8de1903172
This mostly reverts the previous commit, and makes non-NULL ecksums the
consistent API.
Non-NULL ecksums are what the original rbyd-level ecksum API expects,
and enforcing this avoids the ifdef mess required to minimize unused
code impact.
This unfortunately clutters up lfs3_gbmap_set_'s logic with NULL checks,
but at least keeps the mess constrained to lfs3_gbmap_set_.
lfs3_gbmap_set_ is really the only function that uses NULL ecksums, so
they should probably be lfs3_gbmap_set_'s problem to deal with.
Code changes:
code stack ctx
before: 35144 2136 660
after: 35144 (+0.0%) 2136 (+0.0%) 660 (+0.0%)
code stack ctx
gbmap+np before: 38296 2144 776
gbmap+np after: 38272 (-0.1%) 2144 (+0.0%) 776 (+0.0%)
code stack ctx
gbmap+yp before: 38908 2168 796
gbmap+yp after: 38940 (+0.1%) 2168 (+0.0%) 796 (+0.0%)