| // Copyright (C) 2016 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 com.google.auto.value.AutoValue; |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.cache.Cache; |
| import com.google.gerrit.common.Nullable; |
| 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.cache.CacheModule; |
| import com.google.gerrit.server.notedb.AbstractChangeNotes.Args; |
| import com.google.gerrit.server.notedb.ChangeNotesCommit.ChangeNotesRevWalk; |
| import com.google.inject.Inject; |
| import com.google.inject.Module; |
| import com.google.inject.Singleton; |
| import com.google.inject.name.Named; |
| |
| import org.eclipse.jgit.errors.ConfigInvalidException; |
| import org.eclipse.jgit.lib.ObjectId; |
| |
| import java.io.IOException; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutionException; |
| |
| @Singleton |
| public class ChangeNotesCache { |
| @VisibleForTesting |
| static final String CACHE_NAME = "change_notes"; |
| |
| public static Module module() { |
| return new CacheModule() { |
| @Override |
| protected void configure() { |
| bind(ChangeNotesCache.class); |
| cache(CACHE_NAME, |
| Key.class, |
| ChangeNotesState.class) |
| .maximumWeight(1000); |
| } |
| }; |
| } |
| |
| @AutoValue |
| public abstract static class Key { |
| abstract Project.NameKey project(); |
| abstract Change.Id changeId(); |
| abstract ObjectId id(); |
| } |
| |
| @AutoValue |
| abstract static class Value { |
| abstract ChangeNotesState state(); |
| |
| /** |
| * The {@link RevisionNoteMap} produced while parsing this change. |
| * <p> |
| * These instances are mutable and non-threadsafe, so it is only safe to |
| * return it to the caller that actually incurred the cache miss. It is only |
| * used as an optimization; {@link ChangeNotes} is capable of lazily loading |
| * it as necessary. |
| */ |
| @Nullable abstract RevisionNoteMap revisionNoteMap(); |
| } |
| |
| private class Loader implements Callable<ChangeNotesState> { |
| private final Key key; |
| private final ChangeNotesRevWalk rw; |
| |
| private RevisionNoteMap revisionNoteMap; |
| |
| private Loader(Key key, ChangeNotesRevWalk rw) { |
| this.key = key; |
| this.rw = rw; |
| } |
| |
| @Override |
| public ChangeNotesState call() throws ConfigInvalidException, IOException { |
| ChangeNotesParser parser = new ChangeNotesParser( |
| key.changeId(), key.id(), rw, args.noteUtil, args.metrics); |
| ChangeNotesState result = parser.parseAll(); |
| // This assignment only happens if call() was actually called, which only |
| // happens when Cache#get(K, Callable<V>) incurs a cache miss. |
| revisionNoteMap = parser.getRevisionNoteMap(); |
| return result; |
| } |
| } |
| |
| private final Cache<Key, ChangeNotesState> cache; |
| private final Args args; |
| |
| @Inject |
| ChangeNotesCache( |
| @Named(CACHE_NAME) Cache<Key, ChangeNotesState> cache, |
| Args args) { |
| this.cache = cache; |
| this.args = args; |
| } |
| |
| Value get(Project.NameKey project, Change.Id changeId, |
| ObjectId metaId, ChangeNotesRevWalk rw) throws IOException { |
| try { |
| Key key = |
| new AutoValue_ChangeNotesCache_Key(project, changeId, metaId.copy()); |
| Loader loader = new Loader(key, rw); |
| ChangeNotesState s = cache.get(key, loader); |
| return new AutoValue_ChangeNotesCache_Value(s, loader.revisionNoteMap); |
| } catch (ExecutionException e) { |
| throw new IOException(String.format( |
| "Error loading %s in %s at %s", |
| RefNames.changeMetaRef(changeId), project, metaId.name()), |
| e); |
| } |
| } |
| } |