Copyright (c) 2000, 2005 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, 2005 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.core.internal.dtree;

import org.eclipse.core.runtime.IPath;

The result of doing a lookup() in a data tree.  Uses an instance
pool that assumes no more than POOL_SIZE instance will ever be
needed concurrently.  Reclaims and reuses instances on an LRU basis.
/**
 * The result of doing a lookup() in a data tree.  Uses an instance
 * pool that assumes no more than POOL_SIZE instance will ever be
 * needed concurrently.  Reclaims and reuses instances on an LRU basis.
 */
public class DataTreeLookup {
	public IPath key;
	public boolean isPresent;
	public Object data;
	public boolean foundInFirstDelta;
	private static final int POOL_SIZE = 100;
	
The array of lookup instances available for use.
/**
	 * The array of lookup instances available for use.
	 */
	private static DataTreeLookup[] instancePool;
	
The index of the next available lookup instance.
/**
	 * The index of the next available lookup instance.
	 */
	private static int nextFree = 0;
	static {
		instancePool = new DataTreeLookup[POOL_SIZE];
		//fill the pool with objects
		for (int i = 0; i < POOL_SIZE; i++) {
			instancePool[i] = new DataTreeLookup();
		}
	}

	
Constructors for internal use only.  Use factory methods.
/**
	 * Constructors for internal use only.  Use factory methods.
	 */
	private DataTreeLookup() {
		super();
	}

	
Factory method for creating a new lookup object.
/**
	 * Factory method for creating a new lookup object.
	 */
	public static DataTreeLookup newLookup(IPath nodeKey, boolean isPresent, Object data) {
		DataTreeLookup instance;
		synchronized (instancePool) {
			instance = instancePool[nextFree];
			nextFree = ++nextFree % POOL_SIZE;
		}
		instance.key = nodeKey;
		instance.isPresent = isPresent;
		instance.data = data;
		instance.foundInFirstDelta = false;
		return instance;
	}

	
Factory method for creating a new lookup object.
/**
	 * Factory method for creating a new lookup object.
	 */
	public static DataTreeLookup newLookup(IPath nodeKey, boolean isPresent, Object data, boolean foundInFirstDelta) {
		DataTreeLookup instance;
		synchronized (instancePool) {
			instance = instancePool[nextFree];
			nextFree = ++nextFree % POOL_SIZE;
		}
		instance.key = nodeKey;
		instance.isPresent = isPresent;
		instance.data = data;
		instance.foundInFirstDelta = foundInFirstDelta;
		return instance;
	}
}