479 lines
20 KiB
Python
479 lines
20 KiB
Python
#!/usr/bin/env python
|
|
#
|
|
# Copyright 2009 Facebook
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
"""Non-blocking HTTP client implementation using pycurl."""
|
|
|
|
from __future__ import absolute_import, division, print_function, with_statement
|
|
|
|
import collections
|
|
import logging
|
|
import pycurl
|
|
import threading
|
|
import time
|
|
|
|
from tornado import httputil
|
|
from tornado import ioloop
|
|
from tornado.log import gen_log
|
|
from tornado import stack_context
|
|
|
|
from tornado.escape import utf8, native_str
|
|
from tornado.httpclient import HTTPResponse, HTTPError, AsyncHTTPClient, main
|
|
from tornado.util import bytes_type
|
|
|
|
try:
|
|
from io import BytesIO # py3
|
|
except ImportError:
|
|
from cStringIO import StringIO as BytesIO # py2
|
|
|
|
|
|
class CurlAsyncHTTPClient(AsyncHTTPClient):
|
|
def initialize(self, io_loop, max_clients=10, defaults=None):
|
|
super(CurlAsyncHTTPClient, self).initialize(io_loop, defaults=defaults)
|
|
self._multi = pycurl.CurlMulti()
|
|
self._multi.setopt(pycurl.M_TIMERFUNCTION, self._set_timeout)
|
|
self._multi.setopt(pycurl.M_SOCKETFUNCTION, self._handle_socket)
|
|
self._curls = [_curl_create() for i in range(max_clients)]
|
|
self._free_list = self._curls[:]
|
|
self._requests = collections.deque()
|
|
self._fds = {}
|
|
self._timeout = None
|
|
|
|
try:
|
|
self._socket_action = self._multi.socket_action
|
|
except AttributeError:
|
|
# socket_action is found in pycurl since 7.18.2 (it's been
|
|
# in libcurl longer than that but wasn't accessible to
|
|
# python).
|
|
gen_log.warning("socket_action method missing from pycurl; "
|
|
"falling back to socket_all. Upgrading "
|
|
"libcurl and pycurl will improve performance")
|
|
self._socket_action = \
|
|
lambda fd, action: self._multi.socket_all()
|
|
|
|
# libcurl has bugs that sometimes cause it to not report all
|
|
# relevant file descriptors and timeouts to TIMERFUNCTION/
|
|
# SOCKETFUNCTION. Mitigate the effects of such bugs by
|
|
# forcing a periodic scan of all active requests.
|
|
self._force_timeout_callback = ioloop.PeriodicCallback(
|
|
self._handle_force_timeout, 1000, io_loop=io_loop)
|
|
self._force_timeout_callback.start()
|
|
|
|
# Work around a bug in libcurl 7.29.0: Some fields in the curl
|
|
# multi object are initialized lazily, and its destructor will
|
|
# segfault if it is destroyed without having been used. Add
|
|
# and remove a dummy handle to make sure everything is
|
|
# initialized.
|
|
dummy_curl_handle = pycurl.Curl()
|
|
self._multi.add_handle(dummy_curl_handle)
|
|
self._multi.remove_handle(dummy_curl_handle)
|
|
|
|
def close(self):
|
|
self._force_timeout_callback.stop()
|
|
if self._timeout is not None:
|
|
self.io_loop.remove_timeout(self._timeout)
|
|
for curl in self._curls:
|
|
curl.close()
|
|
self._multi.close()
|
|
self._closed = True
|
|
super(CurlAsyncHTTPClient, self).close()
|
|
|
|
def fetch_impl(self, request, callback):
|
|
self._requests.append((request, callback))
|
|
self._process_queue()
|
|
self._set_timeout(0)
|
|
|
|
def _handle_socket(self, event, fd, multi, data):
|
|
"""Called by libcurl when it wants to change the file descriptors
|
|
it cares about.
|
|
"""
|
|
event_map = {
|
|
pycurl.POLL_NONE: ioloop.IOLoop.NONE,
|
|
pycurl.POLL_IN: ioloop.IOLoop.READ,
|
|
pycurl.POLL_OUT: ioloop.IOLoop.WRITE,
|
|
pycurl.POLL_INOUT: ioloop.IOLoop.READ | ioloop.IOLoop.WRITE
|
|
}
|
|
if event == pycurl.POLL_REMOVE:
|
|
if fd in self._fds:
|
|
self.io_loop.remove_handler(fd)
|
|
del self._fds[fd]
|
|
else:
|
|
ioloop_event = event_map[event]
|
|
# libcurl sometimes closes a socket and then opens a new
|
|
# one using the same FD without giving us a POLL_NONE in
|
|
# between. This is a problem with the epoll IOLoop,
|
|
# because the kernel can tell when a socket is closed and
|
|
# removes it from the epoll automatically, causing future
|
|
# update_handler calls to fail. Since we can't tell when
|
|
# this has happened, always use remove and re-add
|
|
# instead of update.
|
|
if fd in self._fds:
|
|
self.io_loop.remove_handler(fd)
|
|
self.io_loop.add_handler(fd, self._handle_events,
|
|
ioloop_event)
|
|
self._fds[fd] = ioloop_event
|
|
|
|
def _set_timeout(self, msecs):
|
|
"""Called by libcurl to schedule a timeout."""
|
|
if self._timeout is not None:
|
|
self.io_loop.remove_timeout(self._timeout)
|
|
self._timeout = self.io_loop.add_timeout(
|
|
self.io_loop.time() + msecs / 1000.0, self._handle_timeout)
|
|
|
|
def _handle_events(self, fd, events):
|
|
"""Called by IOLoop when there is activity on one of our
|
|
file descriptors.
|
|
"""
|
|
action = 0
|
|
if events & ioloop.IOLoop.READ:
|
|
action |= pycurl.CSELECT_IN
|
|
if events & ioloop.IOLoop.WRITE:
|
|
action |= pycurl.CSELECT_OUT
|
|
while True:
|
|
try:
|
|
ret, num_handles = self._socket_action(fd, action)
|
|
except pycurl.error as e:
|
|
ret = e.args[0]
|
|
if ret != pycurl.E_CALL_MULTI_PERFORM:
|
|
break
|
|
self._finish_pending_requests()
|
|
|
|
def _handle_timeout(self):
|
|
"""Called by IOLoop when the requested timeout has passed."""
|
|
with stack_context.NullContext():
|
|
self._timeout = None
|
|
while True:
|
|
try:
|
|
ret, num_handles = self._socket_action(
|
|
pycurl.SOCKET_TIMEOUT, 0)
|
|
except pycurl.error as e:
|
|
ret = e.args[0]
|
|
if ret != pycurl.E_CALL_MULTI_PERFORM:
|
|
break
|
|
self._finish_pending_requests()
|
|
|
|
# In theory, we shouldn't have to do this because curl will
|
|
# call _set_timeout whenever the timeout changes. However,
|
|
# sometimes after _handle_timeout we will need to reschedule
|
|
# immediately even though nothing has changed from curl's
|
|
# perspective. This is because when socket_action is
|
|
# called with SOCKET_TIMEOUT, libcurl decides internally which
|
|
# timeouts need to be processed by using a monotonic clock
|
|
# (where available) while tornado uses python's time.time()
|
|
# to decide when timeouts have occurred. When those clocks
|
|
# disagree on elapsed time (as they will whenever there is an
|
|
# NTP adjustment), tornado might call _handle_timeout before
|
|
# libcurl is ready. After each timeout, resync the scheduled
|
|
# timeout with libcurl's current state.
|
|
new_timeout = self._multi.timeout()
|
|
if new_timeout >= 0:
|
|
self._set_timeout(new_timeout)
|
|
|
|
def _handle_force_timeout(self):
|
|
"""Called by IOLoop periodically to ask libcurl to process any
|
|
events it may have forgotten about.
|
|
"""
|
|
with stack_context.NullContext():
|
|
while True:
|
|
try:
|
|
ret, num_handles = self._multi.socket_all()
|
|
except pycurl.error as e:
|
|
ret = e.args[0]
|
|
if ret != pycurl.E_CALL_MULTI_PERFORM:
|
|
break
|
|
self._finish_pending_requests()
|
|
|
|
def _finish_pending_requests(self):
|
|
"""Process any requests that were completed by the last
|
|
call to multi.socket_action.
|
|
"""
|
|
while True:
|
|
num_q, ok_list, err_list = self._multi.info_read()
|
|
for curl in ok_list:
|
|
self._finish(curl)
|
|
for curl, errnum, errmsg in err_list:
|
|
self._finish(curl, errnum, errmsg)
|
|
if num_q == 0:
|
|
break
|
|
self._process_queue()
|
|
|
|
def _process_queue(self):
|
|
with stack_context.NullContext():
|
|
while True:
|
|
started = 0
|
|
while self._free_list and self._requests:
|
|
started += 1
|
|
curl = self._free_list.pop()
|
|
(request, callback) = self._requests.popleft()
|
|
curl.info = {
|
|
"headers": httputil.HTTPHeaders(),
|
|
"buffer": BytesIO(),
|
|
"request": request,
|
|
"callback": callback,
|
|
"curl_start_time": time.time(),
|
|
}
|
|
# Disable IPv6 to mitigate the effects of this bug
|
|
# on curl versions <= 7.21.0
|
|
# http://sourceforge.net/tracker/?func=detail&aid=3017819&group_id=976&atid=100976
|
|
if pycurl.version_info()[2] <= 0x71500: # 7.21.0
|
|
curl.setopt(pycurl.IPRESOLVE, pycurl.IPRESOLVE_V4)
|
|
_curl_setup_request(curl, request, curl.info["buffer"],
|
|
curl.info["headers"])
|
|
self._multi.add_handle(curl)
|
|
|
|
if not started:
|
|
break
|
|
|
|
def _finish(self, curl, curl_error=None, curl_message=None):
|
|
info = curl.info
|
|
curl.info = None
|
|
self._multi.remove_handle(curl)
|
|
self._free_list.append(curl)
|
|
buffer = info["buffer"]
|
|
if curl_error:
|
|
error = CurlError(curl_error, curl_message)
|
|
code = error.code
|
|
effective_url = None
|
|
buffer.close()
|
|
buffer = None
|
|
else:
|
|
error = None
|
|
code = curl.getinfo(pycurl.HTTP_CODE)
|
|
effective_url = curl.getinfo(pycurl.EFFECTIVE_URL)
|
|
buffer.seek(0)
|
|
# the various curl timings are documented at
|
|
# http://curl.haxx.se/libcurl/c/curl_easy_getinfo.html
|
|
time_info = dict(
|
|
queue=info["curl_start_time"] - info["request"].start_time,
|
|
namelookup=curl.getinfo(pycurl.NAMELOOKUP_TIME),
|
|
connect=curl.getinfo(pycurl.CONNECT_TIME),
|
|
pretransfer=curl.getinfo(pycurl.PRETRANSFER_TIME),
|
|
starttransfer=curl.getinfo(pycurl.STARTTRANSFER_TIME),
|
|
total=curl.getinfo(pycurl.TOTAL_TIME),
|
|
redirect=curl.getinfo(pycurl.REDIRECT_TIME),
|
|
)
|
|
try:
|
|
info["callback"](HTTPResponse(
|
|
request=info["request"], code=code, headers=info["headers"],
|
|
buffer=buffer, effective_url=effective_url, error=error,
|
|
request_time=time.time() - info["curl_start_time"],
|
|
time_info=time_info))
|
|
except Exception:
|
|
self.handle_callback_exception(info["callback"])
|
|
|
|
def handle_callback_exception(self, callback):
|
|
self.io_loop.handle_callback_exception(callback)
|
|
|
|
|
|
class CurlError(HTTPError):
|
|
def __init__(self, errno, message):
|
|
HTTPError.__init__(self, 599, message)
|
|
self.errno = errno
|
|
|
|
|
|
def _curl_create():
|
|
curl = pycurl.Curl()
|
|
if gen_log.isEnabledFor(logging.DEBUG):
|
|
curl.setopt(pycurl.VERBOSE, 1)
|
|
curl.setopt(pycurl.DEBUGFUNCTION, _curl_debug)
|
|
return curl
|
|
|
|
|
|
def _curl_setup_request(curl, request, buffer, headers):
|
|
curl.setopt(pycurl.URL, native_str(request.url))
|
|
|
|
# libcurl's magic "Expect: 100-continue" behavior causes delays
|
|
# with servers that don't support it (which include, among others,
|
|
# Google's OpenID endpoint). Additionally, this behavior has
|
|
# a bug in conjunction with the curl_multi_socket_action API
|
|
# (https://sourceforge.net/tracker/?func=detail&atid=100976&aid=3039744&group_id=976),
|
|
# which increases the delays. It's more trouble than it's worth,
|
|
# so just turn off the feature (yes, setting Expect: to an empty
|
|
# value is the official way to disable this)
|
|
if "Expect" not in request.headers:
|
|
request.headers["Expect"] = ""
|
|
|
|
# libcurl adds Pragma: no-cache by default; disable that too
|
|
if "Pragma" not in request.headers:
|
|
request.headers["Pragma"] = ""
|
|
|
|
# Request headers may be either a regular dict or HTTPHeaders object
|
|
if isinstance(request.headers, httputil.HTTPHeaders):
|
|
curl.setopt(pycurl.HTTPHEADER,
|
|
[native_str("%s: %s" % i) for i in request.headers.get_all()])
|
|
else:
|
|
curl.setopt(pycurl.HTTPHEADER,
|
|
[native_str("%s: %s" % i) for i in request.headers.items()])
|
|
|
|
if request.header_callback:
|
|
curl.setopt(pycurl.HEADERFUNCTION, request.header_callback)
|
|
else:
|
|
curl.setopt(pycurl.HEADERFUNCTION,
|
|
lambda line: _curl_header_callback(headers, line))
|
|
if request.streaming_callback:
|
|
write_function = request.streaming_callback
|
|
else:
|
|
write_function = buffer.write
|
|
if bytes_type is str: # py2
|
|
curl.setopt(pycurl.WRITEFUNCTION, write_function)
|
|
else: # py3
|
|
# Upstream pycurl doesn't support py3, but ubuntu 12.10 includes
|
|
# a fork/port. That version has a bug in which it passes unicode
|
|
# strings instead of bytes to the WRITEFUNCTION. This means that
|
|
# if you use a WRITEFUNCTION (which tornado always does), you cannot
|
|
# download arbitrary binary data. This needs to be fixed in the
|
|
# ported pycurl package, but in the meantime this lambda will
|
|
# make it work for downloading (utf8) text.
|
|
curl.setopt(pycurl.WRITEFUNCTION, lambda s: write_function(utf8(s)))
|
|
curl.setopt(pycurl.FOLLOWLOCATION, request.follow_redirects)
|
|
curl.setopt(pycurl.MAXREDIRS, request.max_redirects)
|
|
curl.setopt(pycurl.CONNECTTIMEOUT_MS, int(1000 * request.connect_timeout))
|
|
curl.setopt(pycurl.TIMEOUT_MS, int(1000 * request.request_timeout))
|
|
if request.user_agent:
|
|
curl.setopt(pycurl.USERAGENT, native_str(request.user_agent))
|
|
else:
|
|
curl.setopt(pycurl.USERAGENT, "Mozilla/5.0 (compatible; pycurl)")
|
|
if request.network_interface:
|
|
curl.setopt(pycurl.INTERFACE, request.network_interface)
|
|
if request.use_gzip:
|
|
curl.setopt(pycurl.ENCODING, "gzip,deflate")
|
|
else:
|
|
curl.setopt(pycurl.ENCODING, "none")
|
|
if request.proxy_host and request.proxy_port:
|
|
curl.setopt(pycurl.PROXY, request.proxy_host)
|
|
curl.setopt(pycurl.PROXYPORT, request.proxy_port)
|
|
if request.proxy_username:
|
|
credentials = '%s:%s' % (request.proxy_username,
|
|
request.proxy_password)
|
|
curl.setopt(pycurl.PROXYUSERPWD, credentials)
|
|
else:
|
|
curl.setopt(pycurl.PROXY, '')
|
|
if request.validate_cert:
|
|
curl.setopt(pycurl.SSL_VERIFYPEER, 1)
|
|
curl.setopt(pycurl.SSL_VERIFYHOST, 2)
|
|
else:
|
|
curl.setopt(pycurl.SSL_VERIFYPEER, 0)
|
|
curl.setopt(pycurl.SSL_VERIFYHOST, 0)
|
|
if request.ca_certs is not None:
|
|
curl.setopt(pycurl.CAINFO, request.ca_certs)
|
|
else:
|
|
# There is no way to restore pycurl.CAINFO to its default value
|
|
# (Using unsetopt makes it reject all certificates).
|
|
# I don't see any way to read the default value from python so it
|
|
# can be restored later. We'll have to just leave CAINFO untouched
|
|
# if no ca_certs file was specified, and require that if any
|
|
# request uses a custom ca_certs file, they all must.
|
|
pass
|
|
|
|
if request.allow_ipv6 is False:
|
|
# Curl behaves reasonably when DNS resolution gives an ipv6 address
|
|
# that we can't reach, so allow ipv6 unless the user asks to disable.
|
|
# (but see version check in _process_queue above)
|
|
curl.setopt(pycurl.IPRESOLVE, pycurl.IPRESOLVE_V4)
|
|
|
|
# Set the request method through curl's irritating interface which makes
|
|
# up names for almost every single method
|
|
curl_options = {
|
|
"GET": pycurl.HTTPGET,
|
|
"POST": pycurl.POST,
|
|
"PUT": pycurl.UPLOAD,
|
|
"HEAD": pycurl.NOBODY,
|
|
}
|
|
custom_methods = set(["DELETE", "OPTIONS", "PATCH"])
|
|
for o in curl_options.values():
|
|
curl.setopt(o, False)
|
|
if request.method in curl_options:
|
|
curl.unsetopt(pycurl.CUSTOMREQUEST)
|
|
curl.setopt(curl_options[request.method], True)
|
|
elif request.allow_nonstandard_methods or request.method in custom_methods:
|
|
curl.setopt(pycurl.CUSTOMREQUEST, request.method)
|
|
else:
|
|
raise KeyError('unknown method ' + request.method)
|
|
|
|
# Handle curl's cryptic options for every individual HTTP method
|
|
if request.method in ("POST", "PUT"):
|
|
request_buffer = BytesIO(utf8(request.body))
|
|
curl.setopt(pycurl.READFUNCTION, request_buffer.read)
|
|
if request.method == "POST":
|
|
def ioctl(cmd):
|
|
if cmd == curl.IOCMD_RESTARTREAD:
|
|
request_buffer.seek(0)
|
|
curl.setopt(pycurl.IOCTLFUNCTION, ioctl)
|
|
curl.setopt(pycurl.POSTFIELDSIZE, len(request.body))
|
|
else:
|
|
curl.setopt(pycurl.INFILESIZE, len(request.body))
|
|
|
|
if request.auth_username is not None:
|
|
userpwd = "%s:%s" % (request.auth_username, request.auth_password or '')
|
|
|
|
if request.auth_mode is None or request.auth_mode == "basic":
|
|
curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_BASIC)
|
|
elif request.auth_mode == "digest":
|
|
curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_DIGEST)
|
|
else:
|
|
raise ValueError("Unsupported auth_mode %s" % request.auth_mode)
|
|
|
|
curl.setopt(pycurl.USERPWD, native_str(userpwd))
|
|
gen_log.debug("%s %s (username: %r)", request.method, request.url,
|
|
request.auth_username)
|
|
else:
|
|
curl.unsetopt(pycurl.USERPWD)
|
|
gen_log.debug("%s %s", request.method, request.url)
|
|
|
|
if request.client_cert is not None:
|
|
curl.setopt(pycurl.SSLCERT, request.client_cert)
|
|
|
|
if request.client_key is not None:
|
|
curl.setopt(pycurl.SSLKEY, request.client_key)
|
|
|
|
if threading.activeCount() > 1:
|
|
# libcurl/pycurl is not thread-safe by default. When multiple threads
|
|
# are used, signals should be disabled. This has the side effect
|
|
# of disabling DNS timeouts in some environments (when libcurl is
|
|
# not linked against ares), so we don't do it when there is only one
|
|
# thread. Applications that use many short-lived threads may need
|
|
# to set NOSIGNAL manually in a prepare_curl_callback since
|
|
# there may not be any other threads running at the time we call
|
|
# threading.activeCount.
|
|
curl.setopt(pycurl.NOSIGNAL, 1)
|
|
if request.prepare_curl_callback is not None:
|
|
request.prepare_curl_callback(curl)
|
|
|
|
|
|
def _curl_header_callback(headers, header_line):
|
|
# header_line as returned by curl includes the end-of-line characters.
|
|
header_line = header_line.strip()
|
|
if header_line.startswith("HTTP/"):
|
|
headers.clear()
|
|
return
|
|
if not header_line:
|
|
return
|
|
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()
|