| /* |
| * 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; |
| |
| /** |
| * Produces commits for RevWalk to return to applications. |
| * <p> |
| * Implementations of this basic class provide the real work behind RevWalk. |
| * Conceptually a Generator is an iterator or a queue, it returns commits until |
| * there are no more relevant. Generators may be piped/stacked together to |
| * create a more complex set of operations. |
| * |
| * @see PendingGenerator |
| * @see StartGenerator |
| */ |
| abstract class Generator { |
| /** Commits are sorted by commit date and time, descending. */ |
| static final int SORT_COMMIT_TIME_DESC = 1 << 0; |
| |
| /** Output may have {@link RevWalk#REWRITE} marked on it. */ |
| static final int HAS_REWRITE = 1 << 1; |
| |
| /** Output needs {@link RewriteGenerator}. */ |
| static final int NEEDS_REWRITE = 1 << 2; |
| |
| /** Topological ordering is enforced (all children before parents). */ |
| static final int SORT_TOPO = 1 << 3; |
| |
| /** Output may have {@link RevWalk#UNINTERESTING} marked on it. */ |
| static final int HAS_UNINTERESTING = 1 << 4; |
| |
| protected final boolean firstParent; |
| |
| protected Generator(boolean firstParent) { |
| this.firstParent = firstParent; |
| } |
| |
| /** |
| * Connect the supplied queue to this generator's own free list (if any). |
| * |
| * @param q |
| * another FIFO queue that wants to share our queue's free list. |
| */ |
| void shareFreeList(BlockRevQueue q) { |
| // Do nothing by default. |
| } |
| |
| /** |
| * Obtain flags describing the output behavior of this generator. |
| * |
| * @return one or more of the constants declared in this class, describing |
| * how this generator produces its results. |
| */ |
| abstract int outputType(); |
| |
| /** |
| * Return the next commit to the application, or the next generator. |
| * |
| * @return next available commit; null if no more are to be returned. |
| * @throws MissingObjectException |
| * @throws IncorrectObjectTypeException |
| * @throws IOException |
| */ |
| abstract RevCommit next() throws MissingObjectException, |
| IncorrectObjectTypeException, IOException; |
| } |