Package org.owasp.csrfguard.config.overlay

Class ExpirableCache<K,​V>

  • Type Parameters:
    K - key type
    V - value type
    All Implemented Interfaces:
    Serializable
    public class ExpirableCache<K,​V>
extends Object
implements Serializable

    This is like a map, but the setters also take an expire time which will mean the items in the cache will be automatically deleted. Also, every so often (e.g. 2 minutes) all items are checked for expiration. If no timetolive is set, it will default to 1 day. The max time to live is one day.

    This is synchronized so that all access is safe.

    Note: evictions are checked for periodically, but only when the map is accessed (and even then only every few minutes). You can check for evictions externally, or clear the map if you are done with it.

    Version:
    $Id: ExpirableCache.java,v 1.1 2008-11-27 14:25:50 mchyzer Exp $
    Author:
    mchyzer
    See Also:
    Serialized Form

    • Constructor Detail

      • ExpirableCache

        public ExpirableCache()

      • ExpirableCache

        public ExpirableCache​(int defaultTimeToLiveInMinutes)
        Parameters:
        defaultTimeToLiveInMinutes - time in minutes is the default cache time to live for content

      • ExpirableCache

        public ExpirableCache​(ExpirableCache.ExpirableCacheUnit expirableCacheUnit,
                      int defaultTimeToLive)
        Parameters:
        defaultTimeToLive - time in whatever unit is the default cache time to live for content
        expirableCacheUnit - is minutes or seconds

    • Method Detail

      • clear

        public void clear()
        delete the cache

      • getDefaultTimeToLiveInMillis

        public long getDefaultTimeToLiveInMillis()
        expose the length of cache
        Returns:
        length of cache

      • put

        public void put​(K key,
                V value)
        put a value into the cache, accept the default time to live for this cache
        Parameters:
        key - key type
        value - value type

      • put

        public void put​(K key,
                V value,
                int timeToLiveInMinutes)
        put a value into the cache, accept the default time to live for this cache
        Parameters:
        key - key type
        value - value type
        timeToLiveInMinutes - time to live for this item in minutes. If -1 then use the default

      • clearAll

        public static void clearAll()
        clear out all caches everywhere (session, request, context, etc)

      • checkForEvictions

        public void checkForEvictions​(boolean onlyCheckIfNeeded)
        check and remove elements that are stale
        Parameters:
        onlyCheckIfNeeded - true if only check every so often (e.g. every two minutes)

      • get

        public V get​(K key)
        get a value or null if not there or expired this will check for eviction, and evict if evictable
        Parameters:
        key - key type
        Returns:
        the value or null if not there or evicted

      • size

        public int size​(boolean evictEvictables)
        number of elements in map (and check for
        Parameters:
        evictEvictables - true if we should evict values that are stale (even if recently checked)
        Returns:
        the number of elements

      • getCacheInserts

        public int getCacheInserts()
        number of items inserted into the cache
        Returns:
        Returns the cacheInserts.

      • getCacheEvictions

        public int getCacheEvictions()
        number of items evicted from cache
        Returns:
        Returns the cacheEvictions.

      • getCacheHits

        public int getCacheHits()
        number of items successfully retrieved from cache
        Returns:
        Returns the cacheHits.

      • staticToString

        public static String staticToString()
        string representation of cache
        Returns:
        the string value