Files
deb-python-cassandra-driver/cassandra/io/geventreactor.py
Adam Holmberg 1f596b4935 fix gevent connection to use only blocking semantics
PYTHON-429
PYTHON-536
2016-04-08 14:42:47 -05:00

150 lines
4.4 KiB
Python

# Copyright 2013-2016 DataStax, Inc.
#
# 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.
import gevent
import gevent.event
from gevent.queue import Queue
from gevent import socket
import gevent.ssl
import logging
import os
import time
from six.moves import range
from errno import EINVAL
from cassandra.connection import Connection, ConnectionShutdown, Timer, TimerManager
log = logging.getLogger(__name__)
def is_timeout(err):
return (
(err == EINVAL and os.name in ('nt', 'ce')) or
isinstance(err, socket.timeout)
)
class GeventConnection(Connection):
"""
An implementation of :class:`.Connection` that utilizes ``gevent``.
This implementation assumes all gevent monkey patching is active. It is not tested with partial patching.
"""
_read_watcher = None
_write_watcher = None
_socket_impl = gevent.socket
_ssl_impl = gevent.ssl
_timers = None
_timeout_watcher = None
_new_timer = None
@classmethod
def initialize_reactor(cls):
if not cls._timers:
cls._timers = TimerManager()
cls._timeout_watcher = gevent.spawn(cls.service_timeouts)
cls._new_timer = gevent.event.Event()
@classmethod
def create_timer(cls, timeout, callback):
timer = Timer(timeout, callback)
cls._timers.add_timer(timer)
cls._new_timer.set()
return timer
@classmethod
def service_timeouts(cls):
timer_manager = cls._timers
timer_event = cls._new_timer
while True:
next_end = timer_manager.service_timeouts()
sleep_time = max(next_end - time.time(), 0) if next_end else 10000
timer_event.wait(sleep_time)
timer_event.clear()
def __init__(self, *args, **kwargs):
Connection.__init__(self, *args, **kwargs)
self._write_queue = Queue()
self._connect_socket()
self._read_watcher = gevent.spawn(self.handle_read)
self._write_watcher = gevent.spawn(self.handle_write)
self._send_options_message()
def close(self):
with self.lock:
if self.is_closed:
return
self.is_closed = True
log.debug("Closing connection (%s) to %s" % (id(self), self.host))
if self._read_watcher:
self._read_watcher.kill(block=False)
if self._write_watcher:
self._write_watcher.kill(block=False)
if self._socket:
self._socket.close()
log.debug("Closed socket to %s" % (self.host,))
if not self.is_defunct:
self.error_all_requests(
ConnectionShutdown("Connection to %s was closed" % self.host))
# don't leave in-progress operations hanging
self.connected_event.set()
def handle_close(self):
log.debug("connection closed by server")
self.close()
def handle_write(self):
while True:
try:
next_msg = self._write_queue.get()
self._socket.sendall(next_msg)
except socket.error as err:
log.debug("Exception in send for %s: %s", self, err)
self.defunct(err)
return
def handle_read(self):
while True:
try:
buf = self._socket.recv(self.in_buffer_size)
self._iobuf.write(buf)
except socket.error as err:
if not is_timeout(err):
log.debug("Exception in read for %s: %s", self, err)
self.defunct(err)
return # leave the read loop
if self._iobuf.tell():
self.process_io_buffer()
else:
log.debug("Connection %s closed by server", self)
self.close()
return
def push(self, data):
chunk_size = self.out_buffer_size
for i in range(0, len(data), chunk_size):
self._write_queue.put(data[i:i + chunk_size])