frames was the one bulk reader still calling the uncached content(), so a delta base was reconstructed once per referencing delta rather than once per run — superlinear work against a linear stream, on corpora that are ~90% deltas after a fossil import.

libfossil (17,449 artifacts): 12.4s -> 2.34s real, 12.0s -> 2.25s user. Output byte-identical, peak RSS down 362MB -> 314MB. memoize_undeltaed stays off: the sweep reads each artifact once, and bases are memoized regardless of their own frame kind, which is the win. closed check-in: 2e3bb0b9db user: dmestas tags: frames-memo