LRU Cache for Page replacement policy ~ HTML Title Kartik Mandal

What is the purpose?

When accessing large amounts of data is deemed too slow, a common speed up technique is to keep a small amount of the data in a more accessible location known as a cache.

In general, a cache is much too small to hold all the data you might possibly need, so at some point you are going to have to remove something from the cache in order to make room for new data. The goal is to retain those items that are more likely to be retrieved again soon. This requires a sensible algorithm for selecting what to remove from the cache. One simple but effective algorithm is the Least Recently Used, or LRU, algorithm.

How to do?


package com.kartik;

import java.util.LinkedHashMap;

import java.util.Map;

public class LruCache<K,V> extends LinkedHashMap<K, V> {

 private static final long serialVersionUID = 1L;

 private int size;

 private LruCache(int size){

  super(size,0.75f,true);

  this.size=size;

 }

   public static<K, V> LruCache<K, V> newInstance(int size){

    return new LruCache<K, V>(size);

   }

   public void setMaxSize(int size){

   this.size=size;

   }

   @Override

   protected boolean removeEldestEntry(Map.Entry<K, V> eledest){

 return size()>size;

  

   }

 public static void main(String[] args) {

LruCache<String,String> lruCache=LruCache.newInstance(5);//number of cache memory block size

lruCache.put("1", "1");//first 1 is block number and second 1 is page number

lruCache.put("3", "3");//first 3 is block number and second 3 is page number

lruCache.put("2", "2");

lruCache.put("4", "4");

lruCache.put("5", "6");

lruCache.put("4", "1");

lruCache.put("2", "23");

lruCache.put("4", "4");

System.out.println(lruCache);

 }

}

Output:

{1=1, 3=3, 5=6, 2=23, 4=4}

Example:

About Kartik Chandra Mandal

I am Kartik Chandra Mandal from Bangalore, India. Working as software engineer in Java technology. Have good knowledge of OWASP and CSRF in security for applications and it's implementation in Java technology.

HTML Title Kartik Mandal