(Debug)]
+pub struct InterestCacheConfig {
+    min_verbosity: Level,
+    lru_cache_size: usize,
+}
+
+impl Default for InterestCacheConfig {
+    fn default() -> Self {
+        InterestCacheConfig {
+            min_verbosity: Level::Debug,
+            lru_cache_size: 1024,
+        }
+    }
+}
+
+impl InterestCacheConfig {
+    fn disabled() -> Self {
+        Self {
+            lru_cache_size: 0,
+            ..Self::default()
+        }
+    }
+}
+
+impl InterestCacheConfig {
+    /// Sets the minimum logging verbosity for which the cache will apply.
+    ///
+    /// The interest for logs with a lower verbosity than specified here
+    /// will not be cached.
+    ///
+    /// It should be set to the lowest verbosity level for which the majority
+    /// of the logs in your application are usually *disabled*.
+    ///
+    /// In normal circumstances with typical logger usage patterns
+    /// you shouldn't ever have to change this.
+    ///
+    /// By default this is set to `Debug`.
+    pub fn with_min_verbosity(mut self, level: Level) -> Self {
+        self.min_verbosity = level;
+        self
+    }
+
+    /// Sets the number of entries in the LRU cache used to cache interests
+    /// for `log` records.
+    ///
+    /// The bigger the cache, the more unlikely it will be for the interest
+    /// in a given callsite to be recalculated, at the expense of extra
+    /// memory usage per every thread which tries to log events.
+    ///
+    /// Every unique [level] + [target] pair consumes a single slot
+    /// in the cache. Entries will be added to the cache until its size
+    /// reaches the value configured here, and from then on it will evict
+    /// the least recently seen level + target pair when adding a new entry.
+    ///
+    /// The ideal value to set here widely depends on how much exactly
+    /// you're logging, and how diverse the targets are to which you are logging.
+    ///
+    /// If your application spends a significant amount of time filtering logs
+    /// which are *not* getting printed out then increasing this value will most
+    /// likely help.
+    ///
+    /// Setting this to zero will disable the cache.
+    ///
+    /// By default this is set to 1024.
+    ///
+    /// [level]: log::Metadata::level
+    /// [target]: log::Metadata::target
+    pub fn with_lru_cache_size(mut self, size: usize) -> Self {
+        self.lru_cache_size = size;
+        self
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+struct Key {
+    target_address: usize,
+    level_and_length: usize,
+}
+
+struct State {
+    min_verbosity: Level,
+    epoch: usize,
+    cache: LruCache<Key, u64, ahash::RandomState>,
+}
+
+impl State {
+    fn new(epoch: usize, config: &InterestCacheConfig) -> Self {
+        State {
+            epoch,
+            min_verbosity: config.min_verbosity,
+            cache: LruCache::new(config.lru_cache_size),
+        }
+    }
+}
+
+// When the logger's filters are reconfigured the interest cache in core is cleared,
+// and we also want to get notified when that happens so that we can clear our cache too.
+//
+// So what we do here is to register a dummy callsite with the core, just so that we can be
+// notified when that happens. It doesn't really matter how exactly our dummy callsite looks
+// like and whether subscribers will actually be interested in it, since nothing will actually
+// be logged from it.
+
+static INTEREST_CACHE_EPOCH: AtomicUsize = AtomicUsize::new(0);
+
+fn interest_cache_epoch() -> usize {
+    INTEREST_CACHE_EPOCH.load(Ordering::Relaxed)
+}
+
+struct SentinelCallsite;
+
+impl tracing_core::Callsite for SentinelCallsite {
+    fn set_interest(&self, _: tracing_core::subscriber::Interest) {
+        INTEREST_CACHE_EPOCH.fetch_add(1, Ordering::SeqCst);
+    }
+
+    fn metadata(&self) -> &tracing_core::Metadata<'_> {
+        &SENTINEL_METADATA
+    }
+}
+
+static SENTINEL_CALLSITE: SentinelCallsite = SentinelCallsite;
+static SENTINEL_METADATA: tracing_core::Metadata<'static> = tracing_core::Metadata::new(
+    "log interest cache",
+    "log",
+    tracing_core::Level::ERROR,
+    None,
+    None,
+    None,
+    tracing_core::field::FieldSet::new(&[], tracing_core::identify_callsite!(&SENTINEL_CALLSITE)),
+    tracing_core::metadata::Kind::EVENT,
+);
+
+lazy_static::lazy_static! {
+    static ref CONFIG: Mutex<InterestCacheConfig> = {
+        tracing_core::callsite::register(&SENTINEL_CALLSITE);
+        Mutex::new(InterestCacheConfig::disabled())
+    };
+}
+
+thread_local! {
+    static STATE: RefCell<State> = {
+        let config = CONFIG.lock().unwrap();
+        RefCell::new(State::new(interest_cache_epoch(), &config))
+    };
+}
+
+pub(crate) fn configure(new_config: Option<InterestCacheConfig>) {
+    *CONFIG.lock().unwrap() = new_config.unwrap_or_else(InterestCacheConfig::disabled);
+    INTEREST_CACHE_EPOCH.fetch_add(1, Ordering::SeqCst);
+}
+
+pub(crate) fn try_cache(metadata: &Metadata<'_>, callback: impl FnOnce() -> bool) -> bool {
+    STATE.with(|state| {
+        let mut state = state.borrow_mut();
+
+        // If the interest cache in core was rebuilt we need to reset the cache here too.
+        let epoch = interest_cache_epoch();
+        if epoch != state.epoch {
+            *state = State::new(epoch, &CONFIG.lock().unwrap());
+        }
+
+        let level = metadata.level();
+        if state.cache.cap() == 0 || level < state.min_verbosity {
+            return callback();
+        }
+
+        let target = metadata.target();
+
+        let mut hasher = AHasher::default();
+        hasher.write(target.as_bytes());
+
+        const HASH_MASK: u64 = !1;
+        const INTEREST_MASK: u64 = 1;
+
+        // We mask out the least significant bit of the hash since we'll use
+        // that space to save the interest.
+        //
+        // Since we use a good hashing function the loss of only a single bit
+        // won't really affect us negatively.
+        let target_hash = hasher.finish() & HASH_MASK;
+
+        // Since log targets are usually static strings we just use the address of the pointer
+        // as the key for our cache.
+        //
+        // We want each level to be cached separately so we also use the level as key, and since
+        // some linkers at certain optimization levels deduplicate strings if their prefix matches
+        // (e.g. "ham" and "hamster" might actually have the same address in memory) we also use the length.
+        let key = Key {
+            target_address: target.as_ptr() as usize,
+            // For extra efficiency we pack both the level and the length into a single field.
+            // The `level` can be between 1 and 5, so it can take at most 3 bits of space.
+            level_and_length: level as usize | target.len().wrapping_shl(3),
+        };
+
+        if let Some(&cached) = state.cache.get(&key) {
+            // And here we make sure that the target actually matches.
+            //
+            // This is just a hash of the target string, so theoretically we're not guaranteed
+            // that it won't collide, however in practice it shouldn't matter as it is quite
+            // unlikely that the target string's address and its length and the level and
+            // the hash will *all* be equal at the same time.
+            //
+            // We could of course actually store the whole target string in our cache,
+            // but we really want to avoid doing that as the necessary memory allocations
+            // would completely tank our performance, especially in cases where the cache's
+            // size is too small so it needs to regularly replace entries.
+            if cached & HASH_MASK == target_hash {
+                return (cached & INTEREST_MASK) != 0;
+            }
+
+            // Realistically we should never land here, unless someone is using a non-static
+            // target string with the same length and level, or is very lucky and found a hash
+            // collision for the cache's key.
+        }
+
+        let interest = callback();
+        state.cache.put(key, target_hash | interest as u64);
+
+        interest
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn lock_for_test() -> impl Drop {
+        // We need to make sure only one test runs at a time.
+
+        lazy_static::lazy_static! {
+            static ref LOCK: Mutex<()> = Mutex::new(());
+        }
+
+        match LOCK.lock() {
+            Ok(guard) => guard,
+            Err(poison) => poison.into_inner(),
+        }
+    }
+
+    #[test]
+    fn test_when_disabled_the_callback_is_always_called() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::disabled();
+
+        std::thread::spawn(|| {
+            let metadata = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy")
+                .build();
+            let mut count = 0;
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 1);
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 2);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_when_enabled_the_callback_is_called_only_once_for_a_high_enough_verbosity() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata = log::MetadataBuilder::new()
+                .level(Level::Debug)
+                .target("dummy")
+                .build();
+            let mut count = 0;
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 1);
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 1);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_when_core_interest_cache_is_rebuilt_this_cache_is_also_flushed() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata = log::MetadataBuilder::new()
+                .level(Level::Debug)
+                .target("dummy")
+                .build();
+            {
+                let mut count = 0;
+                try_cache(&metadata, || {
+                    count += 1;
+                    true
+                });
+                try_cache(&metadata, || {
+                    count += 1;
+                    true
+                });
+                assert_eq!(count, 1);
+            }
+            tracing_core::callsite::rebuild_interest_cache();
+            {
+                let mut count = 0;
+                try_cache(&metadata, || {
+                    count += 1;
+                    true
+                });
+                try_cache(&metadata, || {
+                    count += 1;
+                    true
+                });
+                assert_eq!(count, 1);
+            }
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_when_enabled_the_callback_is_always_called_for_a_low_enough_verbosity() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata = log::MetadataBuilder::new()
+                .level(Level::Info)
+                .target("dummy")
+                .build();
+            let mut count = 0;
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 1);
+            try_cache(&metadata, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 2);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_different_log_levels_are_cached_separately() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata_debug = log::MetadataBuilder::new()
+                .level(Level::Debug)
+                .target("dummy")
+                .build();
+            let metadata_trace = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy")
+                .build();
+            let mut count_debug = 0;
+            let mut count_trace = 0;
+            try_cache(&metadata_debug, || {
+                count_debug += 1;
+                true
+            });
+            try_cache(&metadata_trace, || {
+                count_trace += 1;
+                true
+            });
+            try_cache(&metadata_debug, || {
+                count_debug += 1;
+                true
+            });
+            try_cache(&metadata_trace, || {
+                count_trace += 1;
+                true
+            });
+            assert_eq!(count_debug, 1);
+            assert_eq!(count_trace, 1);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_different_log_targets_are_cached_separately() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata_1 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_1")
+                .build();
+            let metadata_2 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_2")
+                .build();
+            let mut count_1 = 0;
+            let mut count_2 = 0;
+            try_cache(&metadata_1, || {
+                count_1 += 1;
+                true
+            });
+            try_cache(&metadata_2, || {
+                count_2 += 1;
+                true
+            });
+            try_cache(&metadata_1, || {
+                count_1 += 1;
+                true
+            });
+            try_cache(&metadata_2, || {
+                count_2 += 1;
+                true
+            });
+            assert_eq!(count_1, 1);
+            assert_eq!(count_2, 1);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_when_cache_runs_out_of_space_the_callback_is_called_again() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default()
+            .with_min_verbosity(Level::Debug)
+            .with_lru_cache_size(1);
+
+        std::thread::spawn(|| {
+            let metadata_1 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_1")
+                .build();
+            let metadata_2 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_2")
+                .build();
+            let mut count = 0;
+            try_cache(&metadata_1, || {
+                count += 1;
+                true
+            });
+            try_cache(&metadata_1, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 1);
+            try_cache(&metadata_2, || true);
+            try_cache(&metadata_1, || {
+                count += 1;
+                true
+            });
+            assert_eq!(count, 2);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_cache_returns_previously_computed_value() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let metadata_1 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_1")
+                .build();
+            let metadata_2 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target("dummy_2")
+                .build();
+            try_cache(&metadata_1, || true);
+            assert_eq!(try_cache(&metadata_1, || { unreachable!() }), true);
+            try_cache(&metadata_2, || false);
+            assert_eq!(try_cache(&metadata_2, || { unreachable!() }), false);
+        })
+        .join()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_cache_handles_non_static_target_string() {
+        let _lock = lock_for_test();
+
+        *CONFIG.lock().unwrap() = InterestCacheConfig::default().with_min_verbosity(Level::Debug);
+
+        std::thread::spawn(|| {
+            let mut target = *b"dummy_1";
+            let metadata_1 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target(std::str::from_utf8(&target).unwrap())
+                .build();
+
+            try_cache(&metadata_1, || true);
+            assert_eq!(try_cache(&metadata_1, || { unreachable!() }), true);
+
+            *target.last_mut().unwrap() = b'2';
+            let metadata_2 = log::MetadataBuilder::new()
+                .level(Level::Trace)
+                .target(std::str::from_utf8(&target).unwrap())
+                .build();
+
+            try_cache(&metadata_2, || false);
+            assert_eq!(try_cache(&metadata_2, || { unreachable!() }), false);
+        })
+        .join()
+        .unwrap();
+    }
+}
diff --git a/vendor/tracing-log/src/lib.rs b/vendor/tracing-log/src/lib.rs
new file mode 100644
index 000000000..09e9114a4
--- /dev/null
+++ b/vendor/tracing-log/src/lib.rs
@@ -0,0 +1,628 @@
+//! Adapters for connecting unstructured log records from the `log` crate into
+//! the `tracing` ecosystem.
+//!
+//! # Overview
+//!
+//! [`tracing`] is a framework for instrumenting Rust programs with context-aware,
+//! structured, event-based diagnostic information. This crate provides
+//! compatibility layers for using `tracing` alongside the logging facade provided
+//! by the [`log`] crate.
+//!
+//! This crate provides:
+//!
+//! - [`AsTrace`] and [`AsLog`] traits for converting between `tracing` and `log` types.
+//! - [`LogTracer`], a [`log::Log`] implementation that consumes [`log::Record`]s
+//!   and outputs them as [`tracing::Event`].
+//! - An [`env_logger`] module, with helpers for using the [`env_logger` crate]
+//!   with `tracing` (optional, enabled by the `env-logger` feature).
+//!
+//! *Compiler support: [requires `rustc` 1.49+][msrv]*
+//!
+//! [msrv]: #supported-rust-versions
+//!
+//! # Usage
+//!
+//! ## Convert log records to tracing `Event`s
+//!
+//! To convert [`log::Record`]s as [`tracing::Event`]s, set `LogTracer` as the default
+//! logger by calling its [`init`] or [`init_with_filter`] methods.
+//!
+//! ```rust
+//! # use std::error::Error;
+//! use tracing_log::LogTracer;
+//! use log;
+//!
+//! # fn main() -> Result<(), Box<Error>> {
+//! LogTracer::init()?;
+//!
+//! // will be available for Subscribers as a tracing Event
+//! log::trace!("an example trace log");
+//! # Ok(())
+//! # }
+//! ```
+//!
+//! This conversion does not convert unstructured data in log records (such as
+//! values passed as format arguments to the `log!` macro) to structured
+//! `tracing` fields. However, it *does* attach these new events to to the
+//! span that was currently executing when the record was logged. This is the
+//! primary use-case for this library: making it possible to locate the log
+//! records emitted by dependencies which use `log` within the context of a
+//! trace.
+//!
+//! ## Convert tracing `Event`s to logs
+//!
+//! Enabling the ["log" and "log-always" feature flags][flags] on the `tracing`
+//! crate will cause all `tracing` spans and events to emit `log::Record`s as
+//! they occur.
+//!
+//! ## Caution: Mixing both conversions
+//!
+//! Note that logger implementations that convert log records to trace events
+//! should not be used with `Subscriber`s that convert trace events _back_ into
+//! log records (such as the `TraceLogger`), as doing so will result in the
+//! event recursing between the subscriber and the logger forever (or, in real
+//! life, probably overflowing the call stack).
+//!
+//! If the logging of trace events generated from log records produced by the
+//! `log` crate is desired, either the `log` crate should not be used to
+//! implement this logging, or an additional layer of filtering will be
+//! required to avoid infinitely converting between `Event` and `log::Record`.
+//!
+//! # Feature Flags
+//! * `trace-logger`: enables an experimental `log` subscriber, deprecated since
+//!   version 0.1.1.
+//! * `log-tracer`: enables the `LogTracer` type (on by default)
+//! * `env_logger`: enables the `env_logger` module, with helpers for working
+//!   with the [`env_logger` crate].
+//! * `interest-cache`: makes it possible to configure an interest cache for
+//!   logs emitted through the `log` crate (see [`Builder::with_interest_cache`]); requires `std`
+//!
+//! ## Supported Rust Versions
+//!
+//! Tracing is built against the latest stable release. The minimum supported
+//! version is 1.49. The current Tracing version is not guaranteed to build on
+//! Rust versions earlier than the minimum supported version.
+//!
+//! Tracing follows the same compiler support policies as the rest of the Tokio
+//! project. The current stable Rust compiler and the three most recent minor
+//! versions before it will always be supported. For example, if the current
+//! stable compiler version is 1.45, the minimum supported version will not be
+//! increased past 1.42, three minor versions prior. Increasing the minimum
+//! supported compiler version is not considered a semver breaking change as
+//! long as doing so complies with this policy.
+//!
+//! [`init`]: LogTracer::init
+//! [`init_with_filter`]: LogTracer::init_with_filter
+//! [`tracing`]: https://crates.io/crates/tracing
+//! [`env_logger` crate]: https://crates.io/crates/env-logger
+//! [`tracing::Subscriber`]: https://docs.rs/tracing/latest/tracing/trait.Subscriber.html
+//! [`Subscriber`]: https://docs.rs/tracing/latest/tracing/trait.Subscriber.html
+//! [`tracing::Event`]: https://docs.rs/tracing/latest/tracing/struct.Event.html
+//! [flags]: https://docs.rs/tracing/latest/tracing/#crate-feature-flags
+//! [`Builder::with_interest_cache`]: log_tracer::Builder::with_interest_cache
+#![doc(html_root_url = "https://docs.rs/tracing-log/0.1.3")]
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png",
+    issue_tracker_base_url = "https://github.com/tokio-rs/tracing/issues/"
+)]
+#![cfg_attr(docsrs, feature(doc_cfg), deny(rustdoc::broken_intra_doc_links))]
+#![warn(
+    missing_debug_implementations,
+    missing_docs,
+    rust_2018_idioms,
+    unreachable_pub,
+    bad_style,
+    const_err,
+    dead_code,
+    improper_ctypes,
+    non_shorthand_field_patterns,
+    no_mangle_generic_items,
+    overflowing_literals,
+    path_statements,
+    patterns_in_fns_without_body,
+    private_in_public,
+    unconditional_recursion,
+    unused,
+    unused_allocation,
+    unused_comparisons,
+    unused_parens,
+    while_true
+)]
+use lazy_static::lazy_static;
+
+use std::{fmt, io};
+
+use tracing_core::{
+    callsite::{self, Callsite},
+    dispatcher,
+    field::{self, Field, Visit},
+    identify_callsite,
+    metadata::{Kind, Level},
+    subscriber, Event, Metadata,
+};
+
+#[cfg(feature = "log-tracer")]
+#[cfg_attr(docsrs, doc(cfg(feature = "log-tracer")))]
+pub mod log_tracer;
+
+#[cfg(feature = "trace-logger")]
+#[cfg_attr(docsrs, doc(cfg(feature = "trace-logger")))]
+pub mod trace_logger;
+
+#[cfg(feature = "log-tracer")]
+#[cfg_attr(docsrs, doc(cfg(feature = "log-tracer")))]
+#[doc(inline)]
+pub use self::log_tracer::LogTracer;
+
+#[cfg(feature = "trace-logger")]
+#[cfg_attr(docsrs, doc(cfg(feature = "trace-logger")))]
+#[deprecated(
+    since = "0.1.1",
+    note = "use the `tracing` crate's \"log\" feature flag instead"
+)]
+#[allow(deprecated)]
+#[doc(inline)]
+pub use self::trace_logger::TraceLogger;
+
+#[cfg(feature = "env_logger")]
+#[cfg_attr(docsrs, doc(cfg(feature = "env_logger")))]
+pub mod env_logger;
+
+pub use log;
+
+#[cfg(all(feature = "interest-cache", feature = "log-tracer", feature = "std"))]
+mod interest_cache;
+
+#[cfg(all(feature = "interest-cache", feature = "log-tracer", feature = "std"))]
+#[cfg_attr(
+    docsrs,
+    doc(cfg(all(feature = "interest-cache", feature = "log-tracer", feature = "std")))
+)]
+pub use crate::interest_cache::InterestCacheConfig;
+
+/// Format a log record as a trace event in the current span.
+pub fn format_trace(record: &log::Record<'_>) -> io::Result<()> {
+    dispatch_record(record);
+    Ok(())
+}
+
+// XXX(eliza): this is factored out so that we don't have to deal with the pub
+// function `format_trace`'s `Result` return type...maybe we should get rid of
+// that in 0.2...
+pub(crate) fn dispatch_record(record: &log::Record<'_>) {
+    dispatcher::get_default(|dispatch| {
+        let filter_meta = record.as_trace();
+        if !dispatch.enabled(&filter_meta) {
+            return;
+        }
+
+        let (_, keys, meta) = loglevel_to_cs(record.level());
+
+        let log_module = record.module_path();
+        let log_file = record.file();
+        let log_line = record.line();
+
+        let module = log_module.as_ref().map(|s| s as &dyn field::Value);
+        let file = log_file.as_ref().map(|s| s as &dyn field::Value);
+        let line = log_line.as_ref().map(|s| s as &dyn field::Value);
+
+        dispatch.event(&Event::new(
+            meta,
+            &meta.fields().value_set(&[
+                (&keys.message, Some(record.args() as &dyn field::Value)),
+                (&keys.target, Some(&record.target())),
+                (&keys.module, module),
+                (&keys.file, file),
+                (&keys.line, line),
+            ]),
+        ));
+    });
+}
+
+/// Trait implemented for `tracing` types that can be converted to a `log`
+/// equivalent.
+pub trait AsLog: crate::sealed::Sealed {
+    /// The `log` type that this type can be converted into.
+    type Log;
+    /// Returns the `log` equivalent of `self`.
+    fn as_log(&self) -> Self::Log;
+}
+
+/// Trait implemented for `log` types that can be converted to a `tracing`
+/// equivalent.
+pub trait AsTrace: crate::sealed::Sealed {
+    /// The `tracing` type that this type can be converted into.
+    type Trace;
+    /// Returns the `tracing` equivalent of `self`.
+    fn as_trace(&self) -> Self::Trace;
+}
+
+impl<'a> crate::sealed::Sealed for Metadata<'a> {}
+
+impl<'a> AsLog for Metadata<'a> {
+    type Log = log::Metadata<'a>;
+    fn as_log(&self) -> Self::Log {
+        log::Metadata::builder()
+            .level(self.level().as_log())
+            .target(self.target())
+            .build()
+    }
+}
+impl<'a> crate::sealed::Sealed for log::Metadata<'a> {}
+
+impl<'a> AsTrace for log::Metadata<'a> {
+    type Trace = Metadata<'a>;
+    fn as_trace(&self) -> Self::Trace {
+        let cs_id = identify_callsite!(loglevel_to_cs(self.level()).0);
+        Metadata::new(
+            "log record",
+            self.target(),
+            self.level().as_trace(),
+            None,
+            None,
+            None,
+            field::FieldSet::new(FIELD_NAMES, cs_id),
+            Kind::EVENT,
+        )
+    }
+}
+
+struct Fields {
+    message: field::Field,
+    target: field::Field,
+    module: field::Field,
+    file: field::Field,
+    line: field::Field,
+}
+
+static FIELD_NAMES: &[&str] = &[
+    "message",
+    "log.target",
+    "log.module_path",
+    "log.file",
+    "log.line",
+];
+
+impl Fields {
+    fn new(cs: &'static dyn Callsite) -> Self {
+        let fieldset = cs.metadata().fields();
+        let message = fieldset.field("message").unwrap();
+        let target = fieldset.field("log.target").unwrap();
+        let module = fieldset.field("log.module_path").unwrap();
+        let file = fieldset.field("log.file").unwrap();
+        let line = fieldset.field("log.line").unwrap();
+        Fields {
+            message,
+            target,
+            module,
+            file,
+            line,
+        }
+    }
+}
+
+macro_rules! log_cs {
+    ($level:expr, $cs:ident, $meta:ident, $ty:ident) => {
+        struct $ty;
+        static $cs: $ty = $ty;
+        static $meta: Metadata<'static> = Metadata::new(
+            "log event",
+            "log",
+            $level,
+            None,
+            None,
+            None,
+            field::FieldSet::new(FIELD_NAMES, identify_callsite!(&$cs)),
+            Kind::EVENT,
+        );
+
+        impl callsite::Callsite for $ty {
+            fn set_interest(&self, _: subscriber::Interest) {}
+            fn metadata(&self) -> &'static Metadata<'static> {
+                &$meta
+            }
+        }
+    };
+}
+
+log_cs!(
+    tracing_core::Level::TRACE,
+    TRACE_CS,
+    TRACE_META,
+    TraceCallsite
+);
+log_cs!(
+    tracing_core::Level::DEBUG,
+    DEBUG_CS,
+    DEBUG_META,
+    DebugCallsite
+);
+log_cs!(tracing_core::Level::INFO, INFO_CS, INFO_META, InfoCallsite);
+log_cs!(tracing_core::Level::WARN, WARN_CS, WARN_META, WarnCallsite);
+log_cs!(
+    tracing_core::Level::ERROR,
+    ERROR_CS,
+    ERROR_META,
+    ErrorCallsite
+);
+
+lazy_static! {
+    static ref TRACE_FIELDS: Fields = Fields::new(&TRACE_CS);
+    static ref DEBUG_FIELDS: Fields = Fields::new(&DEBUG_CS);
+    static ref INFO_FIELDS: Fields = Fields::new(&INFO_CS);
+    static ref WARN_FIELDS: Fields = Fields::new(&WARN_CS);
+    static ref ERROR_FIELDS: Fields = Fields::new(&ERROR_CS);
+}
+
+fn level_to_cs(level: Level) -> (&'static dyn Callsite, &'static Fields) {
+    match level {
+        Level::TRACE => (&TRACE_CS, &*TRACE_FIELDS),
+        Level::DEBUG => (&DEBUG_CS, &*DEBUG_FIELDS),
+        Level::INFO => (&INFO_CS, &*INFO_FIELDS),
+        Level::WARN => (&WARN_CS, &*WARN_FIELDS),
+        Level::ERROR => (&ERROR_CS, &*ERROR_FIELDS),
+    }
+}
+
+fn loglevel_to_cs(
+    level: log::Level,
+) -> (
+    &'static dyn Callsite,
+    &'static Fields,
+    &'static Metadata<'static>,
+) {
+    match level {
+        log::Level::Trace => (&TRACE_CS, &*TRACE_FIELDS, &TRACE_META),
+        log::Level::Debug => (&DEBUG_CS, &*DEBUG_FIELDS, &DEBUG_META),
+        log::Level::Info => (&INFO_CS, &*INFO_FIELDS, &INFO_META),
+        log::Level::Warn => (&WARN_CS, &*WARN_FIELDS, &WARN_META),
+        log::Level::Error => (&ERROR_CS, &*ERROR_FIELDS, &ERROR_META),
+    }
+}
+
+impl<'a> crate::sealed::Sealed for log::Record<'a> {}
+
+impl<'a> AsTrace for log::Record<'a> {
+    type Trace = Metadata<'a>;
+    fn as_trace(&self) -> Self::Trace {
+        let cs_id = identify_callsite!(loglevel_to_cs(self.level()).0);
+        Metadata::new(
+            "log record",
+            self.target(),
+            self.level().as_trace(),
+            self.file(),
+            self.line(),
+            self.module_path(),
+            field::FieldSet::new(FIELD_NAMES, cs_id),
+            Kind::EVENT,
+        )
+    }
+}
+
+impl crate::sealed::Sealed for tracing_core::Level {}
+
+impl AsLog for tracing_core::Level {
+    type Log = log::Level;
+    fn as_log(&self) -> log::Level {
+        match *self {
+            tracing_core::Level::ERROR => log::Level::Error,
+            tracing_core::Level::WARN => log::Level::Warn,
+            tracing_core::Level::INFO => log::Level::Info,
+            tracing_core::Level::DEBUG => log::Level::Debug,
+            tracing_core::Level::TRACE => log::Level::Trace,
+        }
+    }
+}
+
+impl crate::sealed::Sealed for log::Level {}
+
+impl AsTrace for log::Level {
+    type Trace = tracing_core::Level;
+    #[inline]
+    fn as_trace(&self) -> tracing_core::Level {
+        match self {
+            log::Level::Error => tracing_core::Level::ERROR,
+            log::Level::Warn => tracing_core::Level::WARN,
+            log::Level::Info => tracing_core::Level::INFO,
+            log::Level::Debug => tracing_core::Level::DEBUG,
+            log::Level::Trace => tracing_core::Level::TRACE,
+        }
+    }
+}
+
+impl crate::sealed::Sealed for log::LevelFilter {}
+
+impl AsTrace for log::LevelFilter {
+    type Trace = tracing_core::LevelFilter;
+    #[inline]
+    fn as_trace(&self) -> tracing_core::LevelFilter {
+        match self {
+            log::LevelFilter::Off => tracing_core::LevelFilter::OFF,
+            log::LevelFilter::Error => tracing_core::LevelFilter::ERROR,
+            log::LevelFilter::Warn => tracing_core::LevelFilter::WARN,
+            log::LevelFilter::Info => tracing_core::LevelFilter::INFO,
+            log::LevelFilter::Debug => tracing_core::LevelFilter::DEBUG,
+            log::LevelFilter::Trace => tracing_core::LevelFilter::TRACE,
+        }
+    }
+}
+
+impl crate::sealed::Sealed for tracing_core::LevelFilter {}
+
+impl AsLog for tracing_core::LevelFilter {
+    type Log = log::LevelFilter;
+    #[inline]
+    fn as_log(&self) -> Self::Log {
+        match *self {
+            tracing_core::LevelFilter::OFF => log::LevelFilter::Off,
+            tracing_core::LevelFilter::ERROR => log::LevelFilter::Error,
+            tracing_core::LevelFilter::WARN => log::LevelFilter::Warn,
+            tracing_core::LevelFilter::INFO => log::LevelFilter::Info,
+            tracing_core::LevelFilter::DEBUG => log::LevelFilter::Debug,
+            tracing_core::LevelFilter::TRACE => log::LevelFilter::Trace,
+        }
+    }
+}
+/// Extends log `Event`s to provide complete `Metadata`.
+///
+/// In `tracing-log`, an `Event` produced by a log (through [`AsTrace`]) has an hard coded
+/// "log" target and no `file`, `line`, or `module_path` attributes. This happens because `Event`
+/// requires its `Metadata` to be `'static`, while [`log::Record`]s provide them with a generic
+/// lifetime.
+///
+/// However, these values are stored in the `Event`'s fields and
+/// the [`normalized_metadata`] method allows to build a new `Metadata`
+/// that only lives as long as its source `Event`, but provides complete
+/// data.
+///
+/// It can typically be used by `Subscriber`s when processing an `Event`,
+/// to allow accessing its complete metadata in a consistent way,
+/// regardless of the source of its source.
+///
+/// [`normalized_metadata`]: NormalizeEvent#normalized_metadata
+pub trait NormalizeEvent<'a>: crate::sealed::Sealed {
+    /// If this `Event` comes from a `log`, this method provides a new
+    /// normalized `Metadata` which has all available attributes
+    /// from the original log, including `file`, `line`, `module_path`
+    /// and `target`.
+    /// Returns `None` is the `Event` is not issued from a `log`.
+    fn normalized_metadata(&'a self) -> Option<Metadata<'a>>;
+    /// Returns whether this `Event` represents a log (from the `log` crate)
+    fn is_log(&self) -> bool;
+}
+
+impl<'a> crate::sealed::Sealed for Event<'a> {}
+
+impl<'a> NormalizeEvent<'a> for Event<'a> {
+    fn normalized_metadata(&'a self) -> Option<Metadata<'a>> {
+        let original = self.metadata();
+        if self.is_log() {
+            let mut fields = LogVisitor::new_for(self, level_to_cs(*original.level()).1);
+            self.record(&mut fields);
+
+            Some(Metadata::new(
+                "log event",
+                fields.target.unwrap_or("log"),
+                *original.level(),
+                fields.file,
+                fields.line.map(|l| l as u32),
+                fields.module_path,
+                field::FieldSet::new(&["message"], original.callsite()),
+                Kind::EVENT,
+            ))
+        } else {
+            None
+        }
+    }
+
+    fn is_log(&self) -> bool {
+        self.metadata().callsite() == identify_callsite!(level_to_cs(*self.metadata().level()).0)
+    }
+}
+
+struct LogVisitor<'a> {
+    target: Option<&'a str>,
+    module_path: Option<&'a str>,
+    file: Option<&'a str>,
+    line: Option<u64>,
+    fields: &'static Fields,
+}
+
+impl<'a> LogVisitor<'a> {
+    // We don't actually _use_ the provided event argument; it is simply to
+    // ensure that the `LogVisitor` does not outlive the event whose fields it
+    // is visiting, so that the reference casts in `record_str` are safe.
+    fn new_for(_event: &'a Event<'a>, fields: &'static Fields) -> Self {
+        Self {
+            target: None,
+            module_path: None,
+            file: None,
+            line: None,
+            fields,
+        }
+    }
+}
+
+impl<'a> Visit for LogVisitor<'a> {
+    fn record_debug(&mut self, _field: &Field, _value: &dyn fmt::Debug) {}
+
+    fn record_u64(&mut self, field: &Field, value: u64) {
+        if field == &self.fields.line {
+            self.line = Some(value);
+        }
+    }
+
+    fn record_str(&mut self, field: &Field, value: &str) {
+        unsafe {
+            // The `Visit` API erases the string slice's lifetime. However, we
+            // know it is part of the `Event` struct with a lifetime of `'a`. If
+            // (and only if!) this `LogVisitor` was constructed with the same
+            // lifetime parameter `'a` as the event in question, it's safe to
+            // cast these string slices to the `'a` lifetime.
+            if field == &self.fields.file {
+                self.file = Some(&*(value as *const _));
+            } else if field == &self.fields.target {
+                self.target = Some(&*(value as *const _));
+            } else if field == &self.fields.module {
+                self.module_path = Some(&*(value as *const _));
+            }
+        }
+    }
+}
+
+mod sealed {
+    pub trait Sealed {}
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    fn test_callsite(level: log::Level) {
+        let record = log::Record::builder()
+            .args(format_args!("Error!"))
+            .level(level)
+            .target("myApp")
+            .file(Some("server.rs"))
+            .line(Some(144))
+            .module_path(Some("server"))
+            .build();
+
+        let meta = record.as_trace();
+        let (cs, _keys, _) = loglevel_to_cs(record.level());
+        let cs_meta = cs.metadata();
+        assert_eq!(
+            meta.callsite(),
+            cs_meta.callsite(),
+            "actual: {:#?}\nexpected: {:#?}",
+            meta,
+            cs_meta
+        );
+        assert_eq!(meta.level(), &level.as_trace());
+    }
+
+    #[test]
+    fn error_callsite_is_correct() {
+        test_callsite(log::Level::Error);
+    }
+
+    #[test]
+    fn warn_callsite_is_correct() {
+        test_callsite(log::Level::Warn);
+    }
+
+    #[test]
+    fn info_callsite_is_correct() {
+        test_callsite(log::Level::Info);
+    }
+
+    #[test]
+    fn debug_callsite_is_correct() {
+        test_callsite(log::Level::Debug);
+    }
+
+    #[test]
+    fn trace_callsite_is_correct() {
+        test_callsite(log::Level::Trace);
+    }
+}
diff --git a/vendor/tracing-log/src/log_tracer.rs b/vendor/tracing-log/src/log_tracer.rs
new file mode 100644
index 000000000..6b24dab10
--- /dev/null
+++ b/vendor/tracing-log/src/log_tracer.rs
@@ -0,0 +1,307 @@
+//! An adapter for converting [`log`] records into `tracing` `Event`s.
+//!
+//! This module provides the [`LogTracer`] type which implements `log`'s [logger
+//! interface] by recording log records as `tracing` `Event`s. This is intended for
+//! use in conjunction with a `tracing` `Subscriber` to consume events from
+//! dependencies that emit [`log`] records within a trace context.
+//!
+//! # Usage
+//!
+//! To create and initialize a `LogTracer` with the default configurations, use:
+//!
+//! * [`init`] if you want to convert all logs, regardless of log level,
+//!   allowing the tracing `Subscriber` to perform any filtering
+//! * [`init_with_filter`] to convert all logs up to a specified log level
+//!
+//! In addition, a [builder] is available for cases where more advanced
+//! configuration is required. In particular, the builder can be used to [ignore
+//! log records][ignore] emitted by particular crates. This is useful in cases
+//! such as when a crate emits both `tracing` diagnostics _and_ log records by
+//! default.
+//!
+//! [logger interface]: log::Log
+//! [`init`]: LogTracer.html#method.init
+//! [`init_with_filter`]: LogTracer.html#method.init_with_filter
+//! [builder]: LogTracer::builder()
+//! [ignore]: Builder::ignore_crate()
+use crate::AsTrace;
+pub use log::SetLoggerError;
+use tracing_core::dispatcher;
+
+/// A simple "logger" that converts all log records into `tracing` `Event`s.
+#[derive(Debug)]
+pub struct LogTracer {
+    ignore_crates: Box<[String]>,
+}
+
+/// Configures a new `LogTracer`.
+#[derive(Debug)]
+pub struct Builder {
+    ignore_crates: Vec<String>,
+    filter: log::LevelFilter,
+    #[cfg(all(feature = "interest-cache", feature = "std"))]
+    interest_cache_config: Option<crate::InterestCacheConfig>,
+}
+
+// ===== impl LogTracer =====
+
+impl LogTracer {
+    /// Returns a builder that allows customizing a `LogTracer` and setting it
+    /// the default logger.
+    ///
+    /// For example:
+    /// ```rust
+    /// # use std::error::Error;
+    /// use tracing_log::LogTracer;
+    /// use log;
+    ///
+    /// # fn main() -> Result<(), Box<Error>> {
+    /// LogTracer::builder()
+    ///     .ignore_crate("foo") // suppose the `foo` crate is using `tracing`'s log feature
+    ///     .with_max_level(log::LevelFilter::Info)
+    ///     .init()?;
+    ///
+    /// // will be available for Subscribers as a tracing Event
+    /// log::info!("an example info log");
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn builder() -> Builder {
+        Builder::default()
+    }
+
+    /// Creates a new `LogTracer` that can then be used as a logger for the `log` crate.
+    ///
+    /// It is generally simpler to use the [`init`] or [`init_with_filter`] methods
+    /// which will create the `LogTracer` and set it as the global logger.
+    ///
+    /// Logger setup without the initialization methods can be done with:
+    ///
+    /// ```rust
+    /// # use std::error::Error;
+    /// use tracing_log::LogTracer;
+    /// use log;
+    ///
+    /// # fn main() -> Result<(), Box<Error>> {
+    /// let logger = LogTracer::new();
+    /// log::set_boxed_logger(Box::new(logger))?;
+    /// log::set_max_level(log::LevelFilter::Trace);
+    ///
+    /// // will be available for Subscribers as a tracing Event
+    /// log::trace!("an example trace log");
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`init`]: LogTracer::init()
+    /// [`init_with_filter`]: .#method.init_with_filter
+    pub fn new() -> Self {
+        Self {
+            ignore_crates: Vec::new().into_boxed_slice(),
+        }
+    }
+
+    /// Sets up `LogTracer` as global logger for the `log` crate,
+    /// with the given level as max level filter.
+    ///
+    /// Setting a global logger can only be done once.
+    ///
+    /// The [`builder`] function can be used to customize the `LogTracer` before
+    /// initializing it.
+    ///
+    /// [`builder`]: LogTracer::builder()
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    pub fn init_with_filter(level: log::LevelFilter) -> Result<(), SetLoggerError> {
+        Self::builder().with_max_level(level).init()
+    }
+
+    /// Sets a `LogTracer` as the global logger for the `log` crate.
+    ///
+    /// Setting a global logger can only be done once.
+    ///
+    /// ```rust
+    /// # use std::error::Error;
+    /// use tracing_log::LogTracer;
+    /// use log;
+    ///
+    /// # fn main() -> Result<(), Box<Error>> {
+    /// LogTracer::init()?;
+    ///
+    /// // will be available for Subscribers as a tracing Event
+    /// log::trace!("an example trace log");
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// This will forward all logs to `tracing` and lets the current `Subscriber`
+    /// determine if they are enabled.
+    ///
+    /// The [`builder`] function can be used to customize the `LogTracer` before
+    /// initializing it.
+    ///
+    /// If you know in advance you want to filter some log levels,
+    /// use [`builder`] or [`init_with_filter`] instead.
+    ///
+    /// [`init_with_filter`]: LogTracer::init_with_filter()
+    /// [`builder`]: LogTracer::builder()
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    pub fn init() -> Result<(), SetLoggerError> {
+        Self::builder().init()
+    }
+}
+
+impl Default for LogTracer {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(all(feature = "interest-cache", feature = "std"))]
+use crate::interest_cache::try_cache as try_cache_interest;
+
+#[cfg(not(all(feature = "interest-cache", feature = "std")))]
+fn try_cache_interest(_: &log::Metadata<'_>, callback: impl FnOnce() -> bool) -> bool {
+    callback()
+}
+
+impl log::Log for LogTracer {
+    fn enabled(&self, metadata: &log::Metadata<'_>) -> bool {
+        // First, check the log record against the current max level enabled by
+        // the current `tracing` subscriber.
+        if metadata.level().as_trace() > tracing_core::LevelFilter::current() {
+            // If the log record's level is above that, disable it.
+            return false;
+        }
+
+        // Okay, it wasn't disabled by the max level — do we have any specific
+        // modules to ignore?
+        if !self.ignore_crates.is_empty() {
+            // If we are ignoring certain module paths, ensure that the metadata
+            // does not start with one of those paths.
+            let target = metadata.target();
+            for ignored in &self.ignore_crates[..] {
+                if target.starts_with(ignored) {
+                    return false;
+                }
+            }
+        }
+
+        try_cache_interest(metadata, || {
+            // Finally, check if the current `tracing` dispatcher cares about this.
+            dispatcher::get_default(|dispatch| dispatch.enabled(&metadata.as_trace()))
+        })
+    }
+
+    fn log(&self, record: &log::Record<'_>) {
+        if self.enabled(record.metadata()) {
+            crate::dispatch_record(record);
+        }
+    }
+
+    fn flush(&self) {}
+}
+
+// ===== impl Builder =====
+
+impl Builder {
+    /// Returns a new `Builder` to construct a [`LogTracer`].
+    ///
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Sets a global maximum level for `log` records.
+    ///
+    /// Log records whose level is more verbose than the provided level will be
+    /// disabled.
+    ///
+    /// By default, all `log` records will be enabled.
+    pub fn with_max_level(self, filter: impl Into<log::LevelFilter>) -> Self {
+        let filter = filter.into();
+        Self { filter, ..self }
+    }
+
+    /// Configures the `LogTracer` to ignore all log records whose target
+    /// starts with the given string.
+    ///
+    /// This should be used when a crate enables the `tracing/log` feature to
+    /// emit log records for tracing events. Otherwise, those events will be
+    /// recorded twice.
+    pub fn ignore_crate(mut self, name: impl Into<String>) -> Self {
+        self.ignore_crates.push(name.into());
+        self
+    }
+
+    /// Configures the `LogTracer` to ignore all log records whose target
+    /// starts with any of the given the given strings.
+    ///
+    /// This should be used when a crate enables the `tracing/log` feature to
+    /// emit log records for tracing events. Otherwise, those events will be
+    /// recorded twice.
+    pub fn ignore_all<I>(self, crates: impl IntoIterator<Item = I>) -> Self
+    where
+        I: Into<String>,
+    {
+        crates.into_iter().fold(self, Self::ignore_crate)
+    }
+
+    /// Configures the `LogTracer` to either disable or enable the interest cache.
+    ///
+    /// When enabled, a per-thread LRU cache will be used to cache whenever the logger
+    /// is interested in a given [level] + [target] pair for records generated through
+    /// the `log` crate.
+    ///
+    /// When no `trace!` logs are enabled the logger is able to cheaply filter
+    /// them out just by comparing their log level to the globally specified
+    /// maximum, and immediately reject them. When *any* other `trace!` log is
+    /// enabled (even one which doesn't actually exist!) the logger has to run
+    /// its full filtering machinery on each and every `trace!` log, which can
+    /// potentially be very expensive.
+    ///
+    /// Enabling this cache is useful in such situations to improve performance.
+    ///
+    /// You most likely do not want to enabled this if you have registered any dynamic
+    /// filters on your logger and you want them to be run every time.
+    ///
+    /// This is disabled by default.
+    ///
+    /// [level]: log::Metadata::level
+    /// [target]: log::Metadata::target
+    #[cfg(all(feature = "interest-cache", feature = "std"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "interest-cache", feature = "std"))))]
+    pub fn with_interest_cache(mut self, config: crate::InterestCacheConfig) -> Self {
+        self.interest_cache_config = Some(config);
+        self
+    }
+
+    /// Constructs a new `LogTracer` with the provided configuration and sets it
+    /// as the default logger.
+    ///
+    /// Setting a global logger can only be done once.
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    #[allow(unused_mut)]
+    pub fn init(mut self) -> Result<(), SetLoggerError> {
+        #[cfg(all(feature = "interest-cache", feature = "std"))]
+        crate::interest_cache::configure(self.interest_cache_config.take());
+
+        let ignore_crates = self.ignore_crates.into_boxed_slice();
+        let logger = Box::new(LogTracer { ignore_crates });
+        log::set_boxed_logger(logger)?;
+        log::set_max_level(self.filter);
+        Ok(())
+    }
+}
+
+impl Default for Builder {
+    fn default() -> Self {
+        Self {
+            ignore_crates: Vec::new(),
+            filter: log::LevelFilter::max(),
+            #[cfg(all(feature = "interest-cache", feature = "std"))]
+            interest_cache_config: None,
+        }
+    }
+}
diff --git a/vendor/tracing-log/src/trace_logger.rs b/vendor/tracing-log/src/trace_logger.rs
new file mode 100644
index 000000000..88a52f752
--- /dev/null
+++ b/vendor/tracing-log/src/trace_logger.rs
@@ -0,0 +1,458 @@
+//! A `tracing` [`Subscriber`] that uses the [`log`] crate as a backend for
+//! formatting `tracing` spans and events.
+//!
+//! When a [`TraceLogger`] is set as the current subscriber, it will record
+//! traces by emitting [`log::Record`]s that can be collected by a logger.
+//!
+//! **Note**: This API has been deprecated since version 0.1.1. In order to emit
+//! `tracing` events as `log` records, the ["log" and "log-always" feature
+//! flags][flags] on the `tracing` crate should be used instead.
+//!
+//! [`log`]: log
+//! [`Subscriber`]: https://docs.rs/tracing/0.1.7/tracing/subscriber/trait.Subscriber.html
+//! [`log::Record`]:log::Record
+//! [flags]: https://docs.rs/tracing/latest/tracing/#crate-feature-flags
+#![deprecated(
+    since = "0.1.1",
+    note = "use the `tracing` crate's \"log\" feature flag instead"
+)]
+use crate::AsLog;
+use std::{
+    cell::RefCell,
+    collections::HashMap,
+    fmt::{self, Write},
+    sync::{
+        atomic::{AtomicUsize, Ordering},
+        Mutex,
+    },
+};
+use tracing_core::{
+    field,
+    span::{self, Id},
+    Event, Metadata, Subscriber,
+};
+
+/// A `tracing` [`Subscriber`] implementation that logs all recorded
+/// trace events.
+///
+/// **Note**: This API has been deprecated since version 0.1.1. In order to emit
+/// `tracing` events as `log` records, the ["log" and "log-always" feature
+/// flags][flags] on the `tracing` crate should be used instead.
+///
+/// [`Subscriber`]: https://docs.rs/tracing/0.1.7/tracing/subscriber/trait.Subscriber.html
+/// [flags]: https://docs.rs/tracing/latest/tracing/#crate-feature-flags
+pub struct TraceLogger {
+    settings: Builder,
+    spans: Mutex<HashMap<Id, SpanLineBuilder>>,
+    next_id: AtomicUsize,
+}
+
+thread_local! {
+    static CURRENT: RefCell<Vec<Id>> = RefCell::new(Vec::new());
+}
+/// Configures and constructs a [`TraceLogger`].
+///
+#[derive(Debug)]
+pub struct Builder {
+    log_span_closes: bool,
+    log_enters: bool,
+    log_exits: bool,
+    log_ids: bool,
+    parent_fields: bool,
+    log_parent: bool,
+}
+
+// ===== impl TraceLogger =====
+
+impl TraceLogger {
+    /// Returns a new `TraceLogger` with the default configuration.
+    pub fn new() -> Self {
+        Self::builder().finish()
+    }
+
+    /// Returns a `Builder` for configuring a `TraceLogger`.
+    pub fn builder() -> Builder {
+        Default::default()
+    }
+
+    fn from_builder(settings: Builder) -> Self {
+        Self {
+            settings,
+            ..Default::default()
+        }
+    }
+
+    fn next_id(&self) -> Id {
+        Id::from_u64(self.next_id.fetch_add(1, Ordering::SeqCst) as u64)
+    }
+}
+
+// ===== impl Builder =====
+
+impl Builder {
+    /// Configures whether or not the [`TraceLogger`] being constructed will log
+    /// when a span closes.
+    ///
+    pub fn with_span_closes(self, log_span_closes: bool) -> Self {
+        Self {
+            log_span_closes,
+            ..self
+        }
+    }
+
+    /// Configures whether or not the [`TraceLogger`] being constructed will
+    /// include the fields of parent spans when formatting events.
+    ///
+    pub fn with_parent_fields(self, parent_fields: bool) -> Self {
+        Self {
+            parent_fields,
+            ..self
+        }
+    }
+
+    /// Configures whether or not the [`TraceLogger`] being constructed will log
+    /// when a span is entered.
+    ///
+    /// If this is set to false, fields from the current span will still be
+    /// recorded as context, but the actual entry will not create a log record.
+    ///
+    pub fn with_span_entry(self, log_enters: bool) -> Self {
+        Self { log_enters, ..self }
+    }
+
+    /// Configures whether or not the [`TraceLogger`] being constructed will log
+    /// when a span is exited.
+    ///
+    pub fn with_span_exits(self, log_exits: bool) -> Self {
+        Self { log_exits, ..self }
+    }
+
+    /// Configures whether or not the [`TraceLogger`] being constructed will
+    /// include span IDs when formatting log output.
+    ///
+    pub fn with_ids(self, log_ids: bool) -> Self {
+        Self { log_ids, ..self }
+    }
+
+    /// Configures whether or not the [`TraceLogger`] being constructed will
+    /// include the names of parent spans as context when formatting events.
+    ///
+    pub fn with_parent_names(self, log_parent: bool) -> Self {
+        Self { log_parent, ..self }
+    }
+
+    /// Complete the builder, returning a configured [`TraceLogger`].
+    ///
+    pub fn finish(self) -> TraceLogger {
+        TraceLogger::from_builder(self)
+    }
+}
+
+impl Default for Builder {
+    fn default() -> Self {
+        Builder {
+            log_span_closes: false,
+            parent_fields: true,
+            log_exits: false,
+            log_ids: false,
+            log_parent: true,
+            log_enters: false,
+        }
+    }
+}
+
+impl Default for TraceLogger {
+    fn default() -> Self {
+        TraceLogger {
+            settings: Default::default(),
+            spans: Default::default(),
+            next_id: AtomicUsize::new(1),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct SpanLineBuilder {
+    parent: Option<Id>,
+    ref_count: usize,
+    fields: String,
+    file: Option<String>,
+    line: Option<u32>,
+    module_path: Option<String>,
+    target: String,
+    level: log::Level,
+    name: &'static str,
+}
+
+impl SpanLineBuilder {
+    fn new(parent: Option<Id>, meta: &Metadata<'_>, fields: String) -> Self {
+        Self {
+            parent,
+            ref_count: 1,
+            fields,
+            file: meta.file().map(String::from),
+            line: meta.line(),
+            module_path: meta.module_path().map(String::from),
+            target: String::from(meta.target()),
+            level: meta.level().as_log(),
+            name: meta.name(),
+        }
+    }
+
+    fn log_meta(&self) -> log::Metadata<'_> {
+        log::MetadataBuilder::new()
+            .level(self.level)
+            .target(self.target.as_ref())
+            .build()
+    }
+
+    fn finish(self) {
+        let log_meta = self.log_meta();
+        let logger = log::logger();
+        if logger.enabled(&log_meta) {
+            logger.log(
+                &log::Record::builder()
+                    .metadata(log_meta)
+                    .target(self.target.as_ref())
+                    .module_path(self.module_path.as_ref().map(String::as_ref))
+                    .file(self.file.as_ref().map(String::as_ref))
+                    .line(self.line)
+                    .args(format_args!("close {}; {}", self.name, self.fields))
+                    .build(),
+            );
+        }
+    }
+}
+
+impl field::Visit for SpanLineBuilder {
+    fn record_debug(&mut self, field: &field::Field, value: &dyn fmt::Debug) {
+        write!(self.fields, " {}={:?};", field.name(), value)
+            .expect("write to string should never fail")
+    }
+}
+
+impl Subscriber for TraceLogger {
+    fn enabled(&self, metadata: &Metadata<'_>) -> bool {
+        log::logger().enabled(&metadata.as_log())
+    }
+
+    fn new_span(&self, attrs: &span::Attributes<'_>) -> Id {
+        let id = self.next_id();
+        let mut spans = self.spans.lock().unwrap();
+        let mut fields = String::new();
+        let parent = self.current_id();
+        if self.settings.parent_fields {
+            let mut next_parent = parent.as_ref();
+            while let Some(parent) = next_parent.and_then(|p| spans.get(p)) {
+                write!(&mut fields, "{}", parent.fields).expect("write to string cannot fail");
+                next_parent = parent.parent.as_ref();
+            }
+        }
+        let mut span = SpanLineBuilder::new(parent, attrs.metadata(), fields);
+        attrs.record(&mut span);
+        spans.insert(id.clone(), span);
+        id
+    }
+
+    fn record(&self, span: &Id, values: &span::Record<'_>) {
+        let mut spans = self.spans.lock().unwrap();
+        if let Some(span) = spans.get_mut(span) {
+            values.record(span);
+        }
+    }
+
+    fn record_follows_from(&self, span: &Id, follows: &Id) {
+        // TODO: this should eventually track the relationship?
+        log::logger().log(
+            &log::Record::builder()
+                .level(log::Level::Trace)
+                .args(format_args!("span {:?} follows_from={:?};", span, follows))
+                .build(),
+        );
+    }
+
+    fn enter(&self, id: &Id) {
+        let _ = CURRENT.try_with(|current| {
+            let mut current = current.borrow_mut();
+            if current.contains(id) {
+                // Ignore duplicate enters.
+                return;
+            }
+            current.push(id.clone());
+        });
+        let spans = self.spans.lock().unwrap();
+        if self.settings.log_enters {
+            if let Some(span) = spans.get(id) {
+                let log_meta = span.log_meta();
+                let logger = log::logger();
+                if logger.enabled(&log_meta) {
+                    let current_id = self.current_id();
+                    let current_fields = current_id
+                        .as_ref()
+                        .and_then(|id| spans.get(id))
+                        .map(|span| span.fields.as_ref())
+                        .unwrap_or("");
+                    if self.settings.log_ids {
+                        logger.log(
+                            &log::Record::builder()
+                                .metadata(log_meta)
+                                .target(span.target.as_ref())
+                                .module_path(span.module_path.as_ref().map(String::as_ref))
+                                .file(span.file.as_ref().map(String::as_ref))
+                                .line(span.line)
+                                .args(format_args!(
+                                    "enter {}; in={:?}; {}",
+                                    span.name, current_id, current_fields
+                                ))
+                                .build(),
+                        );
+                    } else {
+                        logger.log(
+                            &log::Record::builder()
+                                .metadata(log_meta)
+                                .target(span.target.as_ref())
+                                .module_path(span.module_path.as_ref().map(String::as_ref))
+                                .file(span.file.as_ref().map(String::as_ref))
+                                .line(span.line)
+                                .args(format_args!("enter {}; {}", span.name, current_fields))
+                                .build(),
+                        );
+                    }
+                }
+            }
+        }
+    }
+
+    fn exit(&self, id: &Id) {
+        let _ = CURRENT.try_with(|current| {
+            let mut current = current.borrow_mut();
+            if current.last() == Some(id) {
+                current.pop()
+            } else {
+                None
+            }
+        });
+        if self.settings.log_exits {
+            let spans = self.spans.lock().unwrap();
+            if let Some(span) = spans.get(id) {
+                let log_meta = span.log_meta();
+                let logger = log::logger();
+                if logger.enabled(&log_meta) {
+                    logger.log(
+                        &log::Record::builder()
+                            .metadata(log_meta)
+                            .target(span.target.as_ref())
+                            .module_path(span.module_path.as_ref().map(String::as_ref))
+                            .file(span.file.as_ref().map(String::as_ref))
+                            .line(span.line)
+                            .args(format_args!("exit {}", span.name))
+                            .build(),
+                    );
+                }
+            }
+        }
+    }
+
+    fn event(&self, event: &Event<'_>) {
+        let meta = event.metadata();
+        let log_meta = meta.as_log();
+        let logger = log::logger();
+        if logger.enabled(&log_meta) {
+            let spans = self.spans.lock().unwrap();
+            let current = self.current_id().and_then(|id| spans.get(&id));
+            let (current_fields, parent) = current
+                .map(|span| {
+                    let fields = span.fields.as_ref();
+                    let parent = if self.settings.log_parent {
+                        Some(span.name)
+                    } else {
+                        None
+                    };
+                    (fields, parent)
+                })
+                .unwrap_or(("", None));
+            logger.log(
+                &log::Record::builder()
+                    .metadata(log_meta)
+                    .target(meta.target())
+                    .module_path(meta.module_path().as_ref().cloned())
+                    .file(meta.file().as_ref().cloned())
+                    .line(meta.line())
+                    .args(format_args!(
+                        "{}{}{}{}",
+                        parent.unwrap_or(""),
+                        if parent.is_some() { ": " } else { "" },
+                        LogEvent(event),
+                        current_fields,
+                    ))
+                    .build(),
+            );
+        }
+    }
+
+    fn clone_span(&self, id: &Id) -> Id {
+        let mut spans = self.spans.lock().unwrap();
+        if let Some(span) = spans.get_mut(id) {
+            span.ref_count += 1;
+        }
+        id.clone()
+    }
+
+    fn try_close(&self, id: Id) -> bool {
+        let mut spans = self.spans.lock().unwrap();
+        if spans.contains_key(&id) {
+            if spans.get(&id).unwrap().ref_count == 1 {
+                let span = spans.remove(&id).unwrap();
+                if self.settings.log_span_closes {
+                    span.finish();
+                }
+                return true;
+            } else {
+                spans.get_mut(&id).unwrap().ref_count -= 1;
+            }
+        }
+        false
+    }
+}
+
+impl TraceLogger {
+    #[inline]
+    fn current_id(&self) -> Option<Id> {
+        CURRENT
+            .try_with(|current| current.borrow().last().map(|span| self.clone_span(span)))
+            .ok()?
+    }
+}
+
+struct LogEvent<'a>(&'a Event<'a>);
+
+impl<'a> fmt::Display for LogEvent<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut has_logged = false;
+        let mut format_fields = |field: &field::Field, value: &dyn fmt::Debug| {
+            let name = field.name();
+            let leading = if has_logged { " " } else { "" };
+            // TODO: handle fmt error?
+            let _ = if name == "message" {
+                write!(f, "{}{:?};", leading, value)
+            } else {
+                write!(f, "{}{}={:?};", leading, name, value)
+            };
+            has_logged = true;
+        };
+
+        self.0.record(&mut format_fields);
+        Ok(())
+    }
+}
+
+impl fmt::Debug for TraceLogger {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TraceLogger")
+            .field("settings", &self.settings)
+            .field("spans", &self.spans)
+            .field("current", &self.current_id())
+            .field("next_id", &self.next_id)
+            .finish()
+    }
+}
diff --git a/vendor/tracing-log/tests/log_tracer.rs b/vendor/tracing-log/tests/log_tracer.rs
new file mode 100644
index 000000000..a1bee93b6
--- /dev/null
+++ b/vendor/tracing-log/tests/log_tracer.rs
@@ -0,0 +1,123 @@
+use std::sync::{Arc, Mutex};
+use tracing::subscriber::with_default;
+use tracing_core::span::{Attributes, Record};
+use tracing_core::{span, Event, Level, LevelFilter, Metadata, Subscriber};
+use tracing_log::{LogTracer, NormalizeEvent};
+
+struct State {
+    last_normalized_metadata: Mutex<(bool, Option<OwnedMetadata>)>,
+}
+
+#[derive(PartialEq, Debug)]
+struct OwnedMetadata {
+    name: String,
+    target: String,
+    level: Level,
+    module_path: Option<String>,
+    file: Option<String>,
+    line: Option<u32>,
+}
+
+struct TestSubscriber(Arc<State>);
+
+impl Subscriber for TestSubscriber {
+    fn enabled(&self, meta: &Metadata<'_>) -> bool {
+        dbg!(meta);
+        true
+    }
+
+    fn max_level_hint(&self) -> Option<LevelFilter> {
+        Some(LevelFilter::from_level(Level::INFO))
+    }
+
+    fn new_span(&self, _span: &Attributes<'_>) -> span::Id {
+        span::Id::from_u64(42)
+    }
+
+    fn record(&self, _span: &span::Id, _values: &Record<'_>) {}
+
+    fn record_follows_from(&self, _span: &span::Id, _follows: &span::Id) {}
+
+    fn event(&self, event: &Event<'_>) {
+        dbg!(event);
+        *self.0.last_normalized_metadata.lock().unwrap() = (
+            event.is_log(),
+            event.normalized_metadata().map(|normalized| OwnedMetadata {
+                name: normalized.name().to_string(),
+                target: normalized.target().to_string(),
+                level: *normalized.level(),
+                module_path: normalized.module_path().map(String::from),
+                file: normalized.file().map(String::from),
+                line: normalized.line(),
+            }),
+        )
+    }
+
+    fn enter(&self, _span: &span::Id) {}
+
+    fn exit(&self, _span: &span::Id) {}
+}
+
+#[test]
+fn normalized_metadata() {
+    LogTracer::init().unwrap();
+    let me = Arc::new(State {
+        last_normalized_metadata: Mutex::new((false, None)),
+    });
+    let state = me.clone();
+
+    with_default(TestSubscriber(me), || {
+        log::info!("expected info log");
+        log::debug!("unexpected debug log");
+        let log = log::Record::builder()
+            .args(format_args!("Error!"))
+            .level(log::Level::Info)
+            .build();
+        log::logger().log(&log);
+        last(
+            &state,
+            true,
+            Some(OwnedMetadata {
+                name: "log event".to_string(),
+                target: "".to_string(),
+                level: Level::INFO,
+                module_path: None,
+                file: None,
+                line: None,
+            }),
+        );
+
+        let log = log::Record::builder()
+            .args(format_args!("Error!"))
+            .level(log::Level::Info)
+            .target("log_tracer_target")
+            .file(Some("server.rs"))
+            .line(Some(144))
+            .module_path(Some("log_tracer"))
+            .build();
+        log::logger().log(&log);
+        last(
+            &state,
+            true,
+            Some(OwnedMetadata {
+                name: "log event".to_string(),
+                target: "log_tracer_target".to_string(),
+                level: Level::INFO,
+                module_path: Some("log_tracer".to_string()),
+                file: Some("server.rs".to_string()),
+                line: Some(144),
+            }),
+        );
+
+        tracing::info!("test with a tracing info");
+        last(&state, false, None);
+    })
+}
+
+fn last(state: &State, should_be_log: bool, expected: Option<OwnedMetadata>) {
+    let lock = state.last_normalized_metadata.lock().unwrap();
+    let (is_log, metadata) = &*lock;
+    dbg!(&metadata);
+    assert_eq!(dbg!(*is_log), should_be_log);
+    assert_eq!(metadata.as_ref(), expected.as_ref());
+}
diff --git a/vendor/tracing-log/tests/reexport_log_crate.rs b/vendor/tracing-log/tests/reexport_log_crate.rs
new file mode 100644
index 000000000..1540941f2
--- /dev/null
+++ b/vendor/tracing-log/tests/reexport_log_crate.rs
@@ -0,0 +1,10 @@
+use tracing_log::{log::LevelFilter, LogTracer};
+
+/// This test makes sure we can access `log::LevelFilter` through the `tracing_log` crate and don't
+/// have to depend on `log` separately.
+///
+/// See https://github.com/tokio-rs/tracing/issues/552.
+#[test]
+fn can_initialize_log_tracer_with_level() {
+    LogTracer::init_with_filter(LevelFilter::Error).unwrap();
+}