| /******************************************************************************* |
| * 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. |
| */ |
| 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; |
| } |
| } |