cpython: b3ef922e6f26 (original) (raw)

Mercurial > cpython

changeset 104305:b3ef922e6f26 3.5

Issue #28370: Speedup asyncio.StreamReader.readexactly Patch by Коренберг Марк. [#28370]

Yury Selivanov yury@magic.io
date	Wed, 05 Oct 2016 18:01:12 -0400
parents	2b502f624753
children	b76553de3a29 c8e71ddf1db5
files	Lib/asyncio/streams.py Misc/NEWS
diffstat	2 files changed, 19 insertions(+), 18 deletions(-)[+] [-] Lib/asyncio/streams.py 34 Misc/NEWS 3

line wrap: on

line diff

--- a/Lib/asyncio/streams.py +++ b/Lib/asyncio/streams.py @@ -448,6 +448,7 @@ class StreamReader: assert not self._eof, '_wait_for_data after EOF' # Waiting for data while paused will make deadlock, so prevent it.

   # This is essential for readexactly(n) for case when n > self._limit.[](#l1.7)
   if self._paused:[](#l1.8)
       self._paused = False[](#l1.9)
       self._transport.resume_reading()[](#l1.10)

@@ -658,25 +659,22 @@ class StreamReader: if n == 0: return b''

   # There used to be "optimized" code here.  It created its own[](#l1.15)

   # Future and waited until self._buffer had at least the n[](#l1.16)

   # bytes, then called read(n).  Unfortunately, this could pause[](#l1.17)

   # the transport if the argument was larger than the pause[](#l1.18)

   # limit (which is twice self._limit).  So now we just read()[](#l1.19)

```
   # into a local buffer.[](#l1.20)
```

   while len(self._buffer) < n:[](#l1.21)

```
       if self._eof:[](#l1.22)
```

           incomplete = bytes(self._buffer)[](#l1.23)

           self._buffer.clear()[](#l1.24)

           raise IncompleteReadError(incomplete, n)[](#l1.25)

       yield from self._wait_for_data('readexactly')[](#l1.27)

```
   blocks = [][](#l1.29)
```
```
   while n > 0:[](#l1.30)
```

       block = yield from self.read(n)[](#l1.31)

```
       if not block:[](#l1.32)
```

           partial = b''.join(blocks)[](#l1.33)

           raise IncompleteReadError(partial, len(partial) + n)[](#l1.34)

```
       blocks.append(block)[](#l1.35)
```
```
       n -= len(block)[](#l1.36)
```

```
   assert n == 0[](#l1.38)
```

```
   return b''.join(blocks)[](#l1.40)
```

```
   if len(self._buffer) == n:[](#l1.41)
```

       data = bytes(self._buffer)[](#l1.42)

```
       self._buffer.clear()[](#l1.43)
```
```
   else:[](#l1.44)
```

       data = bytes(self._buffer[:n])[](#l1.45)

```
       del self._buffer[:n][](#l1.46)
```

   self._maybe_resume_transport()[](#l1.47)

```
   return data[](#l1.48)
```

if compat.PY35: @coroutine

--- a/Misc/NEWS +++ b/Misc/NEWS @@ -353,6 +353,9 @@ Library

Issue #28369: Raise RuntimeError when transport's FD is used with add_reader, add_writer, etc. +- Issue #28370: Speedup asyncio.StreamReader.readexactly.

Patch by Коренберг Марк. + IDLE ----