| /* |
| * Copyright (C) 2019, Google LLC |
| * 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.revwalk; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Optional; |
| |
| import org.eclipse.jgit.errors.IncorrectObjectTypeException; |
| import org.eclipse.jgit.errors.MissingObjectException; |
| import org.eclipse.jgit.lib.BitmapIndex.BitmapBuilder; |
| import org.eclipse.jgit.lib.NullProgressMonitor; |
| |
| /** |
| * Checks the reachability using bitmaps. |
| */ |
| class BitmappedReachabilityChecker implements ReachabilityChecker { |
| |
| private final RevWalk walk; |
| |
| /** |
| * @param walk |
| * walk on the repository to get or create the bitmaps for the |
| * commits. It must have bitmaps. |
| * @throws AssertionError |
| * runtime exception if walk is over a repository without |
| * bitmaps |
| * @throws IOException |
| * if the index or the object reader cannot be opened. |
| */ |
| public BitmappedReachabilityChecker(RevWalk walk) |
| throws IOException { |
| this.walk = walk; |
| if (walk.getObjectReader().getBitmapIndex() == null) { |
| throw new AssertionError( |
| "Trying to use bitmapped reachability check " //$NON-NLS-1$ |
| + "on a repository without bitmaps"); //$NON-NLS-1$ |
| } |
| } |
| |
| /** |
| * Check all targets are reachable from the starters. |
| * <p> |
| * In this implementation, it is recommended to put the most popular |
| * starters (e.g. refs/heads tips) at the beginning of the collection |
| */ |
| @Override |
| public Optional<RevCommit> areAllReachable(Collection<RevCommit> targets, |
| Collection<RevCommit> starters) throws MissingObjectException, |
| IncorrectObjectTypeException, IOException { |
| BitmapCalculator calculator = new BitmapCalculator(walk); |
| |
| /** |
| * Iterate over starters bitmaps and remove targets as they become |
| * reachable. |
| * |
| * Building the total starters bitmap has the same cost (iterating over |
| * all starters adding the bitmaps) and this gives us the chance to |
| * shorcut the loop. |
| * |
| * This is based on the assuption that most of the starters will have |
| * the reachability bitmap precalculated. If many require a walk, the |
| * walk.reset() could start to take too much time. |
| */ |
| List<RevCommit> remainingTargets = new ArrayList<>(targets); |
| for (RevCommit starter : starters) { |
| BitmapBuilder starterBitmap = calculator.getBitmap(starter, |
| NullProgressMonitor.INSTANCE); |
| remainingTargets.removeIf(starterBitmap::contains); |
| if (remainingTargets.isEmpty()) { |
| return Optional.empty(); |
| } |
| } |
| |
| return Optional.of(remainingTargets.get(0)); |
| } |
| |
| } |