Copyright (c) 2000, 2013 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.internal.core.util.LRUCache;

An LRU cache of IBuffers.
/**
 * An LRU cache of <code>IBuffers</code>.
 */
public class BufferCache<K> extends OverflowingLRUCache<K, IBuffer> {

	private ThreadLocal<List<IBuffer>> buffersToClose = new ThreadLocal<>();

	
Constructs a new buffer cache of the given size.
/**
	 * Constructs a new buffer cache of the given size.
	 */
	public BufferCache(int size) {
		super(size);
	}
	
Constructs a new buffer cache of the given size.
/**
	 * Constructs a new buffer cache of the given size.
	 */
	public BufferCache(int size, int overflow) {
		super(size, overflow);
	}

	@Override
	protected boolean close(LRUCacheEntry<K, IBuffer> entry) {
		IBuffer buffer= entry.value;

		// prevent buffer that have unsaved changes or working copy buffer to be removed
		// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=39311
		if (!((Openable)buffer.getOwner()).canBufferBeRemovedFromCache(buffer)) {
			return false;
		} else {
			List<IBuffer> buffers = this.buffersToClose.get();
			if (buffers == null) {
				buffers = new ArrayList<>();
				this.buffersToClose.set(buffers);
			}
			buffers.add(buffer);
			return true;
		}
	}

	void closeBuffers() {
		List<IBuffer> buffers = this.buffersToClose.get();
		if (buffers == null)
			return;
		this.buffersToClose.set(null);
		for (int i = 0, length = buffers.size(); i < length; i++) {
			buffers.get(i).close();
		}
	}

	@Override
	protected LRUCache<K, IBuffer> newInstance(int size, int newOverflow) {
		return new BufferCache<>(size, newOverflow);
	}
}