// Copyright (c) 2003-2009 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:

//

#include <e32base.h>

#include "MSVPANIC.H"

#include "CMsvChangeBuffer.h"

//**********************************

//CMsvChangeRecord

//**********************************

CMsvChangeRecord* CMsvChangeRecord::NewL(const TDesC8& aChange, TUint32 aNotifySequence)

	{

	CMsvChangeRecord* self = new(ELeave)CMsvChangeRecord(aNotifySequence);

	CleanupStack::PushL(self);

	self->ConstructL(aChange);

	CleanupStack::Pop();

	return self;

	}

void CMsvChangeRecord::ConstructL(const TDesC8& aChange)

	{

	iChange = HBufC8::NewL(aChange.Length());

	iChange->Des() = aChange;

	}

CMsvChangeRecord::~CMsvChangeRecord()

	{

	delete iChange;

	}

CMsvChangeRecord::CMsvChangeRecord(TUint32 aNotifySequence)

: iNotifySequence(aNotifySequence)

	{

	}

//**********************************

//CMsvChangeBuffer

//**********************************

CMsvChangeBuffer* CMsvChangeBuffer::NewL()

	{

	CMsvChangeBuffer* self = new(ELeave) CMsvChangeBuffer();

	CleanupStack::PushL(self);

	self->ConstructL();

	CleanupStack::Pop();

	return self;

	}

CMsvChangeBuffer::CMsvChangeBuffer()

	{

	__DECLARE_NAME(_S("CMsvChangeBuffer"));

	}

CMsvChangeBuffer::~CMsvChangeBuffer()

	{

	if (iArray)

		{

		iArray->ResetAndDestroy();

		delete iArray;

		}

	}

void CMsvChangeBuffer::ConstructL()

	{

	iArray = new (ELeave) CArrayPtrFlat<CMsvChangeRecord>(KMsvChangeBufferGranularity);

	CMsvChangeRecord* ptr = NULL;

	iArray->ResizeL(KMsvChangeBufferSize, ptr);

	}

void CMsvChangeBuffer::InL(const TDesC8& aChange)

//

// Inserts an entry into the FIFO buffer.

// 

	{

	iNotifySequence++;

	CMsvChangeRecord* record = CMsvChangeRecord::NewL(aChange, iNotifySequence);

	iArray->At(iInPos++) = record;

	// Check if we've run past the end of the array.  If so, wrap around.

	if (iInPos==iArray->Count())

		iInPos=0;

	// Check if we've run out of space in the array

	if (iInPos==iOutPos)

		{

		// Attempt to grow the array

		TRAPD(ret, GrowArrayL());

		if (ret != KErrNone)

			// Error - possibly out of memory.

			// Delete the last entry and rollback the iInPos variable to ensure

			//  class is in a valid state.

			{

			delete record;

			// If iInPos is not 0, subtract 1 from it,

			//  else set it back to Count-1

			iInPos = (iInPos ? iInPos-1 : iArray->Count()-1);

			User::Leave(ret);

			}

		}

	}

const TDesC8& CMsvChangeBuffer::Next(TUint32& aNotifySequence)

//

// Returns the next entry from the FIFO buffer

//

	{

	__ASSERT_ALWAYS(iOutPos!=iInPos,PanicServer(EMsvChangeBufferEmpty));

	CMsvChangeRecord* record = iArray->At(iOutPos);

	aNotifySequence = record->NotifySequence();

	return record->Change();

	}

void CMsvChangeBuffer::Out()

//

// Removes the next entry from the queue

//

	{

	__ASSERT_ALWAYS(iOutPos!=iInPos,PanicServer(EMsvChangeBufferEmpty));

	delete iArray->At(iOutPos);

	iArray->At(iOutPos++) = NULL;

	if (iOutPos==iArray->Count())

		{

		iOutPos=0;

		ShrinkArray();

		}

	}

void CMsvChangeBuffer::ShrinkArray()

//

// Shrinks the array if possible

//

	{

	while ((iArray->Count()-iInPos)>KMsvChangeBufferGranularity)

		iArray->Delete(iInPos,KMsvChangeBufferGranularity);

	}

void CMsvChangeBuffer::GrowArrayL()

//

// Grows the array

// Can leave with OOM

//

	{

	CMsvChangeRecord* ptr=NULL;

	iArray->InsertL(iOutPos, ptr, KMsvChangeBufferGranularity);

	iOutPos+=KMsvChangeBufferGranularity;

	}