EhcacheCache.java

/**
 * Copyright 2010-2015 the original author or authors.
 *
 * 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 io.github.hengyunabc.mybatis;

import java.util.concurrent.locks.ReadWriteLock;

import net.sf.ehcache.Ehcache;
import net.sf.ehcache.Element;

import org.apache.ibatis.cache.Cache;

public class EhcacheCache implements Cache {

  /**
   * The cache id (namespace)
   */
  protected final String id;

  /**
   * The cache instance
   */
  protected Ehcache cache;

  public EhcacheCache(final String id,  Ehcache cache) {
    if (id == null) {
      throw new IllegalArgumentException("Cache instances require an ID");
    }
    this.id = id;
    this.cache = cache;
  }

  /**
   * {@inheritDoc}
   */
  public void clear() {
    cache.removeAll();
  }

  /**
   * {@inheritDoc}
   */
  public String getId() {
    return id;
  }

  /**
   * {@inheritDoc}
   */
  public Object getObject(Object key) {
    Element cachedElement = cache.get(key);
    if (cachedElement == null) {
      return null;
    }
    return cachedElement.getObjectValue();
  }

  /**
   * {@inheritDoc}
   */
  public int getSize() {
    return cache.getSize();
  }

  /**
   * {@inheritDoc}
   */
  public void putObject(Object key, Object value) {
    cache.put(new Element(key, value));
  }

  /**
   * {@inheritDoc}
   */
  public Object removeObject(Object key) {
    Object obj = getObject(key);
    cache.remove(key);
    return obj;
  }

  /**
   * {@inheritDoc}
   */
  public void unlock(Object key) {}

  /**
   * {@inheritDoc}
   */
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (!(obj instanceof Cache)) {
      return false;
    }

    Cache otherCache = (Cache) obj;
    return id.equals(otherCache.getId());
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public int hashCode() {
    return id.hashCode();
  }

  @Override
  public ReadWriteLock getReadWriteLock() {
    return null;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public String toString() {
    return "EHCache {" + id + "}";
  }

  // DYNAMIC PROPERTIES

  /**
   * Sets the time to idle for an element before it expires. Is only used if the element is not
   * eternal.
   *
   * @param timeToIdleSeconds the default amount of time to live for an element from its last
   *        accessed or modified date
   */
  public void setTimeToIdleSeconds(long timeToIdleSeconds) {
    cache.getCacheConfiguration().setTimeToIdleSeconds(timeToIdleSeconds);
  }

  /**
   * Sets the time to idle for an element before it expires. Is only used if the element is not
   * eternal.
   *
   * @param timeToLiveSeconds the default amount of time to live for an element from its creation
   *        date
   */
  public void setTimeToLiveSeconds(long timeToLiveSeconds) {
    cache.getCacheConfiguration().setTimeToLiveSeconds(timeToLiveSeconds);
  }

  /**
   * Sets the maximum objects to be held in memory (0 = no limit).
   *
   * @param maxElementsInMemory The maximum number of elements in memory, before they are evicted (0
   *        == no limit)
   */
  public void setMaxEntriesLocalHeap(long maxEntriesLocalHeap) {
    cache.getCacheConfiguration().setMaxEntriesLocalHeap(maxEntriesLocalHeap);
  }

  /**
   * Sets the maximum number elements on Disk. 0 means unlimited.
   *
   * @param maxElementsOnDisk the maximum number of Elements to allow on the disk. 0 means
   *        unlimited.
   */
  public void setMaxEntriesLocalDisk(long maxEntriesLocalDisk) {
    cache.getCacheConfiguration().setMaxEntriesLocalDisk(maxEntriesLocalDisk);
  }

  /**
   * Sets the eviction policy. An invalid argument will set it to null.
   *
   * @param memoryStoreEvictionPolicy a String representation of the policy. One of "LRU", "LFU" or
   *        "FIFO".
   */
  public void setMemoryStoreEvictionPolicy(String memoryStoreEvictionPolicy) {
    cache.getCacheConfiguration().setMemoryStoreEvictionPolicy(memoryStoreEvictionPolicy);
  }

}