class Rugged::Tag

def self.extract_signature(repo, oid, prefix=GPG_SIGNATURE_PREFIX)
  object = repo.read(oid)
  unless object.type == :tag
    raise GitRPC::InvalidObject, "Invalid object type #{object.type}, expected tag"
  end
  if index = object.data.index(prefix)
    [
      object.data.byteslice(index..-1),
      object.data.byteslice(0...index)
    ]
  else
    nil
  end
end

def name
  canonical_name.sub(%r{^refs/tags/}, "")
end