kpea/
crc.rs

1use std::io::Error;
2use std::io::Write;
3
4/// Computes sum of all bytes.
5pub struct CrcWriter<W: Write> {
6    writer: W,
7    sum: usize,
8}
9
10impl<W: Write> CrcWriter<W> {
11    pub fn new(writer: W) -> Self {
12        Self { writer, sum: 0 }
13    }
14
15    pub fn into_inner(self) -> W {
16        self.writer
17    }
18
19    pub fn sum(&self) -> u32 {
20        (self.sum & (u32::MAX as usize)) as u32
21    }
22}
23
24impl<W: Write> Write for CrcWriter<W> {
25    fn write(&mut self, buf: &[u8]) -> Result<usize, Error> {
26        let n = self.writer.write(buf)?;
27        for x in &buf[..n] {
28            self.sum = self.sum.wrapping_add(*x as usize);
29        }
30        Ok(n)
31    }
32
33    fn flush(&mut self) -> Result<(), Error> {
34        self.writer.flush()
35    }
36}
kpea/crc.rs

kpea/
crc.rs
