| <!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/futures-util-0.3.28/src/io/chain.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>chain.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="../../../futures_util/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="../../../futures_util/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>futures_core::ready; |
| <span class="kw">use </span>futures_core::task::{Context, Poll}; |
| <span class="kw">use </span>futures_io::{AsyncBufRead, AsyncRead, IoSliceMut}; |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| <span class="kw">use </span>std::fmt; |
| <span class="kw">use </span>std::io; |
| <span class="kw">use </span>std::pin::Pin; |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Reader for the [`chain`](super::AsyncReadExt::chain) method. |
| </span><span class="attribute">#[must_use = <span class="string">"readers do nothing unless polled"</span>] |
| </span><span class="kw">pub struct </span>Chain<T, U> { |
| <span class="attribute">#[pin] |
| </span>first: T, |
| <span class="attribute">#[pin] |
| </span>second: U, |
| done_first: bool, |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> Chain<T, U> |
| <span class="kw">where |
| </span>T: AsyncRead, |
| U: AsyncRead, |
| { |
| <span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>new(first: T, second: U) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ first, second, done_first: <span class="bool-val">false </span>} |
| } |
| |
| <span class="doccomment">/// Gets references to the underlying readers in this `Chain`. |
| </span><span class="kw">pub fn </span>get_ref(<span class="kw-2">&</span><span class="self">self</span>) -> (<span class="kw-2">&</span>T, <span class="kw-2">&</span>U) { |
| (<span class="kw-2">&</span><span class="self">self</span>.first, <span class="kw-2">&</span><span class="self">self</span>.second) |
| } |
| |
| <span class="doccomment">/// Gets mutable references to the underlying readers in this `Chain`. |
| /// |
| /// Care should be taken to avoid modifying the internal I/O state of the |
| /// underlying readers as doing so may corrupt the internal state of this |
| /// `Chain`. |
| </span><span class="kw">pub fn </span>get_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>U) { |
| (<span class="kw-2">&mut </span><span class="self">self</span>.first, <span class="kw-2">&mut </span><span class="self">self</span>.second) |
| } |
| |
| <span class="doccomment">/// Gets pinned mutable references to the underlying readers in this `Chain`. |
| /// |
| /// Care should be taken to avoid modifying the internal I/O state of the |
| /// underlying readers as doing so may corrupt the internal state of this |
| /// `Chain`. |
| </span><span class="kw">pub fn </span>get_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>, Pin<<span class="kw-2">&mut </span>U>) { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| (this.first, this.second) |
| } |
| |
| <span class="doccomment">/// Consumes the `Chain`, returning the wrapped readers. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> (T, U) { |
| (<span class="self">self</span>.first, <span class="self">self</span>.second) |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> fmt::Debug <span class="kw">for </span>Chain<T, U> |
| <span class="kw">where |
| </span>T: fmt::Debug, |
| U: fmt::Debug, |
| { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| f.debug_struct(<span class="string">"Chain"</span>) |
| .field(<span class="string">"t"</span>, <span class="kw-2">&</span><span class="self">self</span>.first) |
| .field(<span class="string">"u"</span>, <span class="kw-2">&</span><span class="self">self</span>.second) |
| .field(<span class="string">"done_first"</span>, <span class="kw-2">&</span><span class="self">self</span>.done_first) |
| .finish() |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> AsyncRead <span class="kw">for </span>Chain<T, U> |
| <span class="kw">where |
| </span>T: AsyncRead, |
| U: AsyncRead, |
| { |
| <span class="kw">fn </span>poll_read( |
| <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>>, |
| buf: <span class="kw-2">&mut </span>[u8], |
| ) -> Poll<io::Result<usize>> { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| |
| <span class="kw">if </span>!<span class="kw-2">*</span>this.done_first { |
| <span class="kw">match </span><span class="macro">ready!</span>(this.first.poll_read(cx, buf)<span class="question-mark">?</span>) { |
| <span class="number">0 </span><span class="kw">if </span>!buf.is_empty() => <span class="kw-2">*</span>this.done_first = <span class="bool-val">true</span>, |
| n => <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(n)), |
| } |
| } |
| this.second.poll_read(cx, buf) |
| } |
| |
| <span class="kw">fn </span>poll_read_vectored( |
| <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>>, |
| bufs: <span class="kw-2">&mut </span>[IoSliceMut<<span class="lifetime">'_</span>>], |
| ) -> Poll<io::Result<usize>> { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| |
| <span class="kw">if </span>!<span class="kw-2">*</span>this.done_first { |
| <span class="kw">let </span>n = <span class="macro">ready!</span>(this.first.poll_read_vectored(cx, bufs)<span class="question-mark">?</span>); |
| <span class="kw">if </span>n == <span class="number">0 </span>&& bufs.iter().any(|b| !b.is_empty()) { |
| <span class="kw-2">*</span>this.done_first = <span class="bool-val">true |
| </span>} <span class="kw">else </span>{ |
| <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(n)); |
| } |
| } |
| this.second.poll_read_vectored(cx, bufs) |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> AsyncBufRead <span class="kw">for </span>Chain<T, U> |
| <span class="kw">where |
| </span>T: AsyncBufRead, |
| U: AsyncBufRead, |
| { |
| <span class="kw">fn </span>poll_fill_buf(<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<io::Result<<span class="kw-2">&</span>[u8]>> { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| |
| <span class="kw">if </span>!<span class="kw-2">*</span>this.done_first { |
| <span class="kw">match </span><span class="macro">ready!</span>(this.first.poll_fill_buf(cx)<span class="question-mark">?</span>) { |
| buf <span class="kw">if </span>buf.is_empty() => { |
| <span class="kw-2">*</span>this.done_first = <span class="bool-val">true</span>; |
| } |
| buf => <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(buf)), |
| } |
| } |
| this.second.poll_fill_buf(cx) |
| } |
| |
| <span class="kw">fn </span>consume(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, amt: usize) { |
| <span class="kw">let </span>this = <span class="self">self</span>.project(); |
| |
| <span class="kw">if </span>!<span class="kw-2">*</span>this.done_first { |
| this.first.consume(amt) |
| } <span class="kw">else </span>{ |
| this.second.consume(amt) |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="futures_util" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |