// 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>

#include <usb/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);

    }

//---