net.sf.ehcache.transaction.TransactionAwareAttributeExtractor Maven / Gradle / Ivy
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/**
* Copyright 2003-2010 Terracotta, Inc.
*
* 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 net.sf.ehcache.transaction;
import net.sf.ehcache.Element;
import net.sf.ehcache.search.attribute.AttributeExtractor;
import net.sf.ehcache.search.attribute.AttributeExtractorException;
import net.sf.ehcache.store.compound.ReadWriteCopyStrategy;
/**
* Used to extract a search attribute value from an element in a transactional store.
*
*
* @author Chris Dennis
*/
public class TransactionAwareAttributeExtractor implements AttributeExtractor {
private final ReadWriteCopyStrategy copyStrategy;
private final AttributeExtractor delegate;
/**
* Creates an attributed delegating to the supplied extractor, via the given copy strategy.
*
* @param copyStrategy copy strategy used by the transactional store
* @param delegate original configured attribute extractor
*/
public TransactionAwareAttributeExtractor(ReadWriteCopyStrategy copyStrategy, AttributeExtractor delegate) {
this.copyStrategy = copyStrategy;
this.delegate = delegate;
}
/**
* {@inheritDoc}
*/
public Object attributeFor(Element element, String attributeName) throws AttributeExtractorException {
Object value = element.getObjectValue();
if (value instanceof SoftLock) {
throw new AssertionError();
} else {
return delegate.attributeFor(copyStrategy.copyForRead(element), attributeName);
}
}
}