[ARROW-3782] [C++] Implement BufferedReader for C++

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.12.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/20137
• Assignee: Wes McKinney
• Reporter: Wes McKinney
• Created: 13/Nov/18 20:57
• Updated: 11/Jan/23 07:29
• Resolved: 24/Nov/18 19:43

Description

This will be the reader companion to arrow::io::BufferedOutputStream and a C++-like version of the io.BufferedReader class in the Python standard library

https://docs.python.org/3/library/io.html#io.BufferedReader

We already have a partial version of this that's used in the Parquet library

https://github.com/apache/arrow/blob/master/cpp/src/parquet/util/memory.h#L413

In particular we need

• Seek implemented for random access (it will invalidate the buffer)
• Peek method returning shared_ptr<Buffer>, a zero copy view into buffered memory

This is needed for ARROW-3126

Issue Links

• links to: GitHub Pull Request #2976
• links to: GitHub Pull Request #2988