org.apache.jackrabbit.oak.plugins.document.persistentCache.CacheMap Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.jackrabbit.oak.plugins.document.persistentCache;
import java.util.Map;
import org.h2.mvstore.MVMap;
import org.h2.mvstore.MVMap.Builder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A cache map. This map supports re-opening the store if this is needed.
*
* @param the key type
* @param the value type
*/
public class CacheMap {
static final Logger LOG = LoggerFactory.getLogger(CacheMap.class);
private final MapFactory factory;
private final String name;
private final MVMap.Builder builder;
private int openCount;
private volatile Map map;
private volatile boolean closed;
public CacheMap(MapFactory factory, String name, Builder builder) {
this.factory = factory;
this.name = name;
this.builder = builder;
openMap();
}
private void reopen(int i, Exception e) {
if (i > 10) {
LOG.warn("Too many re-opens; disabling this cache map", e);
closed = true;
return;
}
// clear the interrupt flag, to avoid re-opening many times
Thread.interrupted();
if (i == 0) {
LOG.warn("Re-opening map " + name, e);
} else {
LOG.debug("Re-opening map " + name + " again", e);
LOG.warn("Re-opening map " + name + " again");
}
openMap();
}
public V put(K key, V value) {
for (int i = 0;; i++) {
if (closed) {
return null;
}
try {
return map.put(key, value);
} catch (Exception e) {
reopen(i, e);
}
}
}
public V get(Object key) {
for (int i = 0;; i++) {
if (closed) {
return null;
}
try {
return map.get(key);
} catch (Exception e) {
reopen(i, e);
}
}
}
public boolean containsKey(Object key) {
for (int i = 0;; i++) {
if (closed) {
return false;
}
try {
return map.containsKey(key);
} catch (Exception e) {
reopen(i, e);
}
}
}
public V remove(Object key) {
for (int i = 0;; i++) {
if (closed) {
return null;
}
try {
return map.remove(key);
} catch (Exception e) {
reopen(i, e);
}
}
}
public void clear() {
for (int i = 0;; i++) {
if (closed) {
return;
}
try {
map.clear();
} catch (Exception e) {
reopen(i, e);
}
}
}
void openMap() {
openCount = factory.reopenStoreIfNeeded(openCount);
Map m2 = factory.openMap(name, builder);
if (m2 != null) {
map = m2;
}
}
}