RevFlag.java

/*
 * 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.text.MessageFormat;

import org.eclipse.jgit.internal.JGitText;

/**
 * Application level mark bit for {@link org.eclipse.jgit.revwalk.RevObject}s.
 * <p>
 * To create a flag use
 * {@link org.eclipse.jgit.revwalk.RevWalk#newFlag(String)}.
 */
public class RevFlag {
    /**
     * Uninteresting by {@link RevWalk#markUninteresting(RevCommit)}.
     * <p>
     * We flag commits as uninteresting if the caller does not want commits
     * reachable from a commit to {@link RevWalk#markUninteresting(RevCommit)}.
     * This flag is always carried into the commit's parents and is a key part
     * of the "rev-list B --not A" feature; A is marked UNINTERESTING.
     * <p>
     * This is a static flag. Its RevWalk is not available.
     */
    public static final RevFlag UNINTERESTING = new StaticRevFlag(
            "UNINTERESTING", RevWalk.UNINTERESTING); //$NON-NLS-1$

    /**
     * Set on RevCommit instances added to {@link RevWalk#pending} queue.
     * <p>
     * We use this flag to avoid adding the same commit instance twice to our
     * queue, especially if we reached it by more than one path.
     * <p>
     * This is a static flag. Its RevWalk is not available.
     *
     * @since 3.0
     */
    public static final RevFlag SEEN = new StaticRevFlag("SEEN", RevWalk.SEEN); //$NON-NLS-1$

    final RevWalk walker;

    final String name;

    final int mask;

    RevFlag(RevWalk w, String n, int m) {
        walker = w;
        name = n;
        mask = m;
    }

    /**
     * Get the revision walk instance this flag was created from.
     *
     * @return the walker this flag was allocated out of, and belongs to.
     */
    public RevWalk getRevWalk() {
        return walker;
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return name;
    }

    static class StaticRevFlag extends RevFlag {
        StaticRevFlag(String n, int m) {
            super(null, n, m);
        }

        @Override
        public RevWalk getRevWalk() {
            throw new UnsupportedOperationException(MessageFormat.format(
                    JGitText.get().isAStaticFlagAndHasNorevWalkInstance, toString()));
        }
    }
}