| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-0.1.37/src/instrument.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>instrument.rs - source</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="../../source-script.js"></script><script defer src="../../source-files.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 source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../tracing/index.html"><div class="logo-container"> |
| <img src="https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../tracing/index.html"> |
| <img src="https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt="logo"></a><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="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| <span id="180">180</span> |
| <span id="181">181</span> |
| <span id="182">182</span> |
| <span id="183">183</span> |
| <span id="184">184</span> |
| <span id="185">185</span> |
| <span id="186">186</span> |
| <span id="187">187</span> |
| <span id="188">188</span> |
| <span id="189">189</span> |
| <span id="190">190</span> |
| <span id="191">191</span> |
| <span id="192">192</span> |
| <span id="193">193</span> |
| <span id="194">194</span> |
| <span id="195">195</span> |
| <span id="196">196</span> |
| <span id="197">197</span> |
| <span id="198">198</span> |
| <span id="199">199</span> |
| <span id="200">200</span> |
| <span id="201">201</span> |
| <span id="202">202</span> |
| <span id="203">203</span> |
| <span id="204">204</span> |
| <span id="205">205</span> |
| <span id="206">206</span> |
| <span id="207">207</span> |
| <span id="208">208</span> |
| <span id="209">209</span> |
| <span id="210">210</span> |
| <span id="211">211</span> |
| <span id="212">212</span> |
| <span id="213">213</span> |
| <span id="214">214</span> |
| <span id="215">215</span> |
| <span id="216">216</span> |
| <span id="217">217</span> |
| <span id="218">218</span> |
| <span id="219">219</span> |
| <span id="220">220</span> |
| <span id="221">221</span> |
| <span id="222">222</span> |
| <span id="223">223</span> |
| <span id="224">224</span> |
| <span id="225">225</span> |
| <span id="226">226</span> |
| <span id="227">227</span> |
| <span id="228">228</span> |
| <span id="229">229</span> |
| <span id="230">230</span> |
| <span id="231">231</span> |
| <span id="232">232</span> |
| <span id="233">233</span> |
| <span id="234">234</span> |
| <span id="235">235</span> |
| <span id="236">236</span> |
| <span id="237">237</span> |
| <span id="238">238</span> |
| <span id="239">239</span> |
| <span id="240">240</span> |
| <span id="241">241</span> |
| <span id="242">242</span> |
| <span id="243">243</span> |
| <span id="244">244</span> |
| <span id="245">245</span> |
| <span id="246">246</span> |
| <span id="247">247</span> |
| <span id="248">248</span> |
| <span id="249">249</span> |
| <span id="250">250</span> |
| <span id="251">251</span> |
| <span id="252">252</span> |
| <span id="253">253</span> |
| <span id="254">254</span> |
| <span id="255">255</span> |
| <span id="256">256</span> |
| <span id="257">257</span> |
| <span id="258">258</span> |
| <span id="259">259</span> |
| <span id="260">260</span> |
| <span id="261">261</span> |
| <span id="262">262</span> |
| <span id="263">263</span> |
| <span id="264">264</span> |
| <span id="265">265</span> |
| <span id="266">266</span> |
| <span id="267">267</span> |
| <span id="268">268</span> |
| <span id="269">269</span> |
| <span id="270">270</span> |
| <span id="271">271</span> |
| <span id="272">272</span> |
| <span id="273">273</span> |
| <span id="274">274</span> |
| <span id="275">275</span> |
| <span id="276">276</span> |
| <span id="277">277</span> |
| <span id="278">278</span> |
| <span id="279">279</span> |
| <span id="280">280</span> |
| <span id="281">281</span> |
| <span id="282">282</span> |
| <span id="283">283</span> |
| <span id="284">284</span> |
| <span id="285">285</span> |
| <span id="286">286</span> |
| <span id="287">287</span> |
| <span id="288">288</span> |
| <span id="289">289</span> |
| <span id="290">290</span> |
| <span id="291">291</span> |
| <span id="292">292</span> |
| <span id="293">293</span> |
| <span id="294">294</span> |
| <span id="295">295</span> |
| <span id="296">296</span> |
| <span id="297">297</span> |
| <span id="298">298</span> |
| <span id="299">299</span> |
| <span id="300">300</span> |
| <span id="301">301</span> |
| <span id="302">302</span> |
| <span id="303">303</span> |
| <span id="304">304</span> |
| <span id="305">305</span> |
| <span id="306">306</span> |
| <span id="307">307</span> |
| <span id="308">308</span> |
| <span id="309">309</span> |
| <span id="310">310</span> |
| <span id="311">311</span> |
| <span id="312">312</span> |
| <span id="313">313</span> |
| <span id="314">314</span> |
| <span id="315">315</span> |
| <span id="316">316</span> |
| <span id="317">317</span> |
| <span id="318">318</span> |
| <span id="319">319</span> |
| <span id="320">320</span> |
| <span id="321">321</span> |
| <span id="322">322</span> |
| <span id="323">323</span> |
| <span id="324">324</span> |
| <span id="325">325</span> |
| <span id="326">326</span> |
| <span id="327">327</span> |
| <span id="328">328</span> |
| <span id="329">329</span> |
| <span id="330">330</span> |
| <span id="331">331</span> |
| <span id="332">332</span> |
| <span id="333">333</span> |
| <span id="334">334</span> |
| <span id="335">335</span> |
| <span id="336">336</span> |
| <span id="337">337</span> |
| <span id="338">338</span> |
| <span id="339">339</span> |
| <span id="340">340</span> |
| <span id="341">341</span> |
| <span id="342">342</span> |
| <span id="343">343</span> |
| <span id="344">344</span> |
| <span id="345">345</span> |
| <span id="346">346</span> |
| <span id="347">347</span> |
| <span id="348">348</span> |
| <span id="349">349</span> |
| <span id="350">350</span> |
| <span id="351">351</span> |
| <span id="352">352</span> |
| <span id="353">353</span> |
| <span id="354">354</span> |
| <span id="355">355</span> |
| <span id="356">356</span> |
| <span id="357">357</span> |
| <span id="358">358</span> |
| <span id="359">359</span> |
| <span id="360">360</span> |
| <span id="361">361</span> |
| <span id="362">362</span> |
| <span id="363">363</span> |
| <span id="364">364</span> |
| <span id="365">365</span> |
| <span id="366">366</span> |
| <span id="367">367</span> |
| <span id="368">368</span> |
| <span id="369">369</span> |
| <span id="370">370</span> |
| </pre><pre class="rust"><code><span class="kw">use </span><span class="kw">crate</span>::stdlib::pin::Pin; |
| <span class="kw">use </span><span class="kw">crate</span>::stdlib::task::{Context, Poll}; |
| <span class="kw">use </span><span class="kw">crate</span>::stdlib::{future::Future, marker::Sized}; |
| <span class="kw">use crate</span>::{ |
| dispatcher::{<span class="self">self</span>, Dispatch}, |
| span::Span, |
| }; |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| |
| <span class="doccomment">/// Attaches spans to a [`std::future::Future`]. |
| /// |
| /// Extension trait allowing futures to be |
| /// instrumented with a `tracing` [span]. |
| /// |
| /// [span]: super::Span |
| </span><span class="kw">pub trait </span>Instrument: Sized { |
| <span class="doccomment">/// Instruments this type with the provided [`Span`], returning an |
| /// `Instrumented` wrapper. |
| /// |
| /// The attached [`Span`] will be [entered] every time the instrumented |
| /// [`Future`] is polled. |
| /// |
| /// # Examples |
| /// |
| /// Instrumenting a future: |
| /// |
| /// ```rust |
| /// use tracing::Instrument; |
| /// |
| /// # async fn doc() { |
| /// let my_future = async { |
| /// // ... |
| /// }; |
| /// |
| /// my_future |
| /// .instrument(tracing::info_span!("my_future")) |
| /// .await |
| /// # } |
| /// ``` |
| /// |
| /// The [`Span::or_current`] combinator can be used in combination with |
| /// `instrument` to ensure that the [current span] is attached to the |
| /// future if the span passed to `instrument` is [disabled]: |
| /// |
| /// ``` |
| /// use tracing::Instrument; |
| /// # mod tokio { |
| /// # pub(super) fn spawn(_: impl std::future::Future) {} |
| /// # } |
| /// |
| /// let my_future = async { |
| /// // ... |
| /// }; |
| /// |
| /// let outer_span = tracing::info_span!("outer").entered(); |
| /// |
| /// // If the "my_future" span is enabled, then the spawned task will |
| /// // be within both "my_future" *and* "outer", since "outer" is |
| /// // "my_future"'s parent. However, if "my_future" is disabled, |
| /// // the spawned task will *not* be in any span. |
| /// tokio::spawn( |
| /// my_future |
| /// .instrument(tracing::debug_span!("my_future")) |
| /// ); |
| /// |
| /// // Using `Span::or_current` ensures the spawned task is instrumented |
| /// // with the current span, if the new span passed to `instrument` is |
| /// // not enabled. This means that if the "my_future" span is disabled, |
| /// // the spawned task will still be instrumented with the "outer" span: |
| /// # let my_future = async {}; |
| /// tokio::spawn( |
| /// my_future |
| /// .instrument(tracing::debug_span!("my_future").or_current()) |
| /// ); |
| /// ``` |
| /// |
| /// [entered]: super::Span::enter() |
| /// [`Span::or_current`]: super::Span::or_current() |
| /// [current span]: super::Span::current() |
| /// [disabled]: super::Span::is_disabled() |
| /// [`Future`]: std::future::Future |
| </span><span class="kw">fn </span>instrument(<span class="self">self</span>, span: Span) -> Instrumented<<span class="self">Self</span>> { |
| Instrumented { inner: <span class="self">self</span>, span } |
| } |
| |
| <span class="doccomment">/// Instruments this type with the [current] [`Span`], returning an |
| /// `Instrumented` wrapper. |
| /// |
| /// The attached [`Span`] will be [entered] every time the instrumented |
| /// [`Future`] is polled. |
| /// |
| /// This can be used to propagate the current span when spawning a new future. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// use tracing::Instrument; |
| /// |
| /// # mod tokio { |
| /// # pub(super) fn spawn(_: impl std::future::Future) {} |
| /// # } |
| /// # async fn doc() { |
| /// let span = tracing::info_span!("my_span"); |
| /// let _enter = span.enter(); |
| /// |
| /// // ... |
| /// |
| /// let future = async { |
| /// tracing::debug!("this event will occur inside `my_span`"); |
| /// // ... |
| /// }; |
| /// tokio::spawn(future.in_current_span()); |
| /// # } |
| /// ``` |
| /// |
| /// [current]: super::Span::current() |
| /// [entered]: super::Span::enter() |
| /// [`Span`]: crate::Span |
| /// [`Future`]: std::future::Future |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>in_current_span(<span class="self">self</span>) -> Instrumented<<span class="self">Self</span>> { |
| <span class="self">self</span>.instrument(Span::current()) |
| } |
| } |
| |
| <span class="doccomment">/// Extension trait allowing futures to be instrumented with |
| /// a `tracing` [`Subscriber`](crate::Subscriber). |
| </span><span class="attribute">#[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"std"</span>)))] |
| </span><span class="kw">pub trait </span>WithSubscriber: Sized { |
| <span class="doccomment">/// Attaches the provided [`Subscriber`] to this type, returning a |
| /// [`WithDispatch`] wrapper. |
| /// |
| /// The attached [`Subscriber`] will be set as the [default] when the returned |
| /// [`Future`] is polled. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # use tracing::subscriber::NoSubscriber as MySubscriber; |
| /// # use tracing::subscriber::NoSubscriber as MyOtherSubscriber; |
| /// # async fn docs() { |
| /// use tracing::instrument::WithSubscriber; |
| /// |
| /// // Set the default `Subscriber` |
| /// let _default = tracing::subscriber::set_default(MySubscriber::default()); |
| /// |
| /// tracing::info!("this event will be recorded by the default `Subscriber`"); |
| /// |
| /// // Create a different `Subscriber` and attach it to a future. |
| /// let other_subscriber = MyOtherSubscriber::default(); |
| /// let future = async { |
| /// tracing::info!("this event will be recorded by the other `Subscriber`"); |
| /// // ... |
| /// }; |
| /// |
| /// future |
| /// // Attach the other `Subscriber` to the future before awaiting it |
| /// .with_subscriber(other_subscriber) |
| /// .await; |
| /// |
| /// // Once the future has completed, we return to the default `Subscriber`. |
| /// tracing::info!("this event will be recorded by the default `Subscriber`"); |
| /// # } |
| /// ``` |
| /// |
| /// [`Subscriber`]: super::Subscriber |
| /// [default]: crate::dispatcher#setting-the-default-subscriber |
| /// [`Future`]: std::future::Future |
| </span><span class="kw">fn </span>with_subscriber<S>(<span class="self">self</span>, subscriber: S) -> WithDispatch<<span class="self">Self</span>> |
| <span class="kw">where |
| </span>S: Into<Dispatch>, |
| { |
| WithDispatch { |
| inner: <span class="self">self</span>, |
| dispatcher: subscriber.into(), |
| } |
| } |
| |
| <span class="doccomment">/// Attaches the current [default] [`Subscriber`] to this type, returning a |
| /// [`WithDispatch`] wrapper. |
| /// |
| /// The attached `Subscriber` will be set as the [default] when the returned |
| /// [`Future`] is polled. |
| /// |
| /// This can be used to propagate the current dispatcher context when |
| /// spawning a new future that may run on a different thread. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # mod tokio { |
| /// # pub(super) fn spawn(_: impl std::future::Future) {} |
| /// # } |
| /// # use tracing::subscriber::NoSubscriber as MySubscriber; |
| /// # async fn docs() { |
| /// use tracing::instrument::WithSubscriber; |
| /// |
| /// // Using `set_default` (rather than `set_global_default`) sets the |
| /// // default `Subscriber` for *this* thread only. |
| /// let _default = tracing::subscriber::set_default(MySubscriber::default()); |
| /// |
| /// let future = async { |
| /// // ... |
| /// }; |
| /// |
| /// // 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. |
| /// tokio::spawn(future); |
| /// |
| /// // 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: |
| /// # let future = async { }; |
| /// tokio::spawn(future.with_current_subscriber()); |
| /// # } |
| /// ``` |
| /// [`Subscriber`]: super::Subscriber |
| /// [default]: crate::dispatcher#setting-the-default-subscriber |
| /// [`Future`]: std::future::Future |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>with_current_subscriber(<span class="self">self</span>) -> WithDispatch<<span class="self">Self</span>> { |
| WithDispatch { |
| inner: <span class="self">self</span>, |
| dispatcher: <span class="kw">crate</span>::dispatcher::get_default(|default| default.clone()), |
| } |
| } |
| } |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// A [`Future`] that has been instrumented with a `tracing` [`Subscriber`]. |
| /// |
| /// This type is returned by the [`WithSubscriber`] extension trait. See that |
| /// trait's documentation for details. |
| /// |
| /// [`Future`]: std::future::Future |
| /// [`Subscriber`]: crate::Subscriber |
| </span><span class="attribute">#[derive(Clone, Debug)] |
| #[must_use = <span class="string">"futures do nothing unless you `.await` or poll them"</span>] |
| #[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"std"</span>)))] |
| </span><span class="kw">pub struct </span>WithDispatch<T> { |
| <span class="attribute">#[pin] |
| </span>inner: T, |
| dispatcher: Dispatch, |
| } |
| } |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// A [`Future`] that has been instrumented with a `tracing` [`Span`]. |
| /// |
| /// This type is returned by the [`Instrument`] extension trait. See that |
| /// trait's documentation for details. |
| /// |
| /// [`Future`]: std::future::Future |
| /// [`Span`]: crate::Span |
| </span><span class="attribute">#[derive(Debug, Clone)] |
| #[must_use = <span class="string">"futures do nothing unless you `.await` or poll them"</span>] |
| </span><span class="kw">pub struct </span>Instrumented<T> { |
| <span class="attribute">#[pin] |
| </span>inner: T, |
| span: Span, |
| } |
| } |
| |
| <span class="comment">// === impl Instrumented === |
| |
| </span><span class="kw">impl</span><T: Future> Future <span class="kw">for </span>Instrumented<T> { |
| <span class="kw">type </span>Output = T::Output; |
| |
| <span class="kw">fn </span>poll(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="self">Self</span>::Output> { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| <span class="kw">let </span>_enter = this.span.enter(); |
| this.inner.poll(cx) |
| } |
| } |
| |
| <span class="kw">impl</span><T: Sized> Instrument <span class="kw">for </span>T {} |
| |
| <span class="kw">impl</span><T> Instrumented<T> { |
| <span class="doccomment">/// Borrows the `Span` that this type is instrumented by. |
| </span><span class="kw">pub fn </span>span(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Span { |
| <span class="kw-2">&</span><span class="self">self</span>.span |
| } |
| |
| <span class="doccomment">/// Mutably borrows the `Span` that this type is instrumented by. |
| </span><span class="kw">pub fn </span>span_mut(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>Span { |
| <span class="kw-2">&mut </span><span class="self">self</span>.span |
| } |
| |
| <span class="doccomment">/// Borrows the wrapped type. |
| </span><span class="kw">pub fn </span>inner(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>T { |
| <span class="kw-2">&</span><span class="self">self</span>.inner |
| } |
| |
| <span class="doccomment">/// Mutably borrows the wrapped type. |
| </span><span class="kw">pub fn </span>inner_mut(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>T { |
| <span class="kw-2">&mut </span><span class="self">self</span>.inner |
| } |
| |
| <span class="doccomment">/// Get a pinned reference to the wrapped type. |
| </span><span class="kw">pub fn </span>inner_pin_ref(<span class="self">self</span>: Pin<<span class="kw-2">&</span><span class="self">Self</span>>) -> Pin<<span class="kw-2">&</span>T> { |
| <span class="self">self</span>.project_ref().inner |
| } |
| |
| <span class="doccomment">/// Get a pinned mutable reference to the wrapped type. |
| </span><span class="kw">pub fn </span>inner_pin_mut(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>) -> Pin<<span class="kw-2">&mut </span>T> { |
| <span class="self">self</span>.project().inner |
| } |
| |
| <span class="doccomment">/// Consumes the `Instrumented`, returning the wrapped type. |
| /// |
| /// Note that this drops the span. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> T { |
| <span class="self">self</span>.inner |
| } |
| } |
| |
| <span class="comment">// === impl WithDispatch === |
| |
| </span><span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] |
| #[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"std"</span>)))] |
| </span><span class="kw">impl</span><T: Future> Future <span class="kw">for </span>WithDispatch<T> { |
| <span class="kw">type </span>Output = T::Output; |
| |
| <span class="kw">fn </span>poll(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="self">Self</span>::Output> { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| <span class="kw">let </span>dispatcher = this.dispatcher; |
| <span class="kw">let </span>future = this.inner; |
| <span class="kw">let </span>_default = dispatcher::set_default(dispatcher); |
| future.poll(cx) |
| } |
| } |
| |
| <span class="attribute">#[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"std"</span>)))] |
| </span><span class="kw">impl</span><T: Sized> WithSubscriber <span class="kw">for </span>T {} |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] |
| #[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"std"</span>)))] |
| </span><span class="kw">impl</span><T> WithDispatch<T> { |
| <span class="doccomment">/// Borrows the [`Dispatch`] that is entered when this type is polled. |
| </span><span class="kw">pub fn </span>dispatcher(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>Dispatch { |
| <span class="kw-2">&</span><span class="self">self</span>.dispatcher |
| } |
| |
| <span class="doccomment">/// Borrows the wrapped type. |
| </span><span class="kw">pub fn </span>inner(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>T { |
| <span class="kw-2">&</span><span class="self">self</span>.inner |
| } |
| |
| <span class="doccomment">/// Mutably borrows the wrapped type. |
| </span><span class="kw">pub fn </span>inner_mut(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>T { |
| <span class="kw-2">&mut </span><span class="self">self</span>.inner |
| } |
| |
| <span class="doccomment">/// Get a pinned reference to the wrapped type. |
| </span><span class="kw">pub fn </span>inner_pin_ref(<span class="self">self</span>: Pin<<span class="kw-2">&</span><span class="self">Self</span>>) -> Pin<<span class="kw-2">&</span>T> { |
| <span class="self">self</span>.project_ref().inner |
| } |
| |
| <span class="doccomment">/// Get a pinned mutable reference to the wrapped type. |
| </span><span class="kw">pub fn </span>inner_pin_mut(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>) -> Pin<<span class="kw-2">&mut </span>T> { |
| <span class="self">self</span>.project().inner |
| } |
| |
| <span class="doccomment">/// Consumes the `Instrumented`, returning the wrapped type. |
| /// |
| /// Note that this drops the span. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> T { |
| <span class="self">self</span>.inner |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="tracing" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |