topical media & game development
lib-of-vs-libs-Poco-include-Poco-Net-SocketConnector.h / h
//
// SocketConnector.h
//
//
//
// Library: Net
// Package: Reactor
// Module: SocketConnector
//
// Definition of the SocketConnector class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// 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, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef Net_SocketConnector_INCLUDED
define Net_SocketConnector_INCLUDED
include "Poco/Net/Net.h"
include "Poco/Net/SocketNotification.h"
include "Poco/Net/SocketAddress.h"
include "Poco/Net/StreamSocket.h"
include "Poco/Observer.h"
namespace Poco {
namespace Net {
template <class ServiceHandler>
class SocketConnector
This class implements the Connector part of the
Acceptor-Connector design pattern.
The Acceptor-Connector pattern has been described in the book
"Pattern Languages of Program Design 3", edited by Robert Martin,
Frank Buschmann and Dirk Riehle (Addison Wesley, 1997).
The Acceptor-Connector design pattern decouples connection
establishment and service initialization in a distributed system
from the processing performed once a service is initialized.
This decoupling is achieved with three components: Acceptors,
Connectors and Service Handlers.
The Connector actively establishes a connection with a remote
server socket (usually managed by an Acceptor) and initializes
a Service Handler to manage the connection.
The SocketConnector sets up a StreamSocket, initiates a non-blocking
connect operation and registers itself for ReadableNotification, WritableNotification
and ErrorNotification. ReadableNotification or WritableNotification denote the successful
establishment of the connection.
When the StreamSocket becomes readable or writeable, the SocketConnector
creates a ServiceHandler to service the connection and unregisters
itself.
In case of an error (ErrorNotification), the SocketConnector unregisters itself
and calls the onError() method, which can be overridden by subclasses
to perform custom error handling.
The ServiceHandler class must provide a constructor that
takes a StreamSocket and a SocketReactor as arguments,
e.g.:
MyServiceHandler(const StreamSocket& socket, ServiceReactor& reactor)
When the ServiceHandler is done, it must destroy itself.
Subclasses can override the createServiceHandler() factory method
if special steps are necessary to create a ServiceHandler object.
{
public:
SocketConnector(SocketAddress& address):
_pReactor(0)
Creates a SocketConnector, using the given Socket.
{
_socket.connectNB(address);
}
SocketConnector(SocketAddress& address, SocketReactor& reactor):
_pReactor(0)
Creates an acceptor, using the given ServerSocket.
The SocketConnector registers itself with the given SocketReactor.
{
_socket.connectNB(address);
registerConnector(reactor);
}
virtual ~SocketConnector()
Destroys the SocketConnector.
{
unregisterConnector();
}
virtual void registerConnector(SocketReactor& reactor)
Registers the SocketConnector with a SocketReactor.
A subclass can override this and, for example, also register
an event handler for a timeout event.
The overriding method must call the baseclass implementation first.
{
_pReactor = &reactor;
_pReactor->addEventHandler(_socket, Poco::Observer<SocketConnector, ReadableNotification>(*this, &SocketConnector::onReadable));
_pReactor->addEventHandler(_socket, Poco::Observer<SocketConnector, WritableNotification>(*this, &SocketConnector::onWritable));
_pReactor->addEventHandler(_socket, Poco::Observer<SocketConnector, ErrorNotification>(*this, &SocketConnector::onError));
}
virtual void unregisterConnector()
Unregisters the SocketConnector.
A subclass can override this and, for example, also unregister
its event handler for a timeout event.
The overriding method must call the baseclass implementation first.
{
if (_pReactor)
{
_pReactor->removeEventHandler(_socket, Poco::Observer<SocketConnector, ReadableNotification>(*this, &SocketConnector::onReadable));
_pReactor->removeEventHandler(_socket, Poco::Observer<SocketConnector, WritableNotification>(*this, &SocketConnector::onWritable));
_pReactor->removeEventHandler(_socket, Poco::Observer<SocketConnector, ErrorNotification>(*this, &SocketConnector::onError));
}
}
void onReadable(ReadableNotification* pNotification)
{
pNotification->release();
int err = _socket.impl()->socketError();
if (err)
{
onError(err);
unregisterConnector();
}
else
{
onConnect();
}
}
void onWritable(WritableNotification* pNotification)
{
pNotification->release();
onConnect();
}
void onConnect()
{
_socket.setBlocking(true);
createServiceHandler();
unregisterConnector();
}
void onError(ErrorNotification* pNotification)
{
pNotification->release();
onError(_socket.impl()->socketError());
unregisterConnector();
}
protected:
virtual ServiceHandler* createServiceHandler()
Create and initialize a new ServiceHandler instance.
Subclasses can override this method.
{
return new ServiceHandler(_socket, *_pReactor);
}
virtual void onError(int errorCode)
Called when the socket cannot be connected.
Subclasses can override this method.
{
}
SocketReactor* reactor()
Returns a pointer to the SocketReactor where
this SocketConnector is registered.
The pointer may be null.
{
return _pReactor;
}
Socket& socket()
Returns a reference to the SocketConnector's socket.
{
return _socket;
}
private:
SocketConnector();
SocketConnector(const SocketConnector&);
SocketConnector& operator = (const SocketConnector&);
StreamSocket _socket;
SocketReactor* _pReactor;
};
} } // namespace Poco::Net
endif // Net_SocketConnector_INCLUDED
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
