From fb6ef096c6841fc68e43e89301a5b617f28fa9af Mon Sep 17 00:00:00 2001 From: Tatsuhiro Tsujikawa Date: Tue, 28 Aug 2012 01:47:21 +0900 Subject: [PATCH] python: document urlfetch --- doc/python.rst | 62 ++++++++++++++ python/spdyclient.py | 187 +++---------------------------------------- 2 files changed, 75 insertions(+), 174 deletions(-) diff --git a/doc/python.rst b/doc/python.rst index d58463f..296a14f 100644 --- a/doc/python.rst +++ b/doc/python.rst @@ -884,6 +884,68 @@ SETTINGS ID Flags .. py:data:: ID_FLAG_SETTINGS_PERSISTED +Simple SPDY Client +------------------ + +This module offers a simple SPDY client implementation. The function +:py:func:`urlfetch()` fetches given URLs. For each URL, +*StreamHandlerClass* is instantiated and its methods are called when +certain event occurs. The *StreamHandlerClass* must be a subclass of +:py:class:`BaseSPDYStreamHandler`. + +.. py:function:: urlfetch(url_or_urls, StreamHandlerClass) + + Opens URL and handles the response from the servers. + + The *url_or_urls* is either one URL string or list of URL string. + For each URL, *StreamHandlerClass* is instantiated and it handles + the request to and response from the server. If successive URLs in + *url_or_urls* list have same origin, they are processed in one + SPDY session. + +.. py:class:: BaseSPDYStreamHandler(url, fetcher) + + This class handles one URL retrieval, which corresponds one SPDY + stream. The *url* is the URL to fetch. The *fetcher* is a driver + object to call methods of this object. For now it is opaque + object. This class is intended to be subclassed by the application + to add specific behavior. + + ``BaseSPDYStreamHandler`` has the following instance variables: + + .. py:attribute:: url + + The URL for this stream. + + .. py:attribute:: stream_id + + The stream ID for this stream. + + ``BaseSPDYStreamHandler`` has the following methods: + + .. py:method:: on_header(nv) + + Called when name/value pairs (headers) *nv* is received. This + method may be overridden by subclasses. The default + implementation does nothing. + + .. py:method:: on_data(data) + + Called when *data* is received. This method may be overridden + by subclass. The default implementation does nothing. + + .. py:method:: on_close(status_code) + + Called when this stream is closed. The *status_code* indicates + the reason of the closure. See `Stream Status Codes`_. This + method may be overridden by subclass. The default + implementation does nothing. + +The example follows: + +.. literalinclude:: ../python/spdyclient.py + :language: python + Simple SPDY Server ------------------ diff --git a/python/spdyclient.py b/python/spdyclient.py index c767e1e..8cdbf8f 100644 --- a/python/spdyclient.py +++ b/python/spdyclient.py @@ -3,185 +3,24 @@ # The example SPDY client. You need Python 3.3 or later because we # use TLS NPN. # -# Usage: spdyclient.py URI +# Usage: spdyclient.py URL... # -import socket import sys -import ssl -import select -import zlib -from urllib.parse import urlsplit import spdylay -def connect(hostname, port): - s = None - for res in socket.getaddrinfo(hostname, port, socket.AF_UNSPEC, - socket.SOCK_STREAM): - af, socktype, proto, canonname, sa = res - try: - s = socket.socket(af, socktype, proto) - except OSError as msg: - s = None - continue - try: - s.connect(sa) - except OSError as msg: - s.close() - s = None - continue - break - return s +class MyStreamHandler(spdylay.BaseSPDYStreamHandler): + def on_header(self, nv): + sys.stdout.write('Stream#{}\n'.format(self.stream_id)) + for k, v in nv: + sys.stdout.write('{}: {}\n'.format(k, v)) -class Request: - def __init__(self, uri): - self.uri = uri - self.stream_id = 0 - self.decomp = None + def on_data(self, data): + sys.stdout.write('Stream#{}\n'.format(self.stream_id)) + sys.stdout.buffer.write(data) -class SessionCtrl: - def __init__(self, sock): - self.sock = sock - self.requests = set() - self.streams = {} - self.finish = False - -def send_cb(session, data): - ssctrl = session.user_data - wlen = ssctrl.sock.send(data) - return wlen - -def before_ctrl_send_cb(session, frame): - if frame.frame_type == spdylay.SYN_STREAM: - req = session.get_stream_user_data(frame.stream_id) - if req: - req.stream_id = frame.stream_id - session.user_data.streams[req.stream_id] = req - -def on_ctrl_recv_cb(session, frame): - if frame.frame_type == spdylay.SYN_REPLY or\ - frame.frame_type == spdylay.HEADERS: - if frame.stream_id in session.user_data.streams: - req = session.user_data.streams[frame.stream_id] - if req.decomp: - return - for k, v in frame.nv: - if k == 'content-encoding' and \ - (v.lower() == 'gzip' or v.lower() == 'deflate'): - req.decomp = zlib.decompressobj() - -def on_data_chunk_recv_cb(session, flags, stream_id, data): - if stream_id in session.user_data.streams: - req = session.user_data.streams[stream_id] - if req.decomp: - sys.stdout.buffer.write(req.decomp.decompress(data)) - else: - sys.stdout.buffer.write(data) - -def on_stream_close_cb(session, stream_id, status_code): - if stream_id in session.user_data.streams: - del session.user_data.streams[stream_id] - session.user_data.finish = True - -def get(uri): - uricomps = urlsplit(uri) - if uricomps.scheme != 'https': - print('Unsupported scheme') - sys.exit(1) - hostname = uricomps.hostname - port = uricomps.port if uricomps.port else 443 - - rawsock = connect(hostname, port) - if rawsock is None: - print('Could not open socket') - sys.exit(1) - - ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23) - ctx.set_npn_protocols(['spdy/3', 'spdy/2']) - - sock = ctx.wrap_socket(rawsock, server_side=False, - do_handshake_on_connect=False) - sock.setblocking(False) - - while True: - try: - sock.do_handshake() - break - except ssl.SSLWantReadError as e: - select.select([sock], [], []) - except ssl.SSLWantWriteError as e: - select.select([], [sock], []) - - if sock.selected_npn_protocol() == 'spdy/3': - version = spdylay.PROTO_SPDY3 - elif sock.selected_npn_protocol() == 'spdy/2': - version = spdylay.PROTO_SPDY2 - else: - return - - sessionctrl = SessionCtrl(sock) - req = Request(uri) - sessionctrl.requests.add(req) - - session = spdylay.Session(spdylay.CLIENT, - version, - send_cb=send_cb, - on_ctrl_recv_cb=on_ctrl_recv_cb, - on_data_chunk_recv_cb=on_data_chunk_recv_cb, - before_ctrl_send_cb=before_ctrl_send_cb, - on_stream_close_cb=on_stream_close_cb, - user_data=sessionctrl) - - session.submit_settings(\ - spdylay.FLAG_SETTINGS_NONE, - [(spdylay.SETTINGS_MAX_CONCURRENT_STREAMS, - spdylay.ID_FLAG_SETTINGS_NONE, - 100)]) - - if uricomps.port != 443: - hostport = uricomps.netloc - else: - hostport = uricomps.hostname - if uricomps.path: - path = uricomps.path - else: - path = '/' - if uricomps.query: - path = '?'.join([path, uricomps.query]) - - session.submit_request(0, [(':method', 'GET'), - (':scheme', 'https'), - (':path', path), - (':version', 'HTTP/1.1'), - (':host', hostport), - ('accept', '*/*'), - ('user-agent', 'python-spdylay')], - stream_user_data=req) - - while (session.want_read() or session.want_write()) \ - and not sessionctrl.finish: - want_read = want_write = False - try: - data = sock.recv(4096) - if data: - session.recv(data) - else: - break - except ssl.SSLWantReadError: - want_read = True - except ssl.SSLWantWriteError: - want_write = True - try: - session.send() - except ssl.SSLWantReadError: - want_read = True - except ssl.SSLWantWriteError: - want_write = True - - if want_read or want_write: - select.select([sock] if want_read else [], - [sock] if want_write else [], - []) + def on_close(self, status_code): + sys.stdout.write('Stream#{} closed\n'.format(self.stream_id)) if __name__ == '__main__': - uri = sys.argv[1] - get(uri) + uris = sys.argv[1:] + spdylay.urlfetch(uris, MyStreamHandler)