// 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);

 	}

 //---