Thanks for the code. I made some (primitive) performance tests. I seems to be ~20-25% slower.
DIGY -----Original Message----- From: x...@mail.ru [mailto:x...@mail.ru] Sent: Tuesday, August 18, 2009 8:19 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 : > I couldn't find a method like Keys.First(). > I found what is the problem. Method First() exists only for Framework 3.5. For Framework 2.0 some work around requied : SortedDictionary<long, object>.Enumerator EnumTimeStamps = TimeStamps.GetEnumerator(); // This method is an O(1) operation EnumTimeStamps.MoveNext(); // Shoud be an O(1) operation. long key = EnumTimeStamps.Current.Key; Ugly, but it works. > Why don't you send your own working copy of LRUCache. If it is faster, we can > use it. > I modified SimpleLRUCache_LUCENENET_190 to use a SortedDictionary. Only few lines of code have to be modified: 1) Declaration: - SortedList<long, object> TimeStamps = new SortedList<long, object>(); + System.Collections.Generic.SortedDictionary<long, object> TimeStamps = new SortedDictionary<long, object>(); 2) Put method: if (Data.Count > Capacity) { SortedDictionary<long, object>.Enumerator EnumTimeStamps = TimeStamps.GetEnumerator(); EnumTimeStamps.MoveNext(); long key = EnumTimeStamps.Current.Key; Data.Remove(TimeStamps[key]); TimeStamps.Remove(key); } It passed Nunit test. I didn't make any performance test yet. ---------- Andrei > DIGY > > > -----Original Message----- > From: x...@mail.ru [mailto:x...@mail.ru] > Sent: Tuesday, August 18, 2009 5:58 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 пишет: > >> 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. >> >> >> > Ok i missed that Keys returns KeyCollection instead of an array. But > you can use Keys.First() instead of Keys[0]. It should be fast. > > > >> 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 >>> >>> >>> >>> >>> >> <http://www.garweb.ru> >> >> >> >> > > > >
