Trait tokio::io::AsyncBufReadExt

pub trait AsyncBufReadExt: AsyncBufRead {
    fn read_until<'a>(
        &'a mut self, 
        byte: u8, 
        buf: &'a mut Vec<u8>
    ) -> ReadUntil<'a, Self>
    where
        Self: Unpin,
    { ... }
    fn read_line<'a>(&'a mut self, buf: &'a mut String) -> ReadLine<'a, Self>
    where
        Self: Unpin,
    { ... }
    fn split(self, byte: u8) -> Split<Self>
    where
        Self: Sized + Unpin,
    { ... }
    fn lines(self) -> Lines<Self>
    where
        Self: Sized,
    { ... }
}

This is supported on feature="io-util" only.

An extension trait which adds utility methods to AsyncBufRead types.

Provided methods

fn read_until<'a>(
    &'a mut self,
    byte: u8,
    buf: &'a mut Vec<u8>
) -> ReadUntil<'a, Self> where
    Self: Unpin, 

This is supported on feature="io-util" only.

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.

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_line<'a>(&'a mut self, buf: &'a mut String) -> ReadLine<'a, Self> where
    Self: Unpin, 

This is supported on feature="io-util" only.

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.

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.

fn split(self, byte: u8) -> Split<Self> where
    Self: Sized + Unpin, 

This is supported on feature="io-util" only.

Returns a stream of the contents of this reader split on the byte byte.

This method is the asynchronous equivalent to BufRead::split.

The stream returned from this function will yield instances of io::Result<Vec<u8>>. Each vector returned will not have the delimiter byte at the end.

Errors

Each item of the stream has the same error semantics as AsyncBufReadExt::read_until.

Examples

use tokio::io::AsyncBufReadExt;

let mut segments = my_buf_read.split(b'f');

while let Some(segment) = segments.next_segment().await? {
    println!("length = {}", segment.len())
}

fn lines(self) -> Lines<Self> where
    Self: Sized, 

This is supported on feature="io-util" only.

Returns a stream over the lines of this reader. This method is the async equivalent to 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.

Errors

Each line of the stream has the same error semantics as AsyncBufReadExt::read_line.

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Implementors

impl<R: AsyncBufRead + ?Sized> AsyncBufReadExt for R

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