python: document urlfetch
This commit is contained in:
Tatsuhiro Tsujikawa
parent
b4758b5701
commit
fb6ef096c6
|
|
@ -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
|
||||
------------------
|
||||
|
||||
|
|
|
|||
|
|
@ -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
|
||||
|
||||
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:
|
||||
def on_data(self, data):
|
||||
sys.stdout.write('Stream#{}\n'.format(self.stream_id))
|
||||
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)
|
||||
|
|
|
|||
Loading…
Reference in New Issue