[jira] [Commented] (DRILL-5517) Provide size-aware set operations in value vectors

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-5517?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16054180#comment-16054180 ] 

ASF GitHub Bot commented on DRILL-5517:
---------------------------------------

Github user bitblender commented on a diff in the pull request:

    https://github.com/apache/drill/pull/840#discussion_r122533121
  
    --- Diff: exec/vector/src/main/codegen/templates/VariableLengthVectors.java ---
    @@ -548,6 +567,23 @@ public void setSafe(int index, ByteBuffer bytes, int start, int length) {
           }
         }
     
    +    public void setScalar(int index, DrillBuf bytes, int start, int length) throws VectorOverflowException {
    +      assert index >= 0;
    +
    +      if (index >= MAX_ROW_COUNT) {
    +        throw new VectorOverflowException();
    +      }
    +      int currentOffset = offsetVector.getAccessor().get(index);
    +      final int newSize = currentOffset + length;
    +      if (newSize > MAX_BUFFER_SIZE) {
    +        throw new VectorOverflowException();
    +      }
    +      while (! data.setBytesBounded(currentOffset, bytes, start, length)) {
    --- End diff --
    
    indentation


> Provide size-aware set operations in value vectors
> --------------------------------------------------
>
>                 Key: DRILL-5517
>                 URL: https://issues.apache.org/jira/browse/DRILL-5517
>             Project: Apache Drill
>          Issue Type: Improvement
>    Affects Versions: 1.11.0
>            Reporter: Paul Rogers
>            Assignee: Paul Rogers
>             Fix For: 1.11.0
>
>
> DRILL-5211 describes a memory fragmentation issue in Drill. The resolution is to limit vector sizes to 16 MB (the size of Netty memory allocation "slabs.") Effort starts by providing "size-aware" set operations in value vectors which:
> * Operate as {{setSafe()}} while vectors are below 16 MB.
> * Throw a new, specific exception ({{VectorOverflowException}}) if setting the value (and growing the vector) would exceed the vector limit.
> The methods in value vectors then become the foundation on which we can construct size-aware record batch "writers."



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)