Files
deb-python-eventlet/eventlet/twistedutil/protocol.py
Jakub Stasiak 75a1ab8caf Remove most of the deprecated code
Closes GH #144
2014-10-10 08:53:11 +01:00

415 lines
13 KiB
Python

"""Basic twisted protocols converted to synchronous mode"""
import sys
from twisted.internet.protocol import Protocol as twistedProtocol
from twisted.internet.error import ConnectionDone
from twisted.internet.protocol import Factory, ClientFactory
from twisted.internet import main
from twisted.python import failure
from eventlet import greenthread
from eventlet import getcurrent
from eventlet.event import Event as BaseEvent
from eventlet.queue import Queue
class ValueQueue(Queue):
"""Queue that keeps the last item forever in the queue if it's an exception.
Useful if you send an exception over queue only once, and once sent it must be always
available.
"""
def send(self, value=None, exc=None):
if exc is not None or not self.has_error():
Queue.send(self, value, exc)
def wait(self):
"""The difference from Queue.wait: if there is an only item in the
Queue and it is an exception, raise it, but keep it in the Queue, so
that future calls to wait() will raise it again.
"""
if self.has_error() and len(self.items)==1:
# the last item, which is an exception, raise without emptying the Queue
getcurrent().throw(*self.items[0][1])
else:
return Queue.wait(self)
def has_error(self):
return self.items and self.items[-1][1] is not None
class Event(BaseEvent):
def send(self, value, exc=None):
if self.ready():
self.reset()
return BaseEvent.send(self, value, exc)
def send_exception(self, *throw_args):
if self.ready():
self.reset()
return BaseEvent.send_exception(self, *throw_args)
class Producer2Event(object):
# implements IPullProducer
def __init__(self, event):
self.event = event
def resumeProducing(self):
self.event.send(1)
def stopProducing(self):
del self.event
class GreenTransportBase(object):
transportBufferSize = None
def __init__(self, transportBufferSize=None):
if transportBufferSize is not None:
self.transportBufferSize = transportBufferSize
self._queue = ValueQueue()
self._write_event = Event()
self._disconnected_event = Event()
def build_protocol(self):
return self.protocol_class(self)
def _got_transport(self, transport):
self._queue.send(transport)
def _got_data(self, data):
self._queue.send(data)
def _connectionLost(self, reason):
self._disconnected_event.send(reason.value)
self._queue.send_exception(reason.value)
self._write_event.send_exception(reason.value)
def _wait(self):
if self.disconnecting or self._disconnected_event.ready():
if self._queue:
return self._queue.wait()
else:
raise self._disconnected_event.wait()
self.resumeProducing()
try:
return self._queue.wait()
finally:
self.pauseProducing()
def write(self, data, wait=True):
if self._disconnected_event.ready():
raise self._disconnected_event.wait()
if wait:
self._write_event.reset()
self.transport.write(data)
self._write_event.wait()
else:
self.transport.write(data)
def loseConnection(self, connDone=failure.Failure(main.CONNECTION_DONE), wait=True):
self.transport.unregisterProducer()
self.transport.loseConnection(connDone)
if wait:
self._disconnected_event.wait()
def __getattr__(self, item):
if item=='transport':
raise AttributeError(item)
if hasattr(self, 'transport'):
try:
return getattr(self.transport, item)
except AttributeError:
me = type(self).__name__
trans = type(self.transport).__name__
raise AttributeError("Neither %r nor %r has attribute %r" % (me, trans, item))
else:
raise AttributeError(item)
def resumeProducing(self):
self.paused -= 1
if self.paused==0:
self.transport.resumeProducing()
def pauseProducing(self):
self.paused += 1
if self.paused==1:
self.transport.pauseProducing()
def _init_transport_producer(self):
self.transport.pauseProducing()
self.paused = 1
def _init_transport(self):
transport = self._queue.wait()
self.transport = transport
if self.transportBufferSize is not None:
transport.bufferSize = self.transportBufferSize
self._init_transport_producer()
transport.registerProducer(Producer2Event(self._write_event), False)
class Protocol(twistedProtocol):
def __init__(self, recepient):
self._recepient = recepient
def connectionMade(self):
self._recepient._got_transport(self.transport)
def dataReceived(self, data):
self._recepient._got_data(data)
def connectionLost(self, reason):
self._recepient._connectionLost(reason)
class UnbufferedTransport(GreenTransportBase):
"""A very simple implementation of a green transport without an additional buffer"""
protocol_class = Protocol
def recv(self):
"""Receive a single chunk of undefined size.
Return '' if connection was closed cleanly, raise the exception if it was closed
in a non clean fashion. After that all successive calls return ''.
"""
if self._disconnected_event.ready():
return ''
try:
return self._wait()
except ConnectionDone:
return ''
def read(self):
"""Read the data from the socket until the connection is closed cleanly.
If connection was closed in a non-clean fashion, the appropriate exception
is raised. In that case already received data is lost.
Next time read() is called it returns ''.
"""
result = ''
while True:
recvd = self.recv()
if not recvd:
break
result += recvd
return result
# iterator protocol:
def __iter__(self):
return self
def next(self):
result = self.recv()
if not result:
raise StopIteration
return result
class GreenTransport(GreenTransportBase):
protocol_class = Protocol
_buffer = ''
_error = None
def read(self, size=-1):
"""Read size bytes or until EOF"""
if not self._disconnected_event.ready():
try:
while len(self._buffer) < size or size < 0:
self._buffer += self._wait()
except ConnectionDone:
pass
except:
if not self._disconnected_event.has_exception():
raise
if size>=0:
result, self._buffer = self._buffer[:size], self._buffer[size:]
else:
result, self._buffer = self._buffer, ''
if not result and self._disconnected_event.has_exception():
try:
self._disconnected_event.wait()
except ConnectionDone:
pass
return result
def recv(self, buflen=None):
"""Receive a single chunk of undefined size but no bigger than buflen"""
if not self._disconnected_event.ready():
self.resumeProducing()
try:
try:
recvd = self._wait()
#print 'received %r' % recvd
self._buffer += recvd
except ConnectionDone:
pass
except:
if not self._disconnected_event.has_exception():
raise
finally:
self.pauseProducing()
if buflen is None:
result, self._buffer = self._buffer, ''
else:
result, self._buffer = self._buffer[:buflen], self._buffer[buflen:]
if not result and self._disconnected_event.has_exception():
try:
self._disconnected_event.wait()
except ConnectionDone:
pass
return result
# iterator protocol:
def __iter__(self):
return self
def next(self):
res = self.recv()
if not res:
raise StopIteration
return res
class GreenInstanceFactory(ClientFactory):
def __init__(self, instance, event):
self.instance = instance
self.event = event
def buildProtocol(self, addr):
return self.instance
def clientConnectionFailed(self, connector, reason):
self.event.send_exception(reason.type, reason.value, reason.tb)
class GreenClientCreator(object):
"""Connect to a remote host and return a connected green transport instance.
"""
gtransport_class = GreenTransport
def __init__(self, reactor=None, gtransport_class=None, *args, **kwargs):
if reactor is None:
from twisted.internet import reactor
self.reactor = reactor
if gtransport_class is not None:
self.gtransport_class = gtransport_class
self.args = args
self.kwargs = kwargs
def _make_transport_and_factory(self):
gtransport = self.gtransport_class(*self.args, **self.kwargs)
protocol = gtransport.build_protocol()
factory = GreenInstanceFactory(protocol, gtransport._queue)
return gtransport, factory
def connectTCP(self, host, port, *args, **kwargs):
gtransport, factory = self._make_transport_and_factory()
self.reactor.connectTCP(host, port, factory, *args, **kwargs)
gtransport._init_transport()
return gtransport
def connectSSL(self, host, port, *args, **kwargs):
gtransport, factory = self._make_transport_and_factory()
self.reactor.connectSSL(host, port, factory, *args, **kwargs)
gtransport._init_transport()
return gtransport
def connectTLS(self, host, port, *args, **kwargs):
gtransport, factory = self._make_transport_and_factory()
self.reactor.connectTLS(host, port, factory, *args, **kwargs)
gtransport._init_transport()
return gtransport
def connectUNIX(self, address, *args, **kwargs):
gtransport, factory = self._make_transport_and_factory()
self.reactor.connectUNIX(address, factory, *args, **kwargs)
gtransport._init_transport()
return gtransport
def connectSRV(self, service, domain, *args, **kwargs):
SRVConnector = kwargs.pop('ConnectorClass', None)
if SRVConnector is None:
from twisted.names.srvconnect import SRVConnector
gtransport, factory = self._make_transport_and_factory()
c = SRVConnector(self.reactor, service, domain, factory, *args, **kwargs)
c.connect()
gtransport._init_transport()
return gtransport
class SimpleSpawnFactory(Factory):
"""Factory that spawns a new greenlet for each incoming connection.
For an incoming connection a new greenlet is created using the provided
callback as a function and a connected green transport instance as an
argument.
"""
gtransport_class = GreenTransport
def __init__(self, handler, gtransport_class=None, *args, **kwargs):
if callable(handler):
self.handler = handler
else:
self.handler = handler.send
if hasattr(handler, 'send_exception'):
self.exc_handler = handler.send_exception
if gtransport_class is not None:
self.gtransport_class = gtransport_class
self.args = args
self.kwargs = kwargs
def exc_handler(self, *args):
pass
def buildProtocol(self, addr):
gtransport = self.gtransport_class(*self.args, **self.kwargs)
protocol = gtransport.build_protocol()
protocol.factory = self
self._do_spawn(gtransport, protocol)
return protocol
def _do_spawn(self, gtransport, protocol):
greenthread.spawn(self._run_handler, gtransport, protocol)
def _run_handler(self, gtransport, protocol):
try:
gtransport._init_transport()
except Exception:
self.exc_handler(*sys.exc_info())
else:
self.handler(gtransport)
class SpawnFactory(SimpleSpawnFactory):
"""An extension to SimpleSpawnFactory that provides some control over
the greenlets it has spawned.
"""
def __init__(self, handler, gtransport_class=None, *args, **kwargs):
self.greenlets = set()
SimpleSpawnFactory.__init__(self, handler, gtransport_class, *args, **kwargs)
def _do_spawn(self, gtransport, protocol):
g = greenthread.spawn(self._run_handler, gtransport, protocol)
self.greenlets.add(g)
g.link(lambda *_: self.greenlets.remove(g))
def waitall(self):
results = []
for g in self.greenlets:
results.append(g.wait())
return results