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-rw-r--r--vendor/tracing-subscriber/src/reload.rs360
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diff --git a/vendor/tracing-subscriber/src/reload.rs b/vendor/tracing-subscriber/src/reload.rs
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--- a/vendor/tracing-subscriber/src/reload.rs
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-//! Wrapper for a `Layer` to allow it to be dynamically reloaded.
-//!
-//! This module provides a [`Layer` type] implementing the [`Layer` trait] or [`Filter` trait]
-//! which wraps another type implementing the corresponding trait. This
-//! allows the wrapped type to be replaced with another
-//! instance of that type at runtime.
-//!
-//! This can be used in cases where a subset of `Layer` or `Filter` functionality
-//! should be dynamically reconfigured, such as when filtering directives may
-//! change at runtime. Note that this layer introduces a (relatively small)
-//! amount of overhead, and should thus only be used as needed.
-//!
-//! # Examples
-//!
-//! Reloading a [global filtering](crate::layer#global-filtering) layer:
-//!
-//! ```rust
-//! # use tracing::info;
-//! use tracing_subscriber::{filter, fmt, reload, prelude::*};
-//! let filter = filter::LevelFilter::WARN;
-//! let (filter, reload_handle) = reload::Layer::new(filter);
-//! tracing_subscriber::registry()
-//! .with(filter)
-//! .with(fmt::Layer::default())
-//! .init();
-//! #
-//! # // specifying the Registry type is required
-//! # let _: &reload::Handle<filter::LevelFilter, tracing_subscriber::Registry> = &reload_handle;
-//! #
-//! info!("This will be ignored");
-//! reload_handle.modify(|filter| *filter = filter::LevelFilter::INFO);
-//! info!("This will be logged");
-//! ```
-//!
-//! Reloading a [`Filtered`](crate::filter::Filtered) layer:
-//!
-//! ```rust
-//! # use tracing::info;
-//! use tracing_subscriber::{filter, fmt, reload, prelude::*};
-//! let filtered_layer = fmt::Layer::default().with_filter(filter::LevelFilter::WARN);
-//! let (filtered_layer, reload_handle) = reload::Layer::new(filtered_layer);
-//! #
-//! # // specifying the Registry type is required
-//! # let _: &reload::Handle<filter::Filtered<fmt::Layer<tracing_subscriber::Registry>,
-//! # filter::LevelFilter, tracing_subscriber::Registry>,tracing_subscriber::Registry>
-//! # = &reload_handle;
-//! #
-//! tracing_subscriber::registry()
-//! .with(filtered_layer)
-//! .init();
-//! info!("This will be ignored");
-//! reload_handle.modify(|layer| *layer.filter_mut() = filter::LevelFilter::INFO);
-//! info!("This will be logged");
-//! ```
-//!
-//! ## Note
-//!
-//! The [`Layer`] implementation is unable to implement downcasting functionality,
-//! so certain [`Layer`] will fail to downcast if wrapped in a `reload::Layer`.
-//!
-//! If you only want to be able to dynamically change the
-//! `Filter` on a layer, prefer wrapping that `Filter` in the `reload::Layer`.
-//!
-//! [`Filter` trait]: crate::layer::Filter
-//! [`Layer` type]: Layer
-//! [`Layer` trait]: super::layer::Layer
-use crate::layer;
-use crate::sync::RwLock;
-
-use std::{
- error, fmt,
- marker::PhantomData,
- sync::{Arc, Weak},
-};
-use tracing_core::{
- callsite, span,
- subscriber::{Interest, Subscriber},
- Event, LevelFilter, Metadata,
-};
-
-/// Wraps a `Layer` or `Filter`, allowing it to be reloaded dynamically at runtime.
-#[derive(Debug)]
-pub struct Layer<L, S> {
- // TODO(eliza): this once used a `crossbeam_util::ShardedRwLock`. We may
- // eventually wish to replace it with a sharded lock implementation on top
- // of our internal `RwLock` wrapper type. If possible, we should profile
- // this first to determine if it's necessary.
- inner: Arc<RwLock<L>>,
- _s: PhantomData<fn(S)>,
-}
-
-/// Allows reloading the state of an associated [`Layer`](crate::layer::Layer).
-#[derive(Debug)]
-pub struct Handle<L, S> {
- inner: Weak<RwLock<L>>,
- _s: PhantomData<fn(S)>,
-}
-
-/// Indicates that an error occurred when reloading a layer.
-#[derive(Debug)]
-pub struct Error {
- kind: ErrorKind,
-}
-
-#[derive(Debug)]
-enum ErrorKind {
- SubscriberGone,
- Poisoned,
-}
-
-// ===== impl Layer =====
-
-impl<L, S> crate::Layer<S> for Layer<L, S>
-where
- L: crate::Layer<S> + 'static,
- S: Subscriber,
-{
- fn on_layer(&mut self, subscriber: &mut S) {
- try_lock!(self.inner.write(), else return).on_layer(subscriber);
- }
-
- #[inline]
- fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest {
- try_lock!(self.inner.read(), else return Interest::sometimes()).register_callsite(metadata)
- }
-
- #[inline]
- fn enabled(&self, metadata: &Metadata<'_>, ctx: layer::Context<'_, S>) -> bool {
- try_lock!(self.inner.read(), else return false).enabled(metadata, ctx)
- }
-
- #[inline]
- fn on_new_span(&self, attrs: &span::Attributes<'_>, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_new_span(attrs, id, ctx)
- }
-
- #[inline]
- fn on_record(&self, span: &span::Id, values: &span::Record<'_>, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_record(span, values, ctx)
- }
-
- #[inline]
- fn on_follows_from(&self, span: &span::Id, follows: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_follows_from(span, follows, ctx)
- }
-
- #[inline]
- fn event_enabled(&self, event: &Event<'_>, ctx: layer::Context<'_, S>) -> bool {
- try_lock!(self.inner.read(), else return false).event_enabled(event, ctx)
- }
-
- #[inline]
- fn on_event(&self, event: &Event<'_>, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_event(event, ctx)
- }
-
- #[inline]
- fn on_enter(&self, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_enter(id, ctx)
- }
-
- #[inline]
- fn on_exit(&self, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_exit(id, ctx)
- }
-
- #[inline]
- fn on_close(&self, id: span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_close(id, ctx)
- }
-
- #[inline]
- fn on_id_change(&self, old: &span::Id, new: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_id_change(old, new, ctx)
- }
-
- #[inline]
- fn max_level_hint(&self) -> Option<LevelFilter> {
- try_lock!(self.inner.read(), else return None).max_level_hint()
- }
-}
-
-// ===== impl Filter =====
-
-#[cfg(all(feature = "registry", feature = "std"))]
-#[cfg_attr(docsrs, doc(cfg(all(feature = "registry", feature = "std"))))]
-impl<S, L> crate::layer::Filter<S> for Layer<L, S>
-where
- L: crate::layer::Filter<S> + 'static,
- S: Subscriber,
-{
- #[inline]
- fn callsite_enabled(&self, metadata: &'static Metadata<'static>) -> Interest {
- try_lock!(self.inner.read(), else return Interest::sometimes()).callsite_enabled(metadata)
- }
-
- #[inline]
- fn enabled(&self, metadata: &Metadata<'_>, ctx: &layer::Context<'_, S>) -> bool {
- try_lock!(self.inner.read(), else return false).enabled(metadata, ctx)
- }
-
- #[inline]
- fn on_new_span(&self, attrs: &span::Attributes<'_>, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_new_span(attrs, id, ctx)
- }
-
- #[inline]
- fn on_record(&self, span: &span::Id, values: &span::Record<'_>, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_record(span, values, ctx)
- }
-
- #[inline]
- fn on_enter(&self, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_enter(id, ctx)
- }
-
- #[inline]
- fn on_exit(&self, id: &span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_exit(id, ctx)
- }
-
- #[inline]
- fn on_close(&self, id: span::Id, ctx: layer::Context<'_, S>) {
- try_lock!(self.inner.read()).on_close(id, ctx)
- }
-
- #[inline]
- fn max_level_hint(&self) -> Option<LevelFilter> {
- try_lock!(self.inner.read(), else return None).max_level_hint()
- }
-}
-
-impl<L, S> Layer<L, S> {
- /// Wraps the given [`Layer`] or [`Filter`], returning a `reload::Layer`
- /// and a `Handle` that allows the inner value to be modified at runtime.
- ///
- /// [`Layer`]: crate::layer::Layer
- /// [`Filter`]: crate::layer::Filter
- pub fn new(inner: L) -> (Self, Handle<L, S>) {
- let this = Self {
- inner: Arc::new(RwLock::new(inner)),
- _s: PhantomData,
- };
- let handle = this.handle();
- (this, handle)
- }
-
- /// Returns a `Handle` that can be used to reload the wrapped [`Layer`] or [`Filter`].
- ///
- /// [`Layer`]: crate::layer::Layer
- /// [`Filter`]: crate::filter::Filter
- pub fn handle(&self) -> Handle<L, S> {
- Handle {
- inner: Arc::downgrade(&self.inner),
- _s: PhantomData,
- }
- }
-}
-
-// ===== impl Handle =====
-
-impl<L, S> Handle<L, S> {
- /// Replace the current [`Layer`] or [`Filter`] with the provided `new_value`.
- ///
- /// [`Handle::reload`] cannot be used with the [`Filtered`] layer; use
- /// [`Handle::modify`] instead (see [this issue] for additional details).
- ///
- /// However, if the _only_ the [`Filter`] needs to be modified, use
- /// `reload::Layer` to wrap the `Filter` directly.
- ///
- /// [`Layer`]: crate::layer::Layer
- /// [`Filter`]: crate::layer::Filter
- /// [`Filtered`]: crate::filter::Filtered
- ///
- /// [this issue]: https://github.com/tokio-rs/tracing/issues/1629
- pub fn reload(&self, new_value: impl Into<L>) -> Result<(), Error> {
- self.modify(|layer| {
- *layer = new_value.into();
- })
- }
-
- /// Invokes a closure with a mutable reference to the current layer or filter,
- /// allowing it to be modified in place.
- pub fn modify(&self, f: impl FnOnce(&mut L)) -> Result<(), Error> {
- let inner = self.inner.upgrade().ok_or(Error {
- kind: ErrorKind::SubscriberGone,
- })?;
-
- let mut lock = try_lock!(inner.write(), else return Err(Error::poisoned()));
- f(&mut *lock);
- // Release the lock before rebuilding the interest cache, as that
- // function will lock the new layer.
- drop(lock);
-
- callsite::rebuild_interest_cache();
- Ok(())
- }
-
- /// Returns a clone of the layer or filter's current value if it still exists.
- /// Otherwise, if the subscriber has been dropped, returns `None`.
- pub fn clone_current(&self) -> Option<L>
- where
- L: Clone,
- {
- self.with_current(L::clone).ok()
- }
-
- /// Invokes a closure with a borrowed reference to the current layer or filter,
- /// returning the result (or an error if the subscriber no longer exists).
- pub fn with_current<T>(&self, f: impl FnOnce(&L) -> T) -> Result<T, Error> {
- let inner = self.inner.upgrade().ok_or(Error {
- kind: ErrorKind::SubscriberGone,
- })?;
- let inner = try_lock!(inner.read(), else return Err(Error::poisoned()));
- Ok(f(&*inner))
- }
-}
-
-impl<L, S> Clone for Handle<L, S> {
- fn clone(&self) -> Self {
- Handle {
- inner: self.inner.clone(),
- _s: PhantomData,
- }
- }
-}
-
-// ===== impl Error =====
-
-impl Error {
- fn poisoned() -> Self {
- Self {
- kind: ErrorKind::Poisoned,
- }
- }
-
- /// Returns `true` if this error occurred because the layer was poisoned by
- /// a panic on another thread.
- pub fn is_poisoned(&self) -> bool {
- matches!(self.kind, ErrorKind::Poisoned)
- }
-
- /// Returns `true` if this error occurred because the `Subscriber`
- /// containing the reloadable layer was dropped.
- pub fn is_dropped(&self) -> bool {
- matches!(self.kind, ErrorKind::SubscriberGone)
- }
-}
-
-impl fmt::Display for Error {
- fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- let msg = match self.kind {
- ErrorKind::SubscriberGone => "subscriber no longer exists",
- ErrorKind::Poisoned => "lock poisoned",
- };
- f.pad(msg)
- }
-}
-
-impl error::Error for Error {}