| <!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-util-0.7.8/src/io/reader_stream.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>reader_stream.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_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="../../../tokio_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>bytes::{Bytes, BytesMut}; |
| <span class="kw">use </span>futures_core::stream::Stream; |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| <span class="kw">use </span>std::pin::Pin; |
| <span class="kw">use </span>std::task::{Context, Poll}; |
| <span class="kw">use </span>tokio::io::AsyncRead; |
| |
| <span class="kw">const </span>DEFAULT_CAPACITY: usize = <span class="number">4096</span>; |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Convert an [`AsyncRead`] into a [`Stream`] of byte chunks. |
| /// |
| /// This stream is fused. It performs the inverse operation of |
| /// [`StreamReader`]. |
| /// |
| /// # Example |
| /// |
| /// ``` |
| /// # #[tokio::main] |
| /// # async fn main() -> std::io::Result<()> { |
| /// use tokio_stream::StreamExt; |
| /// use tokio_util::io::ReaderStream; |
| /// |
| /// // Create a stream of data. |
| /// let data = b"hello, world!"; |
| /// let mut stream = ReaderStream::new(&data[..]); |
| /// |
| /// // Read all of the chunks into a vector. |
| /// let mut stream_contents = Vec::new(); |
| /// while let Some(chunk) = stream.next().await { |
| /// stream_contents.extend_from_slice(&chunk?); |
| /// } |
| /// |
| /// // Once the chunks are concatenated, we should have the |
| /// // original data. |
| /// assert_eq!(stream_contents, data); |
| /// # Ok(()) |
| /// # } |
| /// ``` |
| /// |
| /// [`AsyncRead`]: tokio::io::AsyncRead |
| /// [`StreamReader`]: crate::io::StreamReader |
| /// [`Stream`]: futures_core::Stream |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>ReaderStream<R> { |
| <span class="comment">// Reader itself. |
| // |
| // This value is `None` if the stream has terminated. |
| </span><span class="attribute">#[pin] |
| </span>reader: <span class="prelude-ty">Option</span><R>, |
| <span class="comment">// Working buffer, used to optimize allocations. |
| </span>buf: BytesMut, |
| capacity: usize, |
| } |
| } |
| |
| <span class="kw">impl</span><R: AsyncRead> ReaderStream<R> { |
| <span class="doccomment">/// Convert an [`AsyncRead`] into a [`Stream`] with item type |
| /// `Result<Bytes, std::io::Error>`. |
| /// |
| /// [`AsyncRead`]: tokio::io::AsyncRead |
| /// [`Stream`]: futures_core::Stream |
| </span><span class="kw">pub fn </span>new(reader: R) -> <span class="self">Self </span>{ |
| ReaderStream { |
| reader: <span class="prelude-val">Some</span>(reader), |
| buf: BytesMut::new(), |
| capacity: DEFAULT_CAPACITY, |
| } |
| } |
| |
| <span class="doccomment">/// Convert an [`AsyncRead`] into a [`Stream`] with item type |
| /// `Result<Bytes, std::io::Error>`, |
| /// with a specific read buffer initial capacity. |
| /// |
| /// [`AsyncRead`]: tokio::io::AsyncRead |
| /// [`Stream`]: futures_core::Stream |
| </span><span class="kw">pub fn </span>with_capacity(reader: R, capacity: usize) -> <span class="self">Self </span>{ |
| ReaderStream { |
| reader: <span class="prelude-val">Some</span>(reader), |
| buf: BytesMut::with_capacity(capacity), |
| capacity, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><R: AsyncRead> Stream <span class="kw">for </span>ReaderStream<R> { |
| <span class="kw">type </span>Item = std::io::Result<Bytes>; |
| <span class="kw">fn </span>poll_next(<span class="kw-2">mut </span><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="prelude-ty">Option</span><<span class="self">Self</span>::Item>> { |
| <span class="kw">use </span><span class="kw">crate</span>::util::poll_read_buf; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>this = <span class="self">self</span>.as_mut().project(); |
| |
| <span class="kw">let </span>reader = <span class="kw">match </span>this.reader.as_pin_mut() { |
| <span class="prelude-val">Some</span>(r) => r, |
| <span class="prelude-val">None </span>=> <span class="kw">return </span>Poll::Ready(<span class="prelude-val">None</span>), |
| }; |
| |
| <span class="kw">if </span>this.buf.capacity() == <span class="number">0 </span>{ |
| this.buf.reserve(<span class="kw-2">*</span>this.capacity); |
| } |
| |
| <span class="kw">match </span>poll_read_buf(reader, cx, <span class="kw-2">&mut </span>this.buf) { |
| Poll::Pending => Poll::Pending, |
| Poll::Ready(<span class="prelude-val">Err</span>(err)) => { |
| <span class="self">self</span>.project().reader.set(<span class="prelude-val">None</span>); |
| Poll::Ready(<span class="prelude-val">Some</span>(<span class="prelude-val">Err</span>(err))) |
| } |
| Poll::Ready(<span class="prelude-val">Ok</span>(<span class="number">0</span>)) => { |
| <span class="self">self</span>.project().reader.set(<span class="prelude-val">None</span>); |
| Poll::Ready(<span class="prelude-val">None</span>) |
| } |
| Poll::Ready(<span class="prelude-val">Ok</span>(<span class="kw">_</span>)) => { |
| <span class="kw">let </span>chunk = this.buf.split(); |
| Poll::Ready(<span class="prelude-val">Some</span>(<span class="prelude-val">Ok</span>(chunk.freeze()))) |
| } |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tokio_util" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
