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- /*
- * Copyright (C) 2008, Google Inc.
- * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org>
- * and other copyright owners as documented in the project's IP log.
- *
- * This program and the accompanying materials are made available
- * under the terms of the Eclipse Distribution License v1.0 which
- * accompanies this distribution, is reproduced below, and is
- * available at http://www.eclipse.org/org/documents/edl-v10.php
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials provided
- * with the distribution.
- *
- * - Neither the name of the Eclipse Foundation, Inc. nor the
- * names of its contributors may be used to endorse or promote
- * products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
- package org.eclipse.jgit.lib;
-
- import java.util.zip.Inflater;
-
- /**
- * Creates zlib based inflaters as necessary for object decompression.
- */
- public class InflaterCache {
- private static final int SZ = 4;
-
- private static final Inflater[] inflaterCache;
-
- private static int openInflaterCount;
-
- static {
- inflaterCache = new Inflater[SZ];
- }
-
- /**
- * Obtain an Inflater for decompression.
- * <p>
- * Inflaters obtained through this cache should be returned (if possible) by
- * {@link #release(Inflater)} to avoid garbage collection and reallocation.
- *
- * @return an available inflater. Never null.
- */
- public static Inflater get() {
- final Inflater r = getImpl();
- return r != null ? r : new Inflater(false);
- }
-
- private static synchronized Inflater getImpl() {
- if (openInflaterCount > 0) {
- final Inflater r = inflaterCache[--openInflaterCount];
- inflaterCache[openInflaterCount] = null;
- return r;
- }
- return null;
- }
-
- /**
- * Release an inflater previously obtained from this cache.
- *
- * @param i
- * the inflater to return. May be null, in which case this method
- * does nothing.
- */
- public static void release(Inflater i) {
- if (i != null) {
- i.reset();
- if (releaseImpl(i))
- i.end();
- }
- }
-
- private static synchronized boolean releaseImpl(Inflater i) {
- if (openInflaterCount < SZ) {
- inflaterCache[openInflaterCount++] = i;
- return false;
- }
- return true;
- }
-
- private InflaterCache() {
- throw new UnsupportedOperationException();
- }
- }
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