import json
from ssl import SSLError
import socket
+import sys, select, time
+
+from .api import TwitterCall, wrap_response, TwitterHTTPError
+
+PY_27_OR_HIGHER = sys.version_info >= (2, 7)
+PY_3_OR_HIGHER = sys.version_info >= (3, 0)
+
+Timeout = {'timeout': True}
+Hangup = {'hangup': True}
+HeartbeatTimeout = {'heartbeat_timeout': True, 'hangup': True}
+
+class ChunkDecodeError(Exception):
+ pass
+
+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 not crlf:
+ raise ChunkDecodeError()
+
+ 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 PY_27_OR_HIGHER: # 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.
+
+ return chunk
+
+
+class Timer(object):
+ def __init__(self, timeout):
+ # If timeout is None, we never expire.
+ self.timeout = timeout
+ self.reset()
+
+ def reset(self):
+ self.time = time.time()
+
+ def expired(self):
+ """
+ If expired, reset the timer and return True.
+ """
+ if self.timeout is None:
+ return False
+ elif time.time() - self.time > self.timeout:
+ self.reset()
+ return True
+ return False
-from .api import TwitterCall, wrap_response
class TwitterJSONIter(object):
- def __init__(self, handle, uri, arg_data, block=True):
- self.decoder = json.JSONDecoder()
+ def __init__(self, handle, uri, arg_data, block, timeout, heartbeat_timeout):
self.handle = handle
- self.buf = b""
+ self.uri = uri
+ self.arg_data = arg_data
self.block = block
+ self.timeout = float(timeout) if timeout else None
+ self.heartbeat_timeout = float(heartbeat_timeout) if heartbeat_timeout else None
+
def __iter__(self):
- sock = self.handle.fp._sock.fp._sock
+ actually_block = self.block and not self.timeout
+ sock_timeout = min(self.timeout, self.heartbeat_timeout) if actually_block else None
+ sock = self.handle.fp.raw._sock if PY_3_OR_HIGHER else self.handle.fp._sock.fp._sock
sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
- if not self.block:
- sock.setblocking(False)
+ sock.setblocking(actually_block)
+ buf = ''
+ raw_decode = json.JSONDecoder().raw_decode
+ timer = Timer(self.timeout)
+ heartbeat_timer = Timer(self.heartbeat_timeout)
while True:
+ buf = buf.lstrip() # Remove any keep-alive delimiters
try:
- utf8_buf = self.buf.decode('utf8').lstrip()
- res, ptr = self.decoder.raw_decode(utf8_buf)
- self.buf = utf8_buf[ptr:].encode('utf8')
+ res, ptr = raw_decode(buf)
+ buf = buf[ptr:]
+ except ValueError:
+ if not self.block and not self.timeout:
+ yield None
+ else:
yield wrap_response(res, self.handle.headers)
+ timer.reset()
+ heartbeat_timer.reset()
continue
- except ValueError as e:
- if self.block:
- pass
- else:
- yield None
- except urllib_error.HTTPError as e:
- raise TwitterHTTPError(e, uri, self.format, arg_data)
- # this is a non-blocking read (ie, it will return if any data is available)
+
+ if heartbeat_timer.expired():
+ yield HeartbeatTimeout
+ break
+ if timer.expired():
+ yield Timeout
+
try:
- self.buf += sock.recv(1024)
+ if not buf and sock_timeout:
+ ready_to_read = select.select([sock], [], [], sock_timeout)[0]
+ if not ready_to_read:
+ continue
+ buf += recv_chunk(sock).decode('utf-8')
+ if not buf:
+ yield Hangup
+ break
+ heartbeat_timer.reset()
except SSLError as e:
- if (not self.block) and (e.errno == 2):
- # Apparently this means there was nothing in the socket buf
- pass
- else:
+ # Code 2 is error from a non-blocking read of an empty buffer.
+ if e.errno != 2:
raise
-def handle_stream_response(req, uri, arg_data, block):
- handle = urllib_request.urlopen(req,)
- return iter(TwitterJSONIter(handle, uri, arg_data, block))
+def handle_stream_response(req, uri, arg_data, block, timeout, heartbeat_timeout):
+ 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, heartbeat_timeout))
-class TwitterStreamCall(TwitterCall):
- def _handle_response(self, req, uri, arg_data, _timeout=None):
- return handle_stream_response(req, uri, arg_data, block=True)
-
-class TwitterStreamCallNonBlocking(TwitterCall):
- def _handle_response(self, req, uri, arg_data, _timeout=None):
- return handle_stream_response(req, uri, arg_data, block=False)
-
-class TwitterStream(TwitterStreamCall):
+class TwitterStream(TwitterCall):
"""
- The TwitterStream object is an interface to the Twitter Stream API
- (stream.twitter.com). This can be used pretty much the same as the
- Twitter class except the result of calling a method will be an
- iterator that yields objects decoded from the stream. For
- example::
+ The TwitterStream object is an interface to the Twitter Stream
+ API. This can be used pretty much the same as the Twitter class
+ except the result of calling a method will be an iterator that
+ yields objects decoded from the stream. For example::
- twitter_stream = TwitterStream(auth=UserPassAuth('joe', 'joespassword'))
+ twitter_stream = TwitterStream(auth=OAuth(...))
iterator = twitter_stream.statuses.sample()
for tweet in iterator:
...do something with this tweet...
- The iterator will yield tweets forever and ever (until the stream
- breaks at which point it raises a TwitterHTTPError.)
+ The iterator will yield until the TCP connection breaks. When the
+ connection breaks, the iterator yields `{'hangup': True}`, and
+ raises `StopIteration` if iterated again.
+
+ Similarly, if the stream does not produce heartbeats for more than
+ 90 seconds, the iterator yields `{'hangup': True,
+ 'heartbeat_timeout': True}`, and raises `StopIteration` if
+ iterated again.
- The `block` parameter controls if the stream is blocking. Default
- is blocking (True). When set to False, the iterator will
- occasionally yield None when there is no available message.
+ The `timeout` parameter controls the maximum time between
+ yields. If it is nonzero, then the iterator will yield either
+ stream data or `{'timeout': True}` within the timeout period. This
+ is useful if you want your program to do other stuff in between
+ waiting for tweets.
+
+ The `block` parameter sets the stream to be fully non-blocking. In
+ this mode, the iterator always yields immediately. It returns
+ stream data, or `None`. Note that `timeout` supercedes this
+ argument, so it should also be set `None` to use this mode.
"""
- def __init__(
- self, domain="stream.twitter.com", secure=True, auth=None,
- api_version='1', block=True):
- uriparts = ()
- uriparts += (str(api_version),)
-
- if block:
- call_cls = TwitterStreamCall
- else:
- call_cls = TwitterStreamCallNonBlocking
-
- TwitterStreamCall.__init__(
+ def __init__(self, domain="stream.twitter.com", secure=True, auth=None,
+ api_version='1.1', block=True, timeout=None,
+ heartbeat_timeout=90.0):
+ uriparts = (str(api_version),)
+
+ class TwitterStreamCall(TwitterCall):
+ def _handle_response(self, req, uri, arg_data, _timeout=None):
+ return handle_stream_response(
+ req, uri, arg_data, block,
+ _timeout or timeout, heartbeat_timeout)
+
+ TwitterCall.__init__(
self, auth=auth, format="json", domain=domain,
- callable_cls=call_cls,
- secure=secure, uriparts=uriparts)
+ callable_cls=TwitterStreamCall,
+ secure=secure, uriparts=uriparts, timeout=timeout, gzip=False)
projects / z_archive / twitter.git / blobdiff