Applied-Energistics-2/src/main/java/appeng/util/item/AEItemStackRegistry.java

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2017 AlgorithmX2
 *
 * 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.
 */

package appeng.util.item;


import java.lang.ref.WeakReference;
import java.util.WeakHashMap;

import javax.annotation.Nonnull;

import net.minecraft.item.ItemStack;

import appeng.util.Platform;


public final class AEItemStackRegistry
{
	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> SERVER_REGISTRY = new WeakHashMap<>();
	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> CLIENT_REGISTRY = new WeakHashMap<>();

	private AEItemStackRegistry()
	{
	}

	private static WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> registry()
	{
		if( Platform.isClient() )
		{
			return CLIENT_REGISTRY;
		}
		else
		{
			return SERVER_REGISTRY;
		}
	}

	static synchronized AESharedItemStack getRegisteredStack( final @Nonnull ItemStack itemStack )
	{
		if( itemStack.isEmpty() )
		{
			throw new IllegalArgumentException( "stack cannot be empty" );
		}

		int oldStackSize = itemStack.getCount();
		itemStack.setCount( 1 );

		AESharedItemStack search = new AESharedItemStack( itemStack );
		WeakReference<AESharedItemStack> weak = registry().get( search );
		AESharedItemStack ret = null;

		if( weak != null )
		{
			ret = weak.get();
		}

		if( ret == null )
		{
			ret = new AESharedItemStack( itemStack.copy() );
			registry().put( ret, new WeakReference<>( ret ) );
		}
		itemStack.setCount( oldStackSize );

		return ret;
	}
}