| <!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-core-0.1.31/src/span.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>span.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_core/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_core/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> |
| </pre><pre class="rust"><code><span class="doccomment">//! Spans represent periods of time in the execution of a program. |
| </span><span class="kw">use </span><span class="kw">crate</span>::field::FieldSet; |
| <span class="kw">use </span><span class="kw">crate</span>::parent::Parent; |
| <span class="kw">use </span><span class="kw">crate</span>::stdlib::num::NonZeroU64; |
| <span class="kw">use crate</span>::{field, Metadata}; |
| |
| <span class="doccomment">/// Identifies a span within the context of a subscriber. |
| /// |
| /// They are generated by [`Subscriber`]s for each span as it is created, by |
| /// the [`new_span`] trait method. See the documentation for that method for |
| /// more information on span ID generation. |
| /// |
| /// [`Subscriber`]: super::subscriber::Subscriber |
| /// [`new_span`]: super::subscriber::Subscriber::new_span |
| </span><span class="attribute">#[derive(Clone, Debug, PartialEq, Eq, Hash)] |
| </span><span class="kw">pub struct </span>Id(NonZeroU64); |
| |
| <span class="doccomment">/// Attributes provided to a `Subscriber` describing a new span when it is |
| /// created. |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>Attributes<<span class="lifetime">'a</span>> { |
| metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>, |
| values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>, |
| parent: Parent, |
| } |
| |
| <span class="doccomment">/// A set of fields recorded by a span. |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>Record<<span class="lifetime">'a</span>> { |
| values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>, |
| } |
| |
| <span class="doccomment">/// Indicates what [the `Subscriber` considers] the "current" span. |
| /// |
| /// As subscribers may not track a notion of a current span, this has three |
| /// possible states: |
| /// - "unknown", indicating that the subscriber does not track a current span, |
| /// - "none", indicating that the current context is known to not be in a span, |
| /// - "some", with the current span's [`Id`] and [`Metadata`]. |
| /// |
| /// [the `Subscriber` considers]: super::subscriber::Subscriber::current_span |
| /// [`Metadata`]: super::metadata::Metadata |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>Current { |
| inner: CurrentInner, |
| } |
| |
| <span class="attribute">#[derive(Debug)] |
| </span><span class="kw">enum </span>CurrentInner { |
| Current { |
| id: Id, |
| metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>, |
| }, |
| <span class="prelude-val">None</span>, |
| Unknown, |
| } |
| |
| <span class="comment">// ===== impl Span ===== |
| |
| </span><span class="kw">impl </span>Id { |
| <span class="doccomment">/// Constructs a new span ID from the given `u64`. |
| /// |
| /// <pre class="ignore" style="white-space:normal;font:inherit;"> |
| /// <strong>Note</strong>: Span IDs must be greater than zero. |
| /// </pre> |
| /// |
| /// # Panics |
| /// - If the provided `u64` is 0. |
| </span><span class="kw">pub fn </span>from_u64(u: u64) -> <span class="self">Self </span>{ |
| Id(NonZeroU64::new(u).expect(<span class="string">"span IDs must be > 0"</span>)) |
| } |
| |
| <span class="doccomment">/// Constructs a new span ID from the given `NonZeroU64`. |
| /// |
| /// Unlike [`Id::from_u64`](Id::from_u64()), this will never panic. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub const fn </span>from_non_zero_u64(id: NonZeroU64) -> <span class="self">Self </span>{ |
| Id(id) |
| } |
| |
| <span class="comment">// Allow `into` by-ref since we don't want to impl Copy for Id |
| </span><span class="attribute">#[allow(clippy::wrong_self_convention)] |
| </span><span class="doccomment">/// Returns the span's ID as a `u64`. |
| </span><span class="kw">pub fn </span>into_u64(<span class="kw-2">&</span><span class="self">self</span>) -> u64 { |
| <span class="self">self</span>.<span class="number">0</span>.get() |
| } |
| |
| <span class="comment">// Allow `into` by-ref since we don't want to impl Copy for Id |
| </span><span class="attribute">#[allow(clippy::wrong_self_convention)] |
| </span><span class="doccomment">/// Returns the span's ID as a `NonZeroU64`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub const fn </span>into_non_zero_u64(<span class="kw-2">&</span><span class="self">self</span>) -> NonZeroU64 { |
| <span class="self">self</span>.<span class="number">0 |
| </span>} |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> From<<span class="kw-2">&</span><span class="lifetime">'a </span>Id> <span class="kw">for </span><span class="prelude-ty">Option</span><Id> { |
| <span class="kw">fn </span>from(id: <span class="kw-2">&</span><span class="lifetime">'a </span>Id) -> <span class="self">Self </span>{ |
| <span class="prelude-val">Some</span>(id.clone()) |
| } |
| } |
| |
| <span class="comment">// ===== impl Attributes ===== |
| |
| </span><span class="kw">impl</span><<span class="lifetime">'a</span>> Attributes<<span class="lifetime">'a</span>> { |
| <span class="doccomment">/// Returns `Attributes` describing a new child span of the current span, |
| /// with the provided metadata and values. |
| </span><span class="kw">pub fn </span>new(metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>, values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>) -> <span class="self">Self </span>{ |
| Attributes { |
| metadata, |
| values, |
| parent: Parent::Current, |
| } |
| } |
| |
| <span class="doccomment">/// Returns `Attributes` describing a new span at the root of its own trace |
| /// tree, with the provided metadata and values. |
| </span><span class="kw">pub fn </span>new_root(metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>, values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>) -> <span class="self">Self </span>{ |
| Attributes { |
| metadata, |
| values, |
| parent: Parent::Root, |
| } |
| } |
| |
| <span class="doccomment">/// Returns `Attributes` describing a new child span of the specified |
| /// parent span, with the provided metadata and values. |
| </span><span class="kw">pub fn </span>child_of( |
| parent: Id, |
| metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>, |
| values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>, |
| ) -> <span class="self">Self </span>{ |
| Attributes { |
| metadata, |
| values, |
| parent: Parent::Explicit(parent), |
| } |
| } |
| |
| <span class="doccomment">/// Returns a reference to the new span's metadata. |
| </span><span class="kw">pub fn </span>metadata(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>> { |
| <span class="self">self</span>.metadata |
| } |
| |
| <span class="doccomment">/// Returns a reference to a `ValueSet` containing any values the new span |
| /// was created with. |
| </span><span class="kw">pub fn </span>values(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>field::ValueSet<<span class="lifetime">'a</span>> { |
| <span class="self">self</span>.values |
| } |
| |
| <span class="doccomment">/// Returns true if the new span should be a root. |
| </span><span class="kw">pub fn </span>is_root(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="macro">matches!</span>(<span class="self">self</span>.parent, Parent::Root) |
| } |
| |
| <span class="doccomment">/// Returns true if the new span's parent should be determined based on the |
| /// current context. |
| /// |
| /// If this is true and the current thread is currently inside a span, then |
| /// that span should be the new span's parent. Otherwise, if the current |
| /// thread is _not_ inside a span, then the new span will be the root of its |
| /// own trace tree. |
| </span><span class="kw">pub fn </span>is_contextual(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="macro">matches!</span>(<span class="self">self</span>.parent, Parent::Current) |
| } |
| |
| <span class="doccomment">/// Returns the new span's explicitly-specified parent, if there is one. |
| /// |
| /// Otherwise (if the new span is a root or is a child of the current span), |
| /// returns `None`. |
| </span><span class="kw">pub fn </span>parent(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>Id> { |
| <span class="kw">match </span><span class="self">self</span>.parent { |
| Parent::Explicit(<span class="kw-2">ref </span>p) => <span class="prelude-val">Some</span>(p), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Records all the fields in this set of `Attributes` with the provided |
| /// [Visitor]. |
| /// |
| /// [visitor]: super::field::Visit |
| </span><span class="kw">pub fn </span>record(<span class="kw-2">&</span><span class="self">self</span>, visitor: <span class="kw-2">&mut </span><span class="kw">dyn </span>field::Visit) { |
| <span class="self">self</span>.values.record(visitor) |
| } |
| |
| <span class="doccomment">/// Returns `true` if this set of `Attributes` contains a value for the |
| /// given `Field`. |
| </span><span class="kw">pub fn </span>contains(<span class="kw-2">&</span><span class="self">self</span>, field: <span class="kw-2">&</span>field::Field) -> bool { |
| <span class="self">self</span>.values.contains(field) |
| } |
| |
| <span class="doccomment">/// Returns true if this set of `Attributes` contains _no_ values. |
| </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="self">self</span>.values.is_empty() |
| } |
| |
| <span class="doccomment">/// Returns the set of all [fields] defined by this span's [`Metadata`]. |
| /// |
| /// Note that the [`FieldSet`] returned by this method includes *all* the |
| /// fields declared by this span, not just those with values that are recorded |
| /// as part of this set of `Attributes`. Other fields with values not present in |
| /// this `Attributes`' value set may [record] values later. |
| /// |
| /// [fields]: crate::field |
| /// [record]: Attributes::record() |
| /// [`Metadata`]: crate::metadata::Metadata |
| /// [`FieldSet`]: crate::field::FieldSet |
| </span><span class="kw">pub fn </span>fields(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>FieldSet { |
| <span class="self">self</span>.values.field_set() |
| } |
| } |
| |
| <span class="comment">// ===== impl Record ===== |
| |
| </span><span class="kw">impl</span><<span class="lifetime">'a</span>> Record<<span class="lifetime">'a</span>> { |
| <span class="doccomment">/// Constructs a new `Record` from a `ValueSet`. |
| </span><span class="kw">pub fn </span>new(values: <span class="kw-2">&</span><span class="lifetime">'a </span>field::ValueSet<<span class="lifetime">'a</span>>) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ values } |
| } |
| |
| <span class="doccomment">/// Records all the fields in this `Record` with the provided [Visitor]. |
| /// |
| /// [visitor]: super::field::Visit |
| </span><span class="kw">pub fn </span>record(<span class="kw-2">&</span><span class="self">self</span>, visitor: <span class="kw-2">&mut </span><span class="kw">dyn </span>field::Visit) { |
| <span class="self">self</span>.values.record(visitor) |
| } |
| |
| <span class="doccomment">/// Returns the number of fields that would be visited from this `Record` |
| /// when [`Record::record()`] is called |
| /// |
| /// [`Record::record()`]: Record::record() |
| </span><span class="kw">pub fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="self">self</span>.values.len() |
| } |
| |
| <span class="doccomment">/// Returns `true` if this `Record` contains a value for the given `Field`. |
| </span><span class="kw">pub fn </span>contains(<span class="kw-2">&</span><span class="self">self</span>, field: <span class="kw-2">&</span>field::Field) -> bool { |
| <span class="self">self</span>.values.contains(field) |
| } |
| |
| <span class="doccomment">/// Returns true if this `Record` contains _no_ values. |
| </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="self">self</span>.values.is_empty() |
| } |
| } |
| |
| <span class="comment">// ===== impl Current ===== |
| |
| </span><span class="kw">impl </span>Current { |
| <span class="doccomment">/// Constructs a new `Current` that indicates the current context is a span |
| /// with the given `metadata` and `metadata`. |
| </span><span class="kw">pub fn </span>new(id: Id, metadata: <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| inner: CurrentInner::Current { id, metadata }, |
| } |
| } |
| |
| <span class="doccomment">/// Constructs a new `Current` that indicates the current context is *not* |
| /// in a span. |
| </span><span class="kw">pub fn </span>none() -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| inner: CurrentInner::None, |
| } |
| } |
| |
| <span class="doccomment">/// Constructs a new `Current` that indicates the `Subscriber` does not |
| /// track a current span. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>unknown() -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| inner: CurrentInner::Unknown, |
| } |
| } |
| |
| <span class="doccomment">/// Returns `true` if the `Subscriber` that constructed this `Current` tracks a |
| /// current span. |
| /// |
| /// If this returns `true` and [`id`], [`metadata`], or [`into_inner`] |
| /// return `None`, that indicates that we are currently known to *not* be |
| /// inside a span. If this returns `false`, those methods will also return |
| /// `None`, but in this case, that is because the subscriber does not keep |
| /// track of the currently-entered span. |
| /// |
| /// [`id`]: Current::id() |
| /// [`metadata`]: Current::metadata() |
| /// [`into_inner`]: Current::into_inner() |
| </span><span class="kw">pub fn </span>is_known(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| !<span class="macro">matches!</span>(<span class="self">self</span>.inner, CurrentInner::Unknown) |
| } |
| |
| <span class="doccomment">/// Consumes `self` and returns the span `Id` and `Metadata` of the current |
| /// span, if one exists and is known. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> <span class="prelude-ty">Option</span><(Id, <span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>)> { |
| <span class="kw">match </span><span class="self">self</span>.inner { |
| CurrentInner::Current { id, metadata } => <span class="prelude-val">Some</span>((id, metadata)), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Borrows the `Id` of the current span, if one exists and is known. |
| </span><span class="kw">pub fn </span>id(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>Id> { |
| <span class="kw">match </span><span class="self">self</span>.inner { |
| CurrentInner::Current { <span class="kw-2">ref </span>id, .. } => <span class="prelude-val">Some</span>(id), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Borrows the `Metadata` of the current span, if one exists and is known. |
| </span><span class="kw">pub fn </span>metadata(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>> { |
| <span class="kw">match </span><span class="self">self</span>.inner { |
| CurrentInner::Current { metadata, .. } => <span class="prelude-val">Some</span>(metadata), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> From<<span class="kw-2">&</span><span class="lifetime">'a </span>Current> <span class="kw">for </span><span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Id> { |
| <span class="kw">fn </span>from(cur: <span class="kw-2">&</span><span class="lifetime">'a </span>Current) -> <span class="self">Self </span>{ |
| cur.id() |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> From<<span class="kw-2">&</span><span class="lifetime">'a </span>Current> <span class="kw">for </span><span class="prelude-ty">Option</span><Id> { |
| <span class="kw">fn </span>from(cur: <span class="kw-2">&</span><span class="lifetime">'a </span>Current) -> <span class="self">Self </span>{ |
| cur.id().cloned() |
| } |
| } |
| |
| <span class="kw">impl </span>From<Current> <span class="kw">for </span><span class="prelude-ty">Option</span><Id> { |
| <span class="kw">fn </span>from(cur: Current) -> <span class="self">Self </span>{ |
| <span class="kw">match </span>cur.inner { |
| CurrentInner::Current { id, .. } => <span class="prelude-val">Some</span>(id), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> From<<span class="kw-2">&</span><span class="lifetime">'a </span>Current> <span class="kw">for </span><span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'static </span>Metadata<<span class="lifetime">'static</span>>> { |
| <span class="kw">fn </span>from(cur: <span class="kw-2">&</span><span class="lifetime">'a </span>Current) -> <span class="self">Self </span>{ |
| cur.metadata() |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="tracing_core" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
