[
https://issues.apache.org/jira/browse/CASSANDRA-9975?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14969268#comment-14969268
]
Branimir Lambov commented on CASSANDRA-9975:
--------------------------------------------
The code is complicated, but looks correct and is well documented. I think it's
practically ready to commit once CI is clean.
Wondering if {{BasePartitions.hasNext/applyOne}} shouldn't take responsibility
of closing {{next}} if {{applyToPartitions}} returned {{null}} since other
aspects of the transformer do close automatically?
[toQuery in
checkForShortRead|https://github.com/apache/cassandra/compare/trunk...belliottsmith:9975#diff-8781f9483cca1cfc87145c767295cc79R358]
no longer has division-by-zero protection. Is it no longer necessary?
You should run the {{eclipse-warnings}} ant target and suppress any new
warnings.
> Flatten Iterator call hierarchy with a shared Transformer
> ---------------------------------------------------------
>
> Key: CASSANDRA-9975
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9975
> Project: Cassandra
> Issue Type: Sub-task
> Components: Core
> Reporter: Benedict
> Assignee: Benedict
> Fix For: 3.0.0
>
>
> Stepping through a read response is made exceedingly difficult by the sheer
> depth of the call hierarchy, and how rapidly your context jumps around. This
> ticket intend to partially address that, by flattening one of the main causes
> of this: iterator transformations.
> I have a patch that attempts to mitigate (but not entirely eliminate) this,
> through the introduction of a {{RowTransformer}} class that all
> transformations are applied through. If a transformation has already been
> applied, the {{RowTransformer}} class does not wrap a new iterator, but
> instead returns a new {{RowTransformer}} that wraps the original underlying
> (untransformed) iterator and both transformations. This can accumulate an
> arbitrary number of transformations and, quite importantly, can apply the
> filtration step {{Unfiltered -> Row}} in the same instance as well. The
> intention being that a majority of control flow happens inside this
> {{RowTransformer}}, so there is far less context jumping to cope with.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
