use crate::{Bufferable, ReadLayered, Status};
use std::io::{self, IoSliceMut, Read};
pub struct SliceReader<'slice> {
slice: &'slice [u8],
}
impl<'slice> SliceReader<'slice> {
#[inline]
pub fn new(slice: &'slice [u8]) -> Self {
Self { slice }
}
}
impl<'slice> ReadLayered for SliceReader<'slice> {
#[inline]
fn read_with_status(&mut self, buf: &mut [u8]) -> io::Result<(usize, Status)> {
let size = Read::read(&mut self.slice, buf)?;
Ok((
size,
if self.slice.is_empty() {
Status::End
} else {
Status::active()
},
))
}
#[inline]
fn read_vectored_with_status(
&mut self,
bufs: &mut [IoSliceMut<'_>],
) -> io::Result<(usize, Status)> {
let size = Read::read_vectored(&mut self.slice, bufs)?;
Ok((
size,
if self.slice.is_empty() {
Status::End
} else {
Status::active()
},
))
}
}
impl<'slice> Bufferable for SliceReader<'slice> {
#[inline]
fn abandon(&mut self) {
self.slice = &[];
}
#[inline]
fn suggested_buffer_size(&self) -> usize {
0
}
}
impl<'slice> Read for SliceReader<'slice> {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
Read::read(&mut self.slice, buf)
}
#[inline]
fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
Read::read_vectored(&mut self.slice, bufs)
}
#[cfg(can_vector)]
#[inline]
fn is_read_vectored(&self) -> bool {
Read::is_read_vectored(&self.slice)
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
Read::read_to_end(&mut self.slice, buf)
}
#[inline]
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
Read::read_to_string(&mut self.slice, buf)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
Read::read_exact(&mut self.slice, buf)
}
}
#[test]
fn test_slice_read_with_status() {
let mut reader = SliceReader::new(b"hello world!");
let mut buf = vec![0; 5];
assert_eq!(
reader.read_with_status(&mut buf).unwrap(),
(5, Status::active())
);
assert_eq!(buf, b"hello");
assert_eq!(
reader.read_with_status(&mut buf).unwrap(),
(5, Status::active())
);
assert_eq!(buf, b" worl");
assert_eq!(reader.read_with_status(&mut buf).unwrap(), (2, Status::End));
assert_eq!(&buf[..2], b"d!");
assert_eq!(reader.read_with_status(&mut buf).unwrap(), (0, Status::End));
}
#[test]
fn test_slice_read() {
let mut reader = SliceReader::new(b"hello world!");
let mut buf = vec![0; 5];
assert_eq!(reader.read(&mut buf).unwrap(), 5);
assert_eq!(buf, b"hello");
assert_eq!(reader.read(&mut buf).unwrap(), 5);
assert_eq!(buf, b" worl");
assert_eq!(reader.read(&mut buf).unwrap(), 2);
assert_eq!(&buf[..2], b"d!");
assert_eq!(reader.read(&mut buf).unwrap(), 0);
}