Ben Kietzman created ARROW-12873:
------------------------------------

             Summary: [C++][Compute] Support tagging ExecBatches with arbitrary 
extra information
                 Key: ARROW-12873
                 URL: https://issues.apache.org/jira/browse/ARROW-12873
             Project: Apache Arrow
          Issue Type: Improvement
          Components: C++
            Reporter: Ben Kietzman


Ideally, ExecBatches could be tagged with arbitrary optional objects for 
tracing purposes and to transmit execution hints from one ExecNode to another.

These should *not* be explicit members like ExecBatch::selection_vector is, 
since they may not originate from the arrow library. For an example within the 
arrow project: {{libarrow_dataset}} will be used to produce ScanNodes and a 
WriteNodes and it's useful to tag scanned batches with their {{Fragment}} of 
origin. However adding {{ExecBatch::fragment}} would result in a cyclic 
dependency.

To facilitate this tagging capability, we would need a type erased container 
something like
{code}
struct AnySet {
  void* Get(tag_t tag);
  void Set(tag_t tag, void* value, FnOnce<void(void*)> destructor);
};
{code}





--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to