[
https://issues.apache.org/jira/browse/HDFS-5781?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13876795#comment-13876795
]
Colin Patrick McCabe commented on HDFS-5781:
--------------------------------------------
I agree that using {{Enum#values}} directly is not the right thing here. It
might make backports difficult, as you commented.
How about just using an array that might contain some nulls? A hash map looks
like overkill because there aren't that many entries, and they key numbers are
all close together.
> Use a map to record the mapping between FSEditLogOpCode and the corresponding
> byte value
> ----------------------------------------------------------------------------------------
>
> Key: HDFS-5781
> URL: https://issues.apache.org/jira/browse/HDFS-5781
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: namenode
> Affects Versions: 2.4.0
> Reporter: Jing Zhao
> Assignee: Jing Zhao
> Attachments: HDFS-5781.000.patch
>
>
> HDFS-5674 uses Enum.values and enum.ordinal to identify an editlog op for a
> given byte value. While improving the efficiency, it may cause issue. E.g.,
> when several new editlog ops are added to trunk around the same time (for
> several different new features), it is hard to backport the editlog ops with
> larger byte values to branch-2 before those with smaller values, since there
> will be gaps in the byte values of the enum.
> This jira plans to still use a map to record the mapping between editlog ops
> and their byte values.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
