2024-07-26 09:42:18 +00:00
<!DOCTYPE html> < html lang = "en" > < head > < meta charset = "utf-8" > < meta name = "viewport" content = "width=device-width, initial-scale=1.0" > < meta name = "generator" content = "rustdoc" > < meta name = "description" content = "Extension trait allowing futures to be instrumented with a `tracing` `Subscriber`." > < title > WithSubscriber in tracing::instrument - Rust< / title > < script > if ( window . location . protocol !== "file:" ) document . head . insertAdjacentHTML ( "beforeend" , "SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2" . split ( "," ) . map ( f => ` <link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/ ${ f } "> ` ) . join ( "" ) ) < / script > < link rel = "stylesheet" href = "../../static.files/normalize-76eba96aa4d2e634.css" > < link rel = "stylesheet" href = "../../static.files/rustdoc-dd39b87e5fcfba68.css" > < meta name = "rustdoc-vars" data-root-path = "../../" data-static-root-path = "../../static.files/" data-current-crate = "tracing" data-themes = "" data-resource-suffix = "" data-rustdoc-version = "1.80.0 (051478957 2024-07-21)" data-channel = "1.80.0" data-search-js = "search-d52510db62a78183.js" data-settings-js = "settings-4313503d2e1961c2.js" > < script src = "../../static.files/storage-118b08c4c78b968e.js" > < / script > < script defer src = "sidebar-items.js" > < / script > < script defer src = "../../static.files/main-20a3ad099b048cf2.js" > < / script > < noscript > < link rel = "stylesheet" href = "../../static.files/noscript-df360f571f6edeae.css" > < / noscript > < link rel = "alternate icon" type = "image/png" href = "../../static.files/favicon-32x32-422f7d1d52889060.png" > < link rel = "icon" type = "image/svg+xml" href = "../../static.files/favicon-2c020d218678b618.svg" > < / head > < body class = "rustdoc trait" > <!-- [if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif] --> < nav class = "mobile-topbar" > < button class = "sidebar-menu-toggle" title = "show sidebar" > < / button > < a class = "logo-container" href = "../../tracing/index.html" > < img src = "https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt = "" > < / a > < / nav > < nav class = "sidebar" > < div class = "sidebar-crate" > < a class = "logo-container" href = "../../tracing/index.html" > < img src = "https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt = "logo" > < / a > < h2 > < a href = "../../tracing/index.html" > tracing< / a > < span class = "version" > 0.1.40< / span > < / h2 > < / div > < h2 class = "location" > < a href = "#" > WithSubscriber< / a > < / h2 > < div class = "sidebar-elems" > < section > < h3 > < a href = "#provided-methods" > Provided Methods< / a > < / h3 > < ul class = "block" > < li > < a href = "#method.with_current_subscriber" > with_current_subscriber< / a > < / li > < li > < a href = "#method.with_subscriber" > with_subscriber< / a > < / li > < / ul > < h3 > < a href = "#object-safety" > Object Safety< / a > < / h3 > < h3 > < a href = "#implementors" > Implementors< / a > < / h3 > < / section > < h2 > < a href = "index.html" > In tracing::instrument< / a > < / h2 > < / div > < / nav > < div class = "sidebar-resizer" > < / div > < main > < div class = "width-limiter" > < rustdoc-search > < / rustdoc-search > < section id = "main-content" class = "content" > < div class = "main-heading" > < h1 > Trait < a href = "../index.html" > tracing< / a > ::< wbr > < a href = "index.html" > instrument< / a > ::< wbr > < a class = "trait" href = "#" > WithSubscriber< / a > < button id = "copy-path" title = "Copy item path to clipboard" > Copy item path< / button > < / h1 > < span class = "out-of-band" > < a class = "src" href = "../../src/tracing/instrument.rs.html#136-234" > source< / a > · < button id = "toggle-all-docs" title = "collapse all docs" > [< span > − < / span > ]< / button > < / span > < / div > < pre class = "rust item-decl" > < code > pub trait WithSubscriber: < a class = "trait" href = "https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title = "trait core::marker::Sized" > Sized< / a > {
2024-02-13 06:38:44 +00:00
// Provided methods
fn < a href = "#method.with_subscriber" class = "fn" > with_subscriber< / a > < S> (self, subscriber: S) -> < a class = "struct" href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > WithDispatch< / a > < Self> < a href = "#" class = "tooltip" data-notable-ty = "WithDispatch<Self>" > ⓘ< / a >
2024-07-26 09:42:18 +00:00
< span class = "where" > where S: < a class = "trait" href = "https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html" title = "trait core::convert::Into" > Into< / a > < < a class = "struct" href = "../struct.Dispatch.html" title = "struct tracing::Dispatch" > Dispatch< / a > > < / span > { ... }
2024-02-13 06:38:44 +00:00
< span class = "item-spacer" > < / span > fn < a href = "#method.with_current_subscriber" class = "fn" > with_current_subscriber< / a > (self) -> < a class = "struct" href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > WithDispatch< / a > < Self> < a href = "#" class = "tooltip" data-notable-ty = "WithDispatch<Self>" > ⓘ< / a > { ... }
}< / code > < / pre > < details class = "toggle top-doc" open > < summary class = "hideme" > < span > Expand description< / span > < / summary > < div class = "docblock" > < p > Extension trait allowing futures to be instrumented with
a < code > tracing< / code > < a href = "../trait.Subscriber.html" title = "trait tracing::Subscriber" > < code > Subscriber< / code > < / a > .< / p >
< / div > < / details > < h2 id = "provided-methods" class = "section-header" > Provided Methods< a href = "#provided-methods" class = "anchor" > §< / a > < / h2 > < div class = "methods" > < details class = "toggle method-toggle" open > < summary > < section id = "method.with_subscriber" class = "method" > < a class = "src rightside" href = "../../src/tracing/instrument.rs.html#176-184" > source< / a > < h4 class = "code-header" > fn < a href = "#method.with_subscriber" class = "fn" > with_subscriber< / a > < S> (self, subscriber: S) -> < a class = "struct" href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > WithDispatch< / a > < Self> < a href = "#" class = "tooltip" data-notable-ty = "WithDispatch<Self>" > ⓘ< / a > < div class = "where" > where
2024-07-26 09:42:18 +00:00
S: < a class = "trait" href = "https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html" title = "trait core::convert::Into" > Into< / a > < < a class = "struct" href = "../struct.Dispatch.html" title = "struct tracing::Dispatch" > Dispatch< / a > > ,< / div > < / h4 > < / section > < / summary > < div class = "docblock" > < p > Attaches the provided < a href = "../trait.Subscriber.html" title = "trait tracing::Subscriber" > < code > Subscriber< / code > < / a > to this type, returning a
2024-02-13 06:38:44 +00:00
< a href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > < code > WithDispatch< / code > < / a > wrapper.< / p >
< p > The attached < a href = "../trait.Subscriber.html" title = "trait tracing::Subscriber" > < code > Subscriber< / code > < / a > will be set as the < a href = "../dispatcher/index.html#setting-the-default-subscriber" title = "mod tracing::dispatcher" > default< / a > when the returned
2024-07-26 09:42:18 +00:00
< a href = "https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html" title = "trait core::future::future::Future" > < code > Future< / code > < / a > is polled.< / p >
2024-03-27 11:12:16 +00:00
< h5 id = "examples" > < a class = "doc-anchor" href = "#examples" > §< / a > Examples< / h5 >
2024-02-13 06:38:44 +00:00
< div class = "example-wrap" > < pre class = "rust rust-example-rendered" > < code > < span class = "kw" > use < / span > tracing::instrument::WithSubscriber;
< span class = "comment" > // Set the default `Subscriber`
< / span > < span class = "kw" > let < / span > _default = tracing::subscriber::set_default(MySubscriber::default());
< span class = "macro" > tracing::info!< / span > (< span class = "string" > "this event will be recorded by the default `Subscriber`"< / span > );
< span class = "comment" > // Create a different `Subscriber` and attach it to a future.
< / span > < span class = "kw" > let < / span > other_subscriber = MyOtherSubscriber::default();
< span class = "kw" > let < / span > future = < span class = "kw" > async < / span > {
< span class = "macro" > tracing::info!< / span > (< span class = "string" > "this event will be recorded by the other `Subscriber`"< / span > );
< span class = "comment" > // ...
< / span > };
future
< span class = "comment" > // Attach the other `Subscriber` to the future before awaiting it
< / span > .with_subscriber(other_subscriber)
.< span class = "kw" > await< / span > ;
< span class = "comment" > // Once the future has completed, we return to the default `Subscriber`.
< / span > < span class = "macro" > tracing::info!< / span > (< span class = "string" > "this event will be recorded by the default `Subscriber`"< / span > );< / code > < / pre > < / div >
< / div > < / details > < details class = "toggle method-toggle" open > < summary > < section id = "method.with_current_subscriber" class = "method" > < a class = "src rightside" href = "../../src/tracing/instrument.rs.html#228-233" > source< / a > < h4 class = "code-header" > fn < a href = "#method.with_current_subscriber" class = "fn" > with_current_subscriber< / a > (self) -> < a class = "struct" href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > WithDispatch< / a > < Self> < a href = "#" class = "tooltip" data-notable-ty = "WithDispatch<Self>" > ⓘ< / a > < / h4 > < / section > < / summary > < div class = "docblock" > < p > Attaches the current < a href = "../dispatcher/index.html#setting-the-default-subscriber" title = "mod tracing::dispatcher" > default< / a > < a href = "../trait.Subscriber.html" title = "trait tracing::Subscriber" > < code > Subscriber< / code > < / a > to this type, returning a
< a href = "struct.WithDispatch.html" title = "struct tracing::instrument::WithDispatch" > < code > WithDispatch< / code > < / a > wrapper.< / p >
< p > The attached < code > Subscriber< / code > will be set as the < a href = "../dispatcher/index.html#setting-the-default-subscriber" title = "mod tracing::dispatcher" > default< / a > when the returned
2024-07-26 09:42:18 +00:00
< a href = "https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html" title = "trait core::future::future::Future" > < code > Future< / code > < / a > is polled.< / p >
2024-02-13 06:38:44 +00:00
< p > This can be used to propagate the current dispatcher context when
spawning a new future that may run on a different thread.< / p >
2024-03-27 11:12:16 +00:00
< h5 id = "examples-1" > < a class = "doc-anchor" href = "#examples-1" > §< / a > Examples< / h5 >
2024-02-13 06:38:44 +00:00
< div class = "example-wrap" > < pre class = "rust rust-example-rendered" > < code > < span class = "kw" > use < / span > tracing::instrument::WithSubscriber;
< span class = "comment" > // Using `set_default` (rather than `set_global_default`) sets the
// default `Subscriber` for *this* thread only.
< / span > < span class = "kw" > let < / span > _default = tracing::subscriber::set_default(MySubscriber::default());
< span class = "kw" > let < / span > future = < span class = "kw" > async < / span > {
< span class = "comment" > // ...
< / span > };
< span class = "comment" > // If a multi-threaded async runtime is in use, this spawned task may
// run on a different thread, in a different default `Subscriber`'s context.
< / span > tokio::spawn(future);
< span class = "comment" > // However, calling `with_current_subscriber` on the future before
// spawning it, ensures that the current thread's default `Subscriber` is
// propagated to the spawned task, regardless of where it executes:
< / span > tokio::spawn(future.with_current_subscriber());< / code > < / pre > < / div >
2024-07-26 09:42:18 +00:00
< / div > < / details > < / div > < h2 id = "object-safety" class = "section-header" > Object Safety< a href = "#object-safety" class = "anchor" > §< / a > < / h2 > < div class = "object-safety-info" > This trait is < b > not< / b > < a href = "https://doc.rust-lang.org/1.80.0/reference/items/traits.html#object-safety" > object safe< / a > .< / div > < h2 id = "implementors" class = "section-header" > Implementors< a href = "#implementors" class = "anchor" > §< / a > < / h2 > < div id = "implementors-list" > < section id = "impl-WithSubscriber-for-T" class = "impl" > < a class = "src rightside" href = "../../src/tracing/instrument.rs.html#393" > source< / a > < a href = "#impl-WithSubscriber-for-T" class = "anchor" > §< / a > < h3 class = "code-header" > impl< T: < a class = "trait" href = "https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title = "trait core::marker::Sized" > Sized< / a > > < a class = "trait" href = "trait.WithSubscriber.html" title = "trait tracing::instrument::WithSubscriber" > WithSubscriber< / a > for T< / h3 > < / section > < / div > < script src = "../../trait.impl/tracing/instrument/trait.WithSubscriber.js" async > < / script > < script type = "text/json" id = "notable-traits-data" > { "WithDispatch<Self>" : "<h3>Notable traits for <code><a class=\"struct\" href=\"struct.WithDispatch.html\" title=\"struct tracing::instrument::WithDispatch\">WithDispatch</a><T></code></h3><pre><code><div class=\"where\">impl<T: <a class=\"trait\" href=\"https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a>> <a class=\"trait\" href=\"https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html\" title=\"trait core::future::future::Future\">Future</a> for <a class=\"struct\" href=\"struct.WithDispatch.html\" title=\"struct tracing::instrument::WithDispatch\">WithDispatch</a><T></div><div class=\"where\"> type <a href=\"https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html#associatedtype.Output\" class=\"associatedtype\">Output</a> = T::<a class=\"associatedtype\" href=\"https://doc.rust-lang.org/1.80.0/core/future/future/trait.Future.html#associatedtype.Output\" title=\"type core::future::future::Future::Output\">Output</a>;</div>" } < / script > < / section > < / div > < / main > < / body > < / html >
