| /* |
| * 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.revwalk; |
| |
| import java.io.IOException; |
| import java.util.Arrays; |
| |
| import org.eclipse.jgit.errors.IncorrectObjectTypeException; |
| import org.eclipse.jgit.errors.MissingObjectException; |
| import org.eclipse.jgit.internal.revwalk.AddToBitmapFilter; |
| import org.eclipse.jgit.internal.revwalk.AddUnseenToBitmapFilter; |
| import org.eclipse.jgit.lib.AnyObjectId; |
| import org.eclipse.jgit.lib.BitmapIndex; |
| import org.eclipse.jgit.lib.BitmapIndex.Bitmap; |
| import org.eclipse.jgit.lib.BitmapIndex.BitmapBuilder; |
| import org.eclipse.jgit.lib.NullProgressMonitor; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.lib.ProgressMonitor; |
| import org.eclipse.jgit.revwalk.filter.ObjectFilter; |
| |
| /** |
| * Helper class to do ObjectWalks with pack index bitmaps. |
| * |
| * @since 4.10 |
| */ |
| public final class BitmapWalker { |
| |
| private final ObjectWalk walker; |
| |
| private final BitmapIndex bitmapIndex; |
| |
| private final ProgressMonitor pm; |
| |
| private long countOfBitmapIndexMisses; |
| |
| /** |
| * Create a BitmapWalker. |
| * |
| * @param walker walker to use when traversing the object graph. |
| * @param bitmapIndex index to obtain bitmaps from. |
| * @param pm progress monitor to report progress on. |
| */ |
| public BitmapWalker( |
| ObjectWalk walker, BitmapIndex bitmapIndex, ProgressMonitor pm) { |
| this.walker = walker; |
| this.bitmapIndex = bitmapIndex; |
| this.pm = (pm == null) ? NullProgressMonitor.INSTANCE : pm; |
| } |
| |
| /** |
| * Return the number of objects that had to be walked because they were not covered by a |
| * bitmap. |
| * |
| * @return the number of objects that had to be walked because they were not covered by a |
| * bitmap. |
| */ |
| public long getCountOfBitmapIndexMisses() { |
| return countOfBitmapIndexMisses; |
| } |
| |
| /** |
| * Return, as a bitmap, the objects reachable from the objects in start. |
| * |
| * @param start |
| * the objects to start the object traversal from. |
| * @param seen |
| * the objects to skip if encountered during traversal. |
| * @param ignoreMissing |
| * true to ignore missing objects, false otherwise. |
| * @return as a bitmap, the objects reachable from the objects in start. |
| * @throws org.eclipse.jgit.errors.MissingObjectException |
| * the object supplied is not available from the object |
| * database. This usually indicates the supplied object is |
| * invalid, but the reference was constructed during an earlier |
| * invocation to |
| * {@link org.eclipse.jgit.revwalk.RevWalk#lookupAny(AnyObjectId, int)}. |
| * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException |
| * the object was not parsed yet and it was discovered during |
| * parsing that it is not actually the type of the instance |
| * passed in. This usually indicates the caller used the wrong |
| * type in a |
| * {@link org.eclipse.jgit.revwalk.RevWalk#lookupAny(AnyObjectId, int)} |
| * call. |
| * @throws java.io.IOException |
| * a pack file or loose object could not be read. |
| */ |
| public BitmapBuilder findObjects(Iterable<? extends ObjectId> start, BitmapBuilder seen, |
| boolean ignoreMissing) |
| throws MissingObjectException, IncorrectObjectTypeException, |
| IOException { |
| if (!ignoreMissing) { |
| return findObjectsWalk(start, seen, false); |
| } |
| |
| try { |
| return findObjectsWalk(start, seen, true); |
| } catch (MissingObjectException ignore) { |
| // An object reachable from one of the "start"s is missing. |
| // Walk from the "start"s one at a time so it can be excluded. |
| } |
| |
| final BitmapBuilder result = bitmapIndex.newBitmapBuilder(); |
| for (ObjectId obj : start) { |
| Bitmap bitmap = bitmapIndex.getBitmap(obj); |
| if (bitmap != null) { |
| result.or(bitmap); |
| } |
| } |
| |
| for (ObjectId obj : start) { |
| if (result.contains(obj)) { |
| continue; |
| } |
| try { |
| result.or(findObjectsWalk(Arrays.asList(obj), result, false)); |
| } catch (MissingObjectException ignore) { |
| // An object reachable from this "start" is missing. |
| // |
| // This can happen when the client specified a "have" line |
| // pointing to an object that is present but unreachable: |
| // "git prune" and "git fsck" only guarantee that the object |
| // database will continue to contain all objects reachable |
| // from a ref and does not guarantee connectivity for other |
| // objects in the object database. |
| // |
| // In this situation, skip the relevant "start" and move on |
| // to the next one. |
| // |
| // TODO(czhen): Make findObjectsWalk resume the walk instead |
| // once RevWalk and ObjectWalk support that. |
| } |
| } |
| return result; |
| } |
| |
| private BitmapBuilder findObjectsWalk(Iterable<? extends ObjectId> start, BitmapBuilder seen, |
| boolean ignoreMissingStart) |
| throws MissingObjectException, IncorrectObjectTypeException, |
| IOException { |
| walker.reset(); |
| final BitmapBuilder bitmapResult = bitmapIndex.newBitmapBuilder(); |
| |
| for (ObjectId obj : start) { |
| Bitmap bitmap = bitmapIndex.getBitmap(obj); |
| if (bitmap != null) |
| bitmapResult.or(bitmap); |
| } |
| |
| boolean marked = false; |
| for (ObjectId obj : start) { |
| try { |
| if (!bitmapResult.contains(obj)) { |
| walker.markStart(walker.parseAny(obj)); |
| marked = true; |
| } |
| } catch (MissingObjectException e) { |
| if (ignoreMissingStart) |
| continue; |
| throw e; |
| } |
| } |
| |
| if (marked) { |
| if (seen == null) { |
| walker.setRevFilter(new AddToBitmapFilter(bitmapResult)); |
| } else { |
| walker.setRevFilter( |
| new AddUnseenToBitmapFilter(seen, bitmapResult)); |
| } |
| walker.setObjectFilter(new BitmapObjectFilter(bitmapResult)); |
| |
| while (walker.next() != null) { |
| // Iterate through all of the commits. The BitmapRevFilter does |
| // the work. |
| // |
| // filter.include returns true for commits that do not have |
| // a bitmap in bitmapIndex and are not reachable from a |
| // bitmap in bitmapIndex encountered earlier in the walk. |
| // Thus the number of commits returned by next() measures how |
| // much history was traversed without being able to make use |
| // of bitmaps. |
| pm.update(1); |
| countOfBitmapIndexMisses++; |
| } |
| |
| RevObject ro; |
| while ((ro = walker.nextObject()) != null) { |
| bitmapResult.addObject(ro, ro.getType()); |
| pm.update(1); |
| } |
| } |
| |
| return bitmapResult; |
| } |
| |
| /** |
| * Filter that excludes objects already in the given bitmap. |
| */ |
| static class BitmapObjectFilter extends ObjectFilter { |
| private final BitmapBuilder bitmap; |
| |
| BitmapObjectFilter(BitmapBuilder bitmap) { |
| this.bitmap = bitmap; |
| } |
| |
| @Override |
| public final boolean include(ObjectWalk walker, AnyObjectId objid) |
| throws MissingObjectException, IncorrectObjectTypeException, |
| IOException { |
| return !bitmap.contains(objid); |
| } |
| } |
| } |