package org.apache.ibatis.cache.decorators;
import org.apache.ibatis.cache.Cache;
import java.util.LinkedList;
import java.util.concurrent.locks.ReadWriteLock;
/**
* FIFO (first in, first out) cache decorator
*/
public class FifoCache implements Cache {
private final Cache delegate;
private final LinkedList<Object> keyList;
private int size;
public FifoCache(Cache delegate) {
this.delegate = delegate;
this.keyList = new LinkedList<Object>();
this.size = 1024;
}
public String getId() {
return delegate.getId();
}
public int getSize() {
return delegate.getSize();
}
public void setSize(int size) {
this.size = size;
}
public void putObject(Object key, Object value) {
cycleKeyList(key);
delegate.putObject(key, value);
}
public Object getObject(Object key) {
return delegate.getObject(key);
}
public Object removeObject(Object key) {
return delegate.removeObject(key);
}
public void clear() {
delegate.clear();
keyList.clear();
}
public ReadWriteLock getReadWriteLock() {
return delegate.getReadWriteLock();
}
private void cycleKeyList(Object key) {
keyList.addLast(key);
if (keyList.size() > size) {
Object oldestKey = keyList.removeFirst();
delegate.removeObject(oldestKey);
}
}
}