// Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "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:

// e32\drivers\usbcc\queue.cpp

// Platform independent layer (PIL) of the USB Device controller driver:

// Simple singly linked list + its iterator.

// 

//

/**

 @file queue.cpp

 @internalTechnology

*/

#include <drivers/usbc.h>

void TSglQueLink::Enque(TSglQueLink* aLink)

//

// Enque this after aLink.

//

	{

	iNext = aLink->iNext;

	aLink->iNext = this;

	}

TSglQueBase::TSglQueBase(TInt aOffset)

//

// Constructor

//

	: iHead(NULL), iLast((TSglQueLink*) &iHead), iOffset(aOffset), iElements(0)

	{

	// ESQueOffsetNotAligned

	__ASSERT_ALWAYS((iOffset % 4 == 0), Kern::Fault(KUsbPILPanicCat, __LINE__));

	}

void TSglQueBase::DoAddLast(TAny* aPtr)

//

// Add the object at the end of the queue.

//

	{

	TSglQueLink* pL = PtrAdd((TSglQueLink*) aPtr, iOffset);

	pL->Enque(iLast);

	iLast = pL;

	iElements++;

	__ASSERT_DEBUG((iElements > 0), Kern::Fault(KUsbPILPanicCat, __LINE__));

	}

void TSglQueBase::DoRemove(TAny* aPtr)

//

// Remove the object from the queue.

//

	{

	TSglQueLink* pP = (TSglQueLink*) (&iHead);

	TSglQueLink* pL = PtrAdd((TSglQueLink*) aPtr, iOffset);

	TSglQueLink* pN = pP->iNext;

	while (pN)

		{

		if (pN == pL)

			{

			pP->iNext = pN->iNext;

			if (iLast == pL)

				{

				iLast = pP;

				if (iLast == NULL)

					iLast = (TSglQueLink*) (&iHead);

				}

			iElements--;

			__ASSERT_DEBUG((iElements >= 0), Kern::Fault(KUsbPILPanicCat, __LINE__));

			return;

			}

		pP = pN;

		pN = pP->iNext;

		}

	// This doesn't have to indicate an error (but might):

	__KTRACE_OPT(KPANIC, Kern::Printf("TSglQueBase::DoRemove: ESQueLinkNotQueued"));

	}

TSglQueIterBase::TSglQueIterBase(TSglQueBase& aQue)

//

// Constructor.

//

	: iOffset(aQue.iOffset), iHead(aQue.iHead), iNext(aQue.iHead)

	{

	}

void TSglQueIterBase::SetToFirst()

//

// Start from the beginning of the que.

//

	{

	iNext = iHead->iNext;

	}

TAny* TSglQueIterBase::DoPostInc()

//

// Return the current pointer and increment.

//

	{

	TAny* pN = iNext;

	if (pN == NULL)

		return NULL;

	iNext = iNext->iNext;

	return PtrSub(pN, iOffset);

	}

//---