| /* |
| * Copyright (C) 2012, Google Inc. |
| * 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.internal.storage.file; |
| |
| import org.eclipse.jgit.lib.AnyObjectId; |
| import org.eclipse.jgit.lib.ObjectIdOwnerMap; |
| |
| import com.googlecode.javaewah.EWAHCompressedBitmap; |
| |
| /** |
| * Base implementation of the PackBitmapIndex. |
| */ |
| abstract class BasePackBitmapIndex extends PackBitmapIndex { |
| private final ObjectIdOwnerMap<StoredBitmap> bitmaps; |
| |
| BasePackBitmapIndex(ObjectIdOwnerMap<StoredBitmap> bitmaps) { |
| this.bitmaps = bitmaps; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public EWAHCompressedBitmap getBitmap(AnyObjectId objectId) { |
| StoredBitmap sb = bitmaps.get(objectId); |
| return sb != null ? sb.getBitmap() : null; |
| } |
| |
| ObjectIdOwnerMap<StoredBitmap> getBitmaps() { |
| return bitmaps; |
| } |
| |
| /** |
| * Data representation of the bitmap entry restored from a pack index. The |
| * commit of the bitmap is the map key. |
| */ |
| static final class StoredBitmap extends ObjectIdOwnerMap.Entry { |
| private volatile Object bitmapContainer; |
| private final int flags; |
| |
| StoredBitmap(AnyObjectId objectId, EWAHCompressedBitmap bitmap, |
| StoredBitmap xorBitmap, int flags) { |
| super(objectId); |
| this.bitmapContainer = xorBitmap == null |
| ? bitmap |
| : new XorCompressedBitmap(bitmap, xorBitmap); |
| this.flags = flags; |
| } |
| |
| /** |
| * Computes and returns the full bitmap. |
| * |
| * @return the full bitmap |
| */ |
| EWAHCompressedBitmap getBitmap() { |
| // Fast path to immediately return the expanded result. |
| Object r = bitmapContainer; |
| if (r instanceof EWAHCompressedBitmap) |
| return (EWAHCompressedBitmap) r; |
| |
| // Expand the bitmap and cache the result. |
| XorCompressedBitmap xb = (XorCompressedBitmap) r; |
| EWAHCompressedBitmap out = xb.bitmap; |
| for (;;) { |
| r = xb.xorBitmap.bitmapContainer; |
| if (r instanceof EWAHCompressedBitmap) { |
| out = out.xor((EWAHCompressedBitmap) r); |
| out.trim(); |
| bitmapContainer = out; |
| return out; |
| } |
| xb = (XorCompressedBitmap) r; |
| out = out.xor(xb.bitmap); |
| } |
| } |
| |
| /** @return the flags associated with the bitmap */ |
| int getFlags() { |
| return flags; |
| } |
| } |
| |
| private static final class XorCompressedBitmap { |
| final EWAHCompressedBitmap bitmap; |
| final StoredBitmap xorBitmap; |
| |
| XorCompressedBitmap(EWAHCompressedBitmap b, StoredBitmap xb) { |
| bitmap = b; |
| xorBitmap = xb; |
| } |
| } |
| } |