/usr/lib/python2.7/dist-packages/pika/adapters/libev_connection.py is in python-pika 0.10.0-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 | """Use pika with the libev IOLoop via pyev"""
import pyev
import signal
import array
import logging
import warnings
from collections import deque
from pika.adapters.base_connection import BaseConnection
LOGGER = logging.getLogger(__name__)
global_sigint_watcher, global_sigterm_watcher = None, None
class LibevConnection(BaseConnection):
"""The LibevConnection runs on the libev IOLoop. If you're running the
connection in a web app, make sure you set stop_ioloop_on_close to False,
which is the default behavior for this adapter, otherwise the web app
will stop taking requests.
You should be familiar with pyev and libev to use this adapter, esp.
with regard to the use of libev ioloops.
If an on_signal_callback method is provided, the adapter creates signal
watchers the first time; subsequent instantiations with a provided method
reuse the same watchers but will call the new method upon receiving a
signal. See pyev/libev signal handling to understand why this is done.
:param pika.connection.Parameters parameters: Connection parameters
:param on_open_callback: The method to call when the connection is open
:type on_open_callback: method
:param on_open_error_callback: Method to call if the connection can't
be opened
:type on_open_error_callback: method
:param bool stop_ioloop_on_close: Call ioloop.stop() if disconnected
:param custom_ioloop: Override using the default_loop in libev
:param on_signal_callback: Method to call if SIGINT or SIGTERM occur
:type on_signal_callback: method
"""
WARN_ABOUT_IOLOOP = True
# use static arrays to translate masks between pika and libev
_PIKA_TO_LIBEV_ARRAY = array.array('i', [0] * (
(BaseConnection.READ | BaseConnection.WRITE | BaseConnection.ERROR) + 1
))
_PIKA_TO_LIBEV_ARRAY[BaseConnection.READ] = pyev.EV_READ
_PIKA_TO_LIBEV_ARRAY[BaseConnection.WRITE] = pyev.EV_WRITE
_PIKA_TO_LIBEV_ARRAY[BaseConnection.READ |
BaseConnection.WRITE] = pyev.EV_READ | pyev.EV_WRITE
_PIKA_TO_LIBEV_ARRAY[BaseConnection.READ |
BaseConnection.ERROR] = pyev.EV_READ
_PIKA_TO_LIBEV_ARRAY[BaseConnection.WRITE |
BaseConnection.ERROR] = pyev.EV_WRITE
_PIKA_TO_LIBEV_ARRAY[BaseConnection.READ | BaseConnection.WRITE |
BaseConnection.ERROR] = pyev.EV_READ | pyev.EV_WRITE
_LIBEV_TO_PIKA_ARRAY = array.array('i', [0] *
((pyev.EV_READ | pyev.EV_WRITE) + 1))
_LIBEV_TO_PIKA_ARRAY[pyev.EV_READ] = BaseConnection.READ
_LIBEV_TO_PIKA_ARRAY[pyev.EV_WRITE] = BaseConnection.WRITE
_LIBEV_TO_PIKA_ARRAY[pyev.EV_READ | pyev.EV_WRITE] = \
BaseConnection.READ | BaseConnection.WRITE
def __init__(self,
parameters=None,
on_open_callback=None,
on_open_error_callback=None,
on_close_callback=None,
stop_ioloop_on_close=False,
custom_ioloop=None,
on_signal_callback=None):
"""Create a new instance of the LibevConnection class, connecting
to RabbitMQ automatically
:param pika.connection.Parameters parameters: Connection parameters
:param on_open_callback: The method to call when the connection is open
:type on_open_callback: method
:param on_open_error_callback: Method to call if the connection cannot
be opened
:type on_open_error_callback: method
:param bool stop_ioloop_on_close: Call ioloop.stop() if disconnected
:param custom_ioloop: Override using the default IOLoop in libev
:param on_signal_callback: Method to call if SIGINT or SIGTERM occur
:type on_signal_callback: method
"""
if custom_ioloop:
self.ioloop = custom_ioloop
else:
with warnings.catch_warnings():
warnings.simplefilter("ignore", RuntimeWarning)
self.ioloop = pyev.default_loop()
self.async = None
self._on_signal_callback = on_signal_callback
self._io_watcher = None
self._active_timers = {}
self._stopped_timers = deque()
super(LibevConnection, self).__init__(parameters, on_open_callback,
on_open_error_callback,
on_close_callback, self.ioloop,
stop_ioloop_on_close)
def _adapter_connect(self):
"""Connect to the remote socket, adding the socket to the IOLoop if
connected
:rtype: bool
"""
LOGGER.debug('init io and signal watchers if any')
# reuse existing signal watchers, can only be declared for 1 ioloop
global global_sigint_watcher, global_sigterm_watcher
error = super(LibevConnection, self)._adapter_connect()
if not error:
if self._on_signal_callback and not global_sigterm_watcher:
global_sigterm_watcher = \
self.ioloop.signal(signal.SIGTERM,
self._handle_sigterm)
if self._on_signal_callback and not global_sigint_watcher:
global_sigint_watcher = self.ioloop.signal(signal.SIGINT,
self._handle_sigint)
if not self._io_watcher:
self._io_watcher = \
self.ioloop.io(self.socket.fileno(),
self._PIKA_TO_LIBEV_ARRAY[self.event_state],
self._handle_events)
self.async = pyev.Async(self.ioloop, self._noop_callable)
self.async.start()
if self._on_signal_callback:
global_sigterm_watcher.start()
if self._on_signal_callback:
global_sigint_watcher.start()
self._io_watcher.start()
return error
def _noop_callable(self, *args, **kwargs):
pass
def _init_connection_state(self):
"""Initialize or reset all of our internal state variables for a given
connection. If we disconnect and reconnect, all of our state needs to
be wiped.
"""
for timer in self._active_timers.keys():
self.remove_timeout(timer)
if global_sigint_watcher:
global_sigint_watcher.stop()
if global_sigterm_watcher:
global_sigterm_watcher.stop()
if self._io_watcher:
self._io_watcher.stop()
super(LibevConnection, self)._init_connection_state()
def _handle_sigint(self, signal_watcher, libev_events):
"""If an on_signal_callback has been defined, call it returning the
string 'SIGINT'.
"""
LOGGER.debug('SIGINT')
self._on_signal_callback('SIGINT')
def _handle_sigterm(self, signal_watcher, libev_events):
"""If an on_signal_callback has been defined, call it returning the
string 'SIGTERM'.
"""
LOGGER.debug('SIGTERM')
self._on_signal_callback('SIGTERM')
def _handle_events(self, io_watcher, libev_events, **kwargs):
"""Handle IO events by efficiently translating to BaseConnection
events and calling super.
"""
super(LibevConnection,
self)._handle_events(io_watcher.fd,
self._LIBEV_TO_PIKA_ARRAY[libev_events],
**kwargs)
def _reset_io_watcher(self):
"""Reset the IO watcher; retry as necessary
"""
self._io_watcher.stop()
retries = 0
while True:
try:
self._io_watcher.set(
self._io_watcher.fd,
self._PIKA_TO_LIBEV_ARRAY[self.event_state])
break
except: # sometimes the stop() doesn't complete in time
if retries > 5: raise
self._io_watcher.stop() # so try it again
retries += 1
self._io_watcher.start()
def _manage_event_state(self):
"""Manage the bitmask for reading/writing/error which is used by the
io/event handler to specify when there is an event such as a read or
write.
"""
if self.outbound_buffer:
if not self.event_state & self.WRITE:
self.event_state |= self.WRITE
self._reset_io_watcher()
elif self.event_state & self.WRITE:
self.event_state = self.base_events
self._reset_io_watcher()
def _timer_callback(self, timer, libev_events):
"""Manage timer callbacks indirectly."""
if timer in self._active_timers:
(callback_method, callback_timeout,
kwargs) = self._active_timers[timer]
if callback_timeout:
callback_method(timeout=timer, **kwargs)
else:
callback_method(**kwargs)
self.remove_timeout(timer)
else:
LOGGER.warning('Timer callback_method not found')
def _get_timer(self, deadline):
"""Get a timer from the pool or allocate a new one."""
if self._stopped_timers:
timer = self._stopped_timers.pop()
timer.set(deadline, 0.0)
else:
timer = self.ioloop.timer(deadline, 0.0, self._timer_callback)
return timer
def add_timeout(self, deadline, callback_method,
callback_timeout=False, **callback_kwargs):
"""Add the callback_method indirectly to the IOLoop timer to fire
after deadline seconds. Returns the timer handle.
:param int deadline: The number of seconds to wait to call callback
:param method callback_method: The callback method
:param callback_timeout: Whether timeout kwarg is passed on callback
:type callback_timeout: boolean
:param kwargs callback_kwargs: additional kwargs to pass on callback
:rtype: timer instance handle.
"""
LOGGER.debug('deadline: {0}'.format(deadline))
timer = self._get_timer(deadline)
self._active_timers[timer] = (callback_method, callback_timeout,
callback_kwargs)
timer.start()
return timer
def remove_timeout(self, timer):
"""Remove the timer from the IOLoop using the handle returned from
add_timeout.
param: timer instance handle
"""
LOGGER.debug('stop')
self._active_timers.pop(timer, None)
timer.stop()
self._stopped_timers.append(timer)
def _create_and_connect_to_socket(self, sock_addr_tuple):
"""Call super and then set the socket to nonblocking."""
result = super(LibevConnection,
self)._create_and_connect_to_socket(sock_addr_tuple)
if result:
self.socket.setblocking(0)
return result
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