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# -*- coding: utf-8 -*-
# Copyright 2014 matrix.org
#
# 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.
from syutil.jsonutil import (
encode_canonical_json, encode_pretty_printed_json
)
from synapse.api.errors import cs_exception, CodeMessageException
from twisted.internet import defer, reactor
from twisted.web import server, resource
from twisted.web.server import NOT_DONE_YET
import collections
import logging
logger = logging.getLogger(__name__)
class HttpServer(object):
""" Interface for registering callbacks on a HTTP server
"""
def register_path(self, method, path_pattern, callback):
""" Register a callback that get's fired if we receive a http request
with the given method for a path that matches the given regex.
If the regex contains groups these get's passed to the calback via
an unpacked tuple.
Args:
method (str): The method to listen to.
path_pattern (str): The regex used to match requests.
callback (function): The function to fire if we receive a matched
request. The first argument will be the request object and
subsequent arguments will be any matched groups from the regex.
This should return a tuple of (code, response).
"""
pass
# The actual HTTP server impl, using twisted http server
class TwistedHttpServer(HttpServer, resource.Resource):
""" This wraps the twisted HTTP server, and triggers the correct callbacks
on the transport_layer.
Register callbacks via register_path()
"""
isLeaf = True
_PathEntry = collections.namedtuple("_PathEntry", ["pattern", "callback"])
def __init__(self):
resource.Resource.__init__(self)
self.path_regexs = {}
def register_path(self, method, path_pattern, callback):
self.path_regexs.setdefault(method, []).append(
self._PathEntry(path_pattern, callback)
)
def start_listening(self, port):
""" Registers the http server with the twisted reactor.
Args:
port (int): The port to listen on.
"""
reactor.listenTCP(port, server.Site(self))
# Gets called by twisted
def render(self, request):
""" This get's called by twisted every time someone sends us a request.
"""
self._async_render(request)
return server.NOT_DONE_YET
@defer.inlineCallbacks
def _async_render(self, request):
""" This get's called by twisted every time someone sends us a request.
This checks if anyone has registered a callback for that method and
path.
"""
try:
# Just say yes to OPTIONS.
if request.method == "OPTIONS":
self._send_response(request, 200, {})
return
# Loop through all the registered callbacks to check if the method
# and path regex match
for path_entry in self.path_regexs.get(request.method, []):
m = path_entry.pattern.match(request.path)
if m:
# We found a match! Trigger callback and then return the
# returned response. We pass both the request and any
# matched groups from the regex to the callback.
code, response = yield path_entry.callback(
request,
*m.groups()
)
self._send_response(request, code, response)
return
# Huh. No one wanted to handle that? Fiiiiiine. Send 400.
self._send_response(
request,
400,
{"error": "Unrecognized request"}
)
except CodeMessageException as e:
logger.exception(e)
self._send_response(
request,
e.code,
cs_exception(e)
)
except Exception as e:
logger.exception(e)
self._send_response(
request,
500,
{"error": "Internal server error"}
)
def _send_response(self, request, code, response_json_object):
if not self._request_user_agent_is_curl(request):
json_bytes = encode_canonical_json(response_json_object)
else:
json_bytes = encode_pretty_printed_json(response_json_object)
# TODO: Only enable CORS for the requests that need it.
respond_with_json_bytes(request, code, json_bytes, send_cors=True)
@staticmethod
def _request_user_agent_is_curl(request):
user_agents = request.requestHeaders.getRawHeaders(
"User-Agent", default=[]
)
for user_agent in user_agents:
if "curl" in user_agent:
return True
return False
def respond_with_json_bytes(request, code, json_bytes, send_cors=False):
"""Sends encoded JSON in response to the given request.
Args:
request (twisted.web.http.Request): The http request to respond to.
code (int): The HTTP response code.
json_bytes (bytes): The json bytes to use as the response body.
send_cors (bool): Whether to send Cross-Origin Resource Sharing headers
http://www.w3.org/TR/cors/
Returns:
twisted.web.server.NOT_DONE_YET"""
request.setResponseCode(code)
request.setHeader(b"Content-Type", b"application/json")
if send_cors:
request.setHeader("Access-Control-Allow-Origin", "*")
request.setHeader("Access-Control-Allow-Methods",
"GET, POST, PUT, DELETE, OPTIONS")
request.setHeader("Access-Control-Allow-Headers",
"Origin, X-Requested-With, Content-Type, Accept")
request.write(json_bytes)
request.finish()
return NOT_DONE_YET
|
