pool.cpp

/***************************************************************************
 *   Copyright (C) 2005-2008 by the FIFE team                              *
 *   http://www.fifengine.de                                               *
 *   This file is part of FIFE.                                            *
 *                                                                         *
 *   FIFE 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 2.1 of the License, or (at your option) any later version.    *
 *                                                                         *
 *   This library 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 library; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA          *
 ***************************************************************************/

// Standard C++ library includes

// 3rd party library includes

// FIFE includes
// These includes are split up in two parts, separated by one empty line
// First block: files included from the FIFE root src directory
// Second block: files included from the same folder
#include "util/base/exception.h"
#include "util/log/logger.h"

#include "pool.h"

namespace FIFE {
    static Logger _log(LM_POOL);

    Pool::Pool(const std::string& name):
        m_entries(),
        m_location_to_entry(),
        m_loaders(),
        m_name(name)
    {
    }

    Pool::~Pool() {
        FL_LOG(_log, LMsg("Pool destroyed: ") << m_name);
        printStatistics();
        // This is only usefull for debugging
        //sanityCheck();
        reset();
        std::vector<ResourceLoader*>::iterator loader;
        for (loader = m_loaders.begin(); loader != m_loaders.end(); loader++) {
            delete (*loader);
        }
    }

    void Pool::reset() {
        std::vector<PoolEntry*>::iterator entry;
        for (entry = m_entries.begin(); entry != m_entries.end(); entry++) {
            // Warn about leaks, but at least display ALL of them
            // Instead of bailing out with an exception in the FifeClass destructor.
            if( (*entry)->resource && (*entry)->resource->getRefCount() > 0 ) {
                FL_WARN(_log, LMsg(m_name + " leak: ") << (*entry)->location->getFilename());
                (*entry)->resource = 0;
            }
            delete (*entry);
        }
        m_entries.clear();
        m_location_to_entry.clear();
    }

    int Pool::purgeLoadedResources() {
        int count = 0;
        std::vector<PoolEntry*>::iterator it;
        for (it = m_entries.begin(); it != m_entries.end(); it++) {
            PoolEntry* entry = *it;
            if( entry->resource && entry->resource->getRefCount() == 0 ) {
                delete entry->resource;
                entry->resource = 0;
                ++count;
            }
        }
        return count;
    }

    void Pool::addResourceLoader(ResourceLoader* loader) {
        m_loaders.push_back(loader);
    }

    void Pool::clearResourceLoaders() {
        m_loaders.clear();
    }

    int Pool::addResourceFromLocation(ResourceLocation* loc) {
        ResourceLocationToEntry::const_iterator it = m_location_to_entry.find(loc);
        if (it != m_location_to_entry.end()) {
            return it->second;
        }

        PoolEntry* entry = new PoolEntry();
        entry->location = loc->clone();
        m_entries.push_back(entry);
        size_t index = m_entries.size() - 1;
        m_location_to_entry[entry->location] = index;
        return index;
    }

    int Pool::addResourceFromFile(const std::string& filename) {
        ResourceLocation r = ResourceLocation(filename);
        return addResourceFromLocation(&r);
    }

    IResource& Pool::get(unsigned int index, bool inc) {
        if (index >= m_entries.size()) {
            FL_ERR(_log, LMsg("Tried to get with index ") << index << ", only " << m_entries.size() << " items in pool " + m_name);
            throw IndexOverflow( __FUNCTION__ );
        }
        IResource* res = NULL;
        PoolEntry* entry = m_entries[index];
        if (entry->resource) {
            res = entry->resource;
        } else {
            if (!entry->loader) {
                findAndSetProvider(*entry);
            } else {
                entry->resource = entry->loader->loadResource(*entry->location);
            }

            if (!entry->loader) {
                LMsg msg("No suitable loader was found for resource ");
                msg << "#" << index << "<" << entry->location->getFilename()
                    << "> in pool " << m_name;
                FL_ERR(_log, msg);

                throw NotFound(msg.str);
            }

            // This branch will only be relevant if the resource has been
            // loaded successfully before, but for some reason the loader
            // can't load the resource anymore.
            // Maybe someone deleted a file under FIFE's hands?
            if (!entry->resource) {
                LMsg msg("The loader was unable to load the resource ");
                msg << "#" << index << "<" << entry->location->getFilename()
                    << "> in pool " << m_name;
                FL_ERR(_log, msg);
                throw NotFound(msg.str);
            }
            res = entry->resource;
        }
        if (inc) {
            res->addRef();
        }
        res->setPoolId(index);
        return *res;
    }

    void Pool::release(unsigned int index, bool dec) {
        if (index >= m_entries.size()) {
            throw IndexOverflow( __FUNCTION__ );
        }

        IResource* res = NULL;
        PoolEntry* entry = m_entries[index];
        if (entry->resource) {
            res = entry->resource;
            if (dec) {
                res->decRef();
            }
            if(res->getRefCount() == 0) {
                delete entry->resource;
                entry->resource = 0;
            }
        }
    }

    int Pool::getResourceCount(int status) {
        int amount = 0;
        std::vector<PoolEntry*>::iterator entry;
        for (entry = m_entries.begin(); entry != m_entries.end(); entry++) {
            if (status & RES_LOADED) {
                if ((*entry)->resource) {
                    amount++;
                }
            }
            if (status & RES_NON_LOADED) {
                if (!(*entry)->resource) {
                    amount++;
                }
            }
        }
        return amount;
    }

    void Pool::findAndSetProvider(PoolEntry& entry) {
        std::vector<ResourceLoader*>::iterator it = m_loaders.begin();
        std::vector<ResourceLoader*>::iterator end = m_loaders.end();
        if( it == end ) {
            FL_PANIC(_log, "no loader constructors given for resource pool");
        }
        for(; it != end; ++it) {
            IResource* res = (*it)->loadResource(*entry.location);
            if (res) {
                entry.resource = res;
                entry.loader = *it;
                return;
            }
        };
    }

    void Pool::printStatistics() {
        FL_LOG(_log, LMsg("Pool not loaded =") << getResourceCount(RES_NON_LOADED));
        FL_LOG(_log, LMsg("Pool loaded     =") << getResourceCount(RES_LOADED));
        int amount = 0;
        std::vector<PoolEntry*>::iterator entry;
        for (entry = m_entries.begin(); entry != m_entries.end(); entry++) {
            if ((*entry)->resource) {
                if ((*entry)->resource->getRefCount() > 0) {
                    amount++;
                }
            }
        }
        FL_LOG(_log, LMsg("Pool locked     =") << amount);
        FL_LOG(_log, LMsg("Pool total size =") << m_entries.size());
    }

    void Pool::sanityCheck() {
        // It is easy to mess up the important consistent
        // less-than operator for the location classes.
        // This will check if according to the '==' operator
        // entries are duplicate (=memory leaks).
        // Slow and inaccurate. But should barf at real messups.
        for(unsigned i = 0; i != m_entries.size(); ++i) {
            int count = 0;
            for(unsigned j = i+1; j < m_entries.size(); ++j) {
                if( *m_entries[i]->location == *m_entries[j]->location )
                    count ++;
            }
            if( 0 == count )
                continue;
            FL_WARN(_log, LMsg("Multiple entries: ") << m_entries[i]->location->getFilename()
              << " #entries = " << (count+1) );
        }
    }

}