# *****************************************************************************
# * Copyright (c) 2011, 2013 Wind River Systems, Inc. and others.
# * All rights reserved. This program and the accompanying materials
# * are made available under the terms of the Eclipse Public License v1.0
# * which accompanies this distribution, and is available at
# * http://www.eclipse.org/legal/epl-v10.html
# *
# * Contributors:
# * Wind River Systems - initial API and implementation
# *****************************************************************************
import threading
from . import protocol, channel
from .services import locator
_channels = []
_listeners = []
_transports = {}
_lock = threading.RLock()
class TransportProvider(object):
"""
TransportProvider represents communication protocol that can be used to
open TCF communication channels.
Examples of transports are: TCP/IP, RS-232, USB.
Client can implement this interface if they want to provide support for a
transport that is not supported directly by the framework.
"""
def getName(self):
"""
Return transport name. Same as used as peer attribute,
@see IPeer.ATTR_TRANSPORT_NAME
@return transport name.
"""
raise NotImplementedError("Abstract method")
def openChannel(self, peer):
"""
Open channel to communicate with this peer using this transport.
Note: the channel can be not fully open yet when this method returns.
It's state can be IChannel.STATE_OPENING.
Protocol.Listener will be called when the channel will be opened or
closed.
@param peer - a IPeer object that describes remote end-point of the
channel.
@return TCF communication channel.
"""
raise NotImplementedError("Abstract method")
def addTransportProvider(transport):
name = transport.getName()
assert name
with _lock:
if _transports.get(name):
raise Exception("Already registered: " + name)
_transports[name] = transport
def removeTransportProvider(transport):
name = transport.getName()
assert name
with _lock:
if _transports.get(name) == transport:
del _transports[name]
def openChannel(peer):
name = peer.getTransportName()
if not name:
raise Exception("No transport name")
with _lock:
provider = _transports.get(name)
if not provider:
raise Exception("Unknown transport name: " + name)
return provider.openChannel(peer)
def channelOpened(channel):
assert channel not in _channels
_channels.append(channel)
for l in tuple(_listeners):
try:
l.onChannelOpen(channel)
except Exception as x:
import sys
x.tb = sys.exc_info()[2]
protocol.log("Exception in channel listener", x)
def channelClosed(channel, error):
assert channel in _channels
_channels.remove(channel)
def getOpenChannels():
return _channels[:]
def addChannelOpenListener(listener):
assert listener
_listeners.append(listener)
def removeChannelOpenListener(listener):
try:
_listeners.remove(listener)
except ValueError:
pass # ignore
class TCPTransportProvider(TransportProvider):
def getName(self):
return "TCP"
def openChannel(self, p):
assert self.getName() == p.getTransportName()
from . import peer
attrs = p.getAttributes()
host = attrs.get(peer.ATTR_IP_HOST)
port = attrs.get(peer.ATTR_IP_PORT)
if not host:
raise RuntimeError("No host name")
from channel.ChannelTCP import ChannelTCP
return ChannelTCP(p, host, _parsePort(port))
def _parsePort(port):
if not port:
raise Exception("No port number")
try:
return int(port)
except Exception:
raise RuntimeError(
"Invalid value of \"Port\" attribute. Must be decimal number.")
def sendEvent(service_name, event_name, data):
"""
Transmit TCF event message.
The message is sent to all open communication channels - broadcasted.
This is internal API, TCF clients should use protocol.sendEvent().
"""
for c in _channels:
# Skip channels that are executing "redirect" command - STATE_OPENING
if c.getState() == channel.STATE_OPEN:
s = c.getLocalService(service_name)
if s:
c.sendEvent(s, event_name, data)
def sync(done):
"""
Call back after TCF messages sent by this host up to this moment are
delivered to their intended targets. This method is intended for
synchronization of messages across multiple channels.
Note: Cross channel synchronization can reduce performance and throughput.
Most clients don't need cross channel synchronization and should not call
this method.
@param done will be executed by dispatch thread after communication
messages are delivered to corresponding targets.
This is internal API, TCF clients should use protocol.sync().
"""
tokenSet = set()
class DoneSync(locator.DoneSync):
def doneSync(self, token):
assert tokenSet.contains(token)
tokenSet.remove(token)
if len(tokenSet) == 0:
done()
done_sync = DoneSync()
for c in _channels:
if c.getState() == channel.STATE_OPEN:
s = c.getRemoteService(locator.NAME)
if s:
tokenSet.append(s.sync(done_sync))
if len(tokenSet) == 0:
protocol.invokeLater(done)
# initialize TCP transport
addTransportProvider(TCPTransportProvider())
