from .api import TwitterCall, wrap_response, TwitterHTTPError
-def recv_chunk(sock): # -> bytearray:
-
- timeout = sock.gettimeout(); sock.setblocking(True) # Read the whole HTTP chunk.
- buf = sock.recv(10) # Scan for an up to a 4GiB chunk size (0xffffffff).
- if buf:
- crlf = buf.find(b'\r\n') # Find the HTTP chunk size.
- if crlf > 0:
- remaining = int(buf[:crlf], 16) # Decode the chunk size.
- chunk = bytearray(remaining) # Create the chunk buffer.
-
- start = crlf + 2 # Add in the length of the header's CRLF pair.
- end = len(buf) - start
-
- chunk[:end] = buf[start:]
- chunk[end:] = sock.recv(remaining - end)
-
+python27_3 = sys.version_info >= (2, 7)
+def recv_chunk(sock): # -> bytearray:
+
+ header = sock.recv(8) # Scan for an up to 16MiB chunk size (0xffffff).
+ crlf = header.find(b'\r\n') # Find the HTTP chunk size.
+
+ if crlf > 0: # If there is a length, then process it
+
+ size = int(header[:crlf], 16) # Decode the chunk size. Rarely exceeds 8KiB.
+ chunk = bytearray(size)
+ start = crlf + 2 # Add in the length of the header's CRLF pair.
+
+ if size <= 3: # E.g. an HTTP chunk with just a keep-alive delimiter or end of stream (0).
+ chunk[:size] = header[start:start + size]
+ # There are several edge cases (size == [4-6]) as the chunk size exceeds the length
+ # of the initial read of 8 bytes. With Twitter, these do not, in practice, occur. The
+ # shortest JSON message starts with '{"limit":{'. Hence, it exceeds in size the edge cases
+ # and eliminates the need to address them.
+ else: # There is more to read in the chunk.
+ end = len(header) - start
+ chunk[:end] = header[start:]
+ if python27_3: # When possible, use less memory by reading directly into the buffer.
+ buffer = memoryview(chunk)[end:] # Create a view into the bytearray to hold the rest of the chunk.
+ sock.recv_into(buffer)
+ else: # less efficient for python2.6 compatibility
+ chunk[end:] = sock.recv(max(0, size - end))
sock.recv(2) # Read the trailing CRLF pair. Throw it away.
- sock.settimeout(timeout)
- return chunk
+ return chunk
- sock.settimeout(timeout)
return bytearray()
-## recv_chunk()
-
class TwitterJSONIter(object):
def __iter__(self):
sock = self.handle.fp.raw._sock if sys.version_info >= (3, 0) else self.handle.fp._sock.fp._sock
sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
- sock.setblocking(self.block and not self.timeout) # not (not self.block or self.timeout)
- buf = u''
+ sock.setblocking(self.block and not self.timeout)
+ buf = ''
json_decoder = json.JSONDecoder()
timer = time.time()
while True:
res, ptr = json_decoder.raw_decode(buf)
buf = buf[ptr:]
yield wrap_response(res, self.handle.headers)
- timer = time.time()
continue
except ValueError as e:
- if self.block:
- pass
- else:
- yield None
+ if self.block: pass
+ else: yield None
try:
- if self.timeout: # this is a non-blocking read (ie, it will return if any data is available)
-
+ buf = buf.lstrip() # Remove any keep-alive delimiters to detect hangups.
+ if self.timeout and not buf: # This is a non-blocking read.
ready_to_read = select.select([sock], [], [], self.timeout)
- if ready_to_read[0]:
- buf += recv_chunk(sock).decode('utf-8')
- if time.time() - timer > self.timeout:
- yield {'timeout': True}
- else:
+ if not ready_to_read[0] and time.time() - timer > self.timeout:
yield {'timeout': True}
- else:
- buf += recv_chunk(sock).decode('utf-8')
- if not buf and self.block:
+ continue
+ timer = time.time()
+ buf += recv_chunk(sock).decode('utf-8')
+ if not buf:
yield {'hangup': True}
+ break
except SSLError as e:
- if (not self.block or self.timeout) and (e.errno == 2):
- # Apparently this means there was nothing in the socket buf
- pass
- else:
- raise
- except urllib_error.HTTPError as e:
- raise TwitterHTTPError(e, self.uri, 'json', self.arg_data)
+ # Error from a non-blocking read of an empty buffer.
+ if (not self.block or self.timeout) and (e.errno == 2): pass
+ else: raise
def handle_stream_response(req, uri, arg_data, block, timeout=None):
- handle = urllib_request.urlopen(req,)
+ try:
+ handle = urllib_request.urlopen(req,)
+ except urllib_error.HTTPError as e:
+ raise TwitterHTTPError(e, uri, 'json', arg_data)
return iter(TwitterJSONIter(handle, uri, arg_data, block, timeout=timeout))
class TwitterStreamCallWithTimeout(TwitterCall):