Struct async_std::io::Take[−][src]

pub struct Take<T> { /* fields omitted */ }
Expand description

Reader adaptor which limits the bytes read from an underlying reader.

This struct is generally created by calling take on a reader. Please see the documentation of take for more details.

Implementations

Returns the number of bytes that can be read before this instance will return EOF.

Note

This instance may reach EOF after reading fewer bytes than indicated by this method if the underlying Read instance reaches EOF.

Examples

use async_std::prelude::*;
use async_std::fs::File;

let f = File::open("foo.txt").await?;

// read at most five bytes
let handle = f.take(5);

println!("limit: {}", handle.limit());

Sets the number of bytes that can be read before this instance will return EOF. This is the same as constructing a new Take instance, so the amount of bytes read and the previous limit value don’t matter when calling this method.

Examples

use async_std::prelude::*;
use async_std::fs::File;

let f = File::open("foo.txt").await?;

// read at most five bytes
let mut handle = f.take(5);
handle.set_limit(10);

assert_eq!(handle.limit(), 10);

Consumes the Take, returning the wrapped reader.

Examples

use async_std::prelude::*;
use async_std::fs::File;

let file = File::open("foo.txt").await?;

let mut buffer = [0; 5];
let mut handle = file.take(5);
handle.read(&mut buffer).await?;

let file = handle.into_inner();

Gets a reference to the underlying reader.

Examples

use async_std::prelude::*;
use async_std::fs::File;

let file = File::open("foo.txt").await?;

let mut buffer = [0; 5];
let mut handle = file.take(5);
handle.read(&mut buffer).await?;

let file = handle.get_ref();

Gets a mutable reference to the underlying reader.

Care should be taken to avoid modifying the internal I/O state of the underlying reader as doing so may corrupt the internal limit of this Take.

Examples

use async_std::prelude::*;
use async_std::fs::File;

let file = File::open("foo.txt").await?;

let mut buffer = [0; 5];
let mut handle = file.take(5);
handle.read(&mut buffer).await?;

let file = handle.get_mut();

Trait Implementations

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read. Read more

Reads all bytes into buf until the delimiter byte or EOF is reached. Read more

Reads all bytes and appends them into buf until a newline (the 0xA byte) is reached. Read more

Returns a stream over the lines of this byte stream. Read more

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

Formats the value using the given formatter. Read more

Attempt to read from the AsyncRead into buf.

Attempt to read from the AsyncRead into bufs using vectored IO operations.

Reads some bytes from the byte stream. Read more

Like read, except that it reads into a slice of buffers. Read more

Reads all bytes from the byte stream. Read more

Reads all bytes from the byte stream and appends them into a string. Read more

Reads the exact number of bytes required to fill buf. Read more

Creates an adaptor which will read at most limit bytes from it. Read more

Creates a “by reference” adaptor for this instance of Read. Read more

Transforms this Read instance to a Stream over its bytes. Read more

Creates an adaptor which will chain this stream with another. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.