# -*- coding: utf-8 -*-

# Open Source Initiative OSI - The MIT License (MIT):Licensing

#

# The MIT License (MIT)

# Copyright (c) 2012 DotCloud Inc ([email protected])

#

# Permission is hereby granted, free of charge, to any person obtaining a copy of

# this software and associated documentation files (the "Software"), to deal in

# the Software without restriction, including without limitation the rights to

# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

# of the Software, and to permit persons to whom the Software is furnished to do

# so, subject to the following conditions:

#

# The above copyright notice and this permission notice shall be included in all

# copies or substantial portions of the Software.

#

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

# SOFTWARE.

import sys

import gevent.pool

import gevent.queue

import gevent.event

import gevent.local

import gevent.coros

from .exceptions import TimeoutExpired

class ChannelMultiplexer(object):

def __init__(self, events, ignore_broadcast=False):

self._events = events

self._active_channels = {}

self._channel_dispatcher_task = None

self._broadcast_queue = None

if events.recv_is_available and not ignore_broadcast:

self._broadcast_queue = gevent.queue.Queue(maxsize=1)

self._channel_dispatcher_task = gevent.spawn(

self._channel_dispatcher)

@property

def recv_is_available(self):

return self._events.recv_is_available

def __del__(self):

self.close()

def close(self):

if self._channel_dispatcher_task:

self._channel_dispatcher_task.kill()

def create_event(self, name, args, kwargs = None, xheader=None):

return self._events.create_event(name, args, kwargs, xheader)

def emit_event(self, event, identity=None):

return self._events.emit_event(event, identity)

def emit(self, name, args, kwargs = None, xheader=None):

return self._events.emit(name, args, kwargs, xheader)

def recv(self):

if self._broadcast_queue is not None:

event = self._broadcast_queue.get()

else:

event = self._events.recv()

return event

def _channel_dispatcher(self):

while True:

event = self._events.recv()

channel_id = event.header.get('response_to', None)

queue = None

if channel_id is not None:

channel = self._active_channels.get(channel_id, None)

if channel is not None:

queue = channel._queue

elif self._broadcast_queue is not None:

queue = self._broadcast_queue

if queue is None:

print >> sys.stderr, \

'zerorpc.ChannelMultiplexer, ', \

'unable to route event:', \

event.__str__(ignore_args=True)

else:

queue.put(event)

def channel(self, from_event=None):

if self._channel_dispatcher_task is None:

self._channel_dispatcher_task = gevent.spawn(

self._channel_dispatcher)

return Channel(self, from_event)

@property

def active_channels(self):

return self._active_channels

@property

def context(self):

return self._events.context

class Channel(object):

def __init__(self, multiplexer, from_event=None):

self._multiplexer = multiplexer

self._channel_id = None

self._zmqid = None

self._queue = gevent.queue.Queue(maxsize=1)

if from_event is not None:

self._channel_id = from_event.header['message_id']

self._zmqid = from_event.header.get('zmqid', None)

self._multiplexer._active_channels[self._channel_id] = self

self._queue.put(from_event)

@property

def recv_is_available(self):

return self._multiplexer.recv_is_available

def __del__(self):

self.close()

def close(self):

if self._channel_id is not None:

del self._multiplexer._active_channels[self._channel_id]

self._channel_id = None

def create_event(self, name, args, kwargs=None, xheader=None):

event = self._multiplexer.create_event(name, args, kwargs, xheader)

if self._channel_id is None:

self._channel_id = event.header['message_id']

self._multiplexer._active_channels[self._channel_id] = self

else:

event.header['response_to'] = self._channel_id

return event

def emit(self, name, args, kwargs=None, xheader=None):

event = self.create_event(name, args, kwargs, xheader)

self._multiplexer.emit_event(event, self._zmqid)

def emit_event(self, event):

self._multiplexer.emit_event(event, self._zmqid)

def recv(self, timeout=None):

try:

event = self._queue.get(timeout=timeout)

except gevent.queue.Empty:

raise TimeoutExpired(timeout)

return event

@property

def context(self):

return self._multiplexer.context

class BufferedChannel(object):

def __init__(self, channel, inqueue_size=100):

self._channel = channel

self._input_queue_size = inqueue_size

self._remote_queue_open_slots = 1

self._input_queue_reserved = 1

self._remote_can_recv = gevent.event.Event()

self._input_queue = gevent.queue.Queue()

self._lost_remote = False

self._verbose = False

self._on_close_if = None

self._recv_task = gevent.spawn(self._recver)

@property

def recv_is_available(self):

return self._channel.recv_is_available

@property

def on_close_if(self):

return self._on_close_if

@on_close_if.setter

def on_close_if(self, cb):

self._on_close_if = cb

def __del__(self):

self.close()

def close(self):

if self._recv_task is not None:

self._recv_task.kill()

self._recv_task = None

if self._channel is not None:

self._channel.close()

self._channel = None

def _recver(self):

while True:

event = self._channel.recv()

if event.name == '_zpc_more':

try:

self._remote_queue_open_slots += int(event.args[0])

except Exception as e:

print >> sys.stderr, \

'gevent_zerorpc.BufferedChannel._recver,', \

'exception:', e

if self._remote_queue_open_slots > 0:

self._remote_can_recv.set()

elif self._input_queue.qsize() == self._input_queue_size:

raise RuntimeError(

'BufferedChannel, queue overflow on event:', event)

else:

self._input_queue.put(event)

if self._on_close_if is not None and self._on_close_if(event):

self._recv_task = None

self.close()

return

def create_event(self, name, args, kwargs=None, xheader=None):

return self._channel.create_event(name, args, kwargs, xheader)

def emit_event(self, event, block=True, timeout=None):

if not self._remote_queue_open_slots:

if not block:

return False

self._remote_can_recv.clear()

self._remote_can_recv.wait(timeout=timeout)

self._remote_queue_open_slots -= 1

try:

self._channel.emit_event(event)

except:

self._remote_queue_open_slots += 1

raise

return True

def emit(self, name, args, kwargs = None, xheader=None, block=True, timeout=None):

event = self.create_event(name, args, kwargs, xheader)

return self.emit_event(event, block, timeout)

def _request_data(self):

open_slots = self._input_queue_size - self._input_queue_reserved

self._input_queue_reserved += open_slots

self._channel.emit('_zpc_more', (open_slots,))

def recv(self, timeout=None):

if self._verbose:

if self._input_queue_reserved < self._input_queue_size / 2:

self._request_data()

else:

self._verbose = True

try:

event = self._input_queue.get(timeout=timeout)

except gevent.queue.Empty:

raise TimeoutExpired(timeout)

self._input_queue_reserved -= 1

return event

@property

def channel(self):

return self._channel

@property

def context(self):

return self._channel.context