This crate allows you to specify an offset for reads and writes, without changing the current
position in a file. This is similar to pread()
and pwrite()
in C.
The major advantages of this type of I/O are:
- You don't need to seek before doing a random-access read or write, which is convenient.
- Reads don't modify the file at all, so don't require mutability.
Read the fifth 512-byte sector of a file:
use std::fs::File;
use positioned_io::ReadAt;
// note that file does not need to be mut
let file = File::open("tests/pi.txt")?;
// read up to 512 bytes
let mut buf = [0; 512];
let bytes_read = file.read_at(2048, &mut buf)?;
Note: If possible use the RandomAccessFile
wrapper. On Windows ReadAt
directly on File
is very slow.
positioned-io is licensed under the MIT license.