java-org.hwo.servicelink/src/org/hwo/servicelink/ng/ServiceRegisterCache.java

package org.hwo.servicelink.ng;

import java.util.Hashtable;
import static org.hwo.logging.Logging.*;
import static org.hwo.logging.LogLevel.*;

public class ServiceRegisterCache {
	ServiceLink 		serviceLink;	
	Hashtable<Integer, BaseCacheItem>
						cache;

	public class BaseCacheItem
	{
		Integer	ax,
				node,
				register;
		
		boolean isFloat;
		
		long	lastReadTime;
		
		Object	value;
		
		public BaseCacheItem(int hash){
			this.ax		= axFromHash(hash);
			this.node	= nodeFromHash(hash);
			this.register = regFromHash(hash);
			this.isFloat = ((hash & 0x40000000) != 0);
			this.value = null;
		}
		
		public BaseCacheItem(int ax,int node,int register, boolean isFloat)
		{
			this.ax = ax;
			this.node = node;
			this.register = register;
			this.isFloat = isFloat;
			this.value = null;
		}
		
		long	age()
		{
			return System.currentTimeMillis() - lastReadTime;
		}
		
		boolean isOld()
		{
			return age() > 250;
		}
		
		private void fetchValue(){
			if (isOld() && serviceLink.isConnected())
			{
				try {
					if (isFloat){
						Float f = serviceLink.readFloat(ax.byteValue(),node.byteValue(),register);
						setValue(f);
					} else {
						Integer i = serviceLink.readInteger(ax.byteValue(),node.byteValue(),register);
						setValue(i);
					}
					
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}
		
		public Object getValue(){
			if (isOld()){
				log(DEBUGDETAIL,"OLDCACHE:SLA: [%d:%d:%d:%s] = %s", ax,node,register,isFloat ? "F" : "I",value);
				fetchValue();
				log(DEBUGDETAIL,"NEWCACHE:SLA: [%d:%d:%d:%s] = %s", ax,node,register,isFloat ? "F" : "I",value);
			}
			
			return value;
		}
		
		public void setValue(Object value){
			this.value = value;
			this.lastReadTime = System.currentTimeMillis();
			log(DEBUGDETAIL,"CACHE:   SLA: [%d:%d:%d:%s] = %s", ax,node,register,isFloat ? "F" : "I",value);
		}
		
		public void invalidate(){
			this.lastReadTime = 0;
		}
	}
	
	
	
	public static Integer axFromHash(Integer hash){
		return (hash >> 20) & 0x0F; 
	}
	public static Integer nodeFromHash(Integer hash){
		return (hash >> 16) & 0x0F; 
	}
	public static Integer regFromHash(Integer hash){
		return (hash) & 0xFFFF; 
	}
	
	public int calcHash(int ax,int node,int register,boolean isFloat)
	{
			return (isFloat ? 0x40000000 : 0) | (ax << 20) | (node << 16) | register;
	}
	
	ServiceRegisterCache(ServiceLink serviceLink)
	{
		this.serviceLink = serviceLink;
		this.cache = new Hashtable<>();
	}
	
	public ServiceLink getServiceLink() {
		return serviceLink;
	}
	
	private BaseCacheItem getCacheItem(int hash){
		if (!cache.containsKey(hash)){
			BaseCacheItem bci = new BaseCacheItem(hash);
			cache.put(new Integer(hash), bci);
			log( DEBUGDETAIL, "new cache-item: 0x%08x = %s", hash, bci);
		}
		return cache.get(hash);
	}
	
	public void updateValue(int hash){
		BaseCacheItem bci = getCacheItem(hash);
		bci.invalidate();
		bci.getValue();
	}
	
	public void updateValue(int hash,Object value){
		getCacheItem(hash).setValue(value);
	}
	
	public synchronized Object getCachedValue(int hash){
		return getCacheItem(hash).getValue();
	}
	public synchronized Object getCachedValue(int ax,int node,int register,boolean isFloat){
		int hash = calcHash(ax, node, register, isFloat);
		return getCacheItem(hash).getValue();
	}
	
	public synchronized Integer getCachedInteger(int ax,int node,int register)
	{
		return (Integer)getCachedValue(ax, node, register, false);
	}
	
	public synchronized Float getCachedFloat(int ax,int node,int register)
	{
		return (Float)getCachedValue(ax, node, register, true);
	}
	
	public synchronized void invalidate(int ax,int node,int register,boolean isFloat)
	{
		cache.remove(calcHash(ax, node, register,isFloat));
	}
	
}