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https://issues.apache.org/jira/browse/HBASE-19160?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16237101#comment-16237101
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ramkrishna.s.vasudevan commented on HBASE-19160:
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I think if we need to expose getInstance in CellComparator it should be static
because in your case you don't have access to the region/store. So you need an
instance of CellComparator if you want to do the getInstance(). If you don't
have it you need to have it static.
So seeing this change can we just mark CellComparator @Public? So that even
clients like MR/spark can make use of it?
Coming to the createXXXOnRow() can you see if you can try using
CellBuilder.create(byte[]) in crunch code?
> Re-expose some CellUtil methods
> -------------------------------
>
> Key: HBASE-19160
> URL: https://issues.apache.org/jira/browse/HBASE-19160
> Project: HBase
> Issue Type: Bug
> Affects Versions: 2.0.0-alpha-4
> Reporter: Mike Drob
> Assignee: Mike Drob
> Priority: Critical
> Fix For: 2.0.0-beta-1
>
> Attachments: HBASE-19160.patch
>
>
> On HBASE-18995 we moved a bunch of public methods to Private places. This
> inadvertently breaks donwstream consumers. Let's see if we can ease up on
> some of the lockdown and make life easier for them.
> Copying [~ram_krish]'s previous analysis:
> {quote}
> I read the Crunch projec't hbase-support related code.
> -> It uses both CellUtil (Public exposed) and KeyValueUtil (@Private) classes
> for helper methods.
> -> All methods in CellUtil that are getting used are even now exposed in
> branch-2's CellUtil and they are very common helper methods. So we are safe
> here.
> -> Wrt KeyValueUtil the API is createFirstOnRow(). It is used in test cases
> and in some core code. In most of the places they are trying to create the
> splitKeys from the region's start keys and that is also getting persisted. I
> think here they can safely create a cell out of the given byte[] of the row.
> But there is one place where they are trying to do some scanning on a
> HFileScanner directly (@Private) scanner. So this should be changed because
> it is an internal interface for us. And on this scanner they have copied our
> seekTo() code into their source files for some scanning purpose. In this code
> they are actually using the KvUtil.createFirstOnRow() to seek to that first
> cell of that row.
> More over I think in branch-2 we are restricting even CPs from accessing some
> of our internal scanners and they can only use InternalScanner interface. So
> this code in crunch needs heavy refactoring to work with branch-2 in case
> they want to fit into the Public/Private exposed semantics that HBase
> presents to the downstreamers.
> -> If still they want some APIs like this we can expose
> CellUtil#createFirstOnRow, createLastOnRow, createFirstOnCol and
> createLastOnCol at the maximum. I think others are not useful and are more
> internal stuffs.
> {quote}
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