Motivation

KV now supports a replace_body_with_xattr subdoc operation. This means we can avoid storing the staged content in the SDK, if the server supports that feature.

Changes

• Support the revive_document subdoc flag in the core.
• If the server supports replace_body_with_xattr, we no longer store the staged content when creating a staged_mutation.
• When committing a staged_mutation and the staged content is not present, that indicates that replace_body_with_xattr is supported. Hence, we use that subdocument operation to commit the staged content.
• Fixed handling of FAIL_CAS_MISMATCH for commit_doc errors. We should leave ambiguity_resolution_mode unchanged, according to the spec.
• Updates to do_get:
  • Handle the case where we don't have the content stored in the staged_mutation when the document is in our staged mutations (i.e. the server supports replace_body_with_xattr). In those cases, we now need to fetch it (spec).
  • Implement the optimization where we don't look up the document's ATR if the attempt ID in the document's txn metadata matches our attempt ID. We now immediately return the post-transaction version (spec).

Results

• All ExtReplaceBodyWithXattr FIT tests pass
• No regressions in other FIT tests