[
https://issues.apache.org/jira/browse/RNG-114?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Alex D Herbert updated RNG-114:
-------------------------------
Attachment: LinkedListShufflePerformance.png
> Improve ListSampler shuffle algorithm to detect instances of RandomAccess
> -------------------------------------------------------------------------
>
> Key: RNG-114
> URL: https://issues.apache.org/jira/browse/RNG-114
> Project: Commons RNG
> Issue Type: Improvement
> Components: sampling
> Affects Versions: 1.2
> Reporter: Alex D Herbert
> Assignee: Alex D Herbert
> Priority: Minor
> Attachments: LinkedListShufflePerformance.png
>
>
> The ListSampler shuffle algorithm uses the input list {{set(index)}} method.
> If this runs in constant time then the algorithm is fast. If the list is not
> an instance of {{java.util.RandomAccess}} such as a LinkedList the algorithm
> will suffer from performance slowdown for large lists.
> This is handled in the JDK Collections.shuffle method by detecting if the
> list is not an instance of RandomAccess. If so the list {{set(index)}} method
> is avoided and the list is traversed for update using its iterator.
> Tasks:
> * Benchmark the ListSampler method verses Collections.shuffle with ArrayList
> and LinkedList
> * Update the ListSampler to have comparable performance to
> Collections.shuffle
--
This message was sent by Atlassian Jira
(v8.3.2#803003)
