NoMergeBaseException.java

/*
 * Copyright (C) 2013, Christian Halstrick <christian.halstrick@sap.com> 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.errors;

import java.io.IOException;
import java.text.MessageFormat;

import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.merge.RecursiveMerger;

/**
 * Exception thrown if a merge fails because no merge base could be determined.
 *
 * @since 3.0
 */
public class NoMergeBaseException extends IOException {
    private static final long serialVersionUID = 1L;

    private MergeBaseFailureReason reason;

    /**
     * An enum listing the different reason why no merge base could be
     * determined.
     */
    public enum MergeBaseFailureReason {
        /**
         * Multiple merge bases have been found (e.g. the commits to be merged
         * have multiple common predecessors) but the merge strategy doesn't
         * support this (e.g. ResolveMerge)
         */
        MULTIPLE_MERGE_BASES_NOT_SUPPORTED,

        /**
         * The number of merge bases exceeds {@link RecursiveMerger#MAX_BASES}
         */
        TOO_MANY_MERGE_BASES,

        /**
         * In order to find a single merge base it may required to merge
         * together multiple common predecessors. If during these merges
         * conflicts occur the merge fails with this reason
         */
        CONFLICTS_DURING_MERGE_BASE_CALCULATION
    }


    /**
     * Construct a NoMergeBase exception
     *
     * @param reason
     *            the reason why no merge base could be found
     * @param message
     *            a text describing the problem
     */
    public NoMergeBaseException(MergeBaseFailureReason reason, String message) {
        super(MessageFormat.format(JGitText.get().noMergeBase,
                reason.toString(), message));
        this.reason = reason;
    }

    /**
     * Construct a NoMergeBase exception
     *
     * @param reason
     *            the reason why no merge base could be found
     * @param message
     *            a text describing the problem
     * @param why
     *            an exception causing this error
     */
    public NoMergeBaseException(MergeBaseFailureReason reason, String message,
            Throwable why) {
        super(MessageFormat.format(JGitText.get().noMergeBase,
                reason.toString(), message));
        this.reason = reason;
        initCause(why);
    }

    /**
     * Get the reason why no merge base could be found
     *
     * @return the reason why no merge base could be found
     */
    public MergeBaseFailureReason getReason() {
        return reason;
    }
}