CUBE_OP_ENUM and CUBE_OP_RANGE returned `key | value_len | value`, so a caller
could walk a store and not learn what any record it walked past *was*. A store
could not answer `entries_flagged` from a kernel store at all, and the only way
to find out was to open the device and read the format directly — which is the
second reader of the format this interface exists to make unnecessary.
Both walks now return the flag scan's frame: `key(24) | flags(2) | value_len |
value`, with the space ahead of it when the scope is every space. One frame,
one packer, one `Batch::offer`; the separate `offer_flagged` and `pack_record`
are gone, and so is the reason for them to disagree.
The class comes from wherever the value did: an addressed image's index entry
(the binary search already read it and used to throw it away), a log entry's
mask, or zero for a packed v1/v2 record, which has no field to carry one. The
merge in `SpaceWalker` hands it back alongside the key and the value for the
same reason — a record the log supplied carries the class its writer stamped,
and dropping it there is what left a listing unable to say what it was listing.
surface-camera-build
da0a19786e