use std::{
fmt::Write,
io::{self, Read},
};
use blake2b_simd::State;
pub struct HashReader<R: Read> {
reader: R,
hasher: State,
byte_count: usize,
}
impl<R: Read> HashReader<R> {
pub fn new(reader: R) -> Self {
HashReader {
reader,
hasher: State::new(),
byte_count: 0,
}
}
pub fn into_hash(self) -> String {
let hash = self.hasher.finalize();
let mut s = String::new();
for c in hash.as_bytes().iter() {
write!(&mut s, "{:02x}", c).expect("writing to a string never fails");
}
s
}
pub fn byte_count(&self) -> usize {
self.byte_count
}
}
impl<R: Read> Read for HashReader<R> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let bytes = self.reader.read(buf)?;
if bytes > 0 {
self.hasher.update(&buf[0..bytes]);
self.byte_count += bytes;
}
Ok(bytes)
}
}