This library contains IoWindow, an I/O adapter for a stream of bytes that
limits operations within a byte range.
An IoWindow is conceptually similar to a mutable slice, applied to
a reader or writer. Given a byte range start..end, position 0 of the
IoWindow is position start of the underlying object; the end position of
the IoWindow is position start + end of the underlying object; and the
length of the IoWindow is end - start.
use io_window::IoWindow;
let stream = std::io::Cursor::new([0; 8]);
let mut window = IoWindow::new(stream, 2..6)?;
assert_eq!(window.write(&[42; 16])?, 4);
assert_eq!(
window.into_inner().into_inner(),
[0, 0, 42, 42, 42, 42, 0, 0]
);One use of this library is operating within a partition of a disk image.
For instance, if you have a filesystem implementation that uses a
Read + Write + Seek object, you can use IoWindow to avoid needing to
copy a disk image's partition into memory or another file, or reaching for a
memory-mapped buffer.
const MEBIBYTE: u64 = 1024 * 1024;
let file = File::open(disk)?;
let mut partition = IoWindow::new(file, MEBIBYTE..(64 * MEBIBYTE))?;It's also possible to provide a range with an unbounded end. If you were
working with a file with a header that you needed the ability to modify and
append to, you could use a range like 1024.. to create an IoWindow from
position 1024 to the end of the file.
License: MPL-2.0