1 | //! Collects and records trace data. |
2 | pub use tracing_core::subscriber::*; |
3 | |
4 | #[cfg (feature = "std" )] |
5 | #[cfg_attr (docsrs, doc(cfg(feature = "std" )))] |
6 | pub use tracing_core::dispatcher::DefaultGuard; |
7 | |
8 | /// Sets this [`Subscriber`] as the default for the current thread for the |
9 | /// duration of a closure. |
10 | /// |
11 | /// The default subscriber is used when creating a new [`Span`] or |
12 | /// [`Event`]. |
13 | /// |
14 | /// |
15 | /// [`Span`]: super::span::Span |
16 | /// [`Subscriber`]: super::subscriber::Subscriber |
17 | /// [`Event`]: super::event::Event |
18 | #[cfg (feature = "std" )] |
19 | #[cfg_attr (docsrs, doc(cfg(feature = "std" )))] |
20 | pub fn with_default<T, S>(subscriber: S, f: impl FnOnce() -> T) -> T |
21 | where |
22 | S: Subscriber + Send + Sync + 'static, |
23 | { |
24 | crate::dispatcher::with_default(&crate::Dispatch::new(subscriber), f) |
25 | } |
26 | |
27 | /// Sets this subscriber as the global default for the duration of the entire program. |
28 | /// Will be used as a fallback if no thread-local subscriber has been set in a thread (using `with_default`.) |
29 | /// |
30 | /// Can only be set once; subsequent attempts to set the global default will fail. |
31 | /// Returns whether the initialization was successful. |
32 | /// |
33 | /// Note: Libraries should *NOT* call `set_global_default()`! That will cause conflicts when |
34 | /// executables try to set them later. |
35 | /// |
36 | /// [span]: super::span |
37 | /// [`Subscriber`]: super::subscriber::Subscriber |
38 | /// [`Event`]: super::event::Event |
39 | pub fn set_global_default<S>(subscriber: S) -> Result<(), SetGlobalDefaultError> |
40 | where |
41 | S: Subscriber + Send + Sync + 'static, |
42 | { |
43 | crate::dispatcher::set_global_default(dispatcher:crate::Dispatch::new(subscriber)) |
44 | } |
45 | |
46 | /// Sets the [`Subscriber`] as the default for the current thread for the |
47 | /// duration of the lifetime of the returned [`DefaultGuard`]. |
48 | /// |
49 | /// The default subscriber is used when creating a new [`Span`] or [`Event`]. |
50 | /// |
51 | /// [`Span`]: super::span::Span |
52 | /// [`Subscriber`]: super::subscriber::Subscriber |
53 | /// [`Event`]: super::event::Event |
54 | /// [`DefaultGuard`]: super::dispatcher::DefaultGuard |
55 | #[cfg (feature = "std" )] |
56 | #[cfg_attr (docsrs, doc(cfg(feature = "std" )))] |
57 | #[must_use = "Dropping the guard unregisters the subscriber." ] |
58 | pub fn set_default<S>(subscriber: S) -> DefaultGuard |
59 | where |
60 | S: Subscriber + Send + Sync + 'static, |
61 | { |
62 | crate::dispatcher::set_default(&crate::Dispatch::new(subscriber)) |
63 | } |
64 | |
65 | pub use tracing_core::dispatcher::SetGlobalDefaultError; |
66 | |