com.google.gerrit.server.git.SearchingChangeCacheImpl Maven / Gradle / Ivy
// Copyright (C) 2012 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.git;
import com.google.auto.value.AutoValue;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.flogger.FluentLogger;
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.entities.RefNames;
import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.server.ReviewerSet;
import com.google.gerrit.server.cache.CacheModule;
import com.google.gerrit.server.index.change.ChangeField;
import com.google.gerrit.server.logging.Metadata;
import com.google.gerrit.server.logging.TraceContext;
import com.google.gerrit.server.logging.TraceContext.TraceTimer;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gerrit.server.util.ManualRequestContext;
import com.google.gerrit.server.util.OneOffRequestContext;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import com.google.inject.TypeLiteral;
import com.google.inject.name.Named;
import com.google.inject.util.Providers;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.stream.Stream;
/**
* Cache based on an index query of the most recent changes. The number of cached items depends on
* the index implementation and configuration.
*
* This cache is intended to be used when filtering references. By design it returns only a
* fraction of all changes. These are the changes that were modified last.
*/
@Singleton
public class SearchingChangeCacheImpl implements GitReferenceUpdatedListener {
private static final FluentLogger logger = FluentLogger.forEnclosingClass();
static final String ID_CACHE = "changes";
public static class SearchingChangeCacheImplModule extends CacheModule {
private final boolean slave;
public SearchingChangeCacheImplModule() {
this(false);
}
public SearchingChangeCacheImplModule(boolean slave) {
this.slave = slave;
}
@Override
protected void configure() {
if (slave) {
bind(SearchingChangeCacheImpl.class).toProvider(Providers.of(null));
} else {
cache(ID_CACHE, Project.NameKey.class, new TypeLiteral>() {})
.maximumWeight(0)
.loader(Loader.class);
bind(SearchingChangeCacheImpl.class);
DynamicSet.bind(binder(), GitReferenceUpdatedListener.class)
.to(SearchingChangeCacheImpl.class);
}
}
}
@AutoValue
@UsedAt(UsedAt.Project.GOOGLE)
public abstract static class CachedChange {
// Subset of fields in ChangeData, specifically fields needed to serve
// VisibleRefFilter without touching the database. More can be added as
// necessary.
abstract Change change();
@Nullable
abstract ReviewerSet reviewers();
}
private final LoadingCache> cache;
private final ChangeData.Factory changeDataFactory;
@Inject
SearchingChangeCacheImpl(
@Named(ID_CACHE) LoadingCache> cache,
ChangeData.Factory changeDataFactory) {
this.cache = cache;
this.changeDataFactory = changeDataFactory;
}
/**
* Read changes for the project from the secondary index.
*
* Returned changes only include the {@code Change} object (with id, branch) and the reviewers.
* Additional stored fields are not loaded from the index.
*
* @param project project to read.
* @return stream of known changes; empty if no changes.
*/
public Stream getChangeData(Project.NameKey project) {
List cached;
try {
cached = cache.get(project);
} catch (ExecutionException e) {
logger.atWarning().withCause(e).log("Cannot fetch changes for %s", project);
return Stream.empty();
}
return cached.stream()
.map(
cc -> {
ChangeData cd = changeDataFactory.create(cc.change());
cd.setReviewers(cc.reviewers());
return cd;
});
}
@Override
public void onGitReferenceUpdated(GitReferenceUpdatedListener.Event event) {
if (event.getRefName().startsWith(RefNames.REFS_CHANGES)) {
cache.invalidate(Project.nameKey(event.getProjectName()));
}
}
static class Loader extends CacheLoader> {
private final OneOffRequestContext requestContext;
private final Provider queryProvider;
@Inject
Loader(OneOffRequestContext requestContext, Provider queryProvider) {
this.requestContext = requestContext;
this.queryProvider = queryProvider;
}
@Override
public List load(Project.NameKey key) throws Exception {
try (TraceTimer timer =
TraceContext.newTimer(
"Loading changes of project", Metadata.builder().projectName(key.get()).build());
ManualRequestContext ctx = requestContext.open()) {
List cds =
queryProvider
.get()
.setRequestedFields(ChangeField.CHANGE_SPEC, ChangeField.REVIEWER_SPEC)
.byProject(key);
Map result = new HashMap<>(cds.size());
for (ChangeData cd : cds) {
if (result.containsKey(cd.getId())) {
logger.atWarning().log(
"Duplicate changes returned from change query by project %s: %s, %s",
key, cd.change(), result.get(cd.getId()).change());
}
result.put(
cd.getId(),
new AutoValue_SearchingChangeCacheImpl_CachedChange(cd.change(), cd.reviewers()));
}
return List.copyOf(result.values());
}
}
}
}