javax.cache.configuration.Configuration Maven / Gradle / Ivy
/**
* Copyright 2011-2016 Terracotta, Inc.
* Copyright 2011-2016 Oracle America Incorporated
*
* 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 javax.cache.configuration;
import javax.cache.Cache;
import javax.cache.CacheManager;
import java.io.Serializable;
/**
* A basic read-only representation of a {@link Cache} configuration.
*
* The properties provided by instances of this interface are used by
* {@link CacheManager}s to configure {@link Cache}s.
*
* Implementations of this interface must override {@link Object#hashCode()} and
* {@link Object#equals(Object)} as {@link Configuration}s are often compared at
* runtime.
*
* @param the type of keys maintained the cache
* @param the type of cached values
* @author Greg Luck
* @author Brian Oliver
* @since 1.0
*/
public interface Configuration extends Serializable {
/**
* Determines the required type of keys for {@link Cache}s configured
* with this {@link Configuration}.
*
* @return the key type or Object.class if the type is undefined
*/
Class getKeyType();
/**
* Determines the required type of values for {@link Cache}s configured
* with this {@link Configuration}.
*
* @return the value type or Object.class if the type is undefined
*/
Class getValueType();
/**
* Whether storeByValue (true) or storeByReference (false).
* When true, both keys and values are stored by value.
*
* When false, both keys and values are stored by reference.
* Caches stored by reference are capable of mutation by any threads holding
* the reference. The effects are:
*
* - if the key is mutated, then the key may not be retrievable or
* removable
* - if the value is mutated, then all threads in the JVM can potentially
* observe those mutations, subject to the normal Java Memory Model rules.
*
* Storage by reference only applies to the local heap. If an entry is moved off
* heap it will need to be transformed into a representation. Any mutations that
* occur after transformation may not be reflected in the cache.
*
* When a cache is storeByValue, any mutation to the key or value does not
* affect the key of value stored in the cache.
*
* The default value is true.
*
* @return true if the cache is store by value
*/
boolean isStoreByValue();
}