| // Copyright (C) 2019 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.annotations.VisibleForTesting; |
| 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.index.RefState; |
| import com.google.gerrit.reviewdb.client.Change; |
| import com.google.gerrit.reviewdb.client.Project; |
| import com.google.gerrit.reviewdb.client.RefNames; |
| import com.google.gerrit.server.ReviewerSet; |
| import com.google.gerrit.server.cache.CacheModule; |
| import com.google.gerrit.server.config.GerritOptions; |
| import com.google.gerrit.server.config.GerritServerConfig; |
| import com.google.gerrit.server.index.change.ChangeField; |
| import com.google.gerrit.server.logging.TraceContext; |
| import com.google.gerrit.server.logging.TraceContext.TraceTimer; |
| import com.google.gerrit.server.notedb.ChangeNotes; |
| 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.gwtorm.server.OrmException; |
| 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 java.util.List; |
| import java.util.NoSuchElementException; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.concurrent.CopyOnWriteArraySet; |
| import org.eclipse.jgit.lib.Config; |
| import org.eclipse.jgit.lib.ObjectId; |
| |
| /** |
| * Cache for the minimal information per change that we need to compute visibility. Used for ref |
| * filtering. |
| * |
| * <p>This class is thread safe. |
| */ |
| @Singleton |
| public class ChangeRefCache { |
| private static final FluentLogger logger = FluentLogger.forEnclosingClass(); |
| |
| static final String ID_CACHE = "change_refs"; |
| |
| public static class Module extends CacheModule { |
| @Override |
| protected void configure() { |
| cache(ID_CACHE, Key.class, new TypeLiteral<CachedChange>() {}) |
| .maximumWeight(10000) |
| .loader(Loader.class); |
| |
| bind(ChangeRefCache.class); |
| } |
| } |
| |
| @AutoValue |
| abstract static class Key { |
| abstract Project.NameKey project(); |
| |
| abstract Change.Id changeId(); |
| |
| abstract ObjectId metaId(); |
| } |
| |
| @AutoValue |
| 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<Key, CachedChange> cache; |
| private final ChangeData.Factory changeDataFactory; |
| private final OneOffRequestContext requestContext; |
| private final Provider<InternalChangeQuery> queryProvider; |
| private final GerritOptions gerritOptions; |
| private final Config gerritConfig; |
| private final Set<Project.NameKey> bootstrappedProjects; |
| |
| @Inject |
| ChangeRefCache( |
| @Named(ID_CACHE) LoadingCache<Key, CachedChange> cache, |
| ChangeData.Factory changeDataFactory, |
| OneOffRequestContext requestContext, |
| Provider<InternalChangeQuery> queryProvider, |
| GerritOptions gerritOptions, |
| @GerritServerConfig Config gerritConfig) { |
| this.cache = cache; |
| this.changeDataFactory = changeDataFactory; |
| this.requestContext = requestContext; |
| this.queryProvider = queryProvider; |
| this.gerritOptions = gerritOptions; |
| this.gerritConfig = gerritConfig; |
| // Uses a CopyOnWriteArraySet internally to keep track of projects that are already |
| // bootstrapped. This is efficient because we read from the set on every call to this method to |
| // check if bootstrapping is required. Writes occur only if we bootstrapped, so once per |
| // project. |
| this.bootstrappedProjects = new CopyOnWriteArraySet<>(); |
| } |
| |
| /** |
| * Read changes from the cache. |
| * |
| * <p>Returned changes only include the {@code Change} object (with id, branch) and the reviewers. |
| * There is no guarantee that additional fields are populated, although they can be. |
| * |
| * @param project project to read. |
| * @param changeId change ID to read |
| * @param metaId object ID of the meta branch to read. This is only used to ensure consistency. It |
| * does not allow for reading non-current meta versions. |
| * @return change data |
| * @throws IllegalArgumentException in case no change is found |
| */ |
| public ChangeData getChangeData(Project.NameKey project, Change.Id changeId, ObjectId metaId) { |
| Key key = new AutoValue_ChangeRefCache_Key(project, changeId, metaId); |
| CachedChange cached = cache.getUnchecked(key); |
| if (cached == null) { |
| throw new IllegalArgumentException("no change found for key " + key); |
| } |
| ChangeData cd = changeDataFactory.create(cached.change()); |
| cd.setReviewers(cached.reviewers()); |
| return cd; |
| } |
| |
| /** |
| * This method bootstraps the cache by querying the change index if it hasn't been bootstrapped |
| * before, in which case it is a cheap no-op. |
| * |
| * @param project the project to bootstrap |
| */ |
| public void bootstrapIfNecessary(Project.NameKey project) { |
| if (!gerritOptions.enableMasterFeatures()) { |
| // Bootstrapping using the ChangeIndex is only supported on master in a master-slave replica. |
| return; |
| } |
| if (gerritConfig.getInt("cache", ID_CACHE, "memoryLimit", -1) == 0) { |
| // The cache is disabled, don't bother bootstrapping. |
| return; |
| } |
| if (bootstrappedProjects.contains(project)) { |
| // We have bootstrapped for this project before. If the cache is too small, we might have |
| // evicted all entries by now. Don't bother about this though as we don't want to add the |
| // complexity of checking for existing projects, since that might not be authoritative as well |
| // since we could have already evicted the majority of the entries. |
| return; |
| } |
| |
| try (TraceTimer ignored = |
| TraceContext.newTimer("bootstrapping ChangeRef cache for project " + project); |
| ManualRequestContext ignored2 = requestContext.open()) { |
| List<ChangeData> cds = |
| queryProvider |
| .get() |
| .setRequestedFields(ChangeField.CHANGE, ChangeField.REVIEWER, ChangeField.REF_STATE) |
| .byProject(project); |
| for (ChangeData cd : cds) { |
| Set<RefState> refStates = RefState.parseStates(cd.getRefStates()).get(project); |
| Optional<RefState> refState = |
| refStates |
| .stream() |
| .filter(r -> r.ref().equals(RefNames.changeMetaRef(cd.getId()))) |
| .findAny(); |
| if (!refState.isPresent()) { |
| continue; |
| } |
| cache.put( |
| new AutoValue_ChangeRefCache_Key(project, cd.change().getId(), refState.get().id()), |
| new AutoValue_ChangeRefCache_CachedChange(cd.change(), cd.getReviewers())); |
| } |
| // Mark the project as bootstrapped. We could have bootstrapped it multiple times for |
| // simultaneous requests. We accept this in favor of less thread synchronization and |
| // complexity. |
| bootstrappedProjects.add(project); |
| } catch (OrmException e) { |
| logger.atWarning().withCause(e).log( |
| "unable to bootstrap ChangeRef cache for project " + project); |
| } |
| } |
| |
| static class Loader extends CacheLoader<Key, CachedChange> { |
| private final ChangeNotes.Factory notesFactory; |
| |
| @Inject |
| Loader(ChangeNotes.Factory notesFactory) { |
| this.notesFactory = notesFactory; |
| } |
| |
| @Override |
| public CachedChange load(Key key) throws Exception { |
| ChangeNotes notes = notesFactory.create(key.project(), key.changeId()); |
| if (notes.getMetaId().equals(key.metaId())) { |
| return new AutoValue_ChangeRefCache_CachedChange(notes.getChange(), notes.getReviewers()); |
| } |
| throw new NoSuchElementException("unable to load change"); |
| } |
| } |
| |
| @VisibleForTesting |
| public void resetBootstrappedProjects() { |
| bootstrappedProjects.clear(); |
| } |
| } |