/*

* Copyright (c) 2006-2008 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:  Sensor server channel implemetation

*

*/

#ifndef SENSERVERCHANNEL_H

#define SENSERVERCHANNEL_H

#include <e32base.h>

#include "sensrvtypes.h"

#include "sensrvchannelinfo.h"

#include "sensrvresourcechannelinfo.h"

#include "sensrvmessage.h"

#include "ssypropertyprovider.h"

#include "ssychanneldataprovider.h"

#include "sensrvgeneralproperties.h"

class CSensrvTransaction;

class CSensrvPluginProxy;

class CSensrvTransactionQueue;

class CSensrvPropertyQueue;

class CSensrvChannelListener;

class CSensrvChannelBuffer;

class CSensrvConditionEvaluator;

/**

* Implements channel related handling.

*

* @since S60 5.0

*/

class CSensrvChannel : public CBase

    {

    public:

        /**

        * Channel state.

        */

        enum TSensrvChannelState

            {

            EChannelStateClosed,             ///< Channel is closed

            EChannelStateOpen,               ///< Channel is open to at least one client

            EChannelStateListening           ///< Channel is listening for data

            };

        /**

        * Two phase constructor

        *

        * @since S60 5.0

        * @param aInfo Channel info.

        * @param aProxy Callback proxy.

        * @return New CSensrvChannel instance

        * @exception KErrNoMemory Out of memory

        */

		static CSensrvChannel* NewL( const TSensrvResourceChannelInfo& aInfo,

									 CSensrvPluginProxy& aProxy );

        /**

        * Destructor.

        */

        virtual ~CSensrvChannel();

        /**

        * Returns the channel id

        *

        * @since S60 5.0

        * @return Channel id.

        */

        inline TSensrvChannelId Id() { return iId; };

        /**

        * Gets channel state.

        * Called from both threads.

        *

        * @since S60 5.0

        * @return Current channel state

        */

        inline TSensrvChannelState State() const { return iState; };

        /**

        * Gets parent proxy reference.

        * Called from both threads.

        *

        * @since S60 5.0

        * @return Current channel state

        */

        inline CSensrvPluginProxy& Proxy() { return iProxy; };

        /**

        * Gets data provider pointer.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return Current data provider pointer. Can be NULL.

        */

        inline MSsyChannelDataProvider* DataProvider() { return iDataProvider; };

        /**

        * Gets property provider pointer.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return Current property provider pointer. Can be NULL.

        */

        inline MSsyPropertyProvider* PropertyProvider() { return iPropertyProvider; };

        /**

        * Gets data buffer pointer.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return Data buffer pointer. Can be NULL.

        */

        inline CSensrvChannelBuffer* Buffer() { return iChannelBuffer; };

        /**

        * Gets maximum allowed buffering count.

        * Called from server thread.

        *

        * @since S60 5.0

        * @return Maximum allowed buffering count

        */

        inline TInt MaxBufferingCount() { return iMaxBufferingCount; };

        /**

        * Gets the persistent ETransTypeMediatorNewDataAvailable transaction.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return ETransTypeMediatorNewDataAvailable transaction

        */

        inline CSensrvTransaction* DataAvailableTransaction() const { return iDataAvailableTransaction; };

       /**

        * Gets the persistent ETransTypeMediatorPropertyChanged transaction.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return ETransTypeMediatorPropertyChanged transaction.

        */

        inline CSensrvTransaction* PropertyChangedTransaction() const { return iPropertyChangedTransaction; };

        /**

        * Gets the persistent ETransTypeMediatorForceBufferFilled transaction.

        * Called from server thread.

        *

        * @since S60 5.0

        * @return ETransTypeMediatorForceBufferFilled transaction

        */

        inline CSensrvTransaction* ForceBufferFilledTransaction() const { return iForceBufferFilledTransaction; };

        /**

        * Gets the persistent ETransTypeMediatorForceChannelClose transaction.

        * Called from SSY thread.

        *

        * @since S60 5.0

        * @return ETransTypeMediatorForceChannelClose transaction

        */

        inline CSensrvTransaction*  ForceChannelCloseTransaction() const { return iForceChannelCloseTransaction; };

        /**

        * Gets the listener count.

        * Called from server thread.

        *

        * @since S60 5.0

        * @return Listener count.

        */

        inline TInt ListenerCount() const { return iListenerList.Count(); };

        /**

        * Gets the data item size

        * Called from server thread.

        *

        * @since S60 5.0

        * @return Data item size

        */

        inline TInt DataItemSize() const { return iChannelInfo.iDataItemSize; };

        /**

        * Handles client message.

        * Message completion responsibility transfers.

        * Called only within server thread.

        *

        * @since S60 5.0

        * @param aMessage The message containing the client request.

        */

        void DispatchMessage( CSensrvMessage& aMessage );

        /**

        * Indicates channel has been opened by SSY

        * Called from SSY thread only.

        *

        * @since S60 5.0

        * @param aErrorCode Indicates any error that occurred during channel opening.

        * @param aDataProvider Pointer to channel data provider instance

        * @param aSensorPropertyProvider Pointer to sensor property provider instance

        */

        void ChannelOpened( TInt aErrorCode,

                            MSsyChannelDataProvider* aDataProvider,

                            MSsyPropertyProvider* aSensorPropertyProvider );

        /**

        * Indicates channel has been closed by SSY

        * Called from SSY thread only.

        *

        * @since S60 5.0

        */

        void ChannelClosed();

        /**

        * Store a changed property provided by SSY.

        * Called from SSY thread only.

        *

        * @since S60 5.0

        * @param aProperty Property that has changed

        * @param aIgnoreSession Do not store change for this session. Can be NULL.

        * @return ETrue if property was stored to any listener.

        */

        TBool StoreChangedProperty( const TSensrvProperty& aProperty,

                                    const CSensrvSession* aIgnoreSession );

        /**

        * Completes transaction after it has been handled by SSY.

        * Only called from server thread.

        *

        * @since S60 5.0

        * @param aTransaction The transaction to complete

        */

        void CompleteTransaction( CSensrvTransaction* aTransaction );

        /**

        * Cleans up session related data.

        *

        * @since S60 5.0

        * @param aSession The session that was deleted

        */

        void SessionTerminated( CSensrvSession* aSession );

        /**

        * Handles notify failure at SSY

        *

        * @since S60 5.0

        */

        void HandleSsyNotifyFailure();

        /**

        * Forces buffer filled at SSY

        *

        * @since S60 5.0

        */

        void ForceBufferFilled();

        /**

        * Recalculates buffering count, if there is more than one

        * client.

        *

        * @since S60 5.0

        * @return The new buffering count. If returned value is zero,

        *         it means there are no listeners in channel.

        */

        TInt RecalculateBufferingCount();

        /**

        * Creates a new condition evaluator or returns an existing one.

        *

        * @since S60 5.0

        * @return The condition evaluator reference.

        */

        CSensrvConditionEvaluator* ConditionEvaluatorL();

        /**

        * Get clients of this channel. The client identified by aCallerSecureId

        * is not added to the affected clients list.

        *

        * @since S60 5.0

        * @param[in,out] aAffectedClients On return contains client

        *                 processes priorities for this channel.

        * @param[in]     aCallerSecureId Identifies the listener which is filtered away.

        */

        void GetAffectedClients( RArray<TInt>& aAffectedClients,

                                 TSecureId aCallerSecureId );

        /**

        * Gets listener for session.

        *

        * @since S60 5.0

        * @param aSession Session for which the listener is needed.

        * @return Listener pointer or NULL if not found.

        */

        CSensrvChannelListener* GetListener(CSensrvSession* aSession);

        /**

        * Takes the property set control.

        * Required priority checks must be done by client before using this method.

        *

        * @since S60 5.0

        * @param[in] aListener The listener that takes control or NULL if control is freed.

        */

        void TakePropertySetControl( CSensrvChannelListener* aListener );

        /**

        * Gets the listener that has taken the property set control.

        *

        * @since S60 5.0

        * @return The listener that has taken the property set control or NULL if control has not been taken.

        */

        inline CSensrvChannelListener* TakenPropertySetControl() const { return iCurrentSetPropertyControl; };

        /**

        * Gets the highest priority listener and its multiples from this channel.

        *

        * @since S60 5.0

        * @param[out] aHighestPriority Stores the highest priority.

        * @return Multiples of highest listener priority

        */

        TInt GetHighestListenerPriority( TInt& aHighestPriority );

        /**

        * Gets channel group

        * Called from server thread.

        *

        * @since S60 5.0

        * @return Channel group.

        */

        TSensrvResourceChannelInfo::TSensrvChannelGroup ChannelGroup();

    private:

        /**

        * C++ constructor

        *

        * @since S60 5.0

        * @param aInfo Channel info.

        * @param aProxy Callback proxy.

        */

        CSensrvChannel(const TSensrvChannelInfo& aInfo,

                       CSensrvPluginProxy& aProxy);

        /**

        * 2nd phase of construction

        *

        * @since S60 5.0

        */

        void ConstructL();

        /**

        * Handles next transaction in queue.

        * If first transaction is still executing

        * or the queue is empty, does nothing.

        *

        * @since S60 5.0

        */

        void HandleNextTransaction();

        /**

        * Deletes a listener.

        *

        * @since S60 5.0

        * @param aSession Session for which the listener is deleted.

        */

        void DeleteListener(CSensrvSession* aSession);

        /**

        * Finds a listener by session.

        *

        * @since S60 5.0

        * @param aSession Session for which the listener is found.

        */

		CSensrvChannelListener* FindListener( CSensrvSession* aSession );

        /**

        * Closes the channel to SSY if there are no listeners.

        *

        * @since S60 5.0

        */

        void CloseIfNeeded();

        /**

        * Handles start data and condition listening transactions

        *

        * @since S60 5.0

        * @param aTransaction Reference to the transaction.

        * @return Error code

        */

        TInt HandleStartListeningTransaction(CSensrvTransaction& aTransaction);

        /**

        * Handles stop data and condition listening transactions

        *

        * @since S60 5.0

        * @param aTransaction Reference to the transaction.

        * @param[out] aSsyTransactionNeeded Returns ETrue if SSY transaction is needed.

        * @return Error code

        */

        TInt HandleStopListeningTransaction(CSensrvTransaction& aTransaction,

                                            TBool& aSsyTransactionNeeded);

        /**

        * Gets the highest priority listener and its multiples from all affected channels.

        *

        * @since S60 5.0

        * @param[out] aHighestPriority Stores the highest priority.

        * @return Multiples of highest listener priority

        */

        TInt GetHighestListenerPriorityOfAffectedChannels( TInt& aHighestPriority );

        /**

        * Updated set property success indication to channel listeners

        *

        * @since S60 5.0

        * @param[in] aChannel Channel to update

        * @param aHighestOfAffectedChannels Highest priority of affected channels

        * @param aMultiplesOnAffectedChannels Multiples of highest priority listeners

        */

        static void UpdateSetPropertySuccessIndToChannelListeners(

            CSensrvChannel& aChannel, TInt aHighestOfAffectedChannels, TInt aMultiplesOnAffectedChannels );

        /**

        * Handles set property success indications on property change

        *

        * @since S60 5.0

        */

        void HandleSetPropertySuccessIndOnPropertyChange();

        /**

        * Handles set property success indications on listener creation or deletion

        *

        * @since S60 5.0

        */

        void HandleSetPropertySuccessIndOnCreateOrDelete();

        /**

        * Handles dependent channels on channel open

        *

        * @since S60 5.0

        */

		void HandleDependencyOnOpen();

        /**

        * Handles dependent channels on channel close

        *

        * @since S60 5.0

        */

		void HandleDependencyOnClose( const TInt& aPriority );

        /**

        * Sets dependent channel availability

        *

        * @since S60 5.0

        */

		TInt SetAvailability( TSensrvChannelId aChannelId, TSensrvProperty& aProperty, TSensrvAvailability aValue, const TSecurityInfo& aSecurityInfo );

        /**

        * Sets dependent channel availability

        *

        * @since S60 5.0

        */

		TInt SetChannelAvailability( TSensrvChannelId aChannelIdToEnable, TSensrvChannelId aChannelIdToDisable, TSensrvProperty& aProperty );

        /**

        * Sets dependent channel availability

        *

        * @since S60 5.0

        */

		TInt SetChannelAvailability( TSensrvChannelId aChannelId, TSensrvProperty& aProperty, TSensrvAvailability aValue );

        /**

        * Get channel from affected channels list with the lowest priority

        *

        * @since S60 5.0

        */

		TInt GetLowestChannelPriority( const RSensrvChannelList* aAffectedChannelsList, TSensrvChannelId& aChannelId );

        /**

        * Get channel from affected channels list with the highest priority

        *

        * @since S60 5.0

        */

		TInt GetHighestChannelPriority( const RSensrvChannelList* aAffectedChannelsList, TSensrvChannelId& aChannelId );

        /**

        * Gets the affected channel list from SSY

        *

        * @since S60 5.0

        * @return Affected channel list or NULL

        */

        RSensrvChannelList* GetAffectedChannels() const;

        /**

        * Gets the affected channel list from SSY

        *

        * @since S60 5.0

        * @return Affected channel list or NULL

        */

        RSensrvChannelList* GetAvailabilityAffectedChannels( TSensrvAvailability aValue ) const;

        /**

        * Reads channel group

        *

        * @since S60 5.0

        * @return Channel group.

        */

        TSensrvResourceChannelInfo::TSensrvChannelGroup ReadChannelGroup();

        /**

        * Handles channel availability property change

        *

        * @since S60 5.0

        */

        void HandleAvailabilityChange( const TSensrvProperty& aProperty );

        /**

        * Handles channel availability property change

        *