com.google.gerrit.server.ChangeUtil.java Source code

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Here is the source code for com.google.gerrit.server.ChangeUtil.java

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// Copyright (C) 2009 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.server;

import static java.util.Comparator.comparingInt;

import com.google.common.collect.Maps;
import com.google.common.collect.Ordering;
import com.google.common.io.BaseEncoding;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.inject.Singleton;
import java.io.IOException;
import java.security.SecureRandom;
import java.util.Map;
import java.util.Random;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;

@Singleton
public class ChangeUtil {
    private static final Random UUID_RANDOM = new SecureRandom();
    private static final BaseEncoding UUID_ENCODING = BaseEncoding.base16().lowerCase();

    private static final int SUBJECT_MAX_LENGTH = 80;
    private static final String SUBJECT_CROP_APPENDIX = "...";
    private static final int SUBJECT_CROP_RANGE = 10;

    public static final Ordering<PatchSet> PS_ID_ORDER = Ordering.from(comparingInt(PatchSet::getPatchSetId));

    /** @return a new unique identifier for change message entities. */
    public static String messageUuid() {
        byte[] buf = new byte[8];
        UUID_RANDOM.nextBytes(buf);
        return UUID_ENCODING.encode(buf, 0, 4) + '_' + UUID_ENCODING.encode(buf, 4, 4);
    }

    /**
     * Get the next patch set ID from a previously-read map of all refs.
     *
     * @param allRefs map of full ref name to ref, in the same format returned by {@link
     *     org.eclipse.jgit.lib.RefDatabase#getRefs(String)} when passing {@code ""}.
     * @param id previous patch set ID.
     * @return next unused patch set ID for the same change, skipping any IDs whose corresponding ref
     *     names appear in the {@code allRefs} map.
     */
    public static PatchSet.Id nextPatchSetIdFromAllRefsMap(Map<String, Ref> allRefs, PatchSet.Id id) {
        PatchSet.Id next = nextPatchSetId(id);
        while (allRefs.containsKey(next.toRefName())) {
            next = nextPatchSetId(next);
        }
        return next;
    }

    /**
     * Get the next patch set ID from a previously-read map of refs below the change prefix.
     *
     * @param changeRefs map of ref suffix to SHA-1, where the keys are ref names with the {@code
     *     refs/changes/CD/ABCD/} prefix stripped. All refs should be under {@code id}'s change ref
     *     prefix. The keys match the format returned by {@link
     *     org.eclipse.jgit.lib.RefDatabase#getRefs(String)} when passing the appropriate {@code
     *     refs/changes/CD/ABCD}.
     * @param id previous patch set ID.
     * @return next unused patch set ID for the same change, skipping any IDs whose corresponding ref
     *     names appear in the {@code changeRefs} map.
     */
    public static PatchSet.Id nextPatchSetIdFromChangeRefsMap(Map<String, ObjectId> changeRefs, PatchSet.Id id) {
        int prefixLen = id.getParentKey().toRefPrefix().length();
        PatchSet.Id next = nextPatchSetId(id);
        while (changeRefs.containsKey(next.toRefName().substring(prefixLen))) {
            next = nextPatchSetId(next);
        }
        return next;
    }

    /**
     * Get the next patch set ID just looking at a single previous patch set ID.
     *
     * <p>This patch set ID may or may not be available in the database; callers that want a
     * previously-unused ID should use {@link #nextPatchSetIdFromAllRefsMap} or {@link
     * #nextPatchSetIdFromChangeRefsMap}.
     *
     * @param id previous patch set ID.
     * @return next patch set ID for the same change, incrementing by 1.
     */
    public static PatchSet.Id nextPatchSetId(PatchSet.Id id) {
        return new PatchSet.Id(id.getParentKey(), id.get() + 1);
    }

    /**
     * Get the next patch set ID from scanning refs in the repo.
     *
     * @param git repository to scan for patch set refs.
     * @param id previous patch set ID.
     * @return next unused patch set ID for the same change, skipping any IDs whose corresponding ref
     *     names appear in the repository.
     */
    public static PatchSet.Id nextPatchSetId(Repository git, PatchSet.Id id) throws IOException {
        return nextPatchSetIdFromChangeRefsMap(Maps.transformValues(
                git.getRefDatabase().getRefs(id.getParentKey().toRefPrefix()), Ref::getObjectId), id);
    }

    public static String cropSubject(String subject) {
        if (subject.length() > SUBJECT_MAX_LENGTH) {
            int maxLength = SUBJECT_MAX_LENGTH - SUBJECT_CROP_APPENDIX.length();
            for (int cropPosition = maxLength; cropPosition > maxLength - SUBJECT_CROP_RANGE; cropPosition--) {
                if (Character.isWhitespace(subject.charAt(cropPosition - 1))) {
                    return subject.substring(0, cropPosition) + SUBJECT_CROP_APPENDIX;
                }
            }
            return subject.substring(0, maxLength) + SUBJECT_CROP_APPENDIX;
        }
        return subject;
    }

    private ChangeUtil() {
    }
}