/*

* 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:

*

*/

#include "cxememorymonitorprivate.h"

#ifdef Q_OS_SYMBIAN

#include <hal.h>

#endif // Q_OS_SYMBIAN

#include "cxutils.h"

#include "cxenamespace.h"

#include "cxefeaturemanager.h"

namespace

{

    const int FREEING_RETRIES = 2;

    const int MONITORING_INTERVAL = 10*1000; // in milliseconds

}

/*!

* Constructor

*/

CxeMemoryMonitorPrivate::CxeMemoryMonitorPrivate(CxeFeatureManager &features)

    : mFeatures(features)

{

    CX_DEBUG_ENTER_FUNCTION();

    mFeatures.configuredValues(CxeVariationKeys::FREE_MEMORY_LEVELS, mLevels);

    CX_DEBUG(("CxeMemoryMonitorPrivate - trigger level: %d bytes", mLevels.value(Cxe::FreeMemoryTrigger)));

    CX_DEBUG(("CxeMemoryMonitorPrivate - target level:  %d bytes", mLevels.value(Cxe::FreeMemoryTarget)));

#ifdef Q_OS_SYMBIAN

    // Request free memory as defined in Feature Manager.

    // If we cannot have enough free memory, throw error.

    bool ok = requestFreeMemory(mLevels.value(Cxe::FreeMemoryTarget));

    qt_symbian_throwIfError(ok ? KErrNone : KErrNoMemory);

#endif // Q_OS_SYMBIAN

    CX_DEBUG_EXIT_FUNCTION();

}

/*!

* Destructor

*/

CxeMemoryMonitorPrivate::~CxeMemoryMonitorPrivate()

{

    CX_DEBUG_ENTER_FUNCTION();

    stopMonitoring();

    CX_DEBUG_EXIT_FUNCTION();

}

/*!

* Get the amount of free memory (RAM).

* @return Free RAM in bytes.

*/

int CxeMemoryMonitorPrivate::free() const

{

#ifdef Q_OS_SYMBIAN

    int ram(0);

    HAL::Get(HALData::EMemoryRAMFree, ram);

    return ram;

#else

    //!@todo: real implementation for desktop etc?

    return 1024*1024*1024;

#endif // Q_OS_SYMBIAN

}

/*!

* Request to free memory (RAM) to achieve asked level.

* @param required Required free memory after this call.

* @return Was it possible to achieve the required level of free memory.

*/

bool CxeMemoryMonitorPrivate::requestFreeMemory(int required)

{

    CX_DEBUG_ENTER_FUNCTION();

    if (free() < required) {

#ifdef Q_OS_SYMBIAN

    qt_symbian_throwIfError(mOomMonitor.Connect());

    int i(0);

    int status(KErrGeneral);

    do {

        status = mOomMonitor.RequestFreeMemory(required);

    } while (status != KErrNone && ++i < FREEING_RETRIES);

    mOomMonitor.Close();

#endif // Q_OS_SYMBIAN

    }

    // If we have the free RAM we were asked for, all good.

    bool ok = free() >= required;

    CX_DEBUG_EXIT_FUNCTION();

    return ok;

}

/*!

* Start monitoring free memory.

*/

void CxeMemoryMonitorPrivate::startMonitoring()

{

    if (!mTimer.isActive()) {

        connect(&mTimer, SIGNAL(timeout()), this, SLOT(checkMemory()), Qt::UniqueConnection);

        mTimer.start(MONITORING_INTERVAL);

    }

}

/*!

* Stop monitoring free memory.

*/

void CxeMemoryMonitorPrivate::stopMonitoring()

{

    mTimer.stop();

}

/*!

* Check free memory. Try to release memory if below trigger level.

*/

void CxeMemoryMonitorPrivate::checkMemory()

{

    CX_DEBUG_ENTER_FUNCTION();

    if(free() < mLevels.value(Cxe::FreeMemoryTrigger)) {

        // Memory too low, request more free memory.

        CX_DEBUG(("[WARNING] CxeMemoryMonitorPrivate - memory low, requesting more.."));

        requestFreeMemory(mLevels.value(Cxe::FreeMemoryTarget));

    }

    CX_DEBUG_EXIT_FUNCTION();

}

// end of file