com.google.gerrit.server.notedb.AbstractChangeNotes Maven / Gradle / Ivy
// Copyright (C) 2014 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.notedb;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableSet;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.common.UsedAt;
import com.google.gerrit.entities.Change;
import com.google.gerrit.entities.Project;
import com.google.gerrit.exceptions.StorageException;
import com.google.gerrit.metrics.Timer0;
import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.config.GerritImportedServerIds;
import com.google.gerrit.server.config.GerritServerId;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.notedb.ChangeNotesCommit.ChangeNotesRevWalk;
import com.google.gerrit.server.project.NoSuchChangeException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicBoolean;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
/** View of contents at a single ref related to some change. * */
public abstract class AbstractChangeNotes {
@VisibleForTesting
@Singleton
@UsedAt(UsedAt.Project.PLUGIN_CHECKS)
public static class Args {
// TODO(dborowitz): Some less smelly way of disabling NoteDb in tests.
public final AtomicBoolean failOnLoadForTest;
public final ChangeNoteJson changeNoteJson;
public final GitRepositoryManager repoManager;
public final AllUsersName allUsers;
public final NoteDbMetrics metrics;
public final String serverId;
public final ImmutableSet importedServerIds;
// Providers required to avoid dependency cycles.
// ChangeNoteCache -> Args
public final Provider cache;
@Inject
Args(
GitRepositoryManager repoManager,
AllUsersName allUsers,
ChangeNoteJson changeNoteJson,
NoteDbMetrics metrics,
Provider cache,
@GerritServerId String serverId,
@GerritImportedServerIds ImmutableSet importedServerIds) {
this.failOnLoadForTest = new AtomicBoolean();
this.repoManager = repoManager;
this.allUsers = allUsers;
this.changeNoteJson = changeNoteJson;
this.metrics = metrics;
this.cache = cache;
this.serverId = serverId;
this.importedServerIds = importedServerIds;
}
}
/** An {@link AutoCloseable} for parsing a single commit into ChangeNotesCommits. */
public static class LoadHandle implements AutoCloseable {
private final Repository repo;
private final ObjectId id;
private ChangeNotesRevWalk rw;
private LoadHandle(Repository repo, @Nullable ObjectId id) {
this.repo = requireNonNull(repo);
if (ObjectId.zeroId().equals(id)) {
id = null;
} else if (id != null) {
id = id.copy();
}
this.id = id;
}
public ChangeNotesRevWalk walk() {
if (rw == null) {
rw = ChangeNotesCommit.newRevWalk(repo);
}
return rw;
}
@Nullable
public ObjectId id() {
return id;
}
@Override
public void close() {
if (rw != null) {
rw.close();
}
}
}
protected final Args args;
private final Change.Id changeId;
private ObjectId revision;
private boolean loaded;
protected AbstractChangeNotes(Args args, Change.Id changeId, @Nullable ObjectId metaSha1) {
this.args = requireNonNull(args);
this.changeId = requireNonNull(changeId);
this.revision = metaSha1;
}
protected AbstractChangeNotes(Args args, Change.Id changeId) {
this(args, changeId, null);
}
public Change.Id getChangeId() {
return changeId;
}
/** Returns revision of the metadata that was loaded. */
public ObjectId getRevision() {
return revision;
}
public T load() {
try (Repository repo = args.repoManager.openRepository(getProjectName())) {
load(repo);
return self();
} catch (IOException e) {
throw new StorageException(e);
}
}
public T load(Repository repo) {
if (loaded) {
return self();
}
if (args.failOnLoadForTest.get()) {
throw new StorageException("Reading from NoteDb is disabled");
}
try (Timer0.Context timer = args.metrics.readLatency.start();
// Call openHandle even if reading is disabled, to trigger
// auto-rebuilding before this object may get passed to a ChangeUpdate.
LoadHandle handle = openHandle(repo, revision)) {
revision = handle.id();
onLoad(handle);
loaded = true;
} catch (ConfigInvalidException | IOException e) {
throw new StorageException(e);
}
return self();
}
@Nullable
protected ObjectId readRef(Repository repo) throws IOException {
Ref ref = repo.getRefDatabase().exactRef(getRefName());
return ref != null ? ref.getObjectId() : null;
}
/**
* Open a handle for reading this entity from a repository.
*
* Implementations may override this method to provide auto-rebuilding behavior.
*
* @param repo open repository.
* @param id SHA1 of the entity to read from the repository. The SHA1 is not sanity checked and is
* assumed to be valid. If null, lookup SHA1 from the /meta ref.
* @return handle for reading the entity.
* @throws NoSuchChangeException change does not exist.
* @throws IOException a repo-level error occurred.
*/
protected LoadHandle openHandle(Repository repo, @Nullable ObjectId id)
throws NoSuchChangeException, IOException {
if (id == null) {
id = readRef(repo);
}
return new LoadHandle(repo, id);
}
public T reload() {
loaded = false;
return load();
}
public ObjectId loadRevision() {
if (loaded) {
return getRevision();
}
try (Repository repo = args.repoManager.openRepository(getProjectName())) {
Ref ref = repo.getRefDatabase().exactRef(getRefName());
return ref != null ? ref.getObjectId() : null;
} catch (IOException e) {
throw new StorageException(e);
}
}
/** Load default values for any instance variables when NoteDb is disabled. */
protected abstract void loadDefaults();
/**
* Returns the NameKey for the project where the notes should be stored, which is not necessarily
* the same as the change's project.
*/
public abstract Project.NameKey getProjectName();
/** Returns name of the reference storing this configuration. */
protected abstract String getRefName();
/** Set up the metadata, parsing any state from the loaded revision. */
protected abstract void onLoad(LoadHandle handle)
throws NoSuchChangeException, IOException, ConfigInvalidException;
@SuppressWarnings("unchecked")
protected final T self() {
return (T) this;
}
}