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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:43 +0000 |
commit | 3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245 (patch) | |
tree | daf049b282ab10e8c3d03e409b3cd84ff3f7690c /vendor/tracing-subscriber-0.3.3/src/reload.rs | |
parent | Adding debian version 1.68.2+dfsg1-1. (diff) | |
download | rustc-3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245.tar.xz rustc-3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245.zip |
Merging upstream version 1.69.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/tracing-subscriber-0.3.3/src/reload.rs')
-rw-r--r-- | vendor/tracing-subscriber-0.3.3/src/reload.rs | 237 |
1 files changed, 0 insertions, 237 deletions
diff --git a/vendor/tracing-subscriber-0.3.3/src/reload.rs b/vendor/tracing-subscriber-0.3.3/src/reload.rs deleted file mode 100644 index b8ec67dfa..000000000 --- a/vendor/tracing-subscriber-0.3.3/src/reload.rs +++ /dev/null @@ -1,237 +0,0 @@ -//! Wrapper for a `Layer` to allow it to be dynamically reloaded. -//! -//! This module provides a [`Layer` type] which wraps another type implementing -//! the [`Layer` trait], allowing the wrapped type to be replaced with another -//! instance of that type at runtime. -//! -//! This can be used in cases where a subset of `Subscriber` 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. -//! -//! [`Layer` type]: struct.Layer.html -//! [`Layer` trait]: ../layer/trait.Layer.html -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, Metadata, -}; - -/// Wraps a `Layer`, 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`. -#[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 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) - } -} - -impl<L, S> Layer<L, S> -where - L: crate::Layer<S> + 'static, - S: Subscriber, -{ - /// Wraps the given `Layer`, returning a `Layer` and a `Handle` that allows - /// the inner type to be modified at runtime. - 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`. - pub fn handle(&self) -> Handle<L, S> { - Handle { - inner: Arc::downgrade(&self.inner), - _s: PhantomData, - } - } -} - -// ===== impl Handle ===== - -impl<L, S> Handle<L, S> -where - L: crate::Layer<S> + 'static, - S: Subscriber, -{ - /// Replace the current layer with the provided `new_layer`. - pub fn reload(&self, new_layer: impl Into<L>) -> Result<(), Error> { - self.modify(|layer| { - *layer = new_layer.into(); - }) - } - - /// Invokes a closure with a mutable reference to the current layer, - /// 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'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, - /// 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 {} |