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ASF GitHub Bot commented on ARROW-2328: --------------------------------------- pitrou commented on a change in pull request #1784: ARROW-2328: [C++] Fixed and unit tested feather writing with slice URL: https://github.com/apache/arrow/pull/1784#discussion_r179479896 ########## File path: cpp/src/arrow/ipc/feather.cc ########## @@ -75,6 +75,43 @@ static Status WritePadded(io::OutputStream* stream, const uint8_t* data, int64_t return Status::OK(); } +static Status WritePaddedWithOffset(io::OutputStream* stream, const uint8_t* data, + int64_t bit_offset, const int64_t length, + int64_t* bytes_written) { + data = data + bit_offset / 8; + uint8_t bit_shift = static_cast<uint8_t>(bit_offset % 8); Review comment: Is the cast to int8 necessary here? (for performance perhaps?) ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Writing a slice with feather ignores the offset > ----------------------------------------------- > > Key: ARROW-2328 > URL: https://issues.apache.org/jira/browse/ARROW-2328 > Project: Apache Arrow > Issue Type: Bug > Components: C++ > Affects Versions: 0.8.0 > Reporter: Adrian > Priority: Major > Labels: pull-request-available > Fix For: 0.10.0 > > Original Estimate: 0.5h > Remaining Estimate: 0.5h > > Writing a slice from row n of length m of an array to feather would write the > first m rows, instead of the rows starting at n. > The null bitmap also ends up misaligned. Also tested and fixed in the pull > request below. > I've created a pull request with tests and fix here: > [Pullrequest#1766|https://github.com/apache/arrow/pull/1766] > > -- This message was sent by Atlassian JIRA (v7.6.3#76005)