I haven't observed this, but I haven't really used LRUMap that extensively either.
It seems that nobody replied to this message. Has anyone else observed this?
Just curious.
Otis
On Wed, 09 January 2002, "apache-commons" wrote:
>
> Commons developers,
>
> I noticed that when the list fills up, entries added are at the bottom of
> the list, therefore new entries bump the latest entry off the list - not the
> LRU algorithm I would expect.
>
> I have the source from commons-collections-1.0, I have also attempted to
> verify that it is the latest in cvs. LRUMap.java is from version 1.1.
>
> Further I have noticed that if you remove an item, the "bubbling up" stops
> at that removed item.
>
> Simple test, put the following code fragment into LRUMap and run:
>
> BTW - I found an old copy of: org/apache/tomcat/util/LRUCache.java, which
> has less features, and uses Hashtable (not HashMap) if anyone is interested.
>
> Jon
> -------------------------------
> public void report()
> {
> System.out.println("LRUMap report");
> System.out.println(" maximumSize: " + maximumSize);
> System.out.println(" size: " + size());
> System.out.println(" bubbleList.size: " + bubbleList.size());
> for(int i=0; i<bubbleList.size(); i++)
> {
> System.out.println(" " + i + "\t=" + bubbleList.get(i));
> }
> }
>
> public static void main(String [] args)
> {
> LRUMap m = new LRUMap(5);
> m.put("k1", "v1");
> m.put("k2", "v2");
> m.put("k3", "v3");
> m.put("k4", "v4");
> m.put("k5", "v5");
> m.report();
> m.put("k6", "v6");
> m.put("k7", "v7");
> m.report();
> m.remove("k3");
> m.report();
> m.get("k7");
> m.report();
> m.get("k7");
> m.report();
> m.get("k7");
> m.report();
> m.get("k7");
> m.report();
> }
> ---------------------------------
>
> /* The output with comments below */
>
> /* List is full - OK for now */
> LRUMap report
> maximumSize: 5
> size: 5
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k4
> 4 =k5
>
> /* after adding k6 and k7, only k7 remains - ?? */
> LRUMap report
> maximumSize: 5
> size: 5
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k4
> 4 =k7
>
> /* k3 has been removed from the internal HasMap, remains in array */
> LRUMap report
> maximumSize: 5
> size: 4
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k4
> 4 =k7
>
> /* one bubble up - OK */
> LRUMap report
> maximumSize: 5
> size: 4
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k7
> 4 =k4
>
> /* it's stuck, no more bubbling for k7 */
> LRUMap report
> maximumSize: 5
> size: 4
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k7
> 4 =k4
> LRUMap report
> maximumSize: 5
> size: 4
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k7
> 4 =k4
> LRUMap report
> maximumSize: 5
> size: 4
> bubbleList.size: 5
> 0 =k1
> 1 =k2
> 2 =k3
> 3 =k7
> 4 =k4
>
>
>
>
>
> --
> To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
_________________________________________________________________
iVillage.com: Solutions for Your Life
Check out the most exciting women's community on the Web
http://www.ivillage.com
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
