478 lines
19 KiB
Python
478 lines
19 KiB
Python
#!/usr/bin/env python
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#
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# Copyright 2009 Facebook
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""Non-blocking HTTP client implementation using pycurl."""
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from __future__ import absolute_import, division, print_function, with_statement
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import collections
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import logging
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import pycurl
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import threading
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import time
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from tornado import httputil
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from tornado import ioloop
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from tornado.log import gen_log
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from tornado import stack_context
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from tornado.escape import utf8, native_str
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from tornado.httpclient import HTTPResponse, HTTPError, AsyncHTTPClient, main
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from tornado.util import bytes_type
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try:
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from io import BytesIO # py3
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except ImportError:
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from cStringIO import StringIO as BytesIO # py2
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class CurlAsyncHTTPClient(AsyncHTTPClient):
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def initialize(self, io_loop, max_clients=10, defaults=None):
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super(CurlAsyncHTTPClient, self).initialize(io_loop, defaults=defaults)
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self._multi = pycurl.CurlMulti()
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self._multi.setopt(pycurl.M_TIMERFUNCTION, self._set_timeout)
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self._multi.setopt(pycurl.M_SOCKETFUNCTION, self._handle_socket)
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self._curls = [_curl_create() for i in range(max_clients)]
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self._free_list = self._curls[:]
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self._requests = collections.deque()
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self._fds = {}
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self._timeout = None
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# libcurl has bugs that sometimes cause it to not report all
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# relevant file descriptors and timeouts to TIMERFUNCTION/
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# SOCKETFUNCTION. Mitigate the effects of such bugs by
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# forcing a periodic scan of all active requests.
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self._force_timeout_callback = ioloop.PeriodicCallback(
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self._handle_force_timeout, 1000, io_loop=io_loop)
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self._force_timeout_callback.start()
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# Work around a bug in libcurl 7.29.0: Some fields in the curl
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# multi object are initialized lazily, and its destructor will
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# segfault if it is destroyed without having been used. Add
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# and remove a dummy handle to make sure everything is
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# initialized.
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dummy_curl_handle = pycurl.Curl()
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self._multi.add_handle(dummy_curl_handle)
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self._multi.remove_handle(dummy_curl_handle)
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def close(self):
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self._force_timeout_callback.stop()
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if self._timeout is not None:
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self.io_loop.remove_timeout(self._timeout)
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for curl in self._curls:
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curl.close()
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self._multi.close()
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super(CurlAsyncHTTPClient, self).close()
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def fetch_impl(self, request, callback):
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self._requests.append((request, callback))
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self._process_queue()
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self._set_timeout(0)
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def _handle_socket(self, event, fd, multi, data):
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"""Called by libcurl when it wants to change the file descriptors
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it cares about.
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"""
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event_map = {
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pycurl.POLL_NONE: ioloop.IOLoop.NONE,
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pycurl.POLL_IN: ioloop.IOLoop.READ,
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pycurl.POLL_OUT: ioloop.IOLoop.WRITE,
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pycurl.POLL_INOUT: ioloop.IOLoop.READ | ioloop.IOLoop.WRITE
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}
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if event == pycurl.POLL_REMOVE:
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if fd in self._fds:
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self.io_loop.remove_handler(fd)
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del self._fds[fd]
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else:
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ioloop_event = event_map[event]
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# libcurl sometimes closes a socket and then opens a new
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# one using the same FD without giving us a POLL_NONE in
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# between. This is a problem with the epoll IOLoop,
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# because the kernel can tell when a socket is closed and
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# removes it from the epoll automatically, causing future
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# update_handler calls to fail. Since we can't tell when
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# this has happened, always use remove and re-add
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# instead of update.
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if fd in self._fds:
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self.io_loop.remove_handler(fd)
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self.io_loop.add_handler(fd, self._handle_events,
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ioloop_event)
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self._fds[fd] = ioloop_event
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def _set_timeout(self, msecs):
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"""Called by libcurl to schedule a timeout."""
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if self._timeout is not None:
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self.io_loop.remove_timeout(self._timeout)
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self._timeout = self.io_loop.add_timeout(
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self.io_loop.time() + msecs / 1000.0, self._handle_timeout)
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def _handle_events(self, fd, events):
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"""Called by IOLoop when there is activity on one of our
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file descriptors.
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"""
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action = 0
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if events & ioloop.IOLoop.READ:
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action |= pycurl.CSELECT_IN
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if events & ioloop.IOLoop.WRITE:
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action |= pycurl.CSELECT_OUT
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while True:
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try:
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ret, num_handles = self._multi.socket_action(fd, action)
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except pycurl.error as e:
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ret = e.args[0]
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if ret != pycurl.E_CALL_MULTI_PERFORM:
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break
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self._finish_pending_requests()
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def _handle_timeout(self):
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"""Called by IOLoop when the requested timeout has passed."""
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with stack_context.NullContext():
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self._timeout = None
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while True:
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try:
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ret, num_handles = self._multi.socket_action(
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pycurl.SOCKET_TIMEOUT, 0)
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except pycurl.error as e:
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ret = e.args[0]
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if ret != pycurl.E_CALL_MULTI_PERFORM:
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break
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self._finish_pending_requests()
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# In theory, we shouldn't have to do this because curl will
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# call _set_timeout whenever the timeout changes. However,
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# sometimes after _handle_timeout we will need to reschedule
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# immediately even though nothing has changed from curl's
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# perspective. This is because when socket_action is
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# called with SOCKET_TIMEOUT, libcurl decides internally which
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# timeouts need to be processed by using a monotonic clock
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# (where available) while tornado uses python's time.time()
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# to decide when timeouts have occurred. When those clocks
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# disagree on elapsed time (as they will whenever there is an
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# NTP adjustment), tornado might call _handle_timeout before
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# libcurl is ready. After each timeout, resync the scheduled
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# timeout with libcurl's current state.
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new_timeout = self._multi.timeout()
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if new_timeout >= 0:
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self._set_timeout(new_timeout)
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def _handle_force_timeout(self):
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"""Called by IOLoop periodically to ask libcurl to process any
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events it may have forgotten about.
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"""
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with stack_context.NullContext():
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while True:
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try:
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ret, num_handles = self._multi.socket_all()
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except pycurl.error as e:
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ret = e.args[0]
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if ret != pycurl.E_CALL_MULTI_PERFORM:
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break
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self._finish_pending_requests()
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def _finish_pending_requests(self):
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"""Process any requests that were completed by the last
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call to multi.socket_action.
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"""
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while True:
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num_q, ok_list, err_list = self._multi.info_read()
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for curl in ok_list:
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self._finish(curl)
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for curl, errnum, errmsg in err_list:
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self._finish(curl, errnum, errmsg)
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if num_q == 0:
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break
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self._process_queue()
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def _process_queue(self):
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with stack_context.NullContext():
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while True:
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started = 0
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while self._free_list and self._requests:
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started += 1
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curl = self._free_list.pop()
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(request, callback) = self._requests.popleft()
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curl.info = {
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"headers": httputil.HTTPHeaders(),
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"buffer": BytesIO(),
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"request": request,
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"callback": callback,
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"curl_start_time": time.time(),
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}
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_curl_setup_request(curl, request, curl.info["buffer"],
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curl.info["headers"])
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self._multi.add_handle(curl)
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if not started:
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break
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def _finish(self, curl, curl_error=None, curl_message=None):
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info = curl.info
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curl.info = None
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self._multi.remove_handle(curl)
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self._free_list.append(curl)
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buffer = info["buffer"]
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if curl_error:
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error = CurlError(curl_error, curl_message)
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code = error.code
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effective_url = None
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buffer.close()
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buffer = None
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else:
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error = None
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code = curl.getinfo(pycurl.HTTP_CODE)
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effective_url = curl.getinfo(pycurl.EFFECTIVE_URL)
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buffer.seek(0)
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# the various curl timings are documented at
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# http://curl.haxx.se/libcurl/c/curl_easy_getinfo.html
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time_info = dict(
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queue=info["curl_start_time"] - info["request"].start_time,
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namelookup=curl.getinfo(pycurl.NAMELOOKUP_TIME),
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connect=curl.getinfo(pycurl.CONNECT_TIME),
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pretransfer=curl.getinfo(pycurl.PRETRANSFER_TIME),
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starttransfer=curl.getinfo(pycurl.STARTTRANSFER_TIME),
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total=curl.getinfo(pycurl.TOTAL_TIME),
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redirect=curl.getinfo(pycurl.REDIRECT_TIME),
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)
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try:
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info["callback"](HTTPResponse(
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request=info["request"], code=code, headers=info["headers"],
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buffer=buffer, effective_url=effective_url, error=error,
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reason=info['headers'].get("X-Http-Reason", None),
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request_time=time.time() - info["curl_start_time"],
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time_info=time_info))
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except Exception:
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self.handle_callback_exception(info["callback"])
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def handle_callback_exception(self, callback):
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self.io_loop.handle_callback_exception(callback)
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class CurlError(HTTPError):
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def __init__(self, errno, message):
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HTTPError.__init__(self, 599, message)
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self.errno = errno
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def _curl_create():
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curl = pycurl.Curl()
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if gen_log.isEnabledFor(logging.DEBUG):
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curl.setopt(pycurl.VERBOSE, 1)
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curl.setopt(pycurl.DEBUGFUNCTION, _curl_debug)
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return curl
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def _curl_setup_request(curl, request, buffer, headers):
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curl.setopt(pycurl.URL, native_str(request.url))
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# libcurl's magic "Expect: 100-continue" behavior causes delays
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# with servers that don't support it (which include, among others,
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# Google's OpenID endpoint). Additionally, this behavior has
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# a bug in conjunction with the curl_multi_socket_action API
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# (https://sourceforge.net/tracker/?func=detail&atid=100976&aid=3039744&group_id=976),
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# which increases the delays. It's more trouble than it's worth,
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# so just turn off the feature (yes, setting Expect: to an empty
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# value is the official way to disable this)
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if "Expect" not in request.headers:
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request.headers["Expect"] = ""
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# libcurl adds Pragma: no-cache by default; disable that too
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if "Pragma" not in request.headers:
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request.headers["Pragma"] = ""
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# Request headers may be either a regular dict or HTTPHeaders object
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if isinstance(request.headers, httputil.HTTPHeaders):
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curl.setopt(pycurl.HTTPHEADER,
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[native_str("%s: %s" % i) for i in request.headers.get_all()])
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else:
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curl.setopt(pycurl.HTTPHEADER,
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[native_str("%s: %s" % i) for i in request.headers.items()])
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if request.header_callback:
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curl.setopt(pycurl.HEADERFUNCTION,
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lambda line: request.header_callback(native_str(line)))
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else:
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curl.setopt(pycurl.HEADERFUNCTION,
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lambda line: _curl_header_callback(headers,
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native_str(line)))
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if request.streaming_callback:
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write_function = request.streaming_callback
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else:
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write_function = buffer.write
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if bytes_type is str: # py2
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curl.setopt(pycurl.WRITEFUNCTION, write_function)
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else: # py3
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# Upstream pycurl doesn't support py3, but ubuntu 12.10 includes
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# a fork/port. That version has a bug in which it passes unicode
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# strings instead of bytes to the WRITEFUNCTION. This means that
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# if you use a WRITEFUNCTION (which tornado always does), you cannot
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# download arbitrary binary data. This needs to be fixed in the
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# ported pycurl package, but in the meantime this lambda will
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# make it work for downloading (utf8) text.
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curl.setopt(pycurl.WRITEFUNCTION, lambda s: write_function(utf8(s)))
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curl.setopt(pycurl.FOLLOWLOCATION, request.follow_redirects)
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curl.setopt(pycurl.MAXREDIRS, request.max_redirects)
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curl.setopt(pycurl.CONNECTTIMEOUT_MS, int(1000 * request.connect_timeout))
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curl.setopt(pycurl.TIMEOUT_MS, int(1000 * request.request_timeout))
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if request.user_agent:
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curl.setopt(pycurl.USERAGENT, native_str(request.user_agent))
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else:
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curl.setopt(pycurl.USERAGENT, "Mozilla/5.0 (compatible; pycurl)")
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if request.network_interface:
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curl.setopt(pycurl.INTERFACE, request.network_interface)
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if request.use_gzip:
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curl.setopt(pycurl.ENCODING, "gzip,deflate")
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else:
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curl.setopt(pycurl.ENCODING, "none")
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if request.proxy_host and request.proxy_port:
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curl.setopt(pycurl.PROXY, request.proxy_host)
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curl.setopt(pycurl.PROXYPORT, request.proxy_port)
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if request.proxy_username:
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credentials = '%s:%s' % (request.proxy_username,
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request.proxy_password)
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curl.setopt(pycurl.PROXYUSERPWD, credentials)
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else:
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curl.setopt(pycurl.PROXY, '')
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curl.unsetopt(pycurl.PROXYUSERPWD)
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if request.validate_cert:
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curl.setopt(pycurl.SSL_VERIFYPEER, 1)
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curl.setopt(pycurl.SSL_VERIFYHOST, 2)
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else:
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curl.setopt(pycurl.SSL_VERIFYPEER, 0)
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curl.setopt(pycurl.SSL_VERIFYHOST, 0)
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if request.ca_certs is not None:
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curl.setopt(pycurl.CAINFO, request.ca_certs)
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else:
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# There is no way to restore pycurl.CAINFO to its default value
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# (Using unsetopt makes it reject all certificates).
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# I don't see any way to read the default value from python so it
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# can be restored later. We'll have to just leave CAINFO untouched
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# if no ca_certs file was specified, and require that if any
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# request uses a custom ca_certs file, they all must.
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pass
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if request.allow_ipv6 is False:
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# Curl behaves reasonably when DNS resolution gives an ipv6 address
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# that we can't reach, so allow ipv6 unless the user asks to disable.
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curl.setopt(pycurl.IPRESOLVE, pycurl.IPRESOLVE_V4)
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else:
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curl.setopt(pycurl.IPRESOLVE, pycurl.IPRESOLVE_WHATEVER)
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# Set the request method through curl's irritating interface which makes
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# up names for almost every single method
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curl_options = {
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"GET": pycurl.HTTPGET,
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"POST": pycurl.POST,
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"PUT": pycurl.UPLOAD,
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"HEAD": pycurl.NOBODY,
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}
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custom_methods = set(["DELETE", "OPTIONS", "PATCH"])
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for o in curl_options.values():
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curl.setopt(o, False)
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if request.method in curl_options:
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curl.unsetopt(pycurl.CUSTOMREQUEST)
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curl.setopt(curl_options[request.method], True)
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elif request.allow_nonstandard_methods or request.method in custom_methods:
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curl.setopt(pycurl.CUSTOMREQUEST, request.method)
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else:
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raise KeyError('unknown method ' + request.method)
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# Handle curl's cryptic options for every individual HTTP method
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if request.method in ("POST", "PUT"):
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if request.body is None:
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raise AssertionError(
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'Body must not be empty for "%s" request'
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% request.method)
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request_buffer = BytesIO(utf8(request.body))
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curl.setopt(pycurl.READFUNCTION, request_buffer.read)
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if request.method == "POST":
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def ioctl(cmd):
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if cmd == curl.IOCMD_RESTARTREAD:
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request_buffer.seek(0)
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curl.setopt(pycurl.IOCTLFUNCTION, ioctl)
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curl.setopt(pycurl.POSTFIELDSIZE, len(request.body))
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else:
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curl.setopt(pycurl.INFILESIZE, len(request.body))
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elif request.method == "GET":
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if request.body is not None:
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raise AssertionError('Body must be empty for GET request')
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if request.auth_username is not None:
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userpwd = "%s:%s" % (request.auth_username, request.auth_password or '')
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if request.auth_mode is None or request.auth_mode == "basic":
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curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_BASIC)
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elif request.auth_mode == "digest":
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curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_DIGEST)
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else:
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raise ValueError("Unsupported auth_mode %s" % request.auth_mode)
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curl.setopt(pycurl.USERPWD, native_str(userpwd))
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gen_log.debug("%s %s (username: %r)", request.method, request.url,
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request.auth_username)
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else:
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curl.unsetopt(pycurl.USERPWD)
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gen_log.debug("%s %s", request.method, request.url)
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if request.client_cert is not None:
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curl.setopt(pycurl.SSLCERT, request.client_cert)
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if request.client_key is not None:
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curl.setopt(pycurl.SSLKEY, request.client_key)
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if threading.activeCount() > 1:
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# libcurl/pycurl is not thread-safe by default. When multiple threads
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# are used, signals should be disabled. This has the side effect
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# of disabling DNS timeouts in some environments (when libcurl is
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# not linked against ares), so we don't do it when there is only one
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# thread. Applications that use many short-lived threads may need
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# to set NOSIGNAL manually in a prepare_curl_callback since
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# there may not be any other threads running at the time we call
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# threading.activeCount.
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curl.setopt(pycurl.NOSIGNAL, 1)
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if request.prepare_curl_callback is not None:
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request.prepare_curl_callback(curl)
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def _curl_header_callback(headers, header_line):
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# header_line as returned by curl includes the end-of-line characters.
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header_line = header_line.strip()
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if header_line.startswith("HTTP/"):
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headers.clear()
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try:
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(__, __, reason) = httputil.parse_response_start_line(header_line)
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header_line = "X-Http-Reason: %s" % reason
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except httputil.HTTPInputError:
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return
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if not header_line:
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return
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headers.parse_line(header_line)
|
|
|
|
|
|
def _curl_debug(debug_type, debug_msg):
|
|
debug_types = ('I', '<', '>', '<', '>')
|
|
if debug_type == 0:
|
|
gen_log.debug('%s', debug_msg.strip())
|
|
elif debug_type in (1, 2):
|
|
for line in debug_msg.splitlines():
|
|
gen_log.debug('%s %s', debug_types[debug_type], line)
|
|
elif debug_type == 4:
|
|
gen_log.debug('%s %r', debug_types[debug_type], debug_msg)
|
|
|
|
if __name__ == "__main__":
|
|
AsyncHTTPClient.configure(CurlAsyncHTTPClient)
|
|
main()
|