| /* |
| * Copyright (C) 2012, Google Inc. and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| 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; |
| } |
| |
| @Override |
| public EWAHCompressedBitmap getBitmap(AnyObjectId objectId) { |
| StoredBitmap sb = bitmaps.get(objectId); |
| return sb != null ? sb.getBitmap() : null; |
| } |
| |
| ObjectIdOwnerMap<StoredBitmap> getBitmaps() { |
| return bitmaps; |
| } |
| |
| @Override |
| public int getBaseBitmapCount() { |
| int bases = 0; |
| for (StoredBitmap sb : getBitmaps()) { |
| if (sb.isBase()) { |
| bases += 1; |
| } |
| } |
| return bases; |
| } |
| |
| @Override |
| public long getBaseBitmapSizeInBytes() { |
| long baseSize = 0; |
| for (StoredBitmap sb : getBitmaps()) { |
| if (sb.isBase()) { |
| baseSize += sb.getCurrentSizeInBytes(); |
| } |
| } |
| return baseSize; |
| } |
| |
| @Override |
| public int getXorBitmapCount() { |
| int xored = 0; |
| for (StoredBitmap sb : getBitmaps()) { |
| if (!sb.isBase()) { |
| xored += 1; |
| } |
| } |
| return xored; |
| } |
| |
| @Override |
| public long getXorBitmapSizeInBytes() { |
| long xorSize = 0; |
| for (StoredBitmap sb : getBitmaps()) { |
| if (!sb.isBase()) { |
| xorSize += sb.getCurrentSizeInBytes(); |
| } |
| } |
| return xorSize; |
| } |
| |
| /** |
| * 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() { |
| EWAHCompressedBitmap bitmap = getBitmapWithoutCaching(); |
| // Cache the result. |
| bitmapContainer = bitmap; |
| return bitmap; |
| } |
| |
| /** |
| * Compute and return the full bitmap, do NOT cache the expanded bitmap, |
| * which saves memory and should only be used during bitmap creation in |
| * garbage collection. |
| * |
| * @return the full bitmap |
| */ |
| EWAHCompressedBitmap getBitmapWithoutCaching() { |
| // Fast path to immediately return the expanded result. |
| Object r = bitmapContainer; |
| if (r instanceof EWAHCompressedBitmap) { |
| return (EWAHCompressedBitmap) r; |
| } |
| |
| // Expand the bitmap but not 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(); |
| return out; |
| } |
| xb = (XorCompressedBitmap) r; |
| out = out.xor(xb.bitmap); |
| } |
| } |
| |
| /** |
| * Get flags |
| * |
| * @return the flags associated with the bitmap |
| */ |
| int getFlags() { |
| return flags; |
| } |
| |
| /** |
| * This bitmap is (currently) a base or a XOR mask |
| * |
| * @return true if this bitmap is a base (a ready map). |
| */ |
| boolean isBase() { |
| return bitmapContainer instanceof EWAHCompressedBitmap; |
| } |
| |
| /** |
| * Size in bytes of this bitmap in its current representation |
| * |
| * If this is a XOR'ed bitmap, size is different before/after |
| * {@link #getBitmap()}. Before is the byte size of the xor mask, |
| * afterwards is the size of the "ready" bitmap |
| * |
| * @return size in bytes of the bitmap in its current representation |
| */ |
| long getCurrentSizeInBytes() { |
| Object r = bitmapContainer; |
| if (r instanceof EWAHCompressedBitmap) { |
| return ((EWAHCompressedBitmap) r).sizeInBytes(); |
| } |
| XorCompressedBitmap xor = ((XorCompressedBitmap) r); |
| return xor.bitmap.sizeInBytes(); |
| } |
| } |
| |
| private static final class XorCompressedBitmap { |
| final EWAHCompressedBitmap bitmap; |
| |
| final StoredBitmap xorBitmap; |
| |
| XorCompressedBitmap(EWAHCompressedBitmap b, StoredBitmap xb) { |
| bitmap = b; |
| xorBitmap = xb; |
| } |
| } |
| } |