positioned_io2/
array.rs

1use std::cmp::min;
2use std::io;
3
4use super::{ReadAt, Size, WriteAt};
5
6impl<'a> ReadAt for &'a [u8] {
7    fn read_at(&self, pos: u64, buf: &mut [u8]) -> io::Result<usize> {
8        if pos >= self.len() as u64 {
9            return Ok(0);
10        }
11        let pos = pos as usize;
12        let bytes = min(buf.len(), self.len() - pos);
13        buf[..bytes].copy_from_slice(&self[pos..(pos + bytes)]);
14        Ok(bytes)
15    }
16}
17
18impl<'a> ReadAt for &'a mut [u8] {
19    fn read_at(&self, pos: u64, buf: &mut [u8]) -> io::Result<usize> {
20        let immutable: &[u8] = self;
21        immutable.read_at(pos, buf)
22    }
23}
24
25impl<'a> WriteAt for &'a mut [u8] {
26    fn write_at(&mut self, pos: u64, buf: &[u8]) -> io::Result<usize> {
27        if pos >= self.len() as u64 {
28            return Ok(0);
29        }
30        let pos = pos as usize;
31        let bytes = min(buf.len(), self.len() - pos);
32        self[pos..(pos + bytes)].copy_from_slice(&buf[..bytes]);
33        Ok(bytes)
34    }
35
36    fn flush(&mut self) -> io::Result<()> {
37        Ok(())
38    }
39}
40
41impl<'a> Size for &'a [u8] {
42    fn size(&self) -> io::Result<Option<u64>> {
43        Ok(Some(self.len() as u64))
44    }
45}
46
47impl<'a> Size for &'a mut [u8] {
48    fn size(&self) -> io::Result<Option<u64>> {
49        Ok(Some(self.len() as u64))
50    }
51}
positioned_io2/array.rs

positioned_io2/
array.rs
