diff options
Diffstat (limited to 'Lib/socket.py')
| -rw-r--r-- | Lib/socket.py | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/Lib/socket.py b/Lib/socket.py index f778f3be4d..2a5254730c 100644 --- a/Lib/socket.py +++ b/Lib/socket.py @@ -312,7 +312,8 @@ class _fileobject(object): def read(self, size=-1): # Use max, disallow tiny reads in a loop as they are very inefficient. - # We never leave read() with any leftover data in our internal buffer. + # We never leave read() with any leftover data from a new recv() call + # in our internal buffer. rbufsize = max(self._rbufsize, self.default_bufsize) # Our use of StringIO rather than lists of string objects returned by # recv() minimizes memory usage and fragmentation that occurs when @@ -342,13 +343,12 @@ class _fileobject(object): self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: left = size - buf_len - # Using max() here means that recv() can malloc a - # large amount of memory even though recv may return - # much less data than that. But the returned data - # string is short lived in that case as we copy it - # into a StringIO and free it. - recv_size = max(rbufsize, left) - data = self._sock.recv(recv_size) + # recv() will malloc the amount of memory given as its + # parameter even though it often returns much less data + # than that. The returned data string is short lived + # as we copy it into a StringIO and free it. This avoids + # fragmentation issues on many platforms. + data = self._sock.recv(left) if not data: break n = len(data) @@ -359,13 +359,11 @@ class _fileobject(object): # - Our call to recv returned exactly the # number of bytes we were asked to read. return data - if n >= left: - # avoids data copy of: buf.write(data[:left]) - buf.write(buffer(data, 0, left)) - # avoids data copy of: self._rbuf.write(data[left:]) - self._rbuf.write(buffer(data, left)) + if n == left: + buf.write(data) del data # explicit free break + assert n <= left, "recv(%d) returned %d bytes" % (left, n) buf.write(data) buf_len += n del data # explicit free @@ -374,8 +372,9 @@ class _fileobject(object): def readline(self, size=-1): buf = self._rbuf - if self._rbufsize > 1: - # if we're buffering, check if we already have it in our buffer + buf.seek(0, 2) # seek end + if buf.tell() > 0: + # check if we already have it in our buffer buf.seek(0) bline = buf.readline(size) if bline.endswith('\n') or len(bline) == size: @@ -383,13 +382,13 @@ class _fileobject(object): self._rbuf.write(buf.read()) return bline del bline - buf.seek(0, 2) # seek end if size < 0: # Read until \n or EOF, whichever comes first if self._rbufsize <= 1: # Speed up unbuffered case - assert buf.tell() == 0 - buffers = [] + buf.seek(0) + buffers = [buf.read()] + self._rbuf = StringIO() # reset _rbuf. we consume it via buf. data = None recv = self._sock.recv while data != "\n": @@ -399,7 +398,6 @@ class _fileobject(object): buffers.append(data) return "".join(buffers) - buf = self._rbuf buf.seek(0, 2) # seek end self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: @@ -417,6 +415,7 @@ class _fileobject(object): return buf.getvalue() else: # Read until size bytes or \n or EOF seen, whichever comes first + buf.seek(0, 2) # seek end buf_len = buf.tell() if buf_len >= size: buf.seek(0) |