-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 codecs
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)
+CRLF = b'\r\n'
+MIN_TIMEOUT = 0.0 # Apparenty select with zero wait is okay!
+HEARTBEAT_TIMEOUT = 90.0
Timeout = {'timeout': True}
Hangup = {'hangup': True}
+DecodeError = {'hangup': True, 'decode_error': True}
+HeartbeatTimeout = {'hangup': True, 'heartbeat_timeout': True}
+range = range if PY_3_OR_HIGHER else xrange
-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.
+class HttpChunkDecoder(object):
- if crlf > 0: # If there is a length, then process it
+ def __init__(self):
+ self.buf = bytearray()
+ self.munch_crlf = False
+
+ def decode(self, data): # -> (bytearray, end_of_stream, decode_error)
+ chunks = []
+ buf = self.buf
+ munch_crlf = self.munch_crlf
+ end_of_stream = False
+ decode_error = False
+ buf.extend(data)
+ while True:
+ if munch_crlf:
+ # Dang, Twitter, you crazy. Twitter only sends a terminating
+ # CRLF at the beginning of the *next* message.
+ if len(buf) >= 2:
+ buf = buf[2:]
+ munch_crlf = False
+ else:
+ break
+
+ 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:
+ decode_error = True
+ break
- 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 chunk_len == 0:
+ end_of_stream = True
+ break
- 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.
+ data_end_pos = data_start_pos + chunk_len
- return chunk
+ if len(buf) >= data_end_pos:
+ chunks.append(buf[data_start_pos:data_end_pos])
+ buf = buf[data_end_pos:]
+ munch_crlf = True
+ else:
+ break
+ self.buf = buf
+ self.munch_crlf = munch_crlf
+ return bytearray().join(chunks), end_of_stream, decode_error
- return bytearray()
+
+class JsonDecoder(object):
+
+ def __init__(self):
+ self.buf = u""
+ self.raw_decode = json.JSONDecoder().raw_decode
+
+ def decode(self, data):
+ chunks = []
+ buf = self.buf + data
+ 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 always expire.
+ # If timeout is None, we never expire.
self.timeout = timeout
self.reset()
self.time = time.time()
def expired(self):
+ """
+ If expired, reset the timer and return True.
+ """
if self.timeout is None:
- return True
+ return False
elif time.time() - self.time > self.timeout:
self.reset()
return True
return False
+class SockReader(object):
+ def __init__(self, sock, sock_timeout):
+ self.sock = sock
+ self.sock_timeout = sock_timeout
+
+ def read(self):
+ try:
+ ready_to_read = select.select([self.sock], [], [], self.sock_timeout)[0]
+ if ready_to_read:
+ return self.sock.read()
+ except SSLError as e:
+ # Code 2 is error from a non-blocking read of an empty buffer.
+ if e.errno != 2:
+ raise
+ return bytearray()
+
+
class TwitterJSONIter(object):
- def __init__(self, handle, uri, arg_data, block=True, timeout=None):
+ def __init__(self, handle, uri, arg_data, block, timeout, heartbeat_timeout):
self.handle = handle
self.uri = uri
self.arg_data = arg_data
- self.block = block
- self.timeout = timeout
-
+ self.timeout_token = Timeout
+ self.timeout = HEARTBEAT_TIMEOUT
+ self.heartbeat_timeout = HEARTBEAT_TIMEOUT
+ if timeout and timeout > 0:
+ self.timeout = float(timeout)
+ elif not (block or timeout):
+ self.timeout_token = None
+ self.timeout = MIN_TIMEOUT
+ if heartbeat_timeout and heartbeat_timeout > 0:
+ self.heartbeat_timeout = float(heartbeat_timeout)
def __iter__(self):
- actually_blocking = self.block and not self.timeout
+ sock_timeout = min(self.timeout, 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)
- sock.setblocking(actually_blocking)
- buf = ''
- json_decoder = json.JSONDecoder()
+ headers = self.handle.headers
+ sock_reader = SockReader(sock, sock_timeout)
+ chunk_decoder = HttpChunkDecoder()
+ utf8_decoder = codecs.getincrementaldecoder("utf-8")()
+ json_decoder = JsonDecoder()
timer = Timer(self.timeout)
- timeout_token = Timeout if self.timeout else None
+ heartbeat_timer = Timer(self.heartbeat_timeout)
+
while True:
- buf = buf.lstrip()
- try:
- res, ptr = json_decoder.raw_decode(buf)
- buf = buf[ptr:]
- yield wrap_response(res, self.handle.headers)
+ # Decode all the things:
+ data = sock_reader.read()
+ dechunked_data, end_of_stream, decode_error = chunk_decoder.decode(data)
+ utf8_data = utf8_decoder.decode(dechunked_data)
+ json_data = json_decoder.decode(utf8_data)
+
+ # Yield data-like things:
+ for json_obj in json_data:
+ yield wrap_response(json_obj, headers)
+
+ # Reset timers:
+ if dechunked_data:
+ heartbeat_timer.reset()
+ if json_data:
timer.reset()
- continue
- except ValueError as e:
- if not actually_blocking and timer.expired():
- yield timeout_token
- try:
- 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)[0]
- if not ready_to_read and timer.expired():
- yield timeout_token
- continue
- buf += recv_chunk(sock).decode('utf-8')
- if not buf:
- yield Hangup
- break
- except SSLError as e:
- # Error from a non-blocking read of an empty buffer.
- if not actually_blocking and (e.errno == 2):
- if timer.expired():
- yield timeout_token
- else: raise
-
-def handle_stream_response(req, uri, arg_data, block, timeout=None):
+
+ # Yield timeouts and special things:
+ if end_of_stream:
+ yield Hangup
+ break
+ if decode_error:
+ yield DecodeError
+ break
+ if heartbeat_timer.expired():
+ yield HeartbeatTimeout
+ break
+ if timer.expired():
+ yield self.timeout_token
+
+
+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=timeout))
+ return iter(TwitterJSONIter(handle, uri, arg_data, block, timeout, heartbeat_timeout))
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, timeout=None):
+ 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),)
- timeout = float(timeout) if timeout else None
class TwitterStreamCall(TwitterCall):
def _handle_response(self, req, uri, arg_data, _timeout=None):
return handle_stream_response(
- req, uri, arg_data, block=block, timeout=_timeout or timeout)
+ req, uri, arg_data, block,
+ _timeout or timeout, heartbeat_timeout)
TwitterCall.__init__(
self, auth=auth, format="json", domain=domain,
projects / z_archive / twitter.git / blobdiff