text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
      (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2014 Torus Knot Software Ltd
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  -----------------------------------------------------------------------------
  */
  #include "OgreStableHeaders.h"
  #include "OgreResourceManager.h"
  
  #include "OgreException.h"
  #include "OgreResourceGroupManager.h"
  
  namespace Ogre {
  
      //-----------------------------------------------------------------------
      ResourceManager::ResourceManager()
          : mNextHandle(1), mMemoryUsage(0), mVerbose(true), mLoadOrder(0)
      {
          // Init memory limit & usage
          mMemoryBudget = std::numeric_limits<unsigned long>::max();
      }
      //-----------------------------------------------------------------------
      ResourceManager::~ResourceManager()
      {
          destroyAllResourcePools();
          removeAll();
      }
      //-----------------------------------------------------------------------
      ResourcePtr ResourceManager::createResource(const String& name, const String& group,
          bool isManual, ManualResourceLoader* loader, const NameValuePairList* params)
      {
          // Call creation implementation
          ResourcePtr ret = ResourcePtr(
              createImpl(name, getNextHandle(), group, isManual, loader, params));
          if (params)
              ret->setParameterList(*params);
  
          addImpl(ret);
          // Tell resource group manager
          ResourceGroupManager::getSingleton()._notifyResourceCreated(ret);
          return ret;
  
      }
      //-----------------------------------------------------------------------
      ResourceManager::ResourceCreateOrRetrieveResult 
      ResourceManager::createOrRetrieve(
          const String& name, const String& group, 
          bool isManual, ManualResourceLoader* loader, 
          const NameValuePairList* params)
      {
          // Lock for the whole get / insert
              OGRE_LOCK_AUTO_MUTEX;
  
          ResourcePtr res = getResourceByName(name, group);
          bool created = false;
          if (!res)
          {
              created = true;
              res = createResource(name, group, isManual, loader, params);
          }
  
          return ResourceCreateOrRetrieveResult(res, created);
      }
      //-----------------------------------------------------------------------
      ResourcePtr ResourceManager::prepare(const String& name, 
          const String& group, bool isManual, ManualResourceLoader* loader, 
          const NameValuePairList* loadParams, bool backgroundThread)
      {
          ResourcePtr r = createOrRetrieve(name,group,isManual,loader,loadParams).first;
          // ensure prepared
          r->prepare(backgroundThread);
          return r;
      }
      //-----------------------------------------------------------------------
      ResourcePtr ResourceManager::load(const String& name, 
          const String& group, bool isManual, ManualResourceLoader* loader, 
          const NameValuePairList* loadParams, bool backgroundThread)
      {
          ResourcePtr r = createOrRetrieve(name,group,isManual,loader,loadParams).first;
          // ensure loaded
          r->load(backgroundThread);
  
          return r;
      }
      //-----------------------------------------------------------------------
      void ResourceManager::addImpl( ResourcePtr& res )
      {
              OGRE_LOCK_AUTO_MUTEX;
  
              std::pair<ResourceMap::iterator, bool> result;
          if(ResourceGroupManager::getSingleton().isResourceGroupInGlobalPool(res->getGroup()))
          {
              result = mResources.insert( ResourceMap::value_type( res->getName(), res ) );
          }
          else
          {
              ResourceWithGroupMap::iterator itGroup = mResourcesWithGroup.find(res->getGroup());
  
              // we will create the group if it doesn't exists in our list
              if( itGroup == mResourcesWithGroup.end())
              {
                  ResourceMap dummy;
                  mResourcesWithGroup.insert( ResourceWithGroupMap::value_type( res->getGroup(), dummy ) );
                  itGroup = mResourcesWithGroup.find(res->getGroup());
              }
              result = itGroup->second.insert( ResourceMap::value_type( res->getName(), res ) );
  
          }
  
          // Attempt to resolve the collision
          ResourceLoadingListener* listener = ResourceGroupManager::getSingleton().getLoadingListener();
          if (!result.second && listener && listener->resourceCollision(res.get(), this))
          {
              // Try to do the addition again, no seconds attempts to resolve collisions are allowed
              if(ResourceGroupManager::getSingleton().isResourceGroupInGlobalPool(res->getGroup()))
              {
                  result = mResources.insert( ResourceMap::value_type( res->getName(), res ) );
              }
              else
              {
                  ResourceWithGroupMap::iterator itGroup = mResourcesWithGroup.find(res->getGroup());
                  result = itGroup->second.insert( ResourceMap::value_type( res->getName(), res ) );
              }
          }
  
          if (!result.second)
          {
              OGRE_EXCEPT(Exception::ERR_DUPLICATE_ITEM, "Resource with the name " + res->getName() +
                  " already exists.", "ResourceManager::add");
          }
  
          // Insert the handle
          std::pair<ResourceHandleMap::iterator, bool> resultHandle =
              mResourcesByHandle.insert( ResourceHandleMap::value_type( res->getHandle(), res ) );
          if (!resultHandle.second)
          {
              OGRE_EXCEPT(Exception::ERR_DUPLICATE_ITEM, "Resource with the handle " +
                  StringConverter::toString((long) (res->getHandle())) +
                  " already exists.", "ResourceManager::add");
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::removeImpl(const ResourcePtr& res )
      {
          OgreAssert(res, "attempting to remove nullptr");
  
          OGRE_LOCK_AUTO_MUTEX;
  
          if(ResourceGroupManager::getSingleton().isResourceGroupInGlobalPool(res->getGroup()))
          {
              ResourceMap::iterator nameIt = mResources.find(res->getName());
              if (nameIt != mResources.end())
              {
                  mResources.erase(nameIt);
              }
          }
          else
          {
              ResourceWithGroupMap::iterator groupIt = mResourcesWithGroup.find(res->getGroup());
              if (groupIt != mResourcesWithGroup.end())
              {
                  ResourceMap::iterator nameIt = groupIt->second.find(res->getName());
                  if (nameIt != groupIt->second.end())
                  {
                      groupIt->second.erase(nameIt);
                  }
  
                  if (groupIt->second.empty())
                  {
                      mResourcesWithGroup.erase(groupIt);
                  }
              }
          }
  
          ResourceHandleMap::iterator handleIt = mResourcesByHandle.find(res->getHandle());
          if (handleIt != mResourcesByHandle.end())
          {
              mResourcesByHandle.erase(handleIt);
          }
          // Tell resource group manager
          ResourceGroupManager::getSingleton()._notifyResourceRemoved(res);
      }
      //-----------------------------------------------------------------------
      void ResourceManager::setMemoryBudget( size_t bytes)
      {
          // Update limit & check usage
          mMemoryBudget = bytes;
          checkUsage();
      }
      //-----------------------------------------------------------------------
      size_t ResourceManager::getMemoryBudget(void) const
      {
          return mMemoryBudget;
      }
      //-----------------------------------------------------------------------
      void ResourceManager::unload(const String& name, const String& group)
      {
          ResourcePtr res = getResourceByName(name, group);
  
  #if OGRE_RESOURCEMANAGER_STRICT
          OgreAssert(res, ("attempting to unload unknown resource: "+name+" in group "+group).c_str());
  #endif
  
          if (res)
          {
              res->unload();
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::unload(ResourceHandle handle)
      {
          ResourcePtr res = getByHandle(handle);
  
  #if OGRE_RESOURCEMANAGER_STRICT
          OgreAssert(res, "attempting to unload unknown resource");
  #endif
  
          if (res)
          {
              res->unload();
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::unloadAll(Resource::LoadingFlags flags)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          bool reloadableOnly = (flags & Resource::LF_INCLUDE_NON_RELOADABLE) == 0;
          bool unreferencedOnly = (flags & Resource::LF_ONLY_UNREFERENCED) != 0;
  
          ResourceMap::iterator i, iend;
          iend = mResources.end();
          for (i = mResources.begin(); i != iend; ++i)
          {
              // A use count of 3 means that only RGM and RM have references
              // RGM has one (this one) and RM has 2 (by name and by handle)
              if (!unreferencedOnly || i->second.use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS)
              {
                  Resource* res = i->second.get();
                  if (!reloadableOnly || res->isReloadable())
                  {
                      res->unload();
                  }
              }
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::reloadAll(Resource::LoadingFlags flags)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          bool reloadableOnly = (flags & Resource::LF_INCLUDE_NON_RELOADABLE) == 0;
          bool unreferencedOnly = (flags & Resource::LF_ONLY_UNREFERENCED) != 0;
  
          ResourceMap::iterator i, iend;
          iend = mResources.end();
          for (i = mResources.begin(); i != iend; ++i)
          {
              // A use count of 3 means that only RGM and RM have references
              // RGM has one (this one) and RM has 2 (by name and by handle)
              if (!unreferencedOnly || i->second.use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS)
              {
                  Resource* res = i->second.get();
                  if (!reloadableOnly || res->isReloadable())
                  {
                      res->reload(flags);
                  }
              }
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::remove(const ResourcePtr& res)
      {
          removeImpl(res);
      }
      //-----------------------------------------------------------------------
      void ResourceManager::remove(const String& name, const String& group)
      {
          ResourcePtr res = getResourceByName(name, group);
  
  #if OGRE_RESOURCEMANAGER_STRICT
          OgreAssert(res, ("attempting to remove unknown resource: "+name+" in group "+group).c_str());
  #endif
  
          if (res)
          {
              removeImpl(res);
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::remove(ResourceHandle handle)
      {
          ResourcePtr res = getByHandle(handle);
  
  #if OGRE_RESOURCEMANAGER_STRICT
          OgreAssert(res, "attempting to remove unknown resource");
  #endif
  
          if (res)
          {
              removeImpl(res);
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::removeAll(void)
      {
              OGRE_LOCK_AUTO_MUTEX;
  
          mResources.clear();
          mResourcesWithGroup.clear();
          mResourcesByHandle.clear();
          // Notify resource group manager
          ResourceGroupManager::getSingleton()._notifyAllResourcesRemoved(this);
      }
      //-----------------------------------------------------------------------
      void ResourceManager::removeUnreferencedResources(bool reloadableOnly)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          ResourceMap::iterator i, iend;
          iend = mResources.end();
          for (i = mResources.begin(); i != iend; )
          {
              // A use count of 3 means that only RGM and RM have references
              // RGM has one (this one) and RM has 2 (by name and by handle)
              if (i->second.use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS)
              {
                  Resource* res = (i++)->second.get();
                  if (!reloadableOnly || res->isReloadable())
                  {
                      remove( res->getHandle() );
                  }
              }
              else
              {
                  ++i;
              }
          }
      }
      //-----------------------------------------------------------------------
      ResourcePtr ResourceManager::getResourceByName(const String& name, const String& groupName /* = ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME */)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          // resource should be in global pool
          bool isGlobal = ResourceGroupManager::getSingleton().isResourceGroupInGlobalPool(groupName);
  
          if(isGlobal)
          {
              ResourceMap::iterator it = mResources.find(name);
              if( it != mResources.end())
              {
                  return it->second;
              }
          }
  
          // look in all grouped pools
          if (groupName == ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME)
          {
              ResourceWithGroupMap::iterator iter = mResourcesWithGroup.begin();
              ResourceWithGroupMap::iterator iterE = mResourcesWithGroup.end();
              for ( ; iter != iterE ; ++iter )
              {
                  ResourceMap::iterator resMapIt = iter->second.find(name);
  
                  if( resMapIt != iter->second.end())
                  {
                      return resMapIt->second;
                  }
              }
          }
          else if (!isGlobal)
          {
              // look in the grouped pool
              ResourceWithGroupMap::iterator itGroup = mResourcesWithGroup.find(groupName);
              if( itGroup != mResourcesWithGroup.end())
              {
                  ResourceMap::iterator it = itGroup->second.find(name);
  
                  if( it != itGroup->second.end())
                  {
                      return it->second;
                  }
              }
  
  #if !OGRE_RESOURCEMANAGER_STRICT
              // fall back to global
              ResourceMap::iterator it = mResources.find(name);
              if( it != mResources.end())
              {
                  return it->second;
              }
  #endif
          }
      
          return ResourcePtr();
      }
      //-----------------------------------------------------------------------
      ResourcePtr ResourceManager::getByHandle(ResourceHandle handle)
      {
          OGRE_LOCK_AUTO_MUTEX;
          ResourceHandleMap::iterator it = mResourcesByHandle.find(handle);
          return it == mResourcesByHandle.end() ? ResourcePtr() : it->second;
      }
      //-----------------------------------------------------------------------
      ResourceHandle ResourceManager::getNextHandle(void)
      {
          // This is an atomic operation and hence needs no locking
          return mNextHandle++;
      }
      //-----------------------------------------------------------------------
      void ResourceManager::checkUsage(void)
      {
          if (getMemoryUsage() > mMemoryBudget)
          {
              OGRE_LOCK_AUTO_MUTEX;
              // unload unreferenced resources until we are within our budget again
              ResourceMap::iterator i, iend;
              iend = mResources.end();
              for (i = mResources.begin(); i != iend && getMemoryUsage() > mMemoryBudget; ++i)
              {
                  // A use count of 3 means that only RGM and RM have references
                  // RGM has one (this one) and RM has 2 (by name and by handle)
                  if (i->second.use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS)
                  {
                      Resource* res = i->second.get();
                      if (res->isReloadable())
                      {
                          res->unload();
                      }
                  }
              }
          }
      }
      //-----------------------------------------------------------------------
      void ResourceManager::_notifyResourceTouched(Resource* res)
      {
          // TODO
      }
      //-----------------------------------------------------------------------
      void ResourceManager::_notifyResourceLoaded(Resource* res)
      {
          mMemoryUsage += res->getSize();
          checkUsage();
      }
      //-----------------------------------------------------------------------
      void ResourceManager::_notifyResourceUnloaded(Resource* res)
      {
          mMemoryUsage -= res->getSize();
      }
      //---------------------------------------------------------------------
      ResourceManager::ResourcePool* ResourceManager::getResourcePool(const String& name)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          ResourcePoolMap::iterator i = mResourcePoolMap.find(name);
          if (i == mResourcePoolMap.end())
          {
              i = mResourcePoolMap.insert(ResourcePoolMap::value_type(name, 
                  OGRE_NEW ResourcePool(name))).first;
          }
          return i->second;
  
      }
      //---------------------------------------------------------------------
      void ResourceManager::destroyResourcePool(ResourcePool* pool)
      {
          if(!pool)
              OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS, "Cannot destroy a null ResourcePool.", "ResourceManager::destroyResourcePool");
  
          OGRE_LOCK_AUTO_MUTEX;
  
          ResourcePoolMap::iterator i = mResourcePoolMap.find(pool->getName());
          if (i != mResourcePoolMap.end())
              mResourcePoolMap.erase(i);
  
          OGRE_DELETE pool;
          
      }
      //---------------------------------------------------------------------
      void ResourceManager::destroyResourcePool(const String& name)
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          ResourcePoolMap::iterator i = mResourcePoolMap.find(name);
          if (i != mResourcePoolMap.end())
          {
              OGRE_DELETE i->second;
              mResourcePoolMap.erase(i);
          }
  
      }
      //---------------------------------------------------------------------
      void ResourceManager::destroyAllResourcePools()
      {
          OGRE_LOCK_AUTO_MUTEX;
  
          for (ResourcePoolMap::iterator i = mResourcePoolMap.begin(); 
              i != mResourcePoolMap.end(); ++i)
              OGRE_DELETE i->second;
  
          mResourcePoolMap.clear();
      }
      //-----------------------------------------------------------------------
      //---------------------------------------------------------------------
      ResourceManager::ResourcePool::ResourcePool(const String& name)
          : mName(name)
      {
  
      }
      //---------------------------------------------------------------------
      ResourceManager::ResourcePool::~ResourcePool()
      {
          clear();
      }
      //---------------------------------------------------------------------
      const String& ResourceManager::ResourcePool::getName() const
      {
          return mName;
      }
      //---------------------------------------------------------------------
      void ResourceManager::ResourcePool::clear()
      {
              OGRE_LOCK_AUTO_MUTEX;
          for (ItemList::iterator i = mItems.begin(); i != mItems.end(); ++i)
          {
              (*i)->getCreator()->remove((*i)->getHandle());
          }
          mItems.clear();
      }
  }
  
  
  
  
  