com.google.gerrit.server.util.MagicBranch.java Source code

Introduction

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

Source

// Copyright (C) 2011 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.util;

import com.google.gerrit.common.data.Capable;
import com.google.gerrit.reviewdb.client.Project;

import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Map;

public final class MagicBranch {
    private static final Logger log = LoggerFactory.getLogger(MagicBranch.class);

    public static final String NEW_CHANGE = "refs/for/";
    public static final String NEW_DRAFT_CHANGE = "refs/drafts/";
    public static final String NEW_PUBLISH_CHANGE = "refs/publish/";

    /** Extracts the destination from a ref name */
    public static String getDestBranchName(String refName) {
        String magicBranch = NEW_CHANGE;
        if (refName.startsWith(NEW_DRAFT_CHANGE)) {
            magicBranch = NEW_DRAFT_CHANGE;
        } else if (refName.startsWith(NEW_PUBLISH_CHANGE)) {
            magicBranch = NEW_PUBLISH_CHANGE;
        }
        return refName.substring(magicBranch.length());
    }

    /** Checks if the supplied ref name is a magic branch */
    public static boolean isMagicBranch(String refName) {
        return refName.startsWith(NEW_DRAFT_CHANGE) || refName.startsWith(NEW_PUBLISH_CHANGE)
                || refName.startsWith(NEW_CHANGE);
    }

    /** Returns the ref name prefix for a magic branch, {@code null} if the branch is not magic */
    public static String getMagicRefNamePrefix(String refName) {
        if (refName.startsWith(NEW_DRAFT_CHANGE)) {
            return NEW_DRAFT_CHANGE;
        }
        if (refName.startsWith(NEW_PUBLISH_CHANGE)) {
            return NEW_PUBLISH_CHANGE;
        }
        if (refName.startsWith(NEW_CHANGE)) {
            return NEW_CHANGE;
        }
        return null;
    }

    /**
     * Checks if a (magic branch)/branch_name reference exists in the
     * destination repository and only returns Capable.OK if it does not match any.
     *
     * These block the client from being able to even send us a pack file, as it
     * is very unlikely the user passed the --force flag and the new commit is
     * probably not going to fast-forward the branch.
     */
    public static Capable checkMagicBranchRefs(Repository repo, Project project) {
        Capable result = checkMagicBranchRef(NEW_CHANGE, repo, project);
        if (result != Capable.OK) {
            return result;
        }
        result = checkMagicBranchRef(NEW_DRAFT_CHANGE, repo, project);
        if (result != Capable.OK) {
            return result;
        }
        result = checkMagicBranchRef(NEW_PUBLISH_CHANGE, repo, project);
        if (result != Capable.OK) {
            return result;
        }

        return Capable.OK;
    }

    private static Capable checkMagicBranchRef(String branchName, Repository repo, Project project) {
        Map<String, Ref> blockingFors;
        try {
            blockingFors = repo.getRefDatabase().getRefs(branchName);
        } catch (IOException err) {
            String projName = project.getName();
            log.warn("Cannot scan refs in '" + projName + "'", err);
            return new Capable("Server process cannot read '" + projName + "'");
        }
        if (!blockingFors.isEmpty()) {
            String projName = project.getName();
            log.error("Repository '" + projName + "' needs the following refs removed to receive changes: "
                    + blockingFors.keySet());
            return new Capable("One or more " + branchName + " names blocks change upload");
        }

        return Capable.OK;
    }

    private MagicBranch() {
    }
}