Bug 53821 - IdentityStack.removeAll() is slow
Summary: IdentityStack.removeAll() is slow
Status: RESOLVED FIXED
Alias: None
Product: Ant
Classification: Unclassified
Component: Core (show other bugs)
Version: 1.9.1
Hardware: PC Linux
: P2 normal (vote)
Target Milestone: 1.9.4
Assignee: Ant Notifications List
URL:
Keywords: PatchAvailable
Depends on:
Blocks:
 
Reported: 2012-09-03 15:30 UTC by Adrian Nistor
Modified: 2014-01-02 14:37 UTC (History)
1 user (show)


Attachments
patch (707 bytes, patch)
2012-09-03 15:30 UTC, Adrian Nistor 		Details | Diff
test (641 bytes, text/x-java)
2012-09-03 15:31 UTC, Adrian Nistor 		Details
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Description Adrian Nistor 2012-09-03 15:30:21 UTC 
Created attachment 29320 [details]
patch

"IdentityStack.removeAll(Collection coll)" has the same performance
problem as the previously fixed Bug 53622 (for
"VectorSet.retainAll(Collection coll)").  The problem is that
"removeAll(Collection coll)" performs "coll.contains(e.next())", which
is slow if for example "coll" is a list.

I attached a patch similar to the one used by Jesse Glick in Bug
53622.  I also attached a test that exposes this problem.  For this
test, the patch provides a 97X speedup on my machine.

To run the test, just do:

$ java Test

The output for the un-patched version is:
Time is 2516

The output for the patched version is:
Time is 26
Comment 1 Adrian Nistor 2012-09-03 15:31:16 UTC 
Created attachment 29321 [details]
test
Comment 2 Stefan Bodewig 2014-01-02 14:37:56 UTC 
svn revision 1554813