blob: 234c74b07f79e9b1057fefcf59f9ba6e08d68968 [file] [log] [blame]
/*
* Copyright (C) 2009, Google Inc.
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> 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 org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
/**
* Delays commits to be at least {@link PendingGenerator#OVER_SCAN} late.
* <p>
* This helps to "fix up" weird corner cases resulting from clock skew, by
* slowing down what we produce to the caller we get a better chance to ensure
* PendingGenerator reached back far enough in the graph to correctly mark
* commits {@link RevWalk#UNINTERESTING} if necessary.
* <p>
* This generator should appear before {@link FixUninterestingGenerator} if the
* lower level {@link #pending} isn't already fully buffered.
*/
final class DelayRevQueue extends Generator {
private static final int OVER_SCAN = PendingGenerator.OVER_SCAN;
private final Generator pending;
private final FIFORevQueue delay;
private int size;
DelayRevQueue(Generator g) {
super(g.firstParent);
pending = g;
delay = new FIFORevQueue();
}
@Override
int outputType() {
return pending.outputType();
}
@Override
RevCommit next() throws MissingObjectException,
IncorrectObjectTypeException, IOException {
while (size < OVER_SCAN) {
final RevCommit c = pending.next();
if (c == null)
break;
delay.add(c);
size++;
}
final RevCommit c = delay.next();
if (c == null)
return null;
size--;
return c;
}
}