org.eclipse.jgit.revwalk.Generator Maven / Gradle / Ivy
/*
* Copyright (C) 2008, Shawn O. Pearce
* 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,
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* 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 org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
/**
* Produces commits for RevWalk to return to applications.
*
* 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;
/**
* 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(final 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;
}