lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Robert Muir (Commented) (JIRA)" <>
Subject [jira] [Commented] (LUCENE-3935) Optimize Kuromoji inner loop - rewrite ConnectionCosts.get() method
Date Thu, 29 Mar 2012 10:08:27 GMT


Robert Muir commented on LUCENE-3935:

I agree, this should also help on RAM? currently this is 1316 short[1316]'s i think?

I feel like there is a TODO in here somewhere about this: especially since
the connectioncosts.dat we write is "1 dimensional", we just write forwardSize
and backwardSize first and force it to a 2D array in RAM. But it could just
as well make a single array of forwardSize*backwardSize...
> Optimize Kuromoji inner loop - rewrite ConnectionCosts.get() method
> -------------------------------------------------------------------
>                 Key: LUCENE-3935
>                 URL:
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: modules/analysis
>    Affects Versions: 3.6, 4.0
>            Reporter: Christian Moen
> I've been profiling Kuromoji, and not very surprisingly, method {{ConnectionCosts.get(int
forwardId, int backwardId)}} that looks up costs in the Viterbi is called many many times
and contributes to more processing time than I had expected.
> This method is currently backed by a {{short[][]}}.  This data stored here structure
is a two dimensional array with both dimensions being fixed with 1316 elements in each dimension.
 (The data is {{matrix.def}} in MeCab-IPADIC.)
> We can rewrite this to use a single one-dimensional array instead, and we will at least
save one bounds check, a pointer reference, and we should also get much better cache utilization
since this structure is likely to be in very local CPU cache.
> I think this will be a nice optimization.  Working on it... 

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:!default.jspa
For more information on JIRA, see:


To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message