| <!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/git/checkouts/tokio-377c595163f99a10/dfe252d/tokio/src/io/util/lines.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lines.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::util::read_line::read_line_internal; |
| <span class="kw">use </span><span class="kw">crate</span>::io::AsyncBufRead; |
| |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| <span class="kw">use </span>std::io; |
| <span class="kw">use </span>std::mem; |
| <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">/// Reads lines from an [`AsyncBufRead`]. |
| /// |
| /// A `Lines` can be turned into a `Stream` with [`LinesStream`]. |
| /// |
| /// This type is usually created using the [`lines`] method. |
| /// |
| /// [`AsyncBufRead`]: crate::io::AsyncBufRead |
| /// [`LinesStream`]: https://docs.rs/tokio-stream/0.1/tokio_stream/wrappers/struct.LinesStream.html |
| /// [`lines`]: crate::io::AsyncBufReadExt::lines |
| </span><span class="attribute">#[derive(Debug)] |
| #[must_use = <span class="string">"streams do nothing unless polled"</span>] |
| #[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"io-util"</span>)))] |
| </span><span class="kw">pub struct </span>Lines<R> { |
| <span class="attribute">#[pin] |
| </span>reader: R, |
| buf: String, |
| bytes: Vec<u8>, |
| read: usize, |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>lines<R>(reader: R) -> Lines<R> |
| <span class="kw">where |
| </span>R: AsyncBufRead, |
| { |
| Lines { |
| reader, |
| buf: String::new(), |
| bytes: Vec::new(), |
| read: <span class="number">0</span>, |
| } |
| } |
| |
| <span class="kw">impl</span><R> Lines<R> |
| <span class="kw">where |
| </span>R: AsyncBufRead + Unpin, |
| { |
| <span class="doccomment">/// Returns the next line in the stream. |
| /// |
| /// # Cancel safety |
| /// |
| /// This method is cancellation safe. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # use tokio::io::AsyncBufRead; |
| /// use tokio::io::AsyncBufReadExt; |
| /// |
| /// # async fn dox(my_buf_read: impl AsyncBufRead + Unpin) -> std::io::Result<()> { |
| /// let mut lines = my_buf_read.lines(); |
| /// |
| /// while let Some(line) = lines.next_line().await? { |
| /// println!("length = {}", line.len()) |
| /// } |
| /// # Ok(()) |
| /// # } |
| /// ``` |
| </span><span class="kw">pub async fn </span>next_line(<span class="kw-2">&mut </span><span class="self">self</span>) -> io::Result<<span class="prelude-ty">Option</span><String>> { |
| <span class="kw">use </span><span class="kw">crate</span>::future::poll_fn; |
| |
| poll_fn(|cx| Pin::new(<span class="kw-2">&mut *</span><span class="self">self</span>).poll_next_line(cx)).<span class="kw">await |
| </span>} |
| |
| <span class="doccomment">/// Obtains a mutable reference to the underlying reader. |
| </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>R { |
| <span class="kw-2">&mut </span><span class="self">self</span>.reader |
| } |
| |
| <span class="doccomment">/// Obtains a reference to the underlying reader. |
| </span><span class="kw">pub fn </span>get_ref(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&</span>R { |
| <span class="kw-2">&</span><span class="self">self</span>.reader |
| } |
| |
| <span class="doccomment">/// Unwraps this `Lines<R>`, returning the underlying reader. |
| /// |
| /// Note that any leftover data in the internal buffer is lost. |
| /// Therefore, a following read from the underlying reader may lead to data loss. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> R { |
| <span class="self">self</span>.reader |
| } |
| } |
| |
| <span class="kw">impl</span><R> Lines<R> |
| <span class="kw">where |
| </span>R: AsyncBufRead, |
| { |
| <span class="doccomment">/// Polls for the next line in the stream. |
| /// |
| /// This method returns: |
| /// |
| /// * `Poll::Pending` if the next line is not yet available. |
| /// * `Poll::Ready(Ok(Some(line)))` if the next line is available. |
| /// * `Poll::Ready(Ok(None))` if there are no more lines in this stream. |
| /// * `Poll::Ready(Err(err))` if an IO error occurred while reading the next line. |
| /// |
| /// When the method returns `Poll::Pending`, the `Waker` in the provided |
| /// `Context` is scheduled to receive a wakeup when more bytes become |
| /// available on the underlying IO resource. Note that on multiple calls to |
| /// `poll_next_line`, only the `Waker` from the `Context` passed to the most |
| /// recent call is scheduled to receive a wakeup. |
| </span><span class="kw">pub fn </span>poll_next_line( |
| <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="prelude-ty">Option</span><String>>> { |
| <span class="kw">let </span>me = <span class="self">self</span>.project(); |
| |
| <span class="kw">let </span>n = <span class="macro">ready!</span>(read_line_internal(me.reader, cx, me.buf, me.bytes, me.read))<span class="question-mark">?</span>; |
| <span class="macro">debug_assert_eq!</span>(<span class="kw-2">*</span>me.read, <span class="number">0</span>); |
| |
| <span class="kw">if </span>n == <span class="number">0 </span>&& me.buf.is_empty() { |
| <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(<span class="prelude-val">None</span>)); |
| } |
| |
| <span class="kw">if </span>me.buf.ends_with(<span class="string">'\n'</span>) { |
| me.buf.pop(); |
| |
| <span class="kw">if </span>me.buf.ends_with(<span class="string">'\r'</span>) { |
| me.buf.pop(); |
| } |
| } |
| |
| Poll::Ready(<span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(mem::take(me.buf)))) |
| } |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>assert_unpin() { |
| <span class="kw">crate</span>::is_unpin::<Lines<()>>(); |
| } |
| } |
| </code></pre></div> |
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