[jira] [Comment Edited] (TAP5-2332) Optimize String concatenation performance

["Lance (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TAP5-2332?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14004792#comment-14004792 ] 

Lance edited comment on TAP5-2332 at 5/22/14 7:51 AM:
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{quote}First, those were not my claims{quote}
Sorry, I got lost in the thread

{quote}I disagree with your statement that "most web requests will also hit the database"{quote}
As you said, please replace "hit the database" with "some slow operation"

{quote}this is not only about web requests{quote}
Sorry, most of the patch / discussion has been about webapps

If it's shown that this improvement noticibly speeds up a realistic application, I'm all for it.




was (Author: uklance):
{code}First, those were not my claims{code}
Sorry, I got lost in the thread

{code} I disagree with your statement that "most web requests will also hit the database"{code}
As you said, please replace "hit the database" with "some slow operation"

{code}this is not only about web requests{code}
Sorry, most of the patch / discussion has been about webapps

If it's shown that this improvement noticibly speeds up a realistic application, I'm all for it.



> Optimize String concatenation performance
> -----------------------------------------
>
>                 Key: TAP5-2332
>                 URL: https://issues.apache.org/jira/browse/TAP5-2332
>             Project: Tapestry 5
>          Issue Type: Improvement
>            Reporter: Michael Mikhulya
>            Assignee: Jochen Kemnade
>            Priority: Minor
>              Labels: performance
>         Attachments: 0001-TAP5-2332-get-rid-of-String.format-usage.patch
>
>
> During profiling I found that String.format provides much load on CPU.
> In many cases in Tapestry String.format can be easily replaced with simple String concatenation.
> Simple JMH (http://openjdk.java.net/projects/code-tools/jmh/) test
> {code:java}
> public class FormatVsConcat {
>     private static final String format = "This is a test string with %s";
>     private static final String concat1 = "This is a test string with ";
>     private static final String concat2 = "test word";
>     @GenerateMicroBenchmark
>     public String format() {
>         return String.format(format, concat2);
>     }
>     @GenerateMicroBenchmark
>     public String concat() {
>         return concat1 + concat2;
>     }
> }
> {code}
> shows, that concatenation is 366(!) times faster.
> I removed only hot places in tapestry and get following results with apache benchmark:
> *Not patched* tapestry version:
> Requests per second: *21.38 /sec* (mean)
> Time per request: *46.764 [ms]* (mean)
> *Patched* tapestry version:
> Requests per second: *27.77 /sec* (mean)
> Time per request: *36.013 [ms]* (mean)
> So we gained 10ms per request or 20% of rendering time.
> If you don't mind I would like to get rid of String.format in all places of Tapestry and provide patch. I fixed only hot places which appeared during ab-profiling of one concrete page. So it is very likely that not all hot places were found and fixed.



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