mybatis-3 cache 源码赏析
总结:
从缓存策略源码,可以分析java相关类库
mybatis-3/src/main/java/org/apache/ibatis/cache/decorators/SoftCache.java
package org.apache.ibatis.cache.decorators; | |
import java.lang.ref.ReferenceQueue; | |
import java.lang.ref.SoftReference; | |
import java.util.Deque; | |
import java.util.LinkedList; | |
import java.util.concurrent.locks.ReadWriteLock; | |
import org.apache.ibatis.cache.Cache; | |
https://github.com/mybatis/mybatis-3/blob/67a1c4ea5726c605d297398a8ab9a42ab7d4ebf1/src/main/java/org/apache/ibatis/cache/decorators/FifoCache.java
/** * Copyright 2009-2018 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 org.apache.ibatis.cache.decorators; import java.util.Deque; import java.util.LinkedList; import java.util.concurrent.locks.ReadWriteLock; import org.apache.ibatis.cache.Cache; /** * FIFO (first in, first out) cache decorator * * @author Clinton Begin */ public class FifoCache implements Cache { private final Cache delegate; private final Deque<Object> keyList; private int size; public FifoCache(Cache delegate) { this.delegate = delegate; this.keyList = new LinkedList<>(); this.size = 1024; } @Override public String getId() { return delegate.getId(); } @Override public int getSize() { return delegate.getSize(); } public void setSize(int size) { this.size = size; } @Override public void putObject(Object key, Object value) { cycleKeyList(key); delegate.putObject(key, value); } @Override public Object getObject(Object key) { return delegate.getObject(key); } @Override public Object removeObject(Object key) { return delegate.removeObject(key); } @Override public void clear() { delegate.clear(); keyList.clear(); } @Override public ReadWriteLock getReadWriteLock() { return null; } private void cycleKeyList(Object key) { keyList.addLast(key); if (keyList.size() > size) { Object oldestKey = keyList.removeFirst(); delegate.removeObject(oldestKey); } } }