/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

 *   License, Version 2.0 (the "License"); you may not use this file

 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#include <graphic/Manager.hxx>

#include <impgraph.hxx>

#include <sal/log.hxx>

#include <officecfg/Office/Common.hxx>

#include <unotools/configmgr.hxx>

using namespace css;

namespace

{

void setupConfigurationValuesIfPossible(sal_Int64& rMemoryLimit,

                                        std::chrono::seconds& rAllowedIdleTime, bool& bSwapEnabled)

{

    if (comphelper::IsFuzzing())

        return;

    try

    {

        using officecfg::Office::Common::Cache;

        rMemoryLimit = Cache::GraphicManager::GraphicMemoryLimit::get();

        rAllowedIdleTime

            = std::chrono::seconds(Cache::GraphicManager::GraphicAllowedIdleTime::get());

        bSwapEnabled = Cache::GraphicManager::GraphicSwappingEnabled::get();

    }

    catch (...)

    {

    }

}

}

namespace vcl::graphic

{

MemoryManager::MemoryManager()

    : maSwapOutTimer("MemoryManager::MemoryManager maSwapOutTimer")

{

    setupConfigurationValuesIfPossible(mnMemoryLimit, mnAllowedIdleTime, mbSwapEnabled);

    if (mbSwapEnabled)

    {

        maSwapOutTimer.SetPriority(TaskPriority::DEFAULT_IDLE);

        maSwapOutTimer.SetInvokeHandler(LINK(this, MemoryManager, ReduceMemoryTimerHandler));

        maSwapOutTimer.SetTimeout(mnTimeout);

        maSwapOutTimer.Stop();

    }

}

MemoryManager& MemoryManager::get()

{

    static MemoryManager gStaticManager;

    return gStaticManager;

}

IMPL_LINK_NOARG(MemoryManager, ReduceMemoryTimerHandler, Timer*, void)

{

    std::unique_lock aGuard(maMutex);

    maSwapOutTimer.Stop();

    reduceMemory(aGuard);

    // will be started again on size change

}

void MemoryManager::registerObject(MemoryManaged* pMemoryManaged)

{

    std::unique_lock aGuard(maMutex);

    // Insert and update the used size (bytes)

    assert(aGuard.owns_lock() && aGuard.mutex() == &maMutex);

    // coverity[missing_lock: FALSE] - as above assert

    // Related: tdf#167007 Only add object bytes if the object is

    // actually inserted into the cache

    if (maObjectList.insert(pMemoryManaged).second)

        mnTotalSize += pMemoryManaged->getCurrentSizeInBytes();

    checkStartReduceTimer();

}

void MemoryManager::unregisterObject(MemoryManaged* pMemoryManaged)

{

    std::unique_lock aGuard(maMutex);

    // Related: tdf#167007 Only remove object size if the object is

    // actually removed from the cache

    if (maObjectList.erase(pMemoryManaged))

        mnTotalSize -= pMemoryManaged->getCurrentSizeInBytes();

    checkStartReduceTimer();

}

void MemoryManager::changeExisting(MemoryManaged* pMemoryManaged, sal_Int64 nNewSize)

{

    std::scoped_lock aGuard(maMutex);

    // Related: tdf#167007 Only change total cache bytes if the object

    // actually exists in the cache

    if (maObjectList.find(pMemoryManaged) != maObjectList.end())

    {

        sal_Int64 nOldSize = pMemoryManaged->getCurrentSizeInBytes();

        mnTotalSize -= nOldSize;

        mnTotalSize += nNewSize;

    }

    pMemoryManaged->setCurrentSizeInBytes(nNewSize);

    checkStartReduceTimer();

}

void MemoryManager::swappedIn(MemoryManaged* pMemoryManaged, sal_Int64 nNewSize)

{

    changeExisting(pMemoryManaged, nNewSize);

}

void MemoryManager::swappedOut(MemoryManaged* pMemoryManaged, sal_Int64 nNewSize)

{

    changeExisting(pMemoryManaged, nNewSize);

}

OUString MemoryManager::getCacheName() const { return "MemoryManager"; }

bool MemoryManager::dropCaches()

{

    std::unique_lock aGuard(maMutex);

    reduceMemory(aGuard, true);

    return true;

}

void MemoryManager::dumpState(rtl::OStringBuffer& rState)

{

    std::unique_lock aGuard(maMutex);

    rState.append("\nMemory Manager items:\t");

    rState.append(static_cast<sal_Int32>(maObjectList.size()));

    rState.append("\tsize:\t");

    rState.append(static_cast<sal_Int64>(mnTotalSize / 1024));

    rState.append("\tkb");

    for (MemoryManaged* pMemoryManaged : maObjectList)

    {

        pMemoryManaged->dumpState(rState);

    }

}

void MemoryManager::checkStartReduceTimer()

{

    // maMutex is locked in callers

    if (!mbSwapEnabled || mnTotalSize < mnMemoryLimit)

        return;

    // start the timer

    if (!maSwapOutTimer.IsActive())

        maSwapOutTimer.Start();

}

void MemoryManager::reduceMemory(std::unique_lock<std::mutex>& rGuard, bool bDropAll)

{

    // maMutex is locked in callers

    if (!mbSwapEnabled)

        return;

    if (mnTotalSize < mnMemoryLimit && !bDropAll)

        return;

    // avoid recursive reduceGraphicMemory on reexport of tdf118346-1.odg to odg

    if (mbReducingGraphicMemory)

        return;

    mbReducingGraphicMemory = true;

    loopAndReduceMemory(rGuard, bDropAll);

    mbReducingGraphicMemory = false;

}

void MemoryManager::loopAndReduceMemory(std::unique_lock<std::mutex>& rGuard, bool bDropAll)

{

    // make a copy of m_pImpGraphicList because if we swap out a svg, the svg

    // filter may create more temp Graphics which are auto-added to

    // m_pImpGraphicList invalidating a loop over m_pImpGraphicList, e.g.

    // reexport of tdf118346-1.odg

    o3tl::sorted_vector<MemoryManaged*> aObjectListCopy = maObjectList;

    for (MemoryManaged* pMemoryManaged : aObjectListCopy)

    {

        if (!pMemoryManaged->canReduceMemory())

            continue;

        sal_Int64 nCurrentSizeInBytes = pMemoryManaged->getCurrentSizeInBytes();

        if (nCurrentSizeInBytes > mnSmallFrySize || bDropAll) // ignore small-fry

        {

            auto aCurrent = std::chrono::high_resolution_clock::now();

            auto aDeltaTime = aCurrent - pMemoryManaged->getLastUsed();

            auto aSeconds = std::chrono::duration_cast<std::chrono::seconds>(aDeltaTime);

            if (aSeconds > mnAllowedIdleTime)

            {

                // unlock because svgio can call back into us

                rGuard.unlock();

                pMemoryManaged->reduceMemory();

                rGuard.lock();

            }

        }

    }

}

} // end vcl::graphic

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */