[jira] [Updated] (FLEX-34759) ArrayList/ArrayCollection performance improvements

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

     [ https://issues.apache.org/jira/browse/FLEX-34759?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

shane doolan updated FLEX-34759:
--------------------------------
    Summary: ArrayList/ArrayCollection performance improvements  (was: ArrayList performance improvements)

> ArrayList/ArrayCollection performance improvements
> --------------------------------------------------
>
>                 Key: FLEX-34759
>                 URL: https://issues.apache.org/jira/browse/FLEX-34759
>             Project: Apache Flex
>          Issue Type: Improvement
>          Components: Collections
>            Reporter: shane doolan
>              Labels: newbie, patch, performance
>         Attachments: FLEX-34759.patch
>
>
> Considerable performance gains can be achieved by avoiding the use of array splice when adding/removing items from the start or end of the source array in ArrayList.
> eg/ in ArrayList.addItemAt, replace this:
> {code}
> source.splice(index, 0, item);
> {code}
> with this:   
> {code} 
> if (index == length)
>     source.push(item);
> else if (index == 0)
>     source.unshift(item);
> else
>     source.splice(index, 0, item);
> {code}
> ArrayList.addItem is 10x faster when adding non IEventDispatcher's, and 6x faster for IEventDispatcher's. There is a small trade-off when performing random access add/removes, where the extra logic slightly increases the times taken. 
> Since ArrayCollection wraps an ArrayList by default and ArrayCollection.addItem is used extensively within our apps, this patch has provided considerable performance improvements.
> See profiling results below:
> *Original ArrayList, adding/removing 100k ints*
> * addItemAtStart = "2434ms"
> * addItemAtEnd = "2501ms"
> * addItemAtRandom = "3149ms"
> * removeItemAtStart = "3098ms"
> * removeItemAtEnd = "2401ms"
> * removeItemAtRandom = "2606ms"
> *Original ArrayList, adding/removing 100k IEventDispatcher's*
> * addItemAtStart = "2501ms"
> * addItemAtEnd = "2505ms"
> * addItemAtRandom = "3165ms"
> * removeItemAtStart = "3053ms"
> * removeItemAtEnd = "2453ms"
> * removeItemAtRandom = "2709ms"
> *Patched ArrayList, adding/removing 100k ints*
> * addItemAtStart = "226ms"
> * addItemAtEnd = *"213ms"*
> * addItemAtRandom = "3281ms"
> * removeItemAtStart = "803ms"
> * removeItemAtEnd = "219ms"
> * removeItemAtRandom = "2808ms"
> *Patched ArrayList, adding/removing 100k IEventDispatcher's*
> * addItemAtStart = "415ms"
> * addItemAtEnd = *"488ms"*
> * addItemAtRandom = "3662ms"
> * removeItemAtStart = "878ms"
> * removeItemAtEnd = "264ms"
> * removeItemAtRandom = "2949ms"



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