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https://issues.apache.org/jira/browse/PARQUET-2134?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17550942#comment-17550942
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ASF GitHub Bot commented on PARQUET-2134:
-----------------------------------------
steveloughran opened a new pull request, #971:
URL: https://github.com/apache/parquet-mr/pull/971
This extends #951
It improves binding to streams which implement
ByteBufferReadable through recursive probes of wrapped
streams and direct querying of the stream on Hadoop 3.3.0+.
Since HDFS-14111 all input streams in the hadoop codebase
which implement ByteBufferReadable return true on the
StreamCapabilities probe hasCapability("in:readbytebuffer")
This means the best way to probe for the API on those versions
is to ask the stream.
The StreamCapabilities probe was added in Hadoop 2.9. Along with
making all use of `ByteBufferReadable` non-reflective, this makes
the checks fairly straightforward.
The recursive check is from #951; the change is it no longer
needs to use reflection.
Tests verify that if a stream implements `ByteBufferReadable' then
it will be bonded to H2SeekableInputStream, even if multiply wrapped
by FSDataInputStreams, and that if it doesn't, it won't.
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> Incorrect type checking in HadoopStreams.wrap
> ---------------------------------------------
>
> Key: PARQUET-2134
> URL: https://issues.apache.org/jira/browse/PARQUET-2134
> Project: Parquet
> Issue Type: Bug
> Components: parquet-mr
> Affects Versions: 1.8.3, 1.10.1, 1.11.2, 1.12.2
> Reporter: Todd Gao
> Priority: Minor
>
> The method
> [HadoopStreams.wrap|https://github.com/apache/parquet-mr/blob/4d062dc37577e719dcecc666f8e837843e44a9be/parquet-hadoop/src/main/java/org/apache/parquet/hadoop/util/HadoopStreams.java#L51]
> wraps an FSDataInputStream to a SeekableInputStream.
> It checks whether the underlying stream of the passed FSDataInputStream
> implements ByteBufferReadable: if true, wraps the FSDataInputStream to
> H2SeekableInputStream; otherwise, wraps to H1SeekableInputStream.
> In some cases, we may add another wrapper over FSDataInputStream. For
> example,
> {code:java}
> class CustomDataInputStream extends FSDataInputStream {
> public CustomDataInputStream(FSDataInputStream original) {
> super(original);
> }
> }
> {code}
> When we create an FSDataInputStream, whose underlying stream does not
> implements ByteBufferReadable, and then creates a CustomDataInputStream with
> it. If we use HadoopStreams.wrap to create a SeekableInputStream, we may get
> an error like
> {quote}java.lang.UnsupportedOperationException: Byte-buffer read unsupported
> by input stream{quote}
> We can fix this by taking recursive checks over the underlying stream of
> FSDataInputStream.
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