| /* |
| * 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; |
| |
| /** Sorts commits in topological order. */ |
| class TopoSortGenerator extends Generator { |
| private static final int TOPO_DELAY = RevWalk.TOPO_DELAY; |
| |
| private final FIFORevQueue pending; |
| |
| private final int outputType; |
| |
| /** |
| * Create a new sorter and completely spin the generator. |
| * <p> |
| * When the constructor completes the supplied generator will have no |
| * commits remaining, as all of the commits will be held inside of this |
| * generator's internal buffer. |
| * |
| * @param s |
| * generator to pull all commits out of, and into this buffer. |
| * @throws MissingObjectException |
| * @throws IncorrectObjectTypeException |
| * @throws IOException |
| */ |
| TopoSortGenerator(Generator s) throws MissingObjectException, |
| IncorrectObjectTypeException, IOException { |
| super(s.firstParent); |
| pending = new FIFORevQueue(firstParent); |
| outputType = s.outputType() | SORT_TOPO; |
| s.shareFreeList(pending); |
| for (;;) { |
| final RevCommit c = s.next(); |
| if (c == null) { |
| break; |
| } |
| for (RevCommit p : c.parents) { |
| p.inDegree++; |
| if (firstParent) { |
| break; |
| } |
| } |
| pending.add(c); |
| } |
| } |
| |
| @Override |
| int outputType() { |
| return outputType; |
| } |
| |
| @Override |
| void shareFreeList(BlockRevQueue q) { |
| q.shareFreeList(pending); |
| } |
| |
| @Override |
| RevCommit next() throws MissingObjectException, |
| IncorrectObjectTypeException, IOException { |
| for (;;) { |
| final RevCommit c = pending.next(); |
| if (c == null) |
| return null; |
| |
| if (c.inDegree > 0) { |
| // At least one of our children is missing. We delay |
| // production until all of our children are output. |
| // |
| c.flags |= TOPO_DELAY; |
| continue; |
| } |
| |
| // All of our children have already produced, |
| // so it is OK for us to produce now as well. |
| // |
| for (RevCommit p : c.parents) { |
| if (--p.inDegree == 0 && (p.flags & TOPO_DELAY) != 0) { |
| // This parent tried to come before us, but we are |
| // his last child. unpop the parent so it goes right |
| // behind this child. |
| // |
| p.flags &= ~TOPO_DELAY; |
| pending.unpop(p); |
| } |
| if (firstParent) { |
| break; |
| } |
| } |
| return c; |
| } |
| } |
| } |