Struct core2::io::Take

source · []
pub struct Take<T> { /* private fields */ }
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 std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let f = File::open("foo.txt")?;

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

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

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 std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let f = File::open("foo.txt")?;

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

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

Consumes the Take, returning the wrapped reader.

Examples
use std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut file = File::open("foo.txt")?;

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

    let file = handle.into_inner();
    Ok(())
}

Gets a reference to the underlying reader.

Examples
use std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut file = File::open("foo.txt")?;

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

    let file = handle.get_ref();
    Ok(())
}

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 std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut file = File::open("foo.txt")?;

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

    let file = handle.get_mut();
    Ok(())
}

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

Formats the value using the given formatter. Read more

Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more

Determines if this Reader can work with buffers of uninitialized memory. Read more

Read all bytes until EOF in this source, placing them into buf. Read more

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

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

Transforms this Read instance to an Iterator over its bytes. Read more

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

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

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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.