Trait positioned_io::ReadAt [] [src]

pub trait ReadAt {
    fn read_at(&self, pos: u64, buf: &mut [u8]) -> Result<usize>;

    fn read_exact_at(&self, pos: u64, buf: &mut [u8]) -> Result<()> { ... }

Trait for reading at an offset.

Implementations should be able to read bytes without changing any sort of read-position. Self should not change at all. Buffering reads is unlikely to be useful, since each time read_at() is called, the position may be completely different.


Read the fifth 512-byte sector of a file:

use positioned_io::ReadAt;

let file = try!(File::open(""));
let mut buf = vec![0; 512];
let bytes_read = try!(file.read_at(2048, &mut buf));

Required Methods

Read bytes from an offset in this source into a buffer, returning how many bytes were read.

This function may yield fewer bytes than the size of buf, if it was interrupted or hit end-of-file.

See Read::read().

Provided Methods

Read the exact number of bytes required to fill buf, from an offset.

If only a lesser number of bytes can be read, will yield an error.