4 use crate::alloc::Allocator;
6 use crate::collections::VecDeque;
9 self, BufRead, ErrorKind, IoSlice, IoSliceMut, Read, ReadBuf, Seek, SeekFrom, Write,
13 // =============================================================================
14 // Forwarding implementations
16 #[stable(feature = "rust1", since = "1.0.0")]
17 impl<R: Read + ?Sized> Read for &mut R {
19 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
24 fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
25 (**self).read_buf(buf)
29 fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
30 (**self).read_vectored(bufs)
34 fn is_read_vectored(&self) -> bool {
35 (**self).is_read_vectored()
39 fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
40 (**self).read_to_end(buf)
44 fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
45 (**self).read_to_string(buf)
49 fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
50 (**self).read_exact(buf)
53 #[stable(feature = "rust1", since = "1.0.0")]
54 impl<W: Write + ?Sized> Write for &mut W {
56 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
61 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
62 (**self).write_vectored(bufs)
66 fn is_write_vectored(&self) -> bool {
67 (**self).is_write_vectored()
71 fn flush(&mut self) -> io::Result<()> {
76 fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
77 (**self).write_all(buf)
81 fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
82 (**self).write_fmt(fmt)
85 #[stable(feature = "rust1", since = "1.0.0")]
86 impl<S: Seek + ?Sized> Seek for &mut S {
88 fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
93 fn stream_position(&mut self) -> io::Result<u64> {
94 (**self).stream_position()
97 #[stable(feature = "rust1", since = "1.0.0")]
98 impl<B: BufRead + ?Sized> BufRead for &mut B {
100 fn fill_buf(&mut self) -> io::Result<&[u8]> {
105 fn consume(&mut self, amt: usize) {
106 (**self).consume(amt)
110 fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
111 (**self).read_until(byte, buf)
115 fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
116 (**self).read_line(buf)
120 #[stable(feature = "rust1", since = "1.0.0")]
121 impl<R: Read + ?Sized> Read for Box<R> {
123 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
128 fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
129 (**self).read_buf(buf)
133 fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
134 (**self).read_vectored(bufs)
138 fn is_read_vectored(&self) -> bool {
139 (**self).is_read_vectored()
143 fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
144 (**self).read_to_end(buf)
148 fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
149 (**self).read_to_string(buf)
153 fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
154 (**self).read_exact(buf)
157 #[stable(feature = "rust1", since = "1.0.0")]
158 impl<W: Write + ?Sized> Write for Box<W> {
160 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
165 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
166 (**self).write_vectored(bufs)
170 fn is_write_vectored(&self) -> bool {
171 (**self).is_write_vectored()
175 fn flush(&mut self) -> io::Result<()> {
180 fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
181 (**self).write_all(buf)
185 fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
186 (**self).write_fmt(fmt)
189 #[stable(feature = "rust1", since = "1.0.0")]
190 impl<S: Seek + ?Sized> Seek for Box<S> {
192 fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
197 fn stream_position(&mut self) -> io::Result<u64> {
198 (**self).stream_position()
201 #[stable(feature = "rust1", since = "1.0.0")]
202 impl<B: BufRead + ?Sized> BufRead for Box<B> {
204 fn fill_buf(&mut self) -> io::Result<&[u8]> {
209 fn consume(&mut self, amt: usize) {
210 (**self).consume(amt)
214 fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
215 (**self).read_until(byte, buf)
219 fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
220 (**self).read_line(buf)
224 // =============================================================================
225 // In-memory buffer implementations
227 /// Read is implemented for `&[u8]` by copying from the slice.
229 /// Note that reading updates the slice to point to the yet unread part.
230 /// The slice will be empty when EOF is reached.
231 #[stable(feature = "rust1", since = "1.0.0")]
232 impl Read for &[u8] {
234 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
235 let amt = cmp::min(buf.len(), self.len());
236 let (a, b) = self.split_at(amt);
238 // First check if the amount of bytes we want to read is small:
239 // `copy_from_slice` will generally expand to a call to `memcpy`, and
240 // for a single byte the overhead is significant.
244 buf[..amt].copy_from_slice(a);
252 fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
253 let amt = cmp::min(buf.remaining(), self.len());
254 let (a, b) = self.split_at(amt);
263 fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
266 nread += self.read(buf)?;
276 fn is_read_vectored(&self) -> bool {
281 fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
282 if buf.len() > self.len() {
283 return Err(io::const_io_error!(
284 ErrorKind::UnexpectedEof,
285 "failed to fill whole buffer"
288 let (a, b) = self.split_at(buf.len());
290 // First check if the amount of bytes we want to read is small:
291 // `copy_from_slice` will generally expand to a call to `memcpy`, and
292 // for a single byte the overhead is significant.
296 buf.copy_from_slice(a);
304 fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
305 buf.extend_from_slice(*self);
306 let len = self.len();
307 *self = &self[len..];
312 #[stable(feature = "rust1", since = "1.0.0")]
313 impl BufRead for &[u8] {
315 fn fill_buf(&mut self) -> io::Result<&[u8]> {
320 fn consume(&mut self, amt: usize) {
321 *self = &self[amt..];
325 /// Write is implemented for `&mut [u8]` by copying into the slice, overwriting
328 /// Note that writing updates the slice to point to the yet unwritten part.
329 /// The slice will be empty when it has been completely overwritten.
331 /// If the number of bytes to be written exceeds the size of the slice, write operations will
332 /// return short writes: ultimately, `Ok(0)`; in this situation, `write_all` returns an error of
333 /// kind `ErrorKind::WriteZero`.
334 #[stable(feature = "rust1", since = "1.0.0")]
335 impl Write for &mut [u8] {
337 fn write(&mut self, data: &[u8]) -> io::Result<usize> {
338 let amt = cmp::min(data.len(), self.len());
339 let (a, b) = mem::replace(self, &mut []).split_at_mut(amt);
340 a.copy_from_slice(&data[..amt]);
346 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
347 let mut nwritten = 0;
349 nwritten += self.write(buf)?;
359 fn is_write_vectored(&self) -> bool {
364 fn write_all(&mut self, data: &[u8]) -> io::Result<()> {
365 if self.write(data)? == data.len() {
368 Err(io::const_io_error!(ErrorKind::WriteZero, "failed to write whole buffer"))
373 fn flush(&mut self) -> io::Result<()> {
378 /// Write is implemented for `Vec<u8>` by appending to the vector.
379 /// The vector will grow as needed.
380 #[stable(feature = "rust1", since = "1.0.0")]
381 impl<A: Allocator> Write for Vec<u8, A> {
383 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
384 self.extend_from_slice(buf);
389 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
390 let len = bufs.iter().map(|b| b.len()).sum();
393 self.extend_from_slice(buf);
399 fn is_write_vectored(&self) -> bool {
404 fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
405 self.extend_from_slice(buf);
410 fn flush(&mut self) -> io::Result<()> {
415 /// Read is implemented for `VecDeque<u8>` by consuming bytes from the front of the `VecDeque`.
416 #[stable(feature = "vecdeque_read_write", since = "1.63.0")]
417 impl<A: Allocator> Read for VecDeque<u8, A> {
418 /// Fill `buf` with the contents of the "front" slice as returned by
419 /// [`as_slices`][`VecDeque::as_slices`]. If the contained byte slices of the `VecDeque` are
420 /// discontiguous, multiple calls to `read` will be needed to read the entire content.
422 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
423 let (ref mut front, _) = self.as_slices();
424 let n = Read::read(front, buf)?;
430 fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
431 let (ref mut front, _) = self.as_slices();
432 let n = cmp::min(buf.remaining(), front.len());
433 Read::read_buf(front, buf)?;
439 /// Write is implemented for `VecDeque<u8>` by appending to the `VecDeque`, growing it as needed.
440 #[stable(feature = "vecdeque_read_write", since = "1.63.0")]
441 impl<A: Allocator> Write for VecDeque<u8, A> {
443 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
449 fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
455 fn flush(&mut self) -> io::Result<()> {