1 files changed, 153 insertions, 0 deletions
diff --git a/vendor/tracing-subscriber-0.3.3/src/util.rs b/vendor/tracing-subscriber-0.3.3/src/util.rs
new file mode 100644
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+++ b/vendor/tracing-subscriber-0.3.3/src/util.rs
@@ -0,0 +1,153 @@
+//! Extension traits and other utilities to make working with subscribers more
+//! ergonomic.
+use core::fmt;
+#[cfg(feature = "std")]
+use std::error::Error;
+use tracing_core::dispatcher::{self, Dispatch};
+#[cfg(feature = "tracing-log")]
+use tracing_log::AsLog;
+
+/// Extension trait adding utility methods for subscriber initialization.
+///
+/// This trait provides extension methods to make configuring and setting a
+/// [default subscriber] more ergonomic. It is automatically implemented for all
+/// types that can be converted into a [trace dispatcher]. Since `Dispatch`
+/// implements `From<T>` for all `T: Subscriber`, all `Subscriber`
+/// implementations will implement this extension trait as well. Types which
+/// can be converted into `Subscriber`s, such as builders that construct a
+/// `Subscriber`, may implement `Into<Dispatch>`, and will also receive an
+/// implementation of this trait.
+///
+/// [default subscriber]: https://docs.rs/tracing/0.1.21/tracing/dispatcher/index.html#setting-the-default-subscriber
+/// [trace dispatcher]: https://docs.rs/tracing/0.1.21/tracing/dispatcher/index.html
+pub trait SubscriberInitExt
+where
+    Self: Into<Dispatch>,
+{
+    /// Sets `self` as the [default subscriber] in the current scope, returning a
+    /// guard that will unset it when dropped.
+    ///
+    /// If the "tracing-log" feature flag is enabled, this will also initialize
+    /// a [`log`] compatibility layer. This allows the subscriber to consume
+    /// `log::Record`s as though they were `tracing` `Event`s.
+    ///
+    /// [default subscriber]: https://docs.rs/tracing/0.1.21/tracing/dispatcher/index.html#setting-the-default-subscriber
+    /// [`log`]: https://crates.io/log
+    #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+    fn set_default(self) -> dispatcher::DefaultGuard {
+        #[cfg(feature = "tracing-log")]
+        let _ = tracing_log::LogTracer::init();
+
+        dispatcher::set_default(&self.into())
+    }
+
+    /// Attempts to set `self` as the [global default subscriber] in the current
+    /// scope, returning an error if one is already set.
+    ///
+    /// If the "tracing-log" feature flag is enabled, this will also attempt to
+    /// initialize a [`log`] compatibility layer. This allows the subscriber to
+    /// consume `log::Record`s as though they were `tracing` `Event`s.
+    ///
+    /// This method returns an error if a global default subscriber has already
+    /// been set, or if a `log` logger has already been set (when the
+    /// "tracing-log" feature is enabled).
+    ///
+    /// [global default subscriber]: https://docs.rs/tracing/0.1.21/tracing/dispatcher/index.html#setting-the-default-subscriber
+    /// [`log`]: https://crates.io/log
+    fn try_init(self) -> Result<(), TryInitError> {
+        dispatcher::set_global_default(self.into()).map_err(TryInitError::new)?;
+
+        // Since we are setting the global default subscriber, we can
+        // opportunistically go ahead and set its global max level hint as
+        // the max level for the `log` crate as well. This should make
+        // skipping `log` diagnostics much faster.
+        #[cfg(feature = "tracing-log")]
+        tracing_log::LogTracer::builder()
+            // Note that we must call this *after* setting the global default
+            // subscriber, so that we get its max level hint.
+            .with_max_level(tracing_core::LevelFilter::current().as_log())
+            .init()
+            .map_err(TryInitError::new)?;
+
+        Ok(())
+    }
+
+    /// Attempts to set `self` as the [global default subscriber] in the current
+    /// scope, panicking if this fails.
+    ///
+    /// If the "tracing-log" feature flag is enabled, this will also attempt to
+    /// initialize a [`log`] compatibility layer. This allows the subscriber to
+    /// consume `log::Record`s as though they were `tracing` `Event`s.
+    ///
+    /// This method panics if a global default subscriber has already been set,
+    /// or if a `log` logger has already been set (when the "tracing-log"
+    /// feature is enabled).
+    ///
+    /// [global default subscriber]: https://docs.rs/tracing/0.1.21/tracing/dispatcher/index.html#setting-the-default-subscriber
+    /// [`log`]: https://crates.io/log
+    fn init(self) {
+        self.try_init()
+            .expect("failed to set global default subscriber")
+    }
+}
+
+impl<T> SubscriberInitExt for T where T: Into<Dispatch> {}
+
+/// Error returned by [`try_init`](SubscriberInitExt::try_init) if a global default subscriber could not be initialized.
+pub struct TryInitError {
+    #[cfg(feature = "std")]
+    inner: Box<dyn Error + Send + Sync + 'static>,
+
+    #[cfg(not(feature = "std"))]
+    _p: (),
+}
+
+// ==== impl TryInitError ====
+
+impl TryInitError {
+    #[cfg(feature = "std")]
+    fn new(e: impl Into<Box<dyn Error + Send + Sync + 'static>>) -> Self {
+        Self { inner: e.into() }
+    }
+
+    #[cfg(not(feature = "std"))]
+    fn new<T>(_: T) -> Self {
+        Self { _p: () }
+    }
+}
+
+impl fmt::Debug for TryInitError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(feature = "std")]
+        {
+            fmt::Debug::fmt(&self.inner, f)
+        }
+
+        #[cfg(not(feature = "std"))]
+        {
+            f.write_str("TryInitError(())")
+        }
+    }
+}
+
+impl fmt::Display for TryInitError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(feature = "std")]
+        {
+            fmt::Display::fmt(&self.inner, f)
+        }
+
+        #[cfg(not(feature = "std"))]
+        {
+            f.write_str("failed to set global default subscriber")
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl Error for TryInitError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        self.inner.source()
+    }
+}