diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py index 59e22f523a85c5..d2db1a930c2ad2 100644 --- a/Lib/asyncio/streams.py +++ b/Lib/asyncio/streams.py @@ -667,8 +667,7 @@ async def readuntil(self, separator=b'\n'): # adds data which makes separator be found. That's why we check for # EOF *after* inspecting the buffer. if self._eof: - chunk = bytes(self._buffer) - self._buffer.clear() + chunk = self._buffer.take_bytes() raise exceptions.IncompleteReadError(chunk, None) # _wait_for_data() will resume reading if stream was paused. @@ -678,10 +677,9 @@ async def readuntil(self, separator=b'\n'): raise exceptions.LimitOverrunError( 'Separator is found, but chunk is longer than limit', match_start) - chunk = self._buffer[:match_end] - del self._buffer[:match_end] + chunk = self._buffer.take_bytes(match_end) self._maybe_resume_transport() - return bytes(chunk) + return chunk async def read(self, n=-1): """Read up to `n` bytes from the stream. @@ -716,20 +714,16 @@ async def read(self, n=-1): # collect everything in self._buffer, but that would # deadlock if the subprocess sends more than self.limit # bytes. So just call self.read(self._limit) until EOF. - blocks = [] - while True: - block = await self.read(self._limit) - if not block: - break - blocks.append(block) - return b''.join(blocks) + joined = bytearray() + while block := await self.read(self._limit): + joined += block + return joined.take_bytes() if not self._buffer and not self._eof: await self._wait_for_data('read') # This will work right even if buffer is less than n bytes - data = bytes(memoryview(self._buffer)[:n]) - del self._buffer[:n] + data = self._buffer.take_bytes(min(len(self._buffer), n)) self._maybe_resume_transport() return data @@ -760,18 +754,12 @@ async def readexactly(self, n): while len(self._buffer) < n: if self._eof: - incomplete = bytes(self._buffer) - self._buffer.clear() + incomplete = self._buffer.take_bytes() raise exceptions.IncompleteReadError(incomplete, n) await self._wait_for_data('readexactly') - if len(self._buffer) == n: - data = bytes(self._buffer) - self._buffer.clear() - else: - data = bytes(memoryview(self._buffer)[:n]) - del self._buffer[:n] + data = self._buffer.take_bytes(n) self._maybe_resume_transport() return data diff --git a/Misc/NEWS.d/next/Library/2025-11-22-16-33-48.gh-issue-141863.4PLhnv.rst b/Misc/NEWS.d/next/Library/2025-11-22-16-33-48.gh-issue-141863.4PLhnv.rst new file mode 100644 index 00000000000000..910ab98c950f9e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-11-22-16-33-48.gh-issue-141863.4PLhnv.rst @@ -0,0 +1,2 @@ +Update :ref:`asyncio-streams` to use :func:`bytearray.take_bytes` for a over +10% performance improvement on pyperformance asyncio_tcp benchmark.