/*
*
* * Copyright 2014 Orient Technologies LTD (info(at)orientechnologies.com)
* *
* * 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.
* *
* * For more information: http://www.orientechnologies.com
*
*/
package com.orientechnologies.common.concur.resource;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;
import com.orientechnologies.common.exception.OException;
/**
* Shared container that works with callbacks like closures. If the resource implements the {@link OSharedResource} interface then
* the resource is locked until is removed.
*
* @author Luca Garulli (l.garulli--at--orientechnologies.com)
*
*/
@SuppressWarnings("unchecked")
public class OSharedContainerImpl implements OSharedContainer {
protected Map<String, Object> sharedResources = new HashMap<String, Object>();
public synchronized boolean existsResource(final String iName) {
return sharedResources.containsKey(iName);
}
public synchronized <T> T removeResource(final String iName) {
T resource = (T) sharedResources.remove(iName);
if (resource instanceof OSharedResource)
((OSharedResource) resource).releaseExclusiveLock();
return resource;
}
public synchronized <T> T getResource(final String iName, final Callable<T> iCallback) {
T value = (T) sharedResources.get(iName);
if (value == null) {
// CREATE IT
try {
value = iCallback.call();
} catch (Exception e) {
throw new OException("Error on creation of shared resource", e);
}
if (value instanceof OSharedResource)
((OSharedResource) value).acquireExclusiveLock();
sharedResources.put(iName, value);
}
return value;
}
}