Detecting tar files then falling back for calculating digests turned out to be
fairly unreliable. Likely, the implementation was broken for content that was
not a tarfile. Also, for the use case of the registry, it is really not needed.
This functionality has been removed in FromReader and FromBytes. FromTarArchive
has been added for convenience.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Since the common package no longer exists, the testutil package is being moved
up to the root. Ideally, we don't have large omnibus packages, like testutil,
but we can fix that in another refactoring round.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
The Digest type will be fairly central for blob and layer management. The type
presented in this package provides a number of core features that should enable
reliable use within the registry. This commit will be followed by others that
convert the storage layer and webapp to use this type as the primary layer/blob
CAS identifier.