/* -*- 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 "ZConnectionPool.hxx"
#include <com/sun/star/lang/XComponent.hpp>
#include "ZPooledConnection.hxx"
#include "ZPoolCollection.hxx"
#include <connectivity/ConnectionWrapper.hxx>
#include <com/sun/star/beans/XPropertySet.hpp>
#include <algorithm>


using namespace ::com::sun::star::uno;
using namespace ::com::sun::star::lang;
using namespace ::com::sun::star::sdbc;
using namespace ::com::sun::star::beans;
using namespace ::com::sun::star::container;
using namespace connectivity;


void SAL_CALL OPoolTimer::onShot()
{
    m_pPool->invalidatePooledConnections();
}

constexpr OUString TIMEOUT_NODENAME = u"Timeout"_ustr;

OConnectionPool::OConnectionPool(const Reference< XDriver >& _xDriver,
                                 const Reference< XInterface >& _xDriverNode,
                                 const Reference< css::reflection::XProxyFactory >& _rxProxyFactory)
    :m_xDriver(_xDriver)
    ,m_xDriverNode(_xDriverNode)
    ,m_xProxyFactory(_rxProxyFactory)
    ,m_nTimeOut(10)
    ,m_nALiveCount(10)
{
    OSL_ENSURE(m_xDriverNode.is(),"NO valid Driver node set!");
    Reference< XComponent >  xComponent(m_xDriverNode, UNO_QUERY);
    if (xComponent.is())
        xComponent->addEventListener(this);

    Reference<XPropertySet> xProp(m_xDriverNode,UNO_QUERY);
    if(xProp.is())
        xProp->addPropertyChangeListener(TIMEOUT_NODENAME,this);

    OPoolCollection::getNodeValue(TIMEOUT_NODENAME, m_xDriverNode) >>= m_nALiveCount;
    calculateTimeOuts();

    m_xInvalidator = new OPoolTimer(this,::salhelper::TTimeValue(m_nTimeOut,0));
    m_xInvalidator->start();
}

OConnectionPool::~OConnectionPool()
{
    clear(false);
}

namespace {

struct TRemoveEventListenerFunctor
{
    OConnectionPool* m_pConnectionPool;
    bool m_bDispose;

    TRemoveEventListenerFunctor(OConnectionPool* _pConnectionPool, bool _bDispose)
        : m_pConnectionPool(_pConnectionPool)
        ,m_bDispose(_bDispose)
    {
        OSL_ENSURE(m_pConnectionPool,"No connection pool!");
    }

    void dispose(const Reference<XInterface>& _xComponent)
    {
        Reference< XComponent >  xComponent(_xComponent, UNO_QUERY);

        if ( xComponent.is() )
        {
            xComponent->removeEventListener(m_pConnectionPool);
            if ( m_bDispose )
                xComponent->dispose();
        }
    }

    void operator()(const TPooledConnections::value_type& _aValue)
    {
        dispose(_aValue);
    }

    void operator()(const TActiveConnectionMap::value_type& _aValue)
    {
        dispose(_aValue.first);
    }
};

struct TConnectionPoolFunctor
{
    OConnectionPool* m_pConnectionPool;

    explicit TConnectionPoolFunctor(OConnectionPool* _pConnectionPool)
        : m_pConnectionPool(_pConnectionPool)
    {
        OSL_ENSURE(m_pConnectionPool,"No connection pool!");
    }
    void operator()(const TConnectionMap::value_type& _aValue)
    {
        std::for_each(_aValue.second.aConnections.begin(),_aValue.second.aConnections.end(),TRemoveEventListenerFunctor(m_pConnectionPool,true));
    }
};

}

void OConnectionPool::clear(bool _bDispose)
{
    std::unique_lock aGuard(m_aMutex);

    if(m_xInvalidator->isTicking())
        m_xInvalidator->stop();

    std::for_each(m_aPool.begin(),m_aPool.end(),TConnectionPoolFunctor(this));
    m_aPool.clear();

    std::for_each(m_aActiveConnections.begin(),m_aActiveConnections.end(),TRemoveEventListenerFunctor(this,_bDispose));
    m_aActiveConnections.clear();

    Reference< XComponent >  xComponent(m_xDriverNode, UNO_QUERY);
    if (xComponent.is())
        xComponent->removeEventListener(this);
    Reference< XPropertySet >  xProp(m_xDriverNode, UNO_QUERY);
    if (xProp.is())
        xProp->removePropertyChangeListener(TIMEOUT_NODENAME, this);

    m_xDriverNode.clear();
    m_xDriver.clear();
}

Reference< XConnection > OConnectionPool::getConnectionWithInfo( const OUString& _rURL, const Sequence< PropertyValue >& _rInfo )
{
    std::unique_lock aGuard(m_aMutex);

    Reference<XConnection> xConnection;

    // create a unique id and look for it in our map
    Sequence< PropertyValue > aInfo(_rInfo);
    TConnectionMap::key_type nId;
    OConnectionWrapper::createUniqueId(_rURL,aInfo,nId.m_pBuffer);
    TConnectionMap::iterator aIter = m_aPool.find(nId);

    if ( m_aPool.end() != aIter )
        xConnection = getPooledConnection(aIter);

    if ( !xConnection.is() )
        xConnection = createNewConnection(_rURL,_rInfo);

    return xConnection;
}

void SAL_CALL OConnectionPool::disposing( const css::lang::EventObject& Source )
{
    Reference<XConnection> xConnection(Source.Source,UNO_QUERY);
    if(xConnection.is())
    {
        std::unique_lock aGuard(m_aMutex);
        TActiveConnectionMap::iterator aIter = m_aActiveConnections.find(xConnection);
        OSL_ENSURE(aIter != m_aActiveConnections.end(),"OConnectionPool::disposing: Connection wasn't in pool");
        if(aIter != m_aActiveConnections.end())
        { // move the pooled connection back to the pool
            aIter->second.aPos->second.nALiveCount = m_nALiveCount;
            aIter->second.aPos->second.aConnections.push_back(aIter->second.xPooledConnection);
            m_aActiveConnections.erase(aIter);
        }
    }
    else
    {
        m_xDriverNode.clear();
    }
}

Reference< XConnection> OConnectionPool::createNewConnection(const OUString& _rURL,const Sequence< PropertyValue >& _rInfo)
{
    // create new pooled connection
    Reference< XPooledConnection > xPooledConnection = new ::connectivity::OPooledConnection(m_xDriver->connect(_rURL,_rInfo),m_xProxyFactory);
    // get the new connection from the pooled connection
    Reference<XConnection> xConnection = xPooledConnection->getConnection();
    if(xConnection.is())
    {
        // add our own as dispose listener to know when we should put the connection back to the pool
        Reference< XComponent >  xComponent(xConnection, UNO_QUERY);
        if (xComponent.is())
            xComponent->addEventListener(this);

        // save some information to find the right pool later on
        Sequence< PropertyValue > aInfo(_rInfo);
        TConnectionMap::key_type nId;
        OConnectionWrapper::createUniqueId(_rURL,aInfo,nId.m_pBuffer);
        TConnectionPool aPack;

        // insert the new connection and struct into the active connection map
        aPack.nALiveCount               = m_nALiveCount;
        TActiveConnectionInfo aActiveInfo;
        aActiveInfo.aPos                = m_aPool.emplace(nId,aPack).first;
        aActiveInfo.xPooledConnection   = xPooledConnection;
        m_aActiveConnections.emplace(xConnection,aActiveInfo);

        if(m_xInvalidator->isExpired())
            m_xInvalidator->start();
    }

    return xConnection;
}

void OConnectionPool::invalidatePooledConnections()
{
    std::unique_lock aGuard(m_aMutex);
    TConnectionMap::iterator aIter = m_aPool.begin();
    for (; aIter != m_aPool.end(); )
    {
        if(!(--(aIter->second.nALiveCount))) // connections are invalid
        {
            std::for_each(aIter->second.aConnections.begin(),aIter->second.aConnections.end(),TRemoveEventListenerFunctor(this,true));

            aIter->second.aConnections.clear();

            // look if the iterator aIter is still present in the active connection map
            bool isPresent = std::any_of(m_aActiveConnections.begin(), m_aActiveConnections.end(),
                [&aIter](const TActiveConnectionMap::value_type& rEntry) { return rEntry.second.aPos == aIter; });
            if(!isPresent)
            {// he isn't so we can delete him
                aIter = m_aPool.erase(aIter);
            }
            else
                ++aIter;
        }
        else
            ++aIter;
    }
    if(!m_aPool.empty())
        m_xInvalidator->start();
}

Reference< XConnection> OConnectionPool::getPooledConnection(TConnectionMap::iterator const & _rIter)
{
    Reference<XConnection> xConnection;

    if(!_rIter->second.aConnections.empty())
    {
        Reference< XPooledConnection > xPooledConnection = _rIter->second.aConnections.back();
        _rIter->second.aConnections.pop_back();

        OSL_ENSURE(xPooledConnection.is(),"Can not be null here!");
        xConnection = xPooledConnection->getConnection();
        Reference< XComponent >  xComponent(xConnection, UNO_QUERY);
        if (xComponent.is())
            xComponent->addEventListener(this);

        TActiveConnectionInfo aActiveInfo;
        aActiveInfo.aPos = _rIter;
        aActiveInfo.xPooledConnection = xPooledConnection;
        m_aActiveConnections[xConnection] = aActiveInfo;
    }
    return xConnection;
}

void SAL_CALL OConnectionPool::propertyChange( const PropertyChangeEvent& evt )
{
    if(TIMEOUT_NODENAME == evt.PropertyName)
    {
        OPoolCollection::getNodeValue(TIMEOUT_NODENAME, m_xDriverNode) >>= m_nALiveCount;
        calculateTimeOuts();
    }
}

void OConnectionPool::calculateTimeOuts()
{
    sal_Int32 nTimeOutCorrection = 10;
    if(m_nALiveCount < 100)
        nTimeOutCorrection = 20;

    m_nTimeOut      = m_nALiveCount / nTimeOutCorrection;
    m_nALiveCount   = m_nALiveCount / m_nTimeOut;
}


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