/*

* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  This is an abstract base class for Comms endpoints.

*

*/

#ifndef COMMSENDPOINT_H

#define COMMSENDPOINT_H

#include <pthread.h>

#include <map>

#include <jni.h>

#include "javaosheaders.h"

#include "scopedlocks.h"

#include "transport.h"

namespace java

{

namespace comms

{

class CommsMessage;

class CommsListener;

class ListenerWrapper;

/**

* This is an abstract base class for Comms endpoints. It provides implementation for

* registering listeners and for synchronous message sending.

*

* Comms endpoint provides interprocess communication functionality. Comms communication

* is point-to-point meaning that client endpoint can be connected to a single server at a time.

* Communication is message based, where users wrap their payload to CommsMessage.

* Comms endpoints support synchronous and asynchronous message sending.

*

* Messages can be sent asynchronously or synchronously. Synchronous message sending blocks until

* a reply is received or when specified timeout occurs.

*

* CommsListener provides a way to receive messages asynchronously. Listeners are registered

* to endpoint. When message belonging to listener is received, will Comms endpoint make a

* callback for listener. Application can register as many listeners as need.

*

* Application can register also a default listener, which gets called if there is no registered

* listener for received message.

*

* CommsEndpoint is thread safe.

*

* Usage:

* It is recomended that at least default listener is registered before CommsServerEndpoint

* is started. This ensures that no messages are lost.

* @code

* CommsServerEndpoint comms;

* comms.registerDefaultListener(listener);

* comms.start(MY_SERVER_NAME);

* ...

* comms.stop();

* @endcode

*/

/**

* This constant can be used when timeout functionality of synchronous sendReceive is not needed.

* SendReceive method will return when reply is received or when connection is closed.

* @see CommsEndpoint::sendReceive()

*/

const int WAIT_FOR_EVER = -1;

class CommsEndpoint : public IpcListener

{

public:

    /**

    * A constructor.

    */

    OS_IMPORT CommsEndpoint();

    /**

    * A destructor.

    */

    OS_IMPORT virtual ~CommsEndpoint();

    /**

    * Registers message handler for given module id.

    * CommsListener provides a way to receive messages asynchronously.

    * Module id identifies to which component message belongs. Every message will contain module id

    * information that is used to route message to correct listener.

    *

    * There can be one registered listener for each module id and same listener can be registered

    * for multiple module ids.

    *

    * Listener registration remains valid during connect/disconnect and start/stop.

    * @code

    * CommsClientEndpoint comms;

    * comms.registerListener(MODULE_ID_A, listenerA);

    * comms.registerListener(MODULE_ID_B, listenerB);

    * comms.connect(MY_SERVER_NAME);

    * @endcode

    * @param[in] aModuleId Module id, messages with that module id are forwarded to given listener

    * @param[in] aListener Listener that will be called when message with matching module id is received

    * @see unregisterListener()

    * @see send()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int registerListener(int aModuleId, CommsListener* aListener);

    /**

    * Unregisters message handler for given module id.

    * @code

    * CommsClientEndpoint comms;

    * comms.registerListener(MODULE_ID_A, listenerA);

    * comms.unregisterListener(MODULE_ID_A, listenerA);

    * @endcode

    * @param[in] aModuleId Module id, identifies listener that will be removed

    * @param[in] aListener Listener that will be removed

    * @see unregisterListener()

    * @see send()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int unregisterListener(int aModuleId, CommsListener* aListener);

    /**

    * Registers default listener.

    * There can be only one default listener. Default listener is called if there is no registered listener for received message.

    * If there is no default listener then received messages without listener will be discarded.

    * @param[in] aDefaultListener Default message handler that will be called if no other suitable handlers are found

    * @see unregisterDefaultListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT   virtual int registerDefaultListener(CommsListener* aDefaultListener);

    /**

    * Unregisters default listener.

    * @param[in] aDefaultListener Listener that will be removed

    * @see registerDefaultListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int unregisterDefaultListener(CommsListener* aDefaultListener);

    /**

    * Sends a message.

    * Message recipient must set by CommsMessage::setReceiver() method. It is important that

    * message header is properly filled because header information is used in message routing.

    * @code

    * CommsMessage msg;

    *

    * // set the headers

    * msg.setMessageId(MY_MESSAGE_ID);

    * msg.setModuleId(MY_MODULE_ID);

    * msg.setReceiver(CLIENT_ADDRESS);

    *

    * // set the payload

    * msg << "my payload";

    *

    * // send message

    * int rc = comms.send(msg);

    * @endcode

    * @param[in] aMessage A message to be sent

    * @see sendReceive()

    * @see registerListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int send(CommsMessage& aMessage) = 0;

    /**

    * Sends and receives message syncronously.

    * Method blocks until response message is received or timeout expires.

    * Message recipient must set by CommsMessage::setReceiver() method. It is important that

    * message header is properly filled because header information is used in message routing.

    * @code

    * CommsMessage msg;

    *

    * // set the headers

    * msg.setMessageId(MY_MESSAGE_ID);

    * msg.setModuleId(MY_MODULE_ID);

    *

    * CommsMessage receivedMessage;

    * int timeout = 10; //10s

    *

    * // send and receive message

    * int rc = comms.sendReceive(msg, receivedMessage, timeout);

    * if(rc!=0)

    * {

    * LOG("sendReceive failed");

    * return;

    * }

    * int i;

    * receivedMessage >> i;

    * @endcode

    * @param[in] aMessage A message to be sent

    * @param[out] aReceivedMessage Received message (message content will be empy if method call fails)

    * @param[in] aTimeoutInSecs Timeout in seconds for how long reply is waited

    * @see send()

    * @return 0 in success

    * @return errno in failure and timeout cases

    */

    OS_IMPORT virtual int sendReceive(CommsMessage& aMessage, CommsMessage& aReceivedMessage, int aTimeoutInSecs);

protected:

    /**

    * Routes received message to waiting sendReceive thread or message listener

    * @param[in] aMessage Received message

    * @see -

    * @return -

    */

    OS_IMPORT virtual void handleIpcMessage(CommsMessage& aMessage);

    /**

    * Dispatches received message to listener or default listener

    * @param[in] aMessage Received message

    * @see -

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int handleMessage(CommsMessage& aMessage);

    /**

    * Generates unique message reference

    * @return message reference

    */

    OS_IMPORT virtual int generateMessageReference();

    // IpcListener methods

    /**

    * Callback that is called when underlaying transport stack receives a message

    * Called in the context of message loop thread.

    * @param[out] aMsg Received message

    * @return -

    */

    OS_IMPORT virtual void processMessage(const ipcMessage_t* aMsg);

    /**

    * Callback that is called when underlaying transport stack's message loop thread starts.

    * Called in the context of message loop thread.

    * @param -

    * @return -

    */

    OS_IMPORT virtual void onStart();

    /**

    * Callback that is called when underlaying transport stack's message loop thread exits.

    * Called in the context of message loop thread.

    * @param -

    * @return -

    */

    OS_IMPORT virtual void onExit();

private:

    ListenerWrapper* mDefaultListener;

    typedef std::map<const int, ListenerWrapper*> listeners_t;

    listeners_t mListeners;

    java::util::ScopedMutex mListenersMutex;

    int mMessageRefCounter;

    java::util::ScopedMutex mMessageRefMutex;

    // sendReceive related stuff

    int isSendReceiveMessage(CommsMessage& message);

    typedef struct sendReceiveMessage_s

    {

        CommsMessage*   p_message;

        int*            p_done;

        int*            p_result;

    } sendReceiveMessage_t;

    typedef std::map<int, sendReceiveMessage_t> sendReceiveListeners_t;

    sendReceiveListeners_t mSendReceiveListeners; // access protected by mSendReceiveMutex

    pthread_mutex_t mSendReceiveMutex;

    pthread_cond_t  mSendReceiveCondition;

public:

    /**

    * Registers Java message handler for given module id.

    * @param[in] aModuleId Module id, messages with that module id are forwarded to given listener

    * @param[in] aListener Listener that will be called when message with matching module id is received

    * @param[in] aEnv JNI context

    * @see unregisterJavaListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int registerJavaListener(int aModuleId, jobject aListener, JNIEnv* aEnv);

    /**

    * Unregisters Java message handler for given module id.

    * @param[in] aModuleId Module id

    * @param[in] aListener Listener to be removed

    * @param[in] aEnv JNI context

    * @see registerJavaListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int unregisterJavaListener(int aModuleId, jobject aListener, JNIEnv* aEnv);

    /**

    * Registers default listener.

    * There can be only one default listener. Default listener is called if there is no registered listener for received message.

    * If there is no default listener then received messages without listener will be discarded.

    * @param[in] aDefaultListener Default message handler

    * @see unregisterDefaultJavaListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int registerDefaultJavaListener(jobject aListener, JNIEnv* aEnv);

    /**

    * Unregisters default listener.

    * @param[in] aDefaultListener Listener that will be removed

    * @see registerDefaultJavaListener()

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int unregisterDefaultJavaListener(jobject aListener, JNIEnv* aEnv);

    /**

    * Attach internal message loop thread to JVM.

    * @param[in] aEnv JNI context

    * @see detachFromVm

    * @return 0 in success, errno in failure

    */

    OS_IMPORT virtual int attachToVm(JNIEnv* aEnv);

    /**

    * Detach internal message loop thread from JVM.

    * @see attachToVm

    * @return 0 in success, errno in failure

    */

protected:

    JavaVM* mVm;

    JNIEnv* mJNIEnv;

};

} // namespace comms

} // namespace java

#endif // COMMSENDPOINT_H