# # Copyright (C) 2006-2009 Nexedi SA # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License # as published by the Free Software Foundation; either version 2 # of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. import logging from neo.locking import RLock import sys import traceback from neo import protocol from neo.protocol import Packet, ProtocolError from neo.event import IdleEvent from neo.connector import ConnectorTryAgainException, ConnectorInProgressException from neo.util import dump from neo.exception import OperationFailure def lockCheckWrapper(func): """ This function is to be used as a wrapper around MT(Client|Server)Connection class methods. It uses a "_" method on RLock class, so it might stop working without notice (sadly, RLock does not offer any "acquired" method, but that one will do as it checks that current thread holds this lock). It requires moniroted class to have an RLock instance in self._lock property. """ def wrapper(self, *args, **kw): if not self._lock._is_owned(): import traceback logging.warning('%s called on %s instance without being locked. Stack:\n%s', func.func_code.co_name, self.__class__.__name__, ''.join(traceback.format_stack())) # Call anyway return func(self, *args, **kw) return wrapper class BaseConnection(object): """A base connection.""" def __init__(self, event_manager, handler, connector = None, addr = None, connector_handler = None): self.em = event_manager self.connector = connector self.addr = addr self.handler = handler if connector is not None: self.connector_handler = connector.__class__ event_manager.register(self) else: self.connector_handler = connector_handler def lock(self): return 1 def unlock(self): return None def getConnector(self): return self.connector def getDescriptor(self): return self.connector.getDescriptor() def setConnector(self, connector): if self.connector is not None: raise RuntimeError, 'cannot overwrite a connector in a connection' if connector is not None: self.connector = connector self.em.register(self) def getAddress(self): return self.addr def readable(self): raise NotImplementedError def writable(self): raise NotImplementedError def getHandler(self): return self.handler def setHandler(self, handler): self.handler = handler def getEventManager(self): return self.em def getUUID(self): return None def isListeningConnection(self): raise NotImplementedError class ListeningConnection(BaseConnection): """A listen connection.""" def __init__(self, event_manager, handler, addr = None, connector_handler = None, **kw): logging.info('listening to %s:%d', *addr) BaseConnection.__init__(self, event_manager, handler, addr = addr, connector_handler = connector_handler) connector = self.connector_handler() connector.makeListeningConnection(addr) self.setConnector(connector) self.em.addReader(self) def readable(self): try: new_s, addr = self.connector.getNewConnection() logging.info('accepted a connection from %s:%d', *addr) self.handler.connectionAccepted(self, new_s, addr) except ConnectorTryAgainException: pass def isListeningConnection(self): return True class Connection(BaseConnection): """A connection.""" def __init__(self, event_manager, handler, connector = None, addr = None, connector_handler = None): self.read_buf = "" self.write_buf = "" self.cur_id = 0 self.event_dict = {} self.aborted = False self.uuid = None BaseConnection.__init__(self, event_manager, handler, connector = connector, addr = addr, connector_handler = connector_handler) if connector is not None: event_manager.addReader(self) def getUUID(self): return self.uuid def setUUID(self, uuid): self.uuid = uuid def getNextId(self): next_id = self.cur_id # Deal with an overflow. if self.cur_id == 0xffffffff: self.cur_id = 0 else: self.cur_id += 1 return next_id def close(self): """Close the connection.""" em = self.em if self.connector is not None: logging.debug('closing a connector for %s (%s:%d)', dump(self.uuid), *(self.addr)) em.removeReader(self) em.removeWriter(self) em.unregister(self) self.connector.shutdown() self.connector.close() self.connector = None for event in self.event_dict.itervalues(): em.removeIdleEvent(event) self.event_dict.clear() def __del__(self): self.close() def abort(self): """Abort dealing with this connection.""" logging.debug('aborting a connector for %s (%s:%d)', dump(self.uuid), *(self.addr)) self.aborted = True def writable(self): """Called when self is writable.""" self.send() if not self.pending(): if self.aborted: self.close() else: self.em.removeWriter(self) def readable(self): """Called when self is readable.""" self.recv() self.analyse() if self.aborted: self.em.removeReader(self) def analyse(self): """Analyse received data.""" while 1: try: packet = Packet.parse(self.read_buf) except ProtocolError, m: self.handler.packetMalformed(self, *m) return if packet is None: break # Remove idle events, if appropriate packets were received. for msg_id in (None, packet.getId()): try: event = self.event_dict[msg_id] del self.event_dict[msg_id] self.em.removeIdleEvent(event) except KeyError: pass logging.debug('#0x%04x %-30s from %s (%s:%d)', packet.getId(), packet.getType(), dump(self.uuid), *self.getAddress()) try: self.handler.packetReceived(self, packet) finally: self.read_buf = self.read_buf[len(packet):] def pending(self): return self.connector is not None and self.write_buf def recv(self): """Receive data from a connector.""" try: r = self.connector.receive() if not r: logging.error('cannot read') self.handler.connectionClosed(self) self.close() else: self.read_buf += r except ConnectorTryAgainException: pass except OperationFailure: raise except: traceback.print_exc() logging.warning('recv called on %s(%s) failed.'%(self, self.getAddress())) self.handler.connectionClosed(self) self.close() def send(self): """Send data to a connector.""" if self.write_buf: try: r = self.connector.send(self.write_buf) if not r: logging.error('cannot write') self.handler.connectionClosed(self) self.close() else: self.write_buf = self.write_buf[r:] except ConnectorTryAgainException: return except OperationFailure: raise except: traceback.print_exc() logging.warning('send called on %s(%s) failed.'%(self, self.getAddress())) self.handler.connectionClosed(self) self.close() def addPacket(self, packet): """Add a packet into the write buffer.""" if self.connector is None: return logging.debug('#0x%04x %-30s to %s (%s:%d)', packet.getId(), packet.getType(), dump(self.uuid), *self.getAddress()) try: self.write_buf += packet.encode() except ProtocolError, m: logging.critical('trying to send a too big message') return self.addPacket(protocol.internalError(packet.getId(), m[0])) # If this is the first time, enable polling for writing. if self.write_buf: self.em.addWriter(self) def expectMessage(self, msg_id = None, timeout = 5, additional_timeout = 30): """Expect a message for a reply to a given message ID or any message. The purpose of this method is to define how much amount of time is acceptable to wait for a message, thus to detect a down or broken peer. This is important, because one error may halt a whole cluster otherwise. Although TCP defines a keep-alive feature, the timeout is too long generally, and it does not detect a certain type of reply, thus it is better to probe problems at the application level. The message ID specifies what ID is expected. Usually, this should be identical with an ID for a request message. If it is None, any message is acceptable, so it can be used to check idle time. The timeout is the amount of time to wait until keep-alive messages start. Once the timeout is expired, the connection starts to ping the peer. The additional timeout defines the amount of time after the timeout to invoke a timeoutExpired callback. If it is zero, no ping is sent, and the callback is executed immediately.""" if self.connector is None: return event = IdleEvent(self, msg_id, timeout, additional_timeout) self.event_dict[msg_id] = event self.em.addIdleEvent(event) def isServerConnection(self): raise NotImplementedError def isListeningConnection(self): return False class ClientConnection(Connection): """A connection from this node to a remote node.""" def __init__(self, event_manager, handler, addr = None, connector_handler = None, **kw): self.connecting = True Connection.__init__(self, event_manager, handler, addr = addr, connector_handler = connector_handler) handler.connectionStarted(self) try: connector = self.connector_handler() self.setConnector(connector) try: connector.makeClientConnection(addr) except ConnectorInProgressException: event_manager.addWriter(self) else: self.connecting = False self.handler.connectionCompleted(self) event_manager.addReader(self) except: traceback.print_exc() logging.warning('init called on %s(%s) failed.'%(self, self.getAddress())) handler.connectionFailed(self) self.close() def writable(self): """Called when self is writable.""" if self.connecting: err = self.connector.getError() if err: self.handler.connectionFailed(self) self.close() return else: self.connecting = False self.handler.connectionCompleted(self) self.em.addReader(self) else: Connection.writable(self) def isServerConnection(self): return False class ServerConnection(Connection): """A connection from a remote node to this node.""" def isServerConnection(self): return True class MTClientConnection(ClientConnection): """A Multithread-safe version of ClientConnection.""" def __init__(self, *args, **kwargs): # _lock is only here for lock debugging purposes. Do not use. self._lock = lock = RLock() self.acquire = lock.acquire self.release = lock.release self.lock() try: super(MTClientConnection, self).__init__(*args, **kwargs) finally: self.unlock() def lock(self, blocking = 1): return self.acquire(blocking = blocking) def unlock(self): self.release() @lockCheckWrapper def recv(self, *args, **kw): return super(MTClientConnection, self).recv(*args, **kw) @lockCheckWrapper def send(self, *args, **kw): return super(MTClientConnection, self).send(*args, **kw) @lockCheckWrapper def writable(self, *args, **kw): return super(MTClientConnection, self).writable(*args, **kw) @lockCheckWrapper def readable(self, *args, **kw): return super(MTClientConnection, self).readable(*args, **kw) @lockCheckWrapper def analyse(self, *args, **kw): return super(MTClientConnection, self).analyse(*args, **kw) @lockCheckWrapper def addPacket(self, *args, **kw): return super(MTClientConnection, self).addPacket(*args, **kw) @lockCheckWrapper def getNextId(self, *args, **kw): return super(MTClientConnection, self).getNextId(*args, **kw) @lockCheckWrapper def expectMessage(self, *args, **kw): return super(MTClientConnection, self).expectMessage(*args, **kw) class MTServerConnection(ServerConnection): """A Multithread-safe version of ServerConnection.""" def __init__(self, *args, **kwargs): # _lock is only here for lock debugging purposes. Do not use. self._lock = lock = RLock() self.acquire = lock.acquire self.release = lock.release self.lock() try: super(MTServerConnection, self).__init__(*args, **kwargs) finally: self.unlock() def lock(self, blocking = 1): return self.acquire(blocking = blocking) def unlock(self): self.release() @lockCheckWrapper def recv(self, *args, **kw): return super(MTServerConnection, self).recv(*args, **kw) @lockCheckWrapper def send(self, *args, **kw): return super(MTServerConnection, self).send(*args, **kw) @lockCheckWrapper def writable(self, *args, **kw): return super(MTServerConnection, self).writable(*args, **kw) @lockCheckWrapper def readable(self, *args, **kw): return super(MTServerConnection, self).readable(*args, **kw) @lockCheckWrapper def analyse(self, *args, **kw): return super(MTServerConnection, self).analyse(*args, **kw) @lockCheckWrapper def addPacket(self, *args, **kw): return super(MTServerConnection, self).addPacket(*args, **kw) @lockCheckWrapper def getNextId(self, *args, **kw): return super(MTServerConnection, self).getNextId(*args, **kw) @lockCheckWrapper def expectMessage(self, *args, **kw): return super(MTServerConnection, self).expectMessage(*args, **kw)