1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85

//! Utilities for implementing and composing [`tracing`] subscribers.
//!
//! [`tracing`] is a framework for instrumenting Rust programs to collect
//! scoped, structured, and async-aware diagnostics. The [`Subscriber`] trait
//! represents the functionality necessary to collect this trace data. This
//! crate contains tools for composing subscribers out of smaller units of
//! behaviour, and batteries-included implementations of common subscriber
//! functionality.
//!
//! `tracing-subscriber` is intended for use by both `Subscriber` authors and
//! application authors using `tracing` to instrument their applications.
//!
//! [`tracing`]: https://docs.rs/tracing/latest/tracing/
//! [`Subscriber`]: https://docs.rs/tracing-core/latest/tracing_core/subscriber/trait.Subscriber.html
use tracing_core::span::Id;

#[macro_use]
macro_rules! try_lock {
    ($lock:expr) => {
        try_lock!($lock, else return)
    };
    ($lock:expr, else $els:expr) => {
        match $lock {
            Ok(l) => l,
            Err(_) if std::thread::panicking() => $els,
            Err(_) => panic!("lock poisoned"),
        }
    };
}

#[cfg(feature = "filter")]
pub mod filter;
pub mod layer;
pub mod prelude;
pub mod reload;
pub(crate) mod thread;

#[cfg(feature = "filter")]
pub use filter::Filter;
pub use layer::Layer;

use std::default::Default;

#[deprecated(since = "0.0.1-alpha.2", note = "renamed to `CurrentSpan`")]
pub type CurrentSpanPerThread = CurrentSpan;

/// Tracks the currently executing span on a per-thread basis.
pub struct CurrentSpan {
    current: thread::Local<Vec<Id>>,
}

impl CurrentSpan {
    pub fn new() -> Self {
        Self {
            current: thread::Local::new(),
        }
    }

    /// Returns the [`Id`](::Id) of the span in which the current thread is
    /// executing, or `None` if it is not inside of a span.
    pub fn id(&self) -> Option<Id> {
        self.current.get().last().cloned()
    }

    pub fn enter(&self, span: Id) {
        self.current.get().push(span)
    }

    pub fn exit(&self) {
        self.current.get().pop();
    }
}

impl Default for CurrentSpan {
    fn default() -> Self {
        Self::new()
    }
}

mod sealed {
    pub struct SealedTy {
        _p: (),
    }
    pub trait Sealed<A = SealedTy> {}
}