com.google.gerrit.server.schema.Schema_146.java Source code

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Here is the source code for com.google.gerrit.server.schema.Schema_146.java

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// Copyright (C) 2017 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.schema;

import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.RefNames;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.GerritPersonIdent;
import com.google.gerrit.server.account.AccountsUpdate;
import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.io.IOException;
import java.sql.SQLException;
import java.sql.Timestamp;
import org.eclipse.jgit.lib.CommitBuilder;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.RefUpdate.Result;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevSort;
import org.eclipse.jgit.revwalk.RevWalk;

/**
 * Make sure that for every account a user branch exists that has an initial empty commit with the
 * registration date as commit time.
 *
 * <p>For accounts that don't have a user branch yet the user branch is created with an initial
 * empty commit that has the registration date as commit time.
 *
 * <p>For accounts that already have a user branch the user branch is rewritten and an initial empty
 * commit with the registration date as commit time is inserted (if such a commit doesn't exist
 * yet).
 */
public class Schema_146 extends SchemaVersion {
    private static final String CREATE_ACCOUNT_MSG = "Create Account";

    private final GitRepositoryManager repoManager;
    private final AllUsersName allUsersName;
    private final PersonIdent serverIdent;

    @Inject
    Schema_146(Provider<Schema_145> prior, GitRepositoryManager repoManager, AllUsersName allUsersName,
            @GerritPersonIdent PersonIdent serverIdent) {
        super(prior);
        this.repoManager = repoManager;
        this.allUsersName = allUsersName;
        this.serverIdent = serverIdent;
    }

    @Override
    protected void migrateData(ReviewDb db, UpdateUI ui) throws OrmException, SQLException {
        try (Repository repo = repoManager.openRepository(allUsersName);
                RevWalk rw = new RevWalk(repo);
                ObjectInserter oi = repo.newObjectInserter()) {
            ObjectId emptyTree = emptyTree(oi);

            for (Account account : db.accounts().all()) {
                String refName = RefNames.refsUsers(account.getId());
                Ref ref = repo.exactRef(refName);
                if (ref != null) {
                    rewriteUserBranch(repo, rw, oi, emptyTree, ref, account);
                } else {
                    AccountsUpdate.createUserBranch(repo, oi, serverIdent, serverIdent, account);
                }
            }
        } catch (IOException e) {
            throw new OrmException("Failed to rewrite user branches.", e);
        }
    }

    private void rewriteUserBranch(Repository repo, RevWalk rw, ObjectInserter oi, ObjectId emptyTree, Ref ref,
            Account account) throws IOException {
        ObjectId current = createInitialEmptyCommit(oi, emptyTree, account.getRegisteredOn());

        rw.reset();
        rw.sort(RevSort.TOPO);
        rw.sort(RevSort.REVERSE, true);
        rw.markStart(rw.parseCommit(ref.getObjectId()));

        RevCommit c;
        while ((c = rw.next()) != null) {
            if (isInitialEmptyCommit(emptyTree, c)) {
                return;
            }

            CommitBuilder cb = new CommitBuilder();
            cb.setParentId(current);
            cb.setTreeId(c.getTree());
            cb.setAuthor(c.getAuthorIdent());
            cb.setCommitter(c.getCommitterIdent());
            cb.setMessage(c.getFullMessage());
            cb.setEncoding(c.getEncoding());
            current = oi.insert(cb);
        }

        oi.flush();

        RefUpdate ru = repo.updateRef(ref.getName());
        ru.setExpectedOldObjectId(ref.getObjectId());
        ru.setNewObjectId(current);
        ru.setForceUpdate(true);
        ru.setRefLogIdent(serverIdent);
        ru.setRefLogMessage(getClass().getSimpleName(), true);
        Result result = ru.update();
        if (result != Result.FORCED) {
            throw new IOException(String.format("Failed to update ref %s: %s", ref.getName(), result.name()));
        }
    }

    private ObjectId createInitialEmptyCommit(ObjectInserter oi, ObjectId emptyTree, Timestamp registrationDate)
            throws IOException {
        PersonIdent ident = new PersonIdent(serverIdent, registrationDate);

        CommitBuilder cb = new CommitBuilder();
        cb.setTreeId(emptyTree);
        cb.setCommitter(ident);
        cb.setAuthor(ident);
        cb.setMessage(CREATE_ACCOUNT_MSG);
        return oi.insert(cb);
    }

    private boolean isInitialEmptyCommit(ObjectId emptyTree, RevCommit c) {
        return c.getParentCount() == 0 && c.getTree().equals(emptyTree)
                && c.getShortMessage().equals(CREATE_ACCOUNT_MSG);
    }

    private static ObjectId emptyTree(ObjectInserter oi) throws IOException {
        return oi.insert(Constants.OBJ_TREE, new byte[] {});
    }
}