/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* 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.
*/
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.
*/
private static DataTreeLookup[] instancePool;
/**
* 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.
*/
private DataTreeLookup() {
super();
}
/**
* 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.
*/
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;
}
}