RE: [jira] Updated: (LUCENENET-190) 2.4.0 Performance in TermInfosReader term caching (New implementation of SimpleLRUCache)

[Digy]

This time you will get an error with "TimeStamps.Keys[0]". To get the key at 
index 0, you have to copy the "keys" to a temporary array.

DIGY.


-----Original Message-----
From: x...@mail.ru [mailto:x...@mail.ru] 
Sent: Tuesday, August 18, 2009 5:24 PM
To: lucene-net-dev@incubator.apache.org
Subject: Re: [jira] Updated: (LUCENENET-190) 2.4.0 Performance in 
TermInfosReader term caching (New implementation of SimpleLRUCache)

Digy wrote:
> SortedDictionary does not have a getter with index (like Data[Index]). In a 
> SortedList, Data[0] is always the LRU item. 
>
>   
I didn't find any use of index access for SortedList (TimeStamps) except 
of : 
                if (Data.Count > Capacity)
                {
                    long key = TimeStamps.Keys[0];
                    Data.Remove(TimeStamps[key]);
                    TimeStamps.RemoveAt(0); <-------------
                }

 In case of  SortedDictionary it can be replaced by:
                if (Data.Count > Capacity)
                {
                    long key = TimeStamps.Keys[0];
                    Data.Remove(TimeStamps[key]);
                    TimeStamps.Remove(key);
                }

Am I missed something?

---
Andrei
> I got much more better results with RedBlackCS.RedBlack ( 
> http://www.codeproject.com/KB/recipes/redblackcs.aspx ) but it is huge and 
> there may be licensing problems.
>
>
> DIGY.
>
>
> -----Original Message-----
> From: x...@mail.ru [mailto:x...@mail.ru] 
> Sent: Tuesday, August 18, 2009 4:51 PM
> To: lucene-net-dev@incubator.apache.org
> Subject: Re: [jira] Updated: (LUCENENET-190) 2.4.0 Performance in 
> TermInfosReader term caching (New implementation of SimpleLRUCache)
>
> SimpleLRUCache_LUCENENET_190 uses SortedList<long, object> collection.
>
> Performance of SortedList (see 
> http://msdn.microsoft.com/en-us/library/ms132339.aspx): 
> 1) Add method is an O(n) operation for unsorted data. It is an O(log n) 
> operation if the new element is added at the end of the list. 
> If insertion causes a resize, the operation is O(n).
> 2) Remove method method is an O(n) operation
> 3) RemoveAt method is an O(n) operation 
> 4) Keys property is an O(1) operation
>
> Why not to use SortedDictionary<>? It has better performance for Remove and 
> Add:
>
> 1) Add method is an O(log n) operation
>
> 2) Remove method is an O(log n) operation
>
> 3) Keys property is an O(1) operation
>
>
>   


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