|
|
@@ -0,0 +1,122 @@ |
|
|
|
/* |
|
|
|
* 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. |
|
|
|
* |
|
|
|
* @since 5.5 |
|
|
|
*/ |
|
|
|
public 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)); |
|
|
|
} |
|
|
|
|
|
|
|
} |