// Copyright (C) 2013 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.lucene;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import com.google.common.base.Joiner;
import com.google.common.collect.Sets;
import com.google.common.util.concurrent.AbstractFuture;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import com.google.gerrit.server.config.SitePaths;
import com.google.gerrit.server.index.FieldDef;
import com.google.gerrit.server.index.FieldDef.FillArgs;
import com.google.gerrit.server.index.FieldType;
import com.google.gerrit.server.index.Index;
import com.google.gerrit.server.index.IndexUtils;
import com.google.gerrit.server.index.Schema;
import com.google.gerrit.server.index.Schema.Values;
import java.io.IOException;
import java.sql.Timestamp;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.IntField;
import org.apache.lucene.document.LongField;
import org.apache.lucene.document.StoredField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TrackingIndexWriter;
import org.apache.lucene.search.ControlledRealTimeReopenThread;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ReferenceManager;
import org.apache.lucene.search.ReferenceManager.RefreshListener;
import org.apache.lucene.search.SearcherFactory;
import org.apache.lucene.store.AlreadyClosedException;
import org.apache.lucene.store.Directory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Basic Lucene index implementation. */
public abstract class AbstractLuceneIndex<K, V> implements Index<K, V> {
private static final Logger log = LoggerFactory.getLogger(AbstractLuceneIndex.class);
static String sortFieldName(FieldDef<?, ?> f) {
return f.getName() + "_SORT";
}
private final Schema<V> schema;
private final SitePaths sitePaths;
private final Directory dir;
private final String name;
private final ListeningExecutorService writerThread;
private final TrackingIndexWriter writer;
private final ReferenceManager<IndexSearcher> searcherManager;
private final ControlledRealTimeReopenThread<IndexSearcher> reopenThread;
private final Set<NrtFuture> notDoneNrtFutures;
private ScheduledThreadPoolExecutor autoCommitExecutor;
AbstractLuceneIndex(
Schema<V> schema,
SitePaths sitePaths,
Directory dir,
String name,
String subIndex,
GerritIndexWriterConfig writerConfig,
SearcherFactory searcherFactory)
throws IOException {
this.schema = schema;
this.sitePaths = sitePaths;
this.dir = dir;
this.name = name;
String index = Joiner.on('_').skipNulls().join(name, subIndex);
IndexWriter delegateWriter;
long commitPeriod = writerConfig.getCommitWithinMs();
if (commitPeriod < 0) {
delegateWriter = new AutoCommitWriter(dir, writerConfig.getLuceneConfig());
} else if (commitPeriod == 0) {
delegateWriter = new AutoCommitWriter(dir, writerConfig.getLuceneConfig(), true);
} else {
final AutoCommitWriter autoCommitWriter =
new AutoCommitWriter(dir, writerConfig.getLuceneConfig());
delegateWriter = autoCommitWriter;
autoCommitExecutor =
new ScheduledThreadPoolExecutor(
1,
new ThreadFactoryBuilder()
.setNameFormat(index + " Commit-%d")
.setDaemon(true)
.build());
@SuppressWarnings("unused") // Error handling within Runnable.
Future<?> possiblyIgnoredError =
autoCommitExecutor.scheduleAtFixedRate(
() -> {
try {
if (autoCommitWriter.hasUncommittedChanges()) {
autoCommitWriter.manualFlush();
autoCommitWriter.commit();
}
} catch (IOException e) {
log.error("Error committing " + index + " Lucene index", e);
} catch (OutOfMemoryError e) {
log.error("Error committing " + index + " Lucene index", e);
try {
autoCommitWriter.close();
} catch (IOException e2) {
log.error(
"SEVERE: Error closing "
+ index
+ " Lucene index after OOM;"
+ " index may be corrupted.",
e);
}
}
},
commitPeriod,
commitPeriod,
MILLISECONDS);
}
writer = new TrackingIndexWriter(delegateWriter);
searcherManager = new WrappableSearcherManager(writer.getIndexWriter(), true, searcherFactory);
notDoneNrtFutures = Sets.newConcurrentHashSet();
writerThread =
MoreExecutors.listeningDecorator(
Executors.newFixedThreadPool(
1,
new ThreadFactoryBuilder()
.setNameFormat(index + " Write-%d")
.setDaemon(true)
.build()));
reopenThread =
new ControlledRealTimeReopenThread<>(
writer,
searcherManager,
0.500 /* maximum stale age (seconds) */,
0.010 /* minimum stale age (seconds) */);
reopenThread.setName(index + " NRT");
reopenThread.setPriority(
Math.min(Thread.currentThread().getPriority() + 2, Thread.MAX_PRIORITY));
reopenThread.setDaemon(true);
// This must be added after the reopen thread is created. The reopen thread
// adds its own listener which copies its internally last-refreshed
// generation to the searching generation. removeIfDone() depends on the
// searching generation being up to date when calling
// reopenThread.waitForGeneration(gen, 0), therefore the reopen thread's
// internal listener needs to be called first.
// TODO(dborowitz): This may have been fixed by
// http://issues.apache.org/jira/browse/LUCENE-5461
searcherManager.addListener(
new RefreshListener() {
@Override
public void beforeRefresh() throws IOException {}
@Override
public void afterRefresh(boolean didRefresh) throws IOException {
for (NrtFuture f : notDoneNrtFutures) {
f.removeIfDone();
}
}
});
reopenThread.start();
}
@Override
public void markReady(boolean ready) throws IOException {
IndexUtils.setReady(sitePaths, name, schema.getVersion(), ready);
}
@Override
public void close() {
if (autoCommitExecutor != null) {
autoCommitExecutor.shutdown();
}
writerThread.shutdown();
try {
if (!writerThread.awaitTermination(5, TimeUnit.SECONDS)) {
log.warn("shutting down " + name + " index with pending Lucene writes");
}
} catch (InterruptedException e) {
log.warn("interrupted waiting for pending Lucene writes of " + name + " index", e);
}
reopenThread.close();
// Closing the reopen thread sets its generation to Long.MAX_VALUE, but we
// still need to refresh the searcher manager to let pending NrtFutures
// know.
//
// Any futures created after this method (which may happen due to undefined
// shutdown ordering behavior) will finish immediately, even though they may
// not have flushed.
try {
searcherManager.maybeRefreshBlocking();
} catch (IOException e) {
log.warn("error finishing pending Lucene writes", e);
}
try {
writer.getIndexWriter().close();
} catch (AlreadyClosedException e) {
// Ignore.
} catch (IOException e) {
log.warn("error closing Lucene writer", e);
}
try {
dir.close();
} catch (IOException e) {
log.warn("error closing Lucene directory", e);
}
}
ListenableFuture<?> insert(Document doc) {
return submit(() -> writer.addDocument(doc));
}
ListenableFuture<?> replace(Term term, Document doc) {
return submit(() -> writer.updateDocument(term, doc));
}
ListenableFuture<?> delete(Term term) {
return submit(() -> writer.deleteDocuments(term));
}
private ListenableFuture<?> submit(Callable<Long> task) {
ListenableFuture<Long> future = Futures.nonCancellationPropagating(writerThread.submit(task));
return Futures.transformAsync(
future,
gen -> {
// Tell the reopen thread a future is waiting on this
// generation so it uses the min stale time when refreshing.
reopenThread.waitForGeneration(gen, 0);
return new NrtFuture(gen);
},
directExecutor());
}
@Override
public void deleteAll() throws IOException {
writer.deleteAll();
}
public TrackingIndexWriter getWriter() {
return writer;
}
IndexSearcher acquire() throws IOException {
return searcherManager.acquire();
}
void release(IndexSearcher searcher) throws IOException {
searcherManager.release(searcher);
}
Document toDocument(V obj, FillArgs fillArgs) {
Document result = new Document();
for (Values<V> vs : schema.buildFields(obj, fillArgs)) {
if (vs.getValues() != null) {
add(result, vs);
}
}
return result;
}
void add(Document doc, Values<V> values) {
String name = values.getField().getName();
FieldType<?> type = values.getField().getType();
Store store = store(values.getField());
if (type == FieldType.INTEGER || type == FieldType.INTEGER_RANGE) {
for (Object value : values.getValues()) {
doc.add(new IntField(name, (Integer) value, store));
}
} else if (type == FieldType.LONG) {
for (Object value : values.getValues()) {
doc.add(new LongField(name, (Long) value, store));
}
} else if (type == FieldType.TIMESTAMP) {
for (Object value : values.getValues()) {
doc.add(new LongField(name, ((Timestamp) value).getTime(), store));
}
} else if (type == FieldType.EXACT || type == FieldType.PREFIX) {
for (Object value : values.getValues()) {
doc.add(new StringField(name, (String) value, store));
}
} else if (type == FieldType.FULL_TEXT) {
for (Object value : values.getValues()) {
doc.add(new TextField(name, (String) value, store));
}
} else if (type == FieldType.STORED_ONLY) {
for (Object value : values.getValues()) {
doc.add(new StoredField(name, (byte[]) value));
}
} else {
throw FieldType.badFieldType(type);
}
}
private static Field.Store store(FieldDef<?, ?> f) {
return f.isStored() ? Field.Store.YES : Field.Store.NO;
}
private final class NrtFuture extends AbstractFuture<Void> {
private final long gen;
NrtFuture(long gen) {
this.gen = gen;
}
@Override
public Void get() throws InterruptedException, ExecutionException {
if (!isDone()) {
reopenThread.waitForGeneration(gen);
set(null);
}
return super.get();
}
@Override
public Void get(long timeout, TimeUnit unit)
throws InterruptedException, TimeoutException, ExecutionException {
if (!isDone()) {
if (!reopenThread.waitForGeneration(gen, (int) unit.toMillis(timeout))) {
throw new TimeoutException();
}
set(null);
}
return super.get(timeout, unit);
}
@Override
public boolean isDone() {
if (super.isDone()) {
return true;
} else if (isGenAvailableNowForCurrentSearcher()) {
set(null);
return true;
} else if (!reopenThread.isAlive()) {
setException(new IllegalStateException("NRT thread is dead"));
return true;
}
return false;
}
@Override
public void addListener(Runnable listener, Executor executor) {
if (isGenAvailableNowForCurrentSearcher() && !isCancelled()) {
set(null);
} else if (!isDone()) {
notDoneNrtFutures.add(this);
}
super.addListener(listener, executor);
}
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
boolean result = super.cancel(mayInterruptIfRunning);
if (result) {
notDoneNrtFutures.remove(this);
}
return result;
}
void removeIfDone() {
if (isGenAvailableNowForCurrentSearcher()) {
notDoneNrtFutures.remove(this);
if (!isCancelled()) {
set(null);
}
}
}
private boolean isGenAvailableNowForCurrentSearcher() {
try {
return reopenThread.waitForGeneration(gen, 0);
} catch (InterruptedException e) {
log.warn("Interrupted waiting for searcher generation", e);
return false;
}
}
}
@Override
public Schema<V> getSchema() {
return schema;
}
}