def __init__(self, certificatesDirectory=None):
"""
Initializes the NetworkManager's state.
Args:
certificatesDirectory: the directory where the files server.crt and server.key are.
"""
self.__connectionPool = GenericThreadSafeDictionary()
self.__outgoingDataQueue = GenericThreadSafePriorityQueue()
if (not reactor.running):
self.__networkThread = TwistedReactorThread()
else:
self.__networkThread = None
self.__outgoingDataThread = OutgoingDataThread(
self.__outgoingDataQueue)
self.__connectionThread = ConnectionMonitoringThread(
self.__connectionPool)
self.__certificatesDirectory = certificatesDirectory
def __init__(self, certificatesDirectory = None):
"""
Initializes the NetworkManager's state.
Args:
certificatesDirectory: the directory where the files server.crt and server.key are.
"""
self.__connectionPool = GenericThreadSafeDictionary()
self.__outgoingDataQueue = GenericThreadSafePriorityQueue()
if (not reactor.running) :
self.__networkThread = TwistedReactorThread()
else :
self.__networkThread = None
self.__outgoingDataThread = OutgoingDataThread(self.__outgoingDataQueue)
self.__connectionThread = ConnectionMonitoringThread(self.__connectionPool)
self.__certificatesDirectory = certificatesDirectory
def __allocateConnectionResources(self, callbackObject):
"""
Allocates the resources associated to a new connection (only if necessary)
Args:
callbackObject: The object that will process all the incoming packages.
Returns:
a tuple (queue, thread), where queue and thread are the incoming data queue
and the incoming data processing thread assigned to this new connection.
"""
c = None
for connection in self.__connectionPool.values():
if (connection.getCallback() == callbackObject):
# Everything is allocated. Let's reuse it.
c = connection
break
if c != None:
return (c.getQueue(), c.getThread())
else:
queue = GenericThreadSafePriorityQueue()
thread = IncomingDataThread(queue, callbackObject)
return (queue, thread)
class NetworkManager():
"""
This class provides a facade to use Twisted at a higher abstraction level.
@attention: If you don't want everything to conk out, DO NOT USE MORE THAN
ONE NetworkManager IN THE SAME PROGRAM.
@attention: Due to some Twisted related limitations, do NOT stop the network service
UNTIL you KNOW PERFECTLY WELL that you won't be using it again.
"""
def __init__(self, certificatesDirectory=None):
"""
Initializes the NetworkManager's state.
Args:
certificatesDirectory: the directory where the files server.crt and server.key are.
"""
self.__connectionPool = GenericThreadSafeDictionary()
self.__outgoingDataQueue = GenericThreadSafePriorityQueue()
if (not reactor.running):
self.__networkThread = TwistedReactorThread()
else:
self.__networkThread = None
self.__outgoingDataThread = OutgoingDataThread(
self.__outgoingDataQueue)
self.__connectionThread = ConnectionMonitoringThread(
self.__connectionPool)
self.__certificatesDirectory = certificatesDirectory
def startNetworkService(self):
"""
Starts the network service. When this operation finishes,
new connections can be established.
Args:
None
Returns:
Nothing
"""
if (self.__networkThread != None):
self.__networkThread.start()
self.__outgoingDataThread.start()
self.__connectionThread.start()
def stopNetworkService(self):
"""
Stops the network service.
@attention: Due to Twisted related limitations, do NOT stop the network service
UNTIL you KNOW PERFECTLY WELL that you won't be using it again.
@attention: Remember: there's just one network manager per application, so *please* THINK
before you stop it.
@attention: If this method is called from a network thread, your application will HANG.
Please, call it from your application's MAIN thread.
Args:
None
Returns:
Nothing
"""
for connection in self.__connectionPool.values():
self.closeConnection(connection.getHost(), connection.getPort())
self.__connectionThread.stop()
self.__connectionThread.join()
self.__outgoingDataThread.stop()
self.__outgoingDataThread.join()
if (self.__networkThread != None):
self.__networkThread.stop()
self.__networkThread.join()
def __allocateConnectionResources(self, callbackObject):
"""
Allocates the resources associated to a new connection (only if necessary)
Args:
callbackObject: The object that will process all the incoming packages.
Returns:
a tuple (queue, thread), where queue and thread are the incoming data queue
and the incoming data processing thread assigned to this new connection.
"""
c = None
for connection in self.__connectionPool.values():
if (connection.getCallback() == callbackObject):
# Everything is allocated. Let's reuse it.
c = connection
break
if c != None:
return (c.getQueue(), c.getThread())
else:
queue = GenericThreadSafePriorityQueue()
thread = IncomingDataThread(queue, callbackObject)
return (queue, thread)
def connectTo(self,
host,
port,
timeout,
callbackObject,
useSSL=True,
reconnect=False):
"""
Connects to a remote server using its arguments
@attention: This is a blocking operation. The calling thread will be blocked until
the connection is established or until a timeout error is detected.
Args:
host: host IP address
port: the port where the host is listenning
timeout: timeout in seconds.
callbackObject: the callback object that will process all the incoming
packages received through this connection.
useSSL: if True, the SSL version 4 protocol will be used. Otherwise, we'll stick
to TCP version 4.
reconnect: if True, the network subsystem will try to reconnect to the server
when the connection is lost.
Returns:
Nothing
Raises:
NetworkManagerException: If no answer is received after timeout
seconds, the connection process will be aborted and a
NetworkManagerException will be raised.
"""
if self.__connectionPool.has_key((host, port)):
raise NetworkManagerException("The port " + str(port) +
" is already in use")
# The port is free => proceed
# Allocate the connection resources
(queue, thread) = self.__allocateConnectionResources(callbackObject)
# Create the NetworkConnection object
connection = ClientConnection(useSSL, self.__certificatesDirectory,
host, port, queue, thread, reconnect,
callbackObject)
# Try to establish the connection
try:
if (connection.establish(timeout)):
# The connection could be created => add it to the connection pool
self.__connectionPool[(host, port)] = connection
else:
# Raise an exception
raise NetworkManagerException(str(connection.getError()))
except ConnectionException as e:
raise NetworkManagerException(e.message)
def listenIn(self, port, callbackObject, useSSL=False):
"""
Creates a server using its arguments.
@attention: This is a non-blocking operation. Please, check if the connection is ready BEFORE
you send anything through it.
Args:
port: The port to listen in. If it's not free, a NetworkManagerException will be raised.
callbackObject: the callback object that will process all the incoming
packages received through this connection.
useSSL: if True, the SSL version 4 protocol will be used. Otherwise, we'll stick
to TCP version 4.
Returns:
Nothing
"""
if self.__connectionPool.has_key(('', port)):
raise NetworkManagerException("The port " + str(port) +
" is already in use")
# The port is free => proceed
# Allocate the connection resources
(queue, thread) = self.__allocateConnectionResources(callbackObject)
# Create the NetworkConnection object
connection = ServerConnection(useSSL, self.__certificatesDirectory,
port, queue, thread, callbackObject)
try:
# Establish it
connection.establish(None)
if (connection.getError() == None):
# Register the new connection
self.__connectionPool[('', port)] = connection
else:
raise ConnectionException(str(connection.getError()))
except ConnectionException as e:
raise NetworkManagerException(e.message)
def isConnectionReady(self, host, port):
"""
Checks wether a connection is ready or not.
Args:
port: the port assigned to the connection.
Returns:
True if the connection is ready or False otherwise.
Raises:
NetworkManagerException: a NetworkManagerException will be raised if
- there were errors while establishing the connection, or if
- the connection was abnormally closed, or if
- the supplied port is free
"""
if not self.__connectionPool.has_key((host, port)):
raise NetworkManagerException("The port " + str(port) +
" is not in use")
connection = self.__connectionPool[(host, port)]
self.__detectConnectionErrors(connection)
return connection.isReady()
def __detectConnectionErrors(self, connection):
"""
Checks if the given connection is in an error state or was unexpectedly closed.
Args:
connection: the connection to monitor.
Returns:
Nothing
"""
if connection.isInErrorState():
# Something bad has happened => close the connection, warn the user
self.__connectionPool.pop(
(connection.getHost(), connection.getPort()))
raise NetworkManagerException(str(connection.getError()))
if (connection.wasUnexpectedlyClosed()):
self.__connectionPool.pop(
(connection.getHost(), connection.getPort()))
raise NetworkManagerException(
"The connection was closed abnormally")
def sendPacket(self, host, port, packet, client_IP=None, client_port=None):
"""
Sends a packet through the specified port and IP address.
Args:
port: The port assigned to the connection that will be used to send the packet.
packet: The packet to send.
client_IP: the client's ipv4 address
client_port: the client's port
@attention: The last two parameters can only be used in server connections. In this case,
- if both are None, the packet will be sent to all the clients (MULTICAST mode)
- otherwise, the pacekt will be sent to a specific client (UNICAST mode)
Returns:
None if the packet was successfully sent and an error message if it wasn't.
Raises:
Nothing
@attention: If the connection is not ready, the packet will be discarded.
So PLEASE, check the connection's status BEFORE using it.
"""
if not self.__connectionPool.has_key((host, port)):
return "There's nothing attached to the port " + str(port)
connection = self.__connectionPool[(host, port)]
if connection.isReady():
connection.registerPacket()
self.__outgoingDataQueue.queue(
packet.getPriority(),
(connection, packet, client_IP, client_port))
return None
else:
return "The connection is not ready yet"
def createPacket(self, priority):
"""
Creates an empty data packet and returns it
Args:
priority: The new packet's priority.
Returns:
a new data packet.
Raises:
NetworkManagerException: this exception will be raised when the packet's priority
is not a positive integer.
"""
if not isinstance(priority, int) or priority < 0:
raise NetworkManagerException(
"Data packets\' priorities MUST be positive integers")
p = _Packet(Packet_TYPE.DATA, priority)
return p
def closeConnection(self, host, port):
"""
Closes a connection
Args:
port: The port assigned to the connection. If it's free, a NetworkManagerException will be
raised.
Returns:
Nothing
"""
if not self.__connectionPool.has_key((host, port)):
raise NetworkManagerException(
"There's nothing attached to the port " + str(port))
# Retrieve the connection
connection = self.__connectionPool[(host, port)]
# Ask the connection to close
connection.close()
@staticmethod
def printConnectionWarningIfNecessary(ip, port, packet_type, errorMessage):
if (errorMessage != None):
print "Warning: unable to send {2} to {0}:{1}.".format(
ip, port, packet_type)
print "\t" + errorMessage
class NetworkManager():
"""
This class provides a facade to use Twisted at a higher abstraction level.
@attention: If you don't want everything to conk out, DO NOT USE MORE THAN
ONE NetworkManager IN THE SAME PROGRAM.
@attention: Due to some Twisted related limitations, do NOT stop the network service
UNTIL you KNOW PERFECTLY WELL that you won't be using it again.
"""
def __init__(self, certificatesDirectory = None):
"""
Initializes the NetworkManager's state.
Args:
certificatesDirectory: the directory where the files server.crt and server.key are.
"""
self.__connectionPool = GenericThreadSafeDictionary()
self.__outgoingDataQueue = GenericThreadSafePriorityQueue()
if (not reactor.running) :
self.__networkThread = TwistedReactorThread()
else :
self.__networkThread = None
self.__outgoingDataThread = OutgoingDataThread(self.__outgoingDataQueue)
self.__connectionThread = ConnectionMonitoringThread(self.__connectionPool)
self.__certificatesDirectory = certificatesDirectory
def startNetworkService(self):
"""
Starts the network service. When this operation finishes,
new connections can be established.
Args:
None
Returns:
Nothing
"""
if (self.__networkThread != None) :
self.__networkThread.start()
self.__outgoingDataThread.start()
self.__connectionThread.start()
def stopNetworkService(self):
"""
Stops the network service.
@attention: Due to Twisted related limitations, do NOT stop the network service
UNTIL you KNOW PERFECTLY WELL that you won't be using it again.
@attention: Remember: there's just one network manager per application, so *please* THINK
before you stop it.
@attention: If this method is called from a network thread, your application will HANG.
Please, call it from your application's MAIN thread.
Args:
None
Returns:
Nothing
"""
for connection in self.__connectionPool.values() :
self.closeConnection(connection.getHost(), connection.getPort())
self.__connectionThread.stop()
self.__connectionThread.join()
self.__outgoingDataThread.stop()
self.__outgoingDataThread.join()
if (self.__networkThread != None) :
self.__networkThread.stop()
self.__networkThread.join()
def __allocateConnectionResources(self, callbackObject):
"""
Allocates the resources associated to a new connection (only if necessary)
Args:
callbackObject: The object that will process all the incoming packages.
Returns:
a tuple (queue, thread), where queue and thread are the incoming data queue
and the incoming data processing thread assigned to this new connection.
"""
c = None
for connection in self.__connectionPool.values() :
if (connection.getCallback() == callbackObject) :
# Everything is allocated. Let's reuse it.
c = connection
break
if c != None :
return (c.getQueue(), c.getThread())
else :
queue = GenericThreadSafePriorityQueue()
thread = IncomingDataThread(queue, callbackObject)
return (queue, thread)
def connectTo(self, host, port, timeout, callbackObject, useSSL=True, reconnect=False):
"""
Connects to a remote server using its arguments
@attention: This is a blocking operation. The calling thread will be blocked until
the connection is established or until a timeout error is detected.
Args:
host: host IP address
port: the port where the host is listenning
timeout: timeout in seconds.
callbackObject: the callback object that will process all the incoming
packages received through this connection.
useSSL: if True, the SSL version 4 protocol will be used. Otherwise, we'll stick
to TCP version 4.
reconnect: if True, the network subsystem will try to reconnect to the server
when the connection is lost.
Returns:
Nothing
Raises:
NetworkManagerException: If no answer is received after timeout
seconds, the connection process will be aborted and a
NetworkManagerException will be raised.
"""
if self.__connectionPool.has_key((host,port)) :
raise NetworkManagerException("The port " + str(port) +" is already in use")
# The port is free => proceed
# Allocate the connection resources
(queue, thread) = self.__allocateConnectionResources(callbackObject)
# Create the NetworkConnection object
connection = ClientConnection(useSSL, self.__certificatesDirectory, host, port, queue, thread, reconnect, callbackObject)
# Try to establish the connection
try :
if (connection.establish(timeout)) :
# The connection could be created => add it to the connection pool
self.__connectionPool[(host, port)] = connection
else :
# Raise an exception
raise NetworkManagerException(str(connection.getError()))
except ConnectionException as e:
raise NetworkManagerException(e.message)
def listenIn(self, port, callbackObject, useSSL=False):
"""
Creates a server using its arguments.
@attention: This is a non-blocking operation. Please, check if the connection is ready BEFORE
you send anything through it.
Args:
port: The port to listen in. If it's not free, a NetworkManagerException will be raised.
callbackObject: the callback object that will process all the incoming
packages received through this connection.
useSSL: if True, the SSL version 4 protocol will be used. Otherwise, we'll stick
to TCP version 4.
Returns:
Nothing
"""
if self.__connectionPool.has_key(('', port)) :
raise NetworkManagerException("The port " + str(port) +" is already in use")
# The port is free => proceed
# Allocate the connection resources
(queue, thread) = self.__allocateConnectionResources(callbackObject)
# Create the NetworkConnection object
connection = ServerConnection(useSSL, self.__certificatesDirectory, port, queue, thread, callbackObject)
try :
# Establish it
connection.establish(None)
if (connection.getError() == None) :
# Register the new connection
self.__connectionPool[('', port)] = connection
else :
raise ConnectionException(str(connection.getError()))
except ConnectionException as e:
raise NetworkManagerException(e.message)
def isConnectionReady(self, host, port):
"""
Checks wether a connection is ready or not.
Args:
port: the port assigned to the connection.
Returns:
True if the connection is ready or False otherwise.
Raises:
NetworkManagerException: a NetworkManagerException will be raised if
- there were errors while establishing the connection, or if
- the connection was abnormally closed, or if
- the supplied port is free
"""
if not self.__connectionPool.has_key((host,port)) :
raise NetworkManagerException("The port " + str(port) +" is not in use")
connection = self.__connectionPool[(host, port)]
self.__detectConnectionErrors(connection)
return connection.isReady()
def __detectConnectionErrors(self, connection):
"""
Checks if the given connection is in an error state or was unexpectedly closed.
Args:
connection: the connection to monitor.
Returns:
Nothing
"""
if connection.isInErrorState() :
# Something bad has happened => close the connection, warn the user
self.__connectionPool.pop((connection.getHost(), connection.getPort()))
raise NetworkManagerException(str(connection.getError()))
if (connection.wasUnexpectedlyClosed()):
self.__connectionPool.pop((connection.getHost(), connection.getPort()))
raise NetworkManagerException("The connection was closed abnormally")
def sendPacket(self, host, port, packet, client_IP = None, client_port = None):
"""
Sends a packet through the specified port and IP address.
Args:
port: The port assigned to the connection that will be used to send the packet.
packet: The packet to send.
client_IP: the client's ipv4 address
client_port: the client's port
@attention: The last two parameters can only be used in server connections. In this case,
- if both are None, the packet will be sent to all the clients (MULTICAST mode)
- otherwise, the pacekt will be sent to a specific client (UNICAST mode)
Returns:
None if the packet was successfully sent and an error message if it wasn't.
Raises:
Nothing
@attention: If the connection is not ready, the packet will be discarded.
So PLEASE, check the connection's status BEFORE using it.
"""
if not self.__connectionPool.has_key((host, port)) :
return "There's nothing attached to the port " + str(port)
connection = self.__connectionPool[(host, port)]
if connection.isReady() :
connection.registerPacket()
self.__outgoingDataQueue.queue(packet.getPriority(), (connection, packet, client_IP, client_port))
return None
else :
return "The connection is not ready yet"
def createPacket(self, priority):
"""
Creates an empty data packet and returns it
Args:
priority: The new packet's priority.
Returns:
a new data packet.
Raises:
NetworkManagerException: this exception will be raised when the packet's priority
is not a positive integer.
"""
if not isinstance(priority, int) or priority < 0 :
raise NetworkManagerException("Data packets\' priorities MUST be positive integers")
p = _Packet(Packet_TYPE.DATA, priority)
return p
def closeConnection(self, host, port):
"""
Closes a connection
Args:
port: The port assigned to the connection. If it's free, a NetworkManagerException will be
raised.
Returns:
Nothing
"""
if not self.__connectionPool.has_key((host, port)) :
raise NetworkManagerException("There's nothing attached to the port " + str(port))
# Retrieve the connection
connection = self.__connectionPool[(host, port)]
# Ask the connection to close
connection.close()
@staticmethod
def printConnectionWarningIfNecessary(ip, port, packet_type, errorMessage):
if (errorMessage != None) :
print "Warning: unable to send {2} to {0}:{1}.".format(ip, port, packet_type)
print "\t" + errorMessage