[
https://issues.apache.org/jira/browse/CALCITE-3386?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16944862#comment-16944862
]
Haisheng Yuan commented on CALCITE-3386:
----------------------------------------
Agree
> CyclicMetadataException gives misleading stack trace
> ----------------------------------------------------
>
> Key: CALCITE-3386
> URL: https://issues.apache.org/jira/browse/CALCITE-3386
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Zuozhi Wang
> Priority: Major
>
> Calcite currently reuses the same instance when throwing
> CyclicMetadataException as shown below.
> {code:java}
> /** Singleton instance. Since this exception is thrown for signaling
> purposes, * rather than on an actual error, re-using a singleton instance
> saves the * effort of constructing an exception instance. */
> @SuppressWarnings("ThrowableInstanceNeverThrown")
> public static final CyclicMetadataException INSTANCE = new
> CyclicMetadataException();
> {code}
>
> Reusing the same exception instance gives the wrong stack trace, see:
> [https://stackoverflow.com/questions/15090664/is-it-safe-to-store-an-instance-of-an-exception-and-reuse-it]
> The misleading stack trace causes many confusions when debugging. The
> potential performance impact because of object construction is minor compared
> to the time spent on debugging. Therefore it should be changed to not reuse
> the singleton instance.
> A pull request have been opened to fix this issue:
> [https://github.com/apache/calcite/pull/1484]
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
