Wes McKinney created ARROW-3870:
-----------------------------------

             Summary: [C++] Add Peek to InputStream API
                 Key: ARROW-3870
                 URL: https://issues.apache.org/jira/browse/ARROW-3870
             Project: Apache Arrow
          Issue Type: Improvement
          Components: C++
            Reporter: Wes McKinney
             Fix For: 0.12.0


Some InputStream sources support lookahead without advancing the stream, like 
BufferReader and BufferedInputStream. This is used in Parquet's internal IO 
APIs, so it would be useful to be able to remove these after a deprecation cycle

https://github.com/apache/arrow/blob/master/cpp/src/parquet/util/memory.h#L375

If an InputStream does not support Peek, the returned {{string_view}} would 
have zero size. 

Another option is to have {{Peek}} return {{Status}}, so that NotImplemented 
can be returned. I would prefer to return 0-length if the operation is not 
supported



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to