[jira] [Updated] (ARROW-399) [Java] ListVector.loadFieldBuffers ignores the ArrowFieldNode length metadata

["Rok Mihevc (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-399?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rok Mihevc updated ARROW-399:
-----------------------------
    External issue URL: https://github.com/apache/arrow/issues/16027

> [Java] ListVector.loadFieldBuffers ignores the ArrowFieldNode length metadata
> -----------------------------------------------------------------------------
>
>                 Key: ARROW-399
>                 URL: https://issues.apache.org/jira/browse/ARROW-399
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: Java
>            Reporter: Wes McKinney
>            Assignee: Julien Le Dem
>            Priority: Blocker
>             Fix For: 0.2.0
>
>         Attachments: list_error.json
>
>
> Discovered this during integration testing. Because Arrow-C++ writes buffers padded to 64 bytes, they may appear larger to the Java library than they need to be. In ListVector.loadFieldBuffers, the ArrowFieldNode is never used:
> {code:language=java}
>   @Override
>   public void loadFieldBuffers(ArrowFieldNode fieldNode, List<ArrowBuf> ownBuffers) {
>     BaseDataValueVector.load(getFieldInnerVectors(), ownBuffers);
>   }
> {code}
> The value count of the resulting ListVector is thus inferred from the size of the offsets buffer. In the case of a length-7 vector in C++, the size of the offsets buffer is exactly 64 bytes (padding for SIMD) -- Java infers from 64 bytes that the value count is 15 (64 / 4 - 1), and the integration test fails.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)