Last Call Review of draft-kucherawy-dispatch-zstd-01
review-kucherawy-dispatch-zstd-01-opsdir-lc-hares-2018-04-26-00

Status: ready with issues
Overal-comment: This specification has carefully defined all the Careful
specification the bits and bytes of the compression /decompression.  However,
it unclear how common error codes are shared between implementations.

Error code issues:  Compression/Decompression is normally a specific library
function.  As a library function, it is often tested with reference test suites
against a referece implementation.  What I do not undersatnd form this
specification is how errors get passed to the calling program.

A face book implementation of this zstd return errors codes:
(https://facebook.github.io/zstd/zstd_manual.html)
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)

Should this type of operational information be included in the compression
specification?  It seems like common error codes would help the
interoperability of different implementations  so that compression by one
implementation would correctly be decompressed by a second.

Authors: What you need to do to clear my issue question:
Please talk to your AD and experts to determine the need for the error codes or
the specific codes.  I'm only qualified to suggest this area of inquiry might
be fruitful.   After you consider this concept with your AD, you can send a
message to the OPS-DIR list to indicate the resolution of my question.

reviewer caveat: I am not a expert on compression in media types.  If the
OPS-NM area ADs, feel this should be reviewed again with
compression/decompression expert for media data to determine what error codes
are needed, they should probably select someone who has worked with these
libraries.