[jira] [Resolved] (HBASE-10965) Automate detection of presence of Filter#filterRow()

["Ted Yu (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-10965?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ted Yu resolved HBASE-10965.
----------------------------
    Resolution: Won't Fix

> Automate detection of presence of Filter#filterRow()
> ----------------------------------------------------
>
>                 Key: HBASE-10965
>                 URL: https://issues.apache.org/jira/browse/HBASE-10965
>             Project: HBase
>          Issue Type: Task
>          Components: Filters
>            Reporter: Ted Yu
>            Assignee: Ted Yu
>         Attachments: 10965-v1.txt, 10965-v2.txt, 10965-v3.txt, 10965-v4.txt, 10965-v6.txt, 10965-v7.txt
>
>
> There is potential inconsistency between the return value of Filter#hasFilterRow() and presence of Filter#filterRow().
> Filters may override Filter#filterRow() while leaving return value of Filter#hasFilterRow() being false (inherited from FilterBase).
> Downside to purely depending on hasFilterRow() telling us whether custom filter overrides filterRow(List) or filterRow() is that the check below may be rendered ineffective:
> {code}
>           if (nextKv == KV_LIMIT) {
>             if (this.filter != null && filter.hasFilterRow()) {
>               throw new IncompatibleFilterException(
>                 "Filter whose hasFilterRow() returns true is incompatible with scan with limit!");
>             }
> {code}
> When user forgets to override hasFilterRow(), the above check becomes not useful.
> Another limitation is that we cannot optimize FilterList#filterRow() through short circuit when FilterList#hasFilterRow() turns false.
> See https://issues.apache.org/jira/browse/HBASE-11093?focusedCommentId=13985149&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13985149
> This JIRA aims to remove the inconsistency by automatically detecting the presence of overridden Filter#filterRow(). For FilterBase-derived classes, if filterRow() is implemented and not inherited from FilterBase, it is equivalent to having hasFilterRow() return true.
> With precise detection of presence of Filter#filterRow(), the following code from HRegion is no longer needed while backward compatibility is kept.
> {code}
>       return filter != null && (!filter.hasFilterRow())
>           && filter.filterRow();
> {code}



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)