| Summary: | Improve StatCalculator performance by using HashMap | ||
|---|---|---|---|
| Product: | JMeter - Now in Github | Reporter: | ahit <andrey.hitrin> |
| Component: | Main | Assignee: | JMeter issues mailing list <issues> |
| Status: | RESOLVED FIXED | ||
| Severity: | enhancement | ||
| Priority: | P2 | ||
| Version: | Nightly (Please specify date) | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | All | ||
| Attachments: | Use HashMap for keeping values distribution instead of ArrayList | ||
Thanks for the patch. This has been applied to SVN: URL: http://svn.apache.org/viewvc?rev=890589&view=rev Log: Bug 48259 - Improve StatCalculator performance by using HashMap I made a few changes: - instead of sorting the keys and using last or first to get max and min the code keeps track of the values. - the sorted TreeSet is cached - use MutableLong (Commons LANG) instead of Long This issue has been migrated to GitHub: https://github.com/apache/jmeter/issues/2314 |
Created attachment 24582 [details] Use HashMap for keeping values distribution instead of ArrayList There is no actually need to store *each* value separately in StatCalculator class. It's enough to save only counter of occurrences for every value. I propose HashMap class for that instead of ArrayList. HashMap provides several major benefits: - It occupies less memory than ArrayList, especially for large data sets, because every inserted value will be kept within just one pair (key-value). - It has faster data insert (there is no need to call Collections.binarySearch() for every addValue(), insert into HashMap has O(1) complexity) - It still stays quite fast for reading. It calls for sorting in modified getPercentPoint() method, but sorts only keys. A number of unique keys is usually much less than total count of inserted values. Sorry, I didn't check modified StatCalculator on real data yet, just run JMeter tests. I will do it after the weekend. But I think it will work fine. I worked at SVN build 883037.