[
https://issues.apache.org/jira/browse/LANG-839?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13472034#comment-13472034
]
Sebb commented on LANG-839:
---------------------------
BitSet is considerably faster on Win XP:
Ratio=38% count=0 hash=610134 bits=234388
Ratio=46% count=5 hash=1809448 bits=837536
Ratio=54% count=10 hash=2840584 bits=1536229
Ratio=38% count=200 hash=72772936 bits=28216994
Ratio=37% count=50 hash=17909539 bits=6729347
Ratio=39% count=100 hash=35617096 bits=13972166
Ratio=40% count=1000 hash=339097567 bits=138882176
Ratio=42% count=2000 hash=650113632 bits=278152949
and Continuum:
Ratio=10% count=0 hash=1164164 bits=126956
Ratio=15% count=5 hash=1433866 bits=228518
Ratio=18% count=10 hash=1911315 bits=355922
Ratio=17% count=200 hash=31370106 bits=5439748
Ratio=18% count=50 hash=6947508 bits=1271146
Ratio=18% count=100 hash=13671526 bits=2555063
Ratio=15% count=1000 hash=154243712 bits=24577725
Ratio=10% count=2000 hash=411835139 bits=43056221
> ArrayUtils removeElements methods use unnecessary HashSet
> ---------------------------------------------------------
>
> Key: LANG-839
> URL: https://issues.apache.org/jira/browse/LANG-839
> Project: Commons Lang
> Issue Type: Improvement
> Components: lang.*
> Affects Versions: 3.1
> Reporter: Sebb
> Priority: Minor
> Attachments: LANG-839.patch
>
>
> The removeElements() methods use a HashSet to collect the indexes that need
> removing.
> This requires creating Integer objects for each index, and the HashSet then
> has to be converted into an int[] array.
> It would be more efficient to store the entries in an actual int[] array.
> The maximum size of this is the length of the values array (or the length of
> the input array if that is shorter).
> The array must be truncated before calling the private removeAll() method;
> this can be done with Arrays.copyOf(x[], length).
> However, if the arrays are very large, and most of the values do not appear
> in the input, this might result in using more memory than the HashSet
> implementation.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
