HibernateReadOnlyAccessStrategy.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.ignite.cache.hibernate;

import org.apache.ignite.Ignite;
import org.apache.ignite.IgniteCheckedException;

/**
 * Implementation of READ_ONLY cache access strategy.
 * <p>
 * Configuration of L2 cache and per-entity cache access strategy can be set in the
 * Hibernate configuration file:
 * <pre name="code" class="xml">
 * <hibernate-configuration>
 *     <!-- Enable L2 cache. -->
 *     <property name="cache.use_second_level_cache">true</property>
 *
 *     <!-- Use Ignite as L2 cache provider. -->
 *     <property name="cache.region.factory_class">org.apache.ignite.cache.hibernate.HibernateRegionFactory</property>
 *
 *     <!-- Specify entity. -->
 *     <mapping class="com.example.Entity"/>
 *
 *     <!-- Enable L2 cache with read-only access strategy for entity. -->
 *     <class-cache class="com.example.Entity" usage="read-only"/>
 * </hibernate-configuration>
 * </pre>
 * Also cache access strategy can be set using annotations:
 * <pre name="code" class="java">
 * @javax.persistence.Entity
 * @javax.persistence.Cacheable
 * @org.hibernate.annotations.Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
 * public class Entity { ... }
 * </pre>
 *
 */
public class HibernateReadOnlyAccessStrategy extends HibernateAccessStrategyAdapter {
    /**
     * @param ignite Node.
     * @param cache Cache.
     * @param eConverter Exception converter.
     */
    public HibernateReadOnlyAccessStrategy(Ignite ignite,
        HibernateCacheProxy cache,
        HibernateExceptionConverter eConverter) {
        super(ignite, cache, eConverter);
    }

    /** {@inheritDoc} */
    @Override public boolean insert(Object key, Object val) {
        return false;
    }

    /** {@inheritDoc} */
    @Override public boolean afterInsert(Object key, Object val) {
        try {
            cache.put(key, val);

            return true;
        }
        catch (IgniteCheckedException e) {
            throw convertException(e);
        }
    }

    /** {@inheritDoc} */
    @Override public void lock(Object key) {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override public void unlock(Object key) {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override public void remove(Object key) {
        // No-op.
    }

    /** {@inheritDoc} */
    @Override public boolean update(Object key, Object val) {
        throw new UnsupportedOperationException("Updates are not supported for read-only access strategy.");
    }

    /** {@inheritDoc} */
    @Override public boolean afterUpdate(Object key, Object val) {
        throw new UnsupportedOperationException("Updates are not supported for read-only access strategy.");
    }
}