Files
tokio/tokio-io/src/io/async_buf_read_ext.rs
T
Lucio Franco ff41108834 io: move io helpers back into tokio-io (#1377)
Utilities are made optional with a feature flag.
2019-08-02 12:23:44 -07:00

82 lines
3.2 KiB
Rust

use crate::io::lines::{lines, Lines};
use crate::io::read_line::{read_line, ReadLine};
use crate::io::read_until::{read_until, ReadUntil};
use crate::AsyncBufRead;
/// An extension trait which adds utility methods to `AsyncBufRead` types.
pub trait AsyncBufReadExt: AsyncBufRead {
/// Creates a future which will read all the bytes associated with this I/O
/// object into `buf` until the delimiter `byte` or EOF is reached.
/// This method is the async equivalent to [`BufRead::read_until`](std::io::BufRead::read_until).
///
/// This function will read bytes from the underlying stream until the
/// delimiter or EOF is found. Once found, all bytes up to, and including,
/// the delimiter (if found) will be appended to `buf`.
///
/// The returned future will resolve to the number of bytes read once the read
/// operation is completed.
///
/// In the case of an error the buffer and the object will be discarded, with
/// the error yielded.
fn read_until<'a>(&'a mut self, byte: u8, buf: &'a mut Vec<u8>) -> ReadUntil<'a, Self>
where
Self: Unpin,
{
read_until(self, byte, buf)
}
/// Creates a future which will read all the bytes associated with this I/O
/// object into `buf` until a newline (the 0xA byte) or EOF is reached,
/// This method is the async equivalent to [`BufRead::read_line`](std::io::BufRead::read_line).
///
/// This function will read bytes from the underlying stream until the
/// newline delimiter (the 0xA byte) or EOF is found. Once found, all bytes
/// up to, and including, the delimiter (if found) will be appended to
/// `buf`.
///
/// The returned future will resolve to the number of bytes read once the read
/// operation is completed.
///
/// In the case of an error the buffer and the object will be discarded, with
/// the error yielded.
///
/// # Errors
///
/// This function has the same error semantics as [`read_until`] and will
/// also return an error if the read bytes are not valid UTF-8. If an I/O
/// error is encountered then `buf` may contain some bytes already read in
/// the event that all data read so far was valid UTF-8.
///
/// [`read_until`]: AsyncBufReadExt::read_until
fn read_line<'a>(&'a mut self, buf: &'a mut String) -> ReadLine<'a, Self>
where
Self: Unpin,
{
read_line(self, buf)
}
/// Returns a stream over the lines of this reader.
/// This method is the async equivalent to [`BufRead::lines`](std::io::BufRead::lines).
///
/// The stream returned from this function will yield instances of
/// [`io::Result`]`<`[`String`]`>`. Each string returned will *not* have a newline
/// byte (the 0xA byte) or CRLF (0xD, 0xA bytes) at the end.
///
/// [`io::Result`]: std::io::Result
/// [`String`]: String
///
/// # Errors
///
/// Each line of the stream has the same error semantics as [`AsyncBufReadExt::read_line`].
///
/// [`AsyncBufReadExt::read_line`]: AsyncBufReadExt::read_line
fn lines(self) -> Lines<Self>
where
Self: Sized,
{
lines(self)
}
}
impl<R: AsyncBufRead + ?Sized> AsyncBufReadExt for R {}