// 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.index;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.gerrit.extensions.events.LifecycleListener;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.config.SitePaths;
import com.google.gerrit.server.index.IndexDefinition.IndexFactory;
import com.google.inject.ProvisionException;
import java.io.IOException;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.lib.Config;
public abstract class AbstractVersionManager implements LifecycleListener {
public static class Version<V> {
public final Schema<V> schema;
public final int version;
public final boolean ready;
public Version(Schema<V> schema, int version, boolean ready) {
checkArgument(schema == null || schema.getVersion() == version);
this.schema = schema;
this.version = version;
this.ready = ready;
}
}
protected final boolean onlineUpgrade;
protected final String runReindexMsg;
protected final SitePaths sitePaths;
protected final Map<String, IndexDefinition<?, ?, ?>> defs;
protected final Map<String, OnlineReindexer<?, ?, ?>> reindexers;
protected AbstractVersionManager(
@GerritServerConfig Config cfg,
SitePaths sitePaths,
Collection<IndexDefinition<?, ?, ?>> defs) {
this.sitePaths = sitePaths;
this.defs = Maps.newHashMapWithExpectedSize(defs.size());
for (IndexDefinition<?, ?, ?> def : defs) {
this.defs.put(def.getName(), def);
}
reindexers = Maps.newHashMapWithExpectedSize(defs.size());
onlineUpgrade = cfg.getBoolean("index", null, "onlineUpgrade", true);
runReindexMsg =
"No index versions ready; run java -jar "
+ sitePaths.gerrit_war.toAbsolutePath()
+ " reindex";
}
@Override
public void start() {
GerritIndexStatus cfg = createIndexStatus();
for (IndexDefinition<?, ?, ?> def : defs.values()) {
initIndex(def, cfg);
}
}
@Override
public void stop() {
// Do nothing; indexes are closed on demand by IndexCollection.
}
/**
* Start the online reindexer if the current index is not already the latest.
*
* @param name index name
* @param force start re-index
* @return true if started, otherwise false.
* @throws ReindexerAlreadyRunningException
*/
public synchronized boolean startReindexer(String name, boolean force)
throws ReindexerAlreadyRunningException {
OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
validateReindexerNotRunning(reindexer);
if (force || !isLatestIndexVersion(name, reindexer)) {
reindexer.start();
return true;
}
return false;
}
/**
* Activate the latest index if the current index is not already the latest.
*
* @param name index name
* @return true if index was activated, otherwise false.
* @throws ReindexerAlreadyRunningException
*/
public synchronized boolean activateLatestIndex(String name)
throws ReindexerAlreadyRunningException {
OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
validateReindexerNotRunning(reindexer);
if (!isLatestIndexVersion(name, reindexer)) {
reindexer.activateIndex();
return true;
}
return false;
}
protected <K, V, I extends Index<K, V>> void initIndex(
IndexDefinition<K, V, I> def, GerritIndexStatus cfg) {
TreeMap<Integer, Version<V>> versions = scanVersions(def, cfg);
// Search from the most recent ready version.
// Write to the most recent ready version and the most recent version.
Version<V> search = null;
List<Version<V>> write = Lists.newArrayListWithCapacity(2);
for (Version<V> v : versions.descendingMap().values()) {
if (v.schema == null) {
continue;
}
if (write.isEmpty() && onlineUpgrade) {
write.add(v);
}
if (v.ready) {
search = v;
if (!write.contains(v)) {
write.add(v);
}
break;
}
}
if (search == null) {
throw new ProvisionException(runReindexMsg);
}
IndexFactory<K, V, I> factory = def.getIndexFactory();
I searchIndex = factory.create(search.schema);
IndexCollection<K, V, I> indexes = def.getIndexCollection();
indexes.setSearchIndex(searchIndex);
for (Version<V> v : write) {
if (v.version != search.version) {
indexes.addWriteIndex(factory.create(v.schema));
} else {
indexes.addWriteIndex(searchIndex);
}
}
markNotReady(def.getName(), versions.values(), write);
synchronized (this) {
if (!reindexers.containsKey(def.getName())) {
int latest = write.get(0).version;
OnlineReindexer<K, V, I> reindexer = new OnlineReindexer<>(def, latest);
reindexers.put(def.getName(), reindexer);
if (onlineUpgrade && latest != search.version) {
reindexer.start();
}
}
}
}
protected GerritIndexStatus createIndexStatus() {
try {
return new GerritIndexStatus(sitePaths);
} catch (ConfigInvalidException | IOException e) {
throw fail(e);
}
}
protected abstract <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v);
protected abstract <K, V, I extends Index<K, V>> TreeMap<Integer, Version<V>> scanVersions(
IndexDefinition<K, V, I> def, GerritIndexStatus cfg);
private boolean isLatestIndexVersion(String name, OnlineReindexer<?, ?, ?> reindexer) {
int readVersion = defs.get(name).getIndexCollection().getSearchIndex().getSchema().getVersion();
return reindexer == null || reindexer.getVersion() == readVersion;
}
private static void validateReindexerNotRunning(OnlineReindexer<?, ?, ?> reindexer)
throws ReindexerAlreadyRunningException {
if (reindexer != null && reindexer.isRunning()) {
throw new ReindexerAlreadyRunningException();
}
}
private <V> void markNotReady(
String name, Iterable<Version<V>> versions, Collection<Version<V>> inUse) {
GerritIndexStatus cfg = createIndexStatus();
boolean dirty = false;
for (Version<V> v : versions) {
if (isDirty(inUse, v)) {
cfg.setReady(name, v.version, false);
dirty = true;
}
}
if (dirty) {
try {
cfg.save();
} catch (IOException e) {
throw fail(e);
}
}
}
private ProvisionException fail(Throwable t) {
ProvisionException e = new ProvisionException("Error scanning indexes");
e.initCause(t);
return e;
}
}