X-Git-Url: https://jfr.im/git/z_archive/twitter.git/blobdiff_plain/dcece3a61cb23ca20f55e0f0b2572eb6b75e3941..537752d1e5b17f4867ca6a17e1a715b303fa62a4:/twitter/stream.py diff --git a/twitter/stream.py b/twitter/stream.py index 671a856..bc18f8e 100644 --- a/twitter/stream.py +++ b/twitter/stream.py @@ -1,58 +1,106 @@ -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_SOCK_TIMEOUT = 0.0 # Apparenty select with zero wait is okay! +MAX_SOCK_TIMEOUT = 10.0 +HEARTBEAT_TIMEOUT = 90.0 Timeout = {'timeout': True} Hangup = {'hangup': True} -HeartbeatTimeout = {'heartbeat_timeout': True, 'hangup': True} +DecodeError = {'hangup': True, 'decode_error': True} +HeartbeatTimeout = {'hangup': True, 'heartbeat_timeout': True} + + +class HttpChunkDecoder(object): + + 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 -class ChunkDecodeError(Exception): - pass + 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 -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 chunk_len == 0: + end_of_stream = True + break - if not crlf: - raise ChunkDecodeError() + data_end_pos = data_start_pos + chunk_len - 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 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 - 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 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 never expire. self.timeout = timeout @@ -73,61 +121,84 @@ class Timer(object): 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, timeout, heartbeat_timeout): self.handle = handle 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 - + self.timeout_token = Timeout + self.timeout = None + 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_SOCK_TIMEOUT + if heartbeat_timeout and heartbeat_timeout > 0: + self.heartbeat_timeout = float(heartbeat_timeout) def __iter__(self): - actually_block = self.block and not self.timeout - sock_timeout = min(self.timeout, self.heartbeat_timeout) if actually_block else None + timeouts = [t for t in (self.timeout, self.heartbeat_timeout, MAX_SOCK_TIMEOUT) + if t is not None] + sock_timeout = min(*timeouts) 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_block) - buf = '' - raw_decode = json.JSONDecoder().raw_decode + 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) heartbeat_timer = Timer(self.heartbeat_timeout) + while True: - buf = buf.lstrip() # Remove any keep-alive delimiters - try: - 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() + # Decode all the things: + data = sock_reader.read() + dechunked_data, end_of_stream, decode_error = chunk_decoder.decode(data) + unicode_data = utf8_decoder.decode(dechunked_data) + json_data = json_decoder.decode(unicode_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() - continue + if json_data: + timer.reset() + # 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 Timeout + yield self.timeout_token - try: - 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: - # 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, timeout, heartbeat_timeout): try: