[
https://issues.apache.org/jira/browse/CASSANDRA-12381?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15407871#comment-15407871
]
Sylvain Lebresne commented on CASSANDRA-12381:
----------------------------------------------
Also, out of curiosity, could you indicate your source for the following claim:
bq. If a direct ByteBuffer has a backing array, we should not make any
assumption on how it is actually used.
Cause [the hasArray()
method|https://docs.oracle.com/javase/8/docs/api/java/nio/ByteBuffer.html#hasArray--]
javadoc does states:
{quote}
Tells whether or not this buffer is backed by an accessible byte array.
If this method returns true then the array and arrayOffset methods may safely
be invoked.
{quote}
and along with the javadoc on arrayOffset(), it sounds to me that what we do is
completely fine. And {{hasArray}} sounds much more explicit to me in fact.
Honestly, I'd be surprised if what you say is true as that seems to suggest
that the {{hasArray}} and {{arrayOffset}} methods are completely useless unless
you also check {{isDirect()}} and that's not at all clearly stated in the
javadoc.
> Verify use of ByteBuffer.hasArray() in whole code base
> ------------------------------------------------------
>
> Key: CASSANDRA-12381
> URL: https://issues.apache.org/jira/browse/CASSANDRA-12381
> Project: Cassandra
> Issue Type: Bug
> Reporter: Robert Stupp
> Assignee: Robert Stupp
> Priority: Minor
> Fix For: 3.0.x
>
>
> As [noted
> here|https://docs.oracle.com/javase/8/docs/api/java/nio/ByteBuffer.html#allocateDirect-int-],
> a direct {{ByteBuffer}} can have a backing array.
> If a direct {{ByteBuffer}} has a backing array, we should not make any
> assumption on how it is actually used.
> This ticket is about to check whether uses of {{ByteBuffer.hasArray()}} need
> to be replaced with {{ByteBuffer.isDirect()}}.
> (With CASSANDRA-11870 however, there is no way that such a direct
> {{ByteBuffer}} has a backing array.)
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
