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Posted to dev@flex.apache.org by "RJ Camarillo (JIRA)" <ji...@apache.org> on 2013/02/05 05:12:14 UTC

[jira] [Comment Edited] (FLEX-33273) CSSCondition.matchesStyleClient() is slow and creates excessive garbage

    [ https://issues.apache.org/jira/browse/FLEX-33273?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13570926#comment-13570926 ] 

RJ Camarillo edited comment on FLEX-33273 at 2/5/13 4:10 AM:
-------------------------------------------------------------

Aha! Thanks Justin!

If you guys are interested, we also implemented our own changes to the mx.style.* classes to improve performance in Flex 4.6. I'm currently integrating this change to what we have and see how it goes. Anyhow, the primarily idea is to inline function calls (not my original idea). We are aware that this approach is anti-OO but in terms of performance, it does the job.
                
      was (Author: rj.camarillo):
    Aha! Thanks Justin!
                  
> CSSCondition.matchesStyleClient() is slow and creates excessive garbage
> -----------------------------------------------------------------------
>
>                 Key: FLEX-33273
>                 URL: https://issues.apache.org/jira/browse/FLEX-33273
>             Project: Apache Flex
>          Issue Type: Improvement
>          Components: Styles
>    Affects Versions: Adobe Flex SDK 4.1 (Release), Adobe Flex SDK 4.5 (Release), Adobe Flex SDK 4.5.1 (Release), Adobe Flex SDK 4.6 (Release)
>            Reporter: Maurice Nicholson
>            Assignee: Frédéric THOMAS
>              Labels: patch, performance
>         Attachments: FLEX-33273.patch, PerformanceTest.zip
>
>
> CSSCondition.matchesStyleClient() is called *very* frequently during layout of components in many different scenarios.
> I've done a lot of profiling of Flex apps and it comes up again and again.
> The current implementation is slow and creates unnecessary garbage (which slows down the runtime further, since it needs to collect the garbage instead of doing more useful things).
> Here is the current implementation:
> {code}
>     public function matchesStyleClient(object:IAdvancedStyleClient):Boolean
>     {
>         var match:Boolean = false;
>         if (kind == CSSConditionKind.CLASS)
>         {
>             if (object.styleName != null && object.styleName is String)
>             {
>                 // Look for a match in a potential list of styleNames 
>                 var styleNames:Array = object.styleName.split(/\s+/);
>                 for (var i:uint = 0; i < styleNames.length; i++)
>                 {
>                     if (styleNames[i] == value)
>                     {
>                         match = true;
>                         break;
>                     }
>                 }
>             }
>         }
>         else if (kind == CSSConditionKind.ID)
>         {
>             if (object.id == value)
>                 match = true;
>         }
>         else if (kind == CSSConditionKind.PSEUDO)
>         {
>             if (object.matchesCSSState(value))
>                 match = true;
>         }
>         return match;
>     }
> {code}
> Here is what I suggest instead:
> {code}
>     public function matchesStyleClient(object:IAdvancedStyleClient):Boolean
>     {
>         var match:Boolean = false;
>         if (kind == CSSConditionKind.CLASS)
>         {
>             const styleName:String = object.styleName as String;
>             if (styleName)
>             {
>                 // Look for a match in a potential list of styleNames 
>                 FIND:
>                 {
>                     var index:int = styleName.indexOf(value);
>                     if (index == -1)
>                     {
>                         break FIND;
>                     }
>                     if (index != 0 && styleName.charAt(index - 1) != ' ')
>                     {
>                         break FIND;
>                     }
>                     const next:int = index + value.length;
>                     if (next != styleName.length && styleName.charAt(next) != ' ')
>                     {
>                         break FIND;
>                     }
>                     match = true;
>                 }
>             }
>         }
>         else if (kind == CSSConditionKind.ID)
>         {
>             if (object.id == value)
>                 match = true;
>         }
>         else if (kind == CSSConditionKind.PSEUDO)
>         {
>             if (object.matchesCSSState(value))
>                 match = true;
>         }
>         return match;
>     }
> {code}
> There are obviously more concise ways to express this code, but the above seems to match the current style more or less.
> Here is the output from a benchmark I created using Grant Skinner's PerformanceTest v2 Beta, comparing the current version and the suggested version:
> {noformat}
> Comparing speed of matching a string in space delimited string. 1000000 loops.
> Test                                                           Old ms   New ms Speedup  Old mem  New mem  Change
> matchesStyleClient(styleName: "foo", value: "foo")            1006.00   181.00   -82.0   123.00     0.00  -100.0
> matchesStyleClient(styleName: "foo bar", value: "foo")        2107.00   206.80   -90.2   115.00     0.00  -100.0
> matchesStyleClient(styleName: "bar foo", value: "foo")        2099.80   232.30   -88.9   117.00     0.00  -100.0
> matchesStyleClient(styleName: "baz foo bar", value: "foo")    3193.80   251.30   -92.1   119.00     0.00  -100.0
> matchesStyleClient(styleName: "foobar", value: "foo")         1169.50   192.00   -83.6   112.00     0.00  -100.0
> matchesStyleClient(styleName: "foofoo bar", value: "foo")     2273.80   191.30   -91.6   116.00     0.00  -100.0
> matchesStyleClient(styleName: "fo", value: "foo")              918.80   141.00   -84.7   108.00     0.00  -100.0
> matchesStyleClient(styleName: "fooo", value: "foo")           1052.80   192.00   -81.8   108.00     0.00  -100.0
> matchesStyleClient(styleName: "2foo bar", value: "foo")       2149.50   205.30   -90.4   116.00     0.00  -100.0
> matchesStyleClient(styleName: "foo2 bar", value: "foo")       3849.50   190.80   -95.0   111.00     0.00  -100.0
> matchesStyleClient(styleName: "", value: "foo")               1801.80   141.00   -92.2   132.00     0.00  -100.0
> {noformat}
> As you can see, the new version doesn't create garbage, and is at least 80% faster in the above test cases.
> I would be happy to contribute a patch and a FlexUnit test, but I haven't seen any existing FlexUnit tests in the current source tree, so not sure where to put it.
> Otherwise Mustella seems like a beast to get to know and run, so I will need some guidance as to what to do if you require new Mustella tests.

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Re: [jira] [Comment Edited] (FLEX-33273) CSSCondition.matchesStyleClient() is slow and creates excessive garbage

Posted by Justin Mclean <ju...@classsoftware.com>.
Hi,

Post your findings to the Apache dev list.  If there's significant performance gains I'm sure people would be interested.

Justin