package dk.thoerup.traininfoservice.banedk;

import java.util.concurrent.ConcurrentHashMap;


public class TimeoutCache<K,V> {

	class CacheItem<T> {
		
		public CacheItem(T v) {
			value = v;
			lastupdate = System.currentTimeMillis();
		}
		
		public long lastupdate;
		public T value;
	}
	
	private ConcurrentHashMap<K,CacheItem<V>> cache = new ConcurrentHashMap<K,CacheItem<V>>();
	private long timeout;
	
	public TimeoutCache(int timeout) {
		this.timeout = timeout; 
	}
	
	public void put(K k, V v) {
		CacheItem<V> item= new CacheItem<V>(v);
		cache.put(k, item);
	}
	
	public V get(K k) {
		long now = System.currentTimeMillis();
		
		CacheItem<V> item = cache.get(k);
				
		
		if (item != null) {
			if ( (item.lastupdate+timeout) < now) { //item too old
				return null;
			} else {
				return item.value; //item still good
			}
		} else {
			return null; // no item found
		}
		
	}
	
}