/*
* Copyright 2015 Ben Manes. All Rights Reserved.
*
* 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.github.benmanes.caffeine.jcache.processor;
import static java.util.Objects.requireNonNull;
import java.util.Objects;
import java.util.Optional;
import javax.annotation.Nullable;
import javax.cache.Cache;
import javax.cache.integration.CacheLoader;
import javax.cache.processor.EntryProcessor;
import javax.cache.processor.MutableEntry;
/**
* An entry that is consumed by an {@link EntryProcessor}. The updates to the entry are replayed
* on the cache when the processor completes.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public final class EntryProcessorEntry<K, V> implements MutableEntry<K, V> {
private final K key;
private V value;
private Action action;
private Optional<CacheLoader<K, V>> cacheLoader;
public EntryProcessorEntry(K key, @Nullable V value, Optional<CacheLoader<K, V>> cacheLoader) {
this.cacheLoader = cacheLoader;
this.action = Action.NONE;
this.value = value;
this.key = key;
}
@Override
public boolean exists() {
return (getValue() != null);
}
@Override
public K getKey() {
return key;
}
@Override
public V getValue() {
if (action != Action.NONE) {
return value;
} else if (value != null) {
action = Action.READ;
} else if (cacheLoader.isPresent()) {
value = cacheLoader.get().load(key);
cacheLoader = Optional.empty();
if (value != null) {
action = Action.LOADED;
}
}
return value;
}
@Override
public void remove() {
action = (action == Action.CREATED) ? Action.NONE : Action.DELETED;
value = null;
}
@Override
public void setValue(V value) {
requireNonNull(value);
if (action != Action.CREATED) {
action = exists() ? Action.UPDATED : Action.CREATED;
}
this.value = value;
}
/** @return the dominant action performed by the processor on the entry. */
public Action getAction() {
return action;
}
@Override
public <T> T unwrap(Class<T> clazz) {
if (!clazz.isInstance(this)) {
throw new IllegalArgumentException("Class " + clazz + " is unknown to this implementation");
}
@SuppressWarnings("unchecked")
T castedEntry = (T) this;
return castedEntry;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Cache.Entry<?, ?>)) {
return false;
}
Cache.Entry<?, ?> entry = (Cache.Entry<?, ?>) o;
return Objects.equals(key, entry.getKey())
&& Objects.equals(getValue(), entry.getValue());
}
@Override
public int hashCode() {
return (key == null ? 0 : key.hashCode()) ^ (getValue() == null ? 0 : value.hashCode());
}
@Override
public String toString() {
return key + "=" + getValue();
}
}