]> jfr.im git - z_archive/twitter.git/blobdiff - twitter/stream.py
Version 1.17.0
[z_archive/twitter.git] / twitter / stream.py
index 728b49d9e8efa90f58fc1ba0a2f0ba07028a0988..f7c9419bd406269c0414b210721b20d3c1744a68 100644 (file)
-try:
+# encoding: utf-8
+from __future__ import unicode_literals
+
+from .util import PY_3_OR_HIGHER
+
+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}
+
 
-def recv_chunk(sock): # -> bytearray:
+class HttpChunkDecoder(object):
 
-    header = sock.recv(8)  # Scan for an up to 16MiB chunk size (0xffffff).
-    crlf = header.find(b'\r\n')  # Find the HTTP chunk size.
+    def __init__(self):
+        self.buf = bytearray()
+        self.munch_crlf = False
 
-    if crlf > 0:  # If there is a length, then process it
+    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
 
-        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.
+            header_end_pos = buf.find(CRLF)
+            if header_end_pos == -1:
+                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.
+            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
 
-        return chunk
+            if chunk_len == 0:
+                end_of_stream = True
+                break
 
-    return bytearray()
+            data_end_pos = data_start_pos + chunk_len
+
+            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
+
+
+class JsonDecoder(object):
+
+    def __init__(self):
+        self.buf = ""
+        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
@@ -72,64 +123,84 @@ 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:
-            if buf:
+            # 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()
-
-            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)
+            if json_data:
                 timer.reset()
-                heartbeat_timer.reset()
-                continue
 
+            # 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:
-                    if 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
-            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:
@@ -149,7 +220,37 @@ class TwitterStream(TwitterCall):
         iterator = twitter_stream.statuses.sample()
 
         for tweet in iterator:
-            ...do something with this tweet...
+            # ...do something with this tweet...
+
+    Per default the ``TwitterStream`` object uses
+    [public streams](https://dev.twitter.com/docs/streaming-apis/streams/public).
+    If you want to use one of the other
+    [streaming APIs](https://dev.twitter.com/docs/streaming-apis), specify the URL
+    manually:
+
+    - [Public streams](https://dev.twitter.com/docs/streaming-apis/streams/public): stream.twitter.com
+    - [User streams](https://dev.twitter.com/docs/streaming-apis/streams/user): userstream.twitter.com
+    - [Site streams](https://dev.twitter.com/docs/streaming-apis/streams/site): sitestream.twitter.com
+
+    Note that you require the proper
+    [permissions](https://dev.twitter.com/docs/application-permission-model) to
+    access these streams. E.g. for direct messages your
+    [application](https://dev.twitter.com/apps) needs the "Read, Write & Direct
+    Messages" permission.
+
+    The following example demonstrates how to retrieve all new direct messages
+    from the user stream::
+
+        auth = OAuth(
+            consumer_key='[your consumer key]',
+            consumer_secret='[your consumer secret]',
+            token='[your token]',
+            token_secret='[your token secret]'
+        )
+        twitter_userstream = TwitterStream(auth=auth, domain='userstream.twitter.com')
+        for msg in twitter_userstream.user():
+            if 'direct_message' in msg:
+                print msg['direct_message']['text']
 
     The iterator will yield until the TCP connection breaks. When the
     connection breaks, the iterator yields `{'hangup': True}`, and