blob: 01dff0b3eb3909c25b05057e84089a43ca763699 [file] [log] [blame]
use crate::cmp;
use crate::fmt;
use crate::io::{
self, BufRead, Error, ErrorKind, Initializer, IoSlice, IoSliceMut, Read, Seek, SeekFrom, Write,
};
use crate::mem;
// =============================================================================
// Forwarding implementations
#[stable(feature = "rust1", since = "1.0.0")]
impl<R: Read + ?Sized> Read for &mut R {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
(**self).read_vectored(bufs)
}
#[inline]
fn is_read_vectored(&self) -> bool {
(**self).is_read_vectored()
}
#[inline]
unsafe fn initializer(&self) -> Initializer {
(**self).initializer()
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_to_end(buf)
}
#[inline]
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_to_string(buf)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
(**self).read_exact(buf)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<W: Write + ?Sized> Write for &mut W {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
(**self).write(buf)
}
#[inline]
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
(**self).write_vectored(bufs)
}
#[inline]
fn is_write_vectored(&self) -> bool {
(**self).is_write_vectored()
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
(**self).flush()
}
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
(**self).write_all(buf)
}
#[inline]
fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
(**self).write_fmt(fmt)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<S: Seek + ?Sized> Seek for &mut S {
#[inline]
fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
(**self).seek(pos)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<B: BufRead + ?Sized> BufRead for &mut B {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> {
(**self).fill_buf()
}
#[inline]
fn consume(&mut self, amt: usize) {
(**self).consume(amt)
}
#[inline]
fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_until(byte, buf)
}
#[inline]
fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_line(buf)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<R: Read + ?Sized> Read for Box<R> {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
(**self).read_vectored(bufs)
}
#[inline]
fn is_read_vectored(&self) -> bool {
(**self).is_read_vectored()
}
#[inline]
unsafe fn initializer(&self) -> Initializer {
(**self).initializer()
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_to_end(buf)
}
#[inline]
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_to_string(buf)
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
(**self).read_exact(buf)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<W: Write + ?Sized> Write for Box<W> {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
(**self).write(buf)
}
#[inline]
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
(**self).write_vectored(bufs)
}
#[inline]
fn is_write_vectored(&self) -> bool {
(**self).is_write_vectored()
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
(**self).flush()
}
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
(**self).write_all(buf)
}
#[inline]
fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
(**self).write_fmt(fmt)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<S: Seek + ?Sized> Seek for Box<S> {
#[inline]
fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
(**self).seek(pos)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<B: BufRead + ?Sized> BufRead for Box<B> {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> {
(**self).fill_buf()
}
#[inline]
fn consume(&mut self, amt: usize) {
(**self).consume(amt)
}
#[inline]
fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
(**self).read_until(byte, buf)
}
#[inline]
fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
(**self).read_line(buf)
}
}
// Used by panicking::default_hook
#[cfg(test)]
/// This impl is only used by printing logic, so any error returned is always
/// of kind `Other`, and should be ignored.
impl Write for Box<dyn (::realstd::io::Write) + Send> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
(**self).write(buf).map_err(|_| ErrorKind::Other.into())
}
fn flush(&mut self) -> io::Result<()> {
(**self).flush().map_err(|_| ErrorKind::Other.into())
}
}
// =============================================================================
// In-memory buffer implementations
/// Read is implemented for `&[u8]` by copying from the slice.
///
/// Note that reading updates the slice to point to the yet unread part.
/// The slice will be empty when EOF is reached.
#[stable(feature = "rust1", since = "1.0.0")]
impl Read for &[u8] {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let amt = cmp::min(buf.len(), self.len());
let (a, b) = self.split_at(amt);
// First check if the amount of bytes we want to read is small:
// `copy_from_slice` will generally expand to a call to `memcpy`, and
// for a single byte the overhead is significant.
if amt == 1 {
buf[0] = a[0];
} else {
buf[..amt].copy_from_slice(a);
}
*self = b;
Ok(amt)
}
#[inline]
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
let mut nread = 0;
for buf in bufs {
nread += self.read(buf)?;
if self.is_empty() {
break;
}
}
Ok(nread)
}
#[inline]
fn is_read_vectored(&self) -> bool {
true
}
#[inline]
unsafe fn initializer(&self) -> Initializer {
Initializer::nop()
}
#[inline]
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
if buf.len() > self.len() {
return Err(Error::new(ErrorKind::UnexpectedEof, "failed to fill whole buffer"));
}
let (a, b) = self.split_at(buf.len());
// First check if the amount of bytes we want to read is small:
// `copy_from_slice` will generally expand to a call to `memcpy`, and
// for a single byte the overhead is significant.
if buf.len() == 1 {
buf[0] = a[0];
} else {
buf.copy_from_slice(a);
}
*self = b;
Ok(())
}
#[inline]
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
buf.extend_from_slice(*self);
let len = self.len();
*self = &self[len..];
Ok(len)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl BufRead for &[u8] {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> {
Ok(*self)
}
#[inline]
fn consume(&mut self, amt: usize) {
*self = &self[amt..];
}
}
/// Write is implemented for `&mut [u8]` by copying into the slice, overwriting
/// its data.
///
/// Note that writing updates the slice to point to the yet unwritten part.
/// The slice will be empty when it has been completely overwritten.
#[stable(feature = "rust1", since = "1.0.0")]
impl Write for &mut [u8] {
#[inline]
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
let amt = cmp::min(data.len(), self.len());
let (a, b) = mem::replace(self, &mut []).split_at_mut(amt);
a.copy_from_slice(&data[..amt]);
*self = b;
Ok(amt)
}
#[inline]
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
let mut nwritten = 0;
for buf in bufs {
nwritten += self.write(buf)?;
if self.is_empty() {
break;
}
}
Ok(nwritten)
}
#[inline]
fn is_write_vectored(&self) -> bool {
true
}
#[inline]
fn write_all(&mut self, data: &[u8]) -> io::Result<()> {
if self.write(data)? == data.len() {
Ok(())
} else {
Err(Error::new(ErrorKind::WriteZero, "failed to write whole buffer"))
}
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
/// Write is implemented for `Vec<u8>` by appending to the vector.
/// The vector will grow as needed.
#[stable(feature = "rust1", since = "1.0.0")]
impl Write for Vec<u8> {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.extend_from_slice(buf);
Ok(buf.len())
}
#[inline]
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
let len = bufs.iter().map(|b| b.len()).sum();
self.reserve(len);
for buf in bufs {
self.extend_from_slice(buf);
}
Ok(len)
}
#[inline]
fn is_write_vectored(&self) -> bool {
true
}
#[inline]
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
self.extend_from_slice(buf);
Ok(())
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
#[cfg(test)]
mod tests {
use crate::io::prelude::*;
#[bench]
fn bench_read_slice(b: &mut test::Bencher) {
let buf = [5; 1024];
let mut dst = [0; 128];
b.iter(|| {
let mut rd = &buf[..];
for _ in 0..8 {
let _ = rd.read(&mut dst);
test::black_box(&dst);
}
})
}
#[bench]
fn bench_write_slice(b: &mut test::Bencher) {
let mut buf = [0; 1024];
let src = [5; 128];
b.iter(|| {
let mut wr = &mut buf[..];
for _ in 0..8 {
let _ = wr.write_all(&src);
test::black_box(&wr);
}
})
}
#[bench]
fn bench_read_vec(b: &mut test::Bencher) {
let buf = vec![5; 1024];
let mut dst = [0; 128];
b.iter(|| {
let mut rd = &buf[..];
for _ in 0..8 {
let _ = rd.read(&mut dst);
test::black_box(&dst);
}
})
}
#[bench]
fn bench_write_vec(b: &mut test::Bencher) {
let mut buf = Vec::with_capacity(1024);
let src = [5; 128];
b.iter(|| {
let mut wr = &mut buf[..];
for _ in 0..8 {
let _ = wr.write_all(&src);
test::black_box(&wr);
}
})
}
}