/*

* Copyright (c) 2009-2010 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:

* Common transaction handler of framework and plugins.

*

*/

#include "cmmtransactionhandler.h"

#include "OstTraceDefinitions.h"

#ifdef OST_TRACE_COMPILER_IN_USE

#include "cmmtransactionhandlerTraces.h"

#endif

const TUint32 KMaxOpenTransAttempts = 10;

const TUint32 KRetryAfter = 100000;

// ---------------------------------------------------------------------------

// NewL.

// ---------------------------------------------------------------------------

//

CCmmTransactionHandler* CCmmTransactionHandler::NewL( CommsDat::CMDBSession& aDb )

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_NEWL_ENTRY );

    CCmmTransactionHandler* self = new( ELeave ) CCmmTransactionHandler( aDb );

    CleanupStack::PushL( self );

    self->ConstructL();

    CleanupStack::Pop( self );

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_NEWL_EXIT );

    return self;

    }

// ---------------------------------------------------------------------------

// Destructor.

// ---------------------------------------------------------------------------

//

CCmmTransactionHandler::~CCmmTransactionHandler()

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_CCMTRANSACTIONHANDLER_ENTRY );

    delete &iDb;

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_CCMTRANSACTIONHANDLER_EXIT );

    }

// ---------------------------------------------------------------------------

// Constructor.

// ---------------------------------------------------------------------------

//

CCmmTransactionHandler::CCmmTransactionHandler( CommsDat::CMDBSession& aDb ) : iDb( aDb )

    {

    OstTraceFunctionEntry0( DUP1_CCMTRANSACTIONHANDLER_CCMTRANSACTIONHANDLER_ENTRY );

    iRefCount = 0;

    OstTraceFunctionExit0( DUP1_CCMTRANSACTIONHANDLER_CCMTRANSACTIONHANDLER_EXIT );

    }

// ---------------------------------------------------------------------------

// Second phase constructor.

// ---------------------------------------------------------------------------

//

void CCmmTransactionHandler::ConstructL()

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_CONSTRUCTL_ENTRY );

    iDb.SetAttributeMask( CommsDat::ECDHidden | CommsDat::ECDProtectedWrite );

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_CONSTRUCTL_EXIT );

    }

// ---------------------------------------------------------------------------

// Return the CommsDat session.

// ---------------------------------------------------------------------------

//

CommsDat::CMDBSession& CCmmTransactionHandler::Session() const

    {

    // No traces.

    return iDb;

    }

// ---------------------------------------------------------------------------

// Opens a CommsDat transaction if it is not already open. Reference counter

// is inreased by one.

// ---------------------------------------------------------------------------

//

void CCmmTransactionHandler::OpenTransactionLC()

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_OPENTRANSACTIONLC_ENTRY );

    iRefCount++;

    CleanupClosePushL( *this );

    if ( !iDb.IsInTransaction() )

        {

        TInt err( KErrNone );

        TUint32 attempts( KMaxOpenTransAttempts );

        do

            {

            TRAP( err, iDb.OpenTransactionL() );

            if ( err )

                {

                User::After( KRetryAfter );

                }

            } while ( err && attempts-- );

        User::LeaveIfError( err );

        }

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_OPENTRANSACTIONLC_EXIT );

    }

// ---------------------------------------------------------------------------

// Decreases the reference counter by one. If it reaches zero, commits the open

// CommsDat transaction. If an error code is given as argument, the CommsDat

// transaction is rolled back instead.

// ---------------------------------------------------------------------------

//

void CCmmTransactionHandler::CommitTransactionL( TInt aError )

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_COMMITTRANSACTIONL_ENTRY );

    iRefCount--;

    CleanupStack::Pop( this );

    if ( !iRefCount )

        {

        if ( aError )

            {

            iDb.RollbackTransactionL();

            }

        else

            {

            iDb.CommitTransactionL();

            }

        }

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_COMMITTRANSACTIONL_EXIT );

    }

// ---------------------------------------------------------------------------

// Performs RollbackTransactionL().

// Pay attention to CleanupStack if calling this. The transaction handler

// needs to be popped from CleanupStack manually.

// ---------------------------------------------------------------------------

//

void CCmmTransactionHandler::Close()

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_CLOSE_ENTRY );

    if ( iRefCount == 0 )

        {

        // No active transaction, do nothing.

        OstTraceFunctionExit0( DUP1_CCMTRANSACTIONHANDLER_CLOSE_EXIT );

        return;

        }

    if ( !iDb.IsInTransaction() )

        {

        // Sometimes CommsDat closes the transaction on its own decision w/o any

        // notification or reason. E.g. when you try to delete a non-existing

        // record, it leaves with KErrNotFound, but rolls back the transaction.

        iRefCount = 0;

        }

    else

        {

        iRefCount--;

        if ( !iRefCount )

            {

            if ( iDb.IsInTransaction() )

                {

                TRAP_IGNORE( iDb.RollbackTransactionL() );

                }

            }

        }

    OstTraceFunctionExit0( DUP2_CCMTRANSACTIONHANDLER_CLOSE_EXIT );

    }

// ---------------------------------------------------------------------------

// Return the current reference count. Transaction is currently open if the

// count above 0.

// ---------------------------------------------------------------------------

//

TUint32 CCmmTransactionHandler::GetReferenceCount()

    {

    OstTraceFunctionEntry0( CCMTRANSACTIONHANDLER_GETREFERENCECOUNT_ENTRY );

    OstTraceFunctionExit0( CCMTRANSACTIONHANDLER_GETREFERENCECOUNT_EXIT );

    return iRefCount;

    }

// End of file