| <!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/tokio-1.28.2/src/io/seek.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>seek.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="../../../tokio/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../tokio/index.html"><img class="rust-logo" src="../../../rust-logo.svg" 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> |
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| </pre><pre class="rust"><code><span class="kw">use </span><span class="kw">crate</span>::io::AsyncSeek; |
| |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| <span class="kw">use </span>std::future::Future; |
| <span class="kw">use </span>std::io::{<span class="self">self</span>, SeekFrom}; |
| <span class="kw">use </span>std::marker::PhantomPinned; |
| <span class="kw">use </span>std::pin::Pin; |
| <span class="kw">use </span>std::task::{Context, Poll}; |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Future for the [`seek`](crate::io::AsyncSeekExt::seek) method. |
| </span><span class="attribute">#[derive(Debug)] |
| #[must_use = <span class="string">"futures do nothing unless you `.await` or poll them"</span>] |
| </span><span class="kw">pub struct </span>Seek<<span class="lifetime">'a</span>, S: <span class="question-mark">?</span>Sized> { |
| seek: <span class="kw-2">&</span><span class="lifetime">'a </span><span class="kw-2">mut </span>S, |
| pos: <span class="prelude-ty">Option</span><SeekFrom>, |
| <span class="comment">// Make this future `!Unpin` for compatibility with async trait methods. |
| </span><span class="attribute">#[pin] |
| </span>_pin: PhantomPinned, |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>seek<S>(seek: <span class="kw-2">&mut </span>S, pos: SeekFrom) -> Seek<<span class="lifetime">'_</span>, S> |
| <span class="kw">where |
| </span>S: AsyncSeek + <span class="question-mark">?</span>Sized + Unpin, |
| { |
| Seek { |
| seek, |
| pos: <span class="prelude-val">Some</span>(pos), |
| _pin: PhantomPinned, |
| } |
| } |
| |
| <span class="kw">impl</span><S> Future <span class="kw">for </span>Seek<<span class="lifetime">'_</span>, S> |
| <span class="kw">where |
| </span>S: AsyncSeek + <span class="question-mark">?</span>Sized + Unpin, |
| { |
| <span class="kw">type </span>Output = io::Result<u64>; |
| |
| <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>me = <span class="self">self</span>.project(); |
| <span class="kw">match </span>me.pos { |
| <span class="prelude-val">Some</span>(pos) => { |
| <span class="comment">// ensure no seek in progress |
| </span><span class="macro">ready!</span>(Pin::new(<span class="kw-2">&mut *</span>me.seek).poll_complete(cx))<span class="question-mark">?</span>; |
| <span class="kw">match </span>Pin::new(<span class="kw-2">&mut *</span>me.seek).start_seek(<span class="kw-2">*</span>pos) { |
| <span class="prelude-val">Ok</span>(()) => { |
| <span class="kw-2">*</span>me.pos = <span class="prelude-val">None</span>; |
| Pin::new(<span class="kw-2">&mut *</span>me.seek).poll_complete(cx) |
| } |
| <span class="prelude-val">Err</span>(e) => Poll::Ready(<span class="prelude-val">Err</span>(e)), |
| } |
| } |
| <span class="prelude-val">None </span>=> Pin::new(<span class="kw-2">&mut *</span>me.seek).poll_complete(cx), |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tokio" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |