Bug 48755 - Zip task does O(n) lookup in hashtable
Summary: Zip task does O(n) lookup in hashtable
Status: RESOLVED FIXED
Alias: None
Product: Ant
Classification: Unclassified
Component: Core tasks (show other bugs)
Version: 1.8.0
Hardware: All All
: P2 normal (vote)
Target Milestone: 1.8.1
Assignee: Ant Notifications List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-02-17 03:28 UTC by Marc Bevand
Modified: 2010-02-17 08:56 UTC (History)
0 users


Attachments
Fixes the Zip task performance bug (514 bytes, patch)
2010-02-17 03:28 UTC, Marc Bevand 		Details | Diff
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Marc Bevand 2010-02-17 03:28:14 UTC 
Created attachment 25004 [details]
Fixes the Zip task performance bug

The ant zip task does an O(n) instead of O(1) lookup in a Hashtable when adding files to the archive. The attached patch fixes this embarassing performance bug by calling containsKey() instead of contains(). It applies cleanly to Ant 1.8.0.

I measured a 3x performance improvement with the jar task (based on the zip task) when creating a jar from a directory containing 50 thousand files on my system:

      <jar destfile="foo.jar" basedir="dir-with-50k-files"/>

Before: 103 sec
After: 32 sec
Comment 1 Stefan Bodewig 2010-02-17 05:10:36 UTC 
Ooops.

fixed with svn revision 910825

thanks!
Comment 2 Marc Bevand 2010-02-17 07:01:45 UTC 
Thanks.

PS: you made a typo in my last name in the commit message (Bevand, not Beyand). Oh well :-)
Comment 3 Stefan Bodewig 2010-02-17 08:56:00 UTC 
sorry about the spelling error, fixed now.

an underlined v looks a lot like a y in the font I use in Firefox.