source: downloads/ogre/OgreMain/src/OgreResource.cpp @ 48

/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/
// Ogre includes
#include "OgreStableHeaders.h"

#include "OgreResource.h"
#include "OgreResourceManager.h"
#include "OgreResourceBackgroundQueue.h"
#include "OgreLogManager.h"
#include "OgreException.h"

namespace Ogre 
{
        //-----------------------------------------------------------------------
        Resource::Resource(ResourceManager* creator, const String& name, ResourceHandle handle,
                const String& group, bool isManual, ManualResourceLoader* loader)
                : mCreator(creator), mName(name), mGroup(group), mHandle(handle), 
                mLoadingState(LOADSTATE_UNLOADED), mIsBackgroundLoaded(false),
                mSize(0), mIsManual(isManual), mLoader(loader)
        {
        }
        //-----------------------------------------------------------------------
        Resource::~Resource() 
        { 
        }
        //-----------------------------------------------------------------------
        void Resource::escalateLoading()
        {
                // Just call load as if this is the background thread, locking on
                // load status will prevent race conditions
                load(true);
        }
        //-----------------------------------------------------------------------
        void Resource::load(bool background)
        {
                // Early-out without lock (mitigate perf cost of ensuring loaded)
                // Don't load if:
                // 1. We're already loaded
                // 2. Another thread is loading right now
                // 3. We're marked for background loading and this is not the background
                //    loading thread we're being called by
                if (mLoadingState != LOADSTATE_UNLOADED || (mIsBackgroundLoaded && !background))
                        return;

                // Scope lock over load status
                {
                        OGRE_LOCK_MUTEX(mLoadingStatusMutex)
                        // Check again just in case status changed (since we didn't lock above)
                        if (mLoadingState != LOADSTATE_UNLOADED || (mIsBackgroundLoaded && !background))
                        {
                                // no loading to be done
                                return;
                        }
                        mLoadingState = LOADSTATE_LOADING;
                }

                // Scope lock for actual loading
        try
                {

                        OGRE_LOCK_AUTO_MUTEX
                        preLoadImpl();

                        if (mIsManual)
                        {
                                // Load from manual loader
                                if (mLoader)
                                {
                                        mLoader->loadResource(this);
                                }
                                else
                                {
                                        // Warn that this resource is not reloadable
                                        LogManager::getSingleton().logMessage(
                                                "WARNING: " + mCreator->getResourceType() + 
                                                " instance '" + mName + "' was defined as manually "
                                                "loaded, but no manual loader was provided. This Resource "
                                                "will be lost if it has to be reloaded.");
                                }
                        }
                        else
                        {
                                if (mGroup == ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME)
                                {
                                        // Derive resource group
                                        changeGroupOwnership(
                                                ResourceGroupManager::getSingleton()
                                                .findGroupContainingResource(mName));
                                }
                                loadImpl();
                        }
                        // Calculate resource size
                        mSize = calculateSize();

                        postLoadImpl();
                }
        catch (...)
        {
            // Reset loading in-progress flag in case failed for some reason
            OGRE_LOCK_MUTEX(mLoadingStatusMutex)
            mLoadingState = LOADSTATE_UNLOADED;
            // Re-throw
            throw;
        }

                // Scope lock for loading progress
                {
                        OGRE_LOCK_MUTEX(mLoadingStatusMutex)
                
                        // Now loaded
                        mLoadingState = LOADSTATE_LOADED;
                }

                // Notify manager
                if(mCreator)
                        mCreator->_notifyResourceLoaded(this);

                // Fire (deferred) events
                if (mIsBackgroundLoaded)
                        queueFireBackgroundLoadingComplete();


        }
        //-----------------------------------------------------------------------
        void Resource::changeGroupOwnership(const String& newGroup)
        {
                if (mGroup != newGroup)
                {
                        String oldGroup = mGroup;
                        mGroup = newGroup;
                        ResourceGroupManager::getSingleton()
                                ._notifyResourceGroupChanged(oldGroup, this);
                }
        }
        //-----------------------------------------------------------------------
        void Resource::unload(void) 
        { 
                // Early-out without lock (mitigate perf cost of ensuring unloaded)
                if (mLoadingState != LOADSTATE_LOADED)
                        return;

                // Scope lock for loading status
                {
                        OGRE_LOCK_MUTEX(mLoadingStatusMutex)
                        if (mLoadingState == LOADSTATE_LOADING)
                        {
                                OGRE_EXCEPT(Exception::ERR_INTERNAL_ERROR, 
                                        "Cannot unload resource " + mName + " whilst loading is in progress!", 
                                        "Resource::unload");
                        }
                        if (mLoadingState != LOADSTATE_LOADED)
                                return; // nothing to do

                        mLoadingState = LOADSTATE_UNLOADING;
                }

                // Scope lock for actual unload
                {
                        OGRE_LOCK_AUTO_MUTEX
                        preUnloadImpl();
                        unloadImpl();
                        postUnloadImpl();
                }

                // Scope lock for loading status
                {
                        OGRE_LOCK_MUTEX(mLoadingStatusMutex)
                        mLoadingState = LOADSTATE_UNLOADED;
                }

                // Notify manager
                if(mCreator)
                        mCreator->_notifyResourceUnloaded(this);

        }
        //-----------------------------------------------------------------------
        void Resource::reload(void) 
        { 
                OGRE_LOCK_AUTO_MUTEX
                if (mLoadingState == LOADSTATE_LOADED)
                {
                        unload();
                        load();
                }
        }
        //-----------------------------------------------------------------------
        void Resource::touch(void) 
        {
                OGRE_LOCK_AUTO_MUTEX
        // make sure loaded
        load();

                if(mCreator)
                        mCreator->_notifyResourceTouched(this);
        }
        //-----------------------------------------------------------------------
        void Resource::addListener(Resource::Listener* lis)
        {
                mListenerList.push_back(lis);
        }
        //-----------------------------------------------------------------------
        void Resource::removeListener(Resource::Listener* lis)
        {
                // O(n) but not called very often
                mListenerList.remove(lis);
        }
        //-----------------------------------------------------------------------
        void Resource::queueFireBackgroundLoadingComplete(void)
        {
                ResourceBackgroundQueue& rbq = ResourceBackgroundQueue::getSingleton();
                for (ListenerList::iterator i = mListenerList.begin();
                        i != mListenerList.end(); ++i)
                {
                        rbq._queueFireBackgroundLoadingComplete(*i, this);
                }
        }


}