BasePackBitmapIndex.java
- /*
- * 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;
- }
- }
- }