-try:
+import sys
+PY_3_OR_HIGHER = sys.version_info >= (3, 0)
+
+if PY_3_OR_HIGHER:
import urllib.request as urllib_request
import urllib.error as urllib_error
- import io
-except ImportError:
+else:
import urllib2 as urllib_request
import urllib2 as urllib_error
import json
from ssl import SSLError
import socket
-import sys
+import io
+import codecs
+import sys, select, time
from .api import TwitterCall, wrap_response, TwitterHTTPError
+CRLF = b'\r\n'
+
+Timeout = {'timeout': True}
+Hangup = {'hangup': True}
+HeartbeatTimeout = {'heartbeat_timeout': True, 'hangup': True}
+
+class ChunkDecodeError(Exception):
+ pass
+
+class EndOfStream(Exception):
+ pass
+
+range = range if PY_3_OR_HIGHER else xrange
+
+
+class HttpDeChunker(object):
+
+ def __init__(self):
+ self.buf = bytearray()
+
+ def extend(self, data):
+ self.buf.extend(data)
+
+ def read_chunks(self): # -> [bytearray]
+ chunks = []
+ buf = self.buf
+ while True:
+ header_end_pos = buf.find(CRLF)
+ if header_end_pos == -1:
+ break
+
+ header = buf[:header_end_pos]
+ data_start_pos = header_end_pos + 2
+ try:
+ chunk_len = int(header.decode('ascii'), 16)
+ except ValueError:
+ raise ChunkDecodeError()
+
+ if chunk_len == 0:
+ raise EndOfStream()
+
+ data_end_pos = data_start_pos + chunk_len
+
+ if len(buf) > data_end_pos + 2:
+ chunks.append(buf[data_start_pos:data_end_pos])
+ buf = buf[data_end_pos + 2:]
+ else:
+ break
+ self.buf = buf
+ return chunks
+
+
+class JsonDeChunker(object):
+
+ def __init__(self):
+ self.buf = u""
+ self.raw_decode = json.JSONDecoder().raw_decode
+
+ def extend(self, data):
+ self.buf += data
+
+ def read_json_chunks(self):
+ chunks = []
+ buf = self.buf
+ while True:
+ try:
+ buf = buf.lstrip()
+ res, ptr = self.raw_decode(buf)
+ buf = buf[ptr:]
+ chunks.append(res)
+ except ValueError:
+ break
+ self.buf = buf
+ return chunks
+
+
+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
+
+
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):
- if sys.version_info >= (3, 0):
- sock = self.handle.fp.raw._sock
- else:
- sock = self.handle.fp._sock.fp._sock
+ actually_block = self.block and not self.timeout
+ sock_timeout = min(self.timeout or 1000000, self.heartbeat_timeout)
+ 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)
+ headers = self.handle.headers
+ dechunker = HttpDeChunker()
+ utf8decoder = codecs.getincrementaldecoder("utf-8")()
+ json_dechunker = JsonDeChunker()
+ timer = Timer(self.timeout)
+ heartbeat_timer = Timer(self.heartbeat_timeout)
while True:
+ json_chunks = json_dechunker.read_json_chunks()
+ for json in json_chunks:
+ yield wrap_response(json, headers)
+ if json_chunks:
+ timer.reset()
+ heartbeat_timer.reset()
+
+ if not self.block and not self.timeout:
+ yield None
+ if heartbeat_timer.expired():
+ yield HeartbeatTimeout
+ break
+ if timer.expired():
+ yield Timeout
+
try:
- utf8_buf = self.buf.decode('utf8').lstrip()
- res, ptr = self.decoder.raw_decode(utf8_buf)
- self.buf = utf8_buf[ptr:].encode('utf8')
- yield wrap_response(res, self.handle.headers)
- 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)
- try:
- self.buf += sock.recv(1024)
+ ready_to_read = select.select([sock], [], [], sock_timeout)[0]
+ if not ready_to_read:
+ continue
+ data = sock.read()
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
+ continue
+
+ dechunker.extend(data)
-def handle_stream_response(req, uri, arg_data, block):
- handle = urllib_request.urlopen(req,)
- return iter(TwitterJSONIter(handle, uri, arg_data, block))
+ try:
+ chunks = dechunker.read_chunks()
+ except (ChunkDecodeError, EndOfStream):
+ yield Hangup
+ break
-class TwitterStreamCall(TwitterCall):
- def _handle_response(self, req, uri, arg_data, _timeout=None):
- return handle_stream_response(req, uri, arg_data, block=True)
+ for chunk in chunks:
+ if chunk:
+ json_dechunker.extend(utf8decoder.decode(chunk))
+ if chunks:
+ heartbeat_timer.reset()
-class TwitterStreamCallNonBlocking(TwitterCall):
- def _handle_response(self, req, uri, arg_data, _timeout=None):
- return handle_stream_response(req, uri, arg_data, block=False)
+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 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=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 `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 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 `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='1.1', 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)