/*
* 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.chemistry.opencmis.client.runtime.cache;
import java.io.Serializable;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.chemistry.opencmis.client.api.CmisObject;
import org.apache.chemistry.opencmis.commons.PropertyIds;
/**
* Non synchronized cache implementation. The cache is limited to a specific
* size of entries and works in a LRU mode.
*/
public class CacheImpl implements Cache, Serializable {
private static final long serialVersionUID = 1L;
private static final float HASHTABLE_LOAD_FACTOR = 0.75f;
private int cacheSize;
private LinkedHashMap<String, Map<String, CmisObject>> objectMap;
private Map<String, String> pathToIdMap;
private final ReentrantReadWriteLock fLock = new ReentrantReadWriteLock();
/**
* Creates a new cache instance with a default size.
*/
public static Cache newInstance() {
return new CacheImpl();
}
/**
* Creates a new cache instance with the given size.
*/
public static Cache newInstance(int cacheSize) {
return new CacheImpl(cacheSize);
}
/**
* Default constructor.
*/
protected CacheImpl() {
this(1000); // default cache size
}
/**
* Constructor taking a cache size.
*/
protected CacheImpl(int cacheSize) {
this.cacheSize = cacheSize;
initialize();
}
/**
* Sets up the internal objects.
*/
protected void initialize() {
fLock.writeLock().lock();
try {
int hashTableCapacity = (int) Math.ceil(cacheSize / HASHTABLE_LOAD_FACTOR) + 1;
final int cs = cacheSize;
objectMap = new LinkedHashMap<String, Map<String, CmisObject>>(hashTableCapacity, HASHTABLE_LOAD_FACTOR) {
private static final long serialVersionUID = 1L;
@Override
protected boolean removeEldestEntry(Map.Entry<String, Map<String, CmisObject>> eldest) {
return size() > cs;
}
};
resetPathCache();
} finally {
fLock.writeLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see org.apache.opencmis.client.runtime.cache.Cache#clear()
*/
public void clear() {
initialize();
}
/*
* (non-Javadoc)
*
* @see org.apache.opencmis.client.runtime.cache.Cache#resetPathCache()
*/
public void resetPathCache() {
fLock.writeLock().lock();
try {
pathToIdMap = new HashMap<String, String>();
} finally {
fLock.writeLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#containsId(java.lang.String
* , java.lang.String)
*/
public boolean containsId(String objectId, String cacheKey) {
fLock.readLock().lock();
try {
if (!objectMap.containsKey(objectId)) {
return false;
}
return objectMap.get(objectId).containsKey(cacheKey);
} finally {
fLock.readLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#containsPath(java.lang
* .String, java.lang.String)
*/
public boolean containsPath(String path, String cacheKey) {
fLock.readLock().lock();
try {
if (!pathToIdMap.containsKey(path)) {
return false;
}
return containsId(pathToIdMap.get(path), cacheKey);
} finally {
fLock.readLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#getById(java.lang.String,
* java.lang.String)
*/
public CmisObject getById(String objectId, String cacheKey) {
fLock.readLock().lock();
try {
Map<String, CmisObject> cacheKeyMap = objectMap.get(objectId);
if (cacheKeyMap == null) {
return null; // not found
}
return cacheKeyMap.get(cacheKey);
} finally {
fLock.readLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#getByPath(java.lang.String
* , java.lang.String)
*/
public CmisObject getByPath(String path, String cacheKey) {
fLock.readLock().lock();
try {
String id = pathToIdMap.get(path);
if (id == null) {
return null; // not found
}
CmisObject object = getById(id, cacheKey);
if ((object == null) && (!objectMap.containsKey(id))) {
// clean up
fLock.readLock().unlock();
fLock.writeLock().lock();
try {
pathToIdMap.remove(path);
} finally {
fLock.writeLock().unlock();
fLock.readLock().lock();
}
}
return object;
} finally {
fLock.readLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#put(org.apache.opencmis
* .client.api.CmisObject, java.lang.String)
*/
public void put(CmisObject object, String cacheKey) {
// no object, no cache key - no cache
if ((object == null) || (cacheKey == null)) {
return;
}
// no id - no cache
if (object.getId() == null) {
return;
}
fLock.writeLock().lock();
try {
// get cache key map
Map<String, CmisObject> cacheKeyMap = objectMap.get(object.getId());
if (cacheKeyMap == null) {
cacheKeyMap = new HashMap<String, CmisObject>();
objectMap.put(object.getId(), cacheKeyMap);
}
// put into id cache
cacheKeyMap.put(cacheKey, object);
// folders may have a path, use it!
String path = object.getPropertyValue(PropertyIds.PATH);
if (path != null) {
pathToIdMap.put(path, object.getId());
}
} finally {
fLock.writeLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see
* org.apache.opencmis.client.runtime.cache.Cache#putPath(java.lang.String,
* org.apache.opencmis.client.api.CmisObject, java.lang.String)
*/
public void putPath(String path, CmisObject object, String cacheKey) {
fLock.writeLock().lock();
try {
put(object, cacheKey);
if ((object != null) && (object.getId() != null) && (cacheKey != null)) {
pathToIdMap.put(path, object.getId());
}
} finally {
fLock.writeLock().unlock();
}
}
/*
* (non-Javadoc)
*
* @see org.apache.opencmis.client.runtime.cache.Cache#getCacheSize()
*/
public int getCacheSize() {
return this.cacheSize;
}
}