com.google.gerrit.index.IndexCollection Maven / Gradle / Ivy
// 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.index;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Lists;
import com.google.gerrit.extensions.events.LifecycleListener;
import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicReference;
/** Dynamic pointers to the index versions used for searching and writing. */
public abstract class IndexCollection> implements LifecycleListener {
private final CopyOnWriteArrayList writeIndexes;
private final AtomicReference searchIndex;
protected IndexCollection() {
this.writeIndexes = Lists.newCopyOnWriteArrayList();
this.searchIndex = new AtomicReference<>();
}
/** Returns the current search index version. */
public I getSearchIndex() {
return searchIndex.get();
}
public void setSearchIndex(I index) {
setSearchIndex(index, true);
}
@VisibleForTesting
public void setSearchIndex(I index, boolean closeOld) {
I old = searchIndex.getAndSet(index);
if (closeOld && old != null && old != index && !writeIndexes.contains(old)) {
old.close();
}
}
public Collection getWriteIndexes() {
return Collections.unmodifiableCollection(writeIndexes);
}
public synchronized I addWriteIndex(I index) {
int version = index.getSchema().getVersion();
for (int i = 0; i < writeIndexes.size(); i++) {
if (writeIndexes.get(i).getSchema().getVersion() == version) {
return writeIndexes.set(i, index);
}
}
writeIndexes.add(index);
return null;
}
public synchronized void removeWriteIndex(int version) {
int removeIndex = -1;
for (int i = 0; i < writeIndexes.size(); i++) {
if (writeIndexes.get(i).getSchema().getVersion() == version) {
removeIndex = i;
break;
}
}
if (removeIndex >= 0) {
try {
writeIndexes.get(removeIndex).close();
} finally {
writeIndexes.remove(removeIndex);
}
}
}
public I getWriteIndex(int version) {
for (I i : writeIndexes) {
if (i.getSchema().getVersion() == version) {
return i;
}
}
return null;
}
@Override
public void start() {}
@Override
public void stop() {
I read = searchIndex.get();
if (read != null) {
read.close();
}
for (I write : writeIndexes) {
if (write != read) {
write.close();
}
}
}
}