com.hazelcast.cache.impl.nearcache.NearCache Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2008-2016, Hazelcast, Inc. 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.hazelcast.cache.impl.nearcache;

import com.hazelcast.config.InMemoryFormat;
import com.hazelcast.monitor.NearCacheStats;

/**
 * {@link NearCache} is the contract point to store keys and values in underlying
 * {@link com.hazelcast.cache.impl.nearcache.NearCacheRecordStore}.
 *
 * @param  the type of the key
 * @param  the type of the value
 */
public interface NearCache {

    /**
     * Default expiration task initial delay time as seconds
     */
    int DEFAULT_EXPIRATION_TASK_INITIAL_DELAY_IN_SECONDS = 5;

    /**
     * Default expiration task delay time as seconds
     */
    int DEFAULT_EXPIRATION_TASK_DELAY_IN_SECONDS = 5;

    /**
     * NULL Object
     */
    Object NULL_OBJECT = new Object();

    /**
     * Gets the name of the this {@link com.hazelcast.cache.impl.nearcache.NearCache} instance.
     *
     * @return the name of the this {@link com.hazelcast.cache.impl.nearcache.NearCache} instance
     */
    String getName();

    /**
     * Gets the value associated with the given key.
     *
     * @param key the key of the requested value
     * @return the value associated with the given key
     */
    V get(K key);

    /**
     * Puts (associates) a value with the given key.
     *
     * @param key   the key of the value will be stored
     * @param value the value will be stored
     */
    void put(K key, V value);

    /**
     * Removes the value associated with the given key.
     *
     * @param key the key of the value will be removed
     */
    boolean remove(K key);

    /**
     * @return
     */
    boolean isInvalidateOnChange();

    /**
     * Removes all stored values.
     */
    void clear();

    /**
     * Clears the record store and destroys it.
     */
    void destroy();

    /**
     * Gets the {@link com.hazelcast.config.InMemoryFormat} of the storage for internal records.
     *
     * @return the {@link com.hazelcast.config.InMemoryFormat} of the storage for internal records
     */
    InMemoryFormat getInMemoryFormat();

    /**
     * Get the {@link com.hazelcast.monitor.NearCacheStats} instance to monitor this store.
     *
     * @return the {@link com.hazelcast.monitor.NearCacheStats} instance to monitor this store
     */
    NearCacheStats getNearCacheStats();

    /**
     * Selects the best candidate object to store from the given candidates.
     *
     * @param candidates the candidates from which the best candidate object will be selected.
     * @return the best candidate object to store, selected from the given candidates.
     */
    Object selectToSave(Object... candidates);

    /**
     * Gets the count of stored records.
     *
     * @return the count of stored records
     */
    int size();

}