This adds a temporary subpackage implementing the experimental "Blob
Listing with Apache Arrow" feature on top of the released Azure azblob
SDK.
The Azure SDK for Go supports Arrow listing on its unreleased
feature/storage/bifrost branch (commit c6fa341ca22b) but that can't be
used in a release. This package exposes the same options and pager
interface as the experimental SDK, built on the released SDK's public
API plus verbatim copies of its Arrow decoder and of the two internal
auth policies (shared key signing and storage bearer challenge) which
the released SDK does not export. Copied files carry MIT attribution
headers pinned to their upstream source.
When Arrow listing ships in a released azblob the whole package will be
deleted and callers pointed back at the SDK - the interface is
deliberately source compatible to make that a mechanical change.
Also exports auth.Transporter so the new package's pipeline can use
rclone's fshttp transport, and adds github.com/apache/arrow-go/v18 as a
direct dependency for decoding the Arrow IPC stream.
Nick Craig-Wood
267f1560d2