/*

 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.java2d.jules;

import java.util.*;

public class IdleTileCache {

    ArrayList<JulesTile> idleTileWorkerCacheList = new ArrayList<JulesTile>();

    ArrayList<JulesTile> idleTileConsumerCacheList =

              new ArrayList<JulesTile>(IDLE_TILE_SYNC_GRANULARITY);

    /**

     * Return a cached Tile, if possible from cache.

     * Allowed caller: Rasterizer/Producer-Thread

     *

     * @param: maxCache - Specify the maximum amount of tiles needed

     */

    public JulesTile getIdleTileWorker(int maxCache) {

        /* Try to fetch idle tiles from the global cache list */

        if (idleTileWorkerCacheList.size() == 0) {

            idleTileWorkerCacheList.ensureCapacity(maxCache);

            synchronized (idleBuffers) {

                for (int i = 0; i < maxCache && idleBuffers.size() > 0; i++) {

                    idleTileWorkerCacheList.add(

                            idleBuffers.remove(idleBuffers.size() - 1));

                }

            }

        }

        if (idleTileWorkerCacheList.size() > 0) {

            return idleTileWorkerCacheList.remove(idleTileWorkerCacheList.size() - 1);

        }

        return new JulesTile();

    }

    /**

     * Release tile and allow it to be re-used by another thread. Allowed

     *  Allowed caller: MaskBlit/Consumer-Thread

     */

    public void releaseTile(JulesTile tile) {

        if (tile != null && tile.hasBuffer()) {

            idleTileConsumerCacheList.add(tile);

            if (idleTileConsumerCacheList.size() > IDLE_TILE_SYNC_GRANULARITY) {

                synchronized (idleBuffers) {

                    idleBuffers.addAll(idleTileConsumerCacheList);

                }

                idleTileConsumerCacheList.clear();

            }

        }

    }

    /**

     * Releases thread-local tiles cached for use by the rasterizing thread.

     * Allowed caller: Rasterizer/Producer-Thread

     */

    public void disposeRasterizerResources() {

        releaseTiles(idleTileWorkerCacheList);

    }

    /**

     * Releases thread-local tiles cached for performance reasons. Allowed

     * Allowed caller: MaskBlit/Consumer-Thread

     */

    public void disposeConsumerResources() {

        releaseTiles(idleTileConsumerCacheList);

    }

    /**

     * Release a list of tiles and allow it to be re-used by another thread.

     * Thread safe.

     */

    public void releaseTiles(List<JulesTile> tileList) {

        if (tileList.size() > 0) {

            synchronized (idleBuffers) {

                idleBuffers.addAll(tileList);

            }

            tileList.clear();

        }

    }

}