| <!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="Attaches `H`-typed completion tracker to `V` typed values."><meta name="keywords" content="rust, rustlang, rust-lang, TrackCompletion"><title>TrackCompletion in tower::load::completion - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.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">☰</button><a class="sidebar-logo" href="../../../tower/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../../tower/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">TrackCompletion</a></h2><div class="sidebar-elems"><section><h3><a href="#required-associated-types">Required Associated Types</a></h3><ul class="block"><li><a href="#associatedtype.Output">Output</a></li></ul><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.track_completion">track_completion</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><h2><a href="index.html">In tower::load::completion</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Trait <a href="../../index.html">tower</a>::<wbr><a href="../index.html">load</a>::<wbr><a href="index.html">completion</a>::<wbr><a class="trait" href="#">TrackCompletion</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../../src/tower/load/completion.rs.html#33-39">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust trait"><code>pub trait TrackCompletion<H, V>: Clone { |
| type <a href="#associatedtype.Output" class="associatedtype">Output</a>; |
| |
| fn <a href="#tymethod.track_completion" class="fnname">track_completion</a>(&self, handle: H, value: V) -> Self::<a class="associatedtype" href="trait.TrackCompletion.html#associatedtype.Output" title="type tower::load::completion::TrackCompletion::Output">Output</a>; |
| }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Attaches <code>H</code>-typed completion tracker to <code>V</code> typed values.</p> |
| <p>Handles (of type <code>H</code>) are intended to be RAII guards that primarily implement [<code>Drop</code>] and update |
| load metric state as they are dropped. This trait allows implementors to “forward” the handle |
| to later parts of the request-handling pipeline, so that the handle is only dropped when the |
| request has truly completed.</p> |
| <p>This utility allows load metrics to have a protocol-agnostic means to track streams past their |
| initial response future. For example, if <code>V</code> represents an HTTP response type, an |
| implementation could add <code>H</code>-typed handles to each response’s extensions to detect when all the |
| response’s extensions have been dropped.</p> |
| <p>A base <code>impl<H, V> TrackCompletion<H, V> for CompleteOnResponse</code> is provided to drop the handle |
| once the response future is resolved. This is appropriate when a response is discrete and |
| cannot comprise multiple messages.</p> |
| <p>In many cases, the <code>Output</code> type is simply <code>V</code>. However, <a href="trait.TrackCompletion.html" title="TrackCompletion"><code>TrackCompletion</code></a> may alter the type |
| in order to instrument it appropriately. For example, an HTTP <a href="trait.TrackCompletion.html" title="TrackCompletion"><code>TrackCompletion</code></a> may modify |
| the body type: so a <a href="trait.TrackCompletion.html" title="TrackCompletion"><code>TrackCompletion</code></a> that takes values of type |
| <a href="https://docs.rs/http/latest/http/response/struct.Response.html"><code>http::Response<A></code></a> may output values of type <a href="https://docs.rs/http/latest/http/response/struct.Response.html"><code>http::Response<B></code></a>.</p> |
| </div></details><h2 id="required-associated-types" class="small-section-header">Required Associated Types<a href="#required-associated-types" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="associatedtype.Output" class="method has-srclink"><a class="srclink rightside" href="../../../src/tower/load/completion.rs.html#35">source</a><h4 class="code-header">type <a href="#associatedtype.Output" class="associatedtype">Output</a></h4></section></summary><div class="docblock"><p>The instrumented value type.</p> |
| </div></details></div><h2 id="required-methods" class="small-section-header">Required Methods<a href="#required-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="tymethod.track_completion" class="method has-srclink"><a class="srclink rightside" href="../../../src/tower/load/completion.rs.html#38">source</a><h4 class="code-header">fn <a href="#tymethod.track_completion" class="fnname">track_completion</a>(&self, handle: H, value: V) -> Self::<a class="associatedtype" href="trait.TrackCompletion.html#associatedtype.Output" title="type tower::load::completion::TrackCompletion::Output">Output</a></h4></section></summary><div class="docblock"><p>Attaches a <code>H</code>-typed handle to a <code>V</code>-typed value.</p> |
| </div></details></div><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div id="implementors-list"><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TrackCompletion%3CH%2C%20V%3E-for-CompleteOnResponse" class="impl has-srclink"><a class="srclink rightside" href="../../../src/tower/load/completion.rs.html#88-95">source</a><a href="#impl-TrackCompletion%3CH%2C%20V%3E-for-CompleteOnResponse" class="anchor"></a><h3 class="code-header">impl<H, V> <a class="trait" href="trait.TrackCompletion.html" title="trait tower::load::completion::TrackCompletion">TrackCompletion</a><H, V> for <a class="struct" href="struct.CompleteOnResponse.html" title="struct tower::load::completion::CompleteOnResponse">CompleteOnResponse</a></h3></section></summary><div class="impl-items"><section id="associatedtype.Output-1" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Output-1" class="anchor"></a><h4 class="code-header">type <a href="#associatedtype.Output" class="associatedtype">Output</a> = V</h4></section></div></details></div><script src="../../../implementors/tower/load/completion/trait.TrackCompletion.js" async></script></section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tower" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
