[
https://issues.apache.org/jira/browse/STORM-1481?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15104159#comment-15104159
]
ASF GitHub Bot commented on STORM-1481:
---------------------------------------
Github user zhuoliu commented on the pull request:
https://github.com/apache/storm/pull/1023#issuecomment-172423672
+1.
The fix is necessary due to follows, which can cause problem during
grouping.
Integer.MAX_VALUE % 1 = 0
Integer.MAX_VALUE % 2 = 0
Integer.MAX_VALUE % 3 = -2
Integer.MAX_VALUE % 4 = 0
Integer.MAX_VALUE % 5 = -3
Integer.MAX_VALUE % 6 = -2
Integer.MAX_VALUE % 7 = -2
Integer.MAX_VALUE % 8 = 0
> avoid Math.abs(Integer) get a negative value
> --------------------------------------------
>
> Key: STORM-1481
> URL: https://issues.apache.org/jira/browse/STORM-1481
> Project: Apache Storm
> Issue Type: Bug
> Components: storm-core
> Reporter: Xin Wang
> Assignee: Xin Wang
>
> before fix:
> {code:title=org.apache.storm.trident.partition.IndexHashGrouping}
> public static int objectToIndex(Object val, int numPartitions) {
> if(val==null) return 0;
> else {
> return Math.abs(val.hashCode()) % numPartitions;
> }
> }
> {code}
> If the hashcode is Integer.MIN_VALUE, then the result will be negative as
> well (since Math.abs(Integer.MIN_VALUE) == Integer.MIN_VALUE).
> after fix:
> Use toPositive replace Math.abs:
> {code}
> public static int toPositive(int number) {
> return number & Integer.MAX_VALUE;
> }
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
