Timeline

Extend the full-form (.zlib) compression-headroom probe with a dictionary sub-arm: train a candidate preset dictionary on the sampled full-form population and recompress the SAME frames with it preloaded, reporting the net byte gain over the empty-window baseline. This is the GO/NO-GO signal for adding a preset-dictionary frame class. At-rest MEASUREMENT only: it never touches the store or the production §4.1 codec, and it preloads the dictionary through a throwaway reference-difference method because Zig 0.16 std flate hardcodes FDICT=0 and exposes no setDictionary.

The dictionary-compression lineage this arm measures: RFC 1950 reserves the FDICT bit and the 32 KiB preset-dictionary window, and its §9 says the most- referenced strings belong at the dictionary tail (shortest back-references); Yann Collet's zstd --train/COVER is the reference for training a shared dictionary from a population of small, mutually-similar records; Chromium productionised shared-dictionary transport at scale (SDCH, later the Compression-Dictionary-Transport work); Fabrice Bellard's LZEXE established the practical art of squeezing highly-repetitive input with a tiny back- reference machine. closed check-in: 1027cba83c user: dmestas tags: storage

These four bench-run outputs (baseline / step2-pickbase / step3-pack-redeltify / step4-samepath) were measurement artifacts committed under docs/plans/bench — they do not belong in version control (docs/ is for the RFCs only). Remove them from the tip and add docs/plans/* to the versioned ignore-glob so the pattern cannot recur. They remain in the historical check-ins that added them (9aaf485847 and the integration merges) — Fossil history is immutable; purging them from provenance entirely would require fossil shun, deliberately not done. check-in: 0ad7fa92c6 user: dmestas tags: trunk

Lands amend, artifact, bisect, log PATH, annotate, merge --cherrypick/--backout, and addremove — the VCS-verb-survey recommendations — onto trunk, already integrated with the storage branch's pack re-deltification.

- amend: mint display-metadata T cards, never rewrite history (also corrects the git-reflex table's wrong immutability lesson). - artifact: the plumbing window (whatis + raw dump) over the one parser. - bisect: DAG binary search (bad/good/next/status/reset), state in .zit-bisect. - log PATH: per-file history folded into log (fossil finfo). - annotate: per-line provenance; the version chain is ordered by TOPOLOGY (matching fossil's generation walk), not mtime, so a parent is never misattributed to its child on a timestamp collision. - merge --cherrypick/--backout: alternate-baseline special merges recording a 4.7.14 Q card, rendered by info; the plain merge surface is byte-identical. - addremove: one sweep, add every extra and drop every missing.

Built decomposed (focused implementers + adversarial review) after the monolithic workflow thrashed on API instability. 1678 unit + 376 e2e + dst 6x1000 green. check-in: e5fffafdb8 user: dmestas tags: trunk

Brings trunk bab930 (the storage branch's at-rest re-deltification / zit pack generational rewrite, plus src/pack.zig and its bench baselines) into the cli-verbs-2 slice. One conflict, in src/root.zig — both branches added a module export at the same spot; resolved by keeping both (pub const bisect and pub const pack). logstore.zig and main.zig auto-merged. Integrated tree green: 1678 unit + 376 e2e; the seven new verbs and the pack pass together. closed check-in: e640119891 user: dmestas tags: cli

zit info on a cherrypick or backout check-in now shows a provenance line derived from the parsed 4.7.14 Q card: a 'cherrypick:' line for Q plus and a 'backout:' line for Q minus, each carrying the full REV hash, placed right after the parent and merge lines with the value column aligned. It reads through the shipped artifact parse path (repo.manifest then artifact.parse then parseQCard, iterating manifest.q) — no bespoke re-parse. A check-in with no Q card prints no such line and is byte-identical to before.

Also fixes an allocator-symmetry bug uncovered here: renderInfo now threads gpa (was arena) so info's manifest frees against the same allocator, ending an Invalid free panic at repo.deinit on every info call. Closes the last deferred clause of the cli-verbs-2 slice. 1678 unit + 376 e2e green. check-in: 4b1be918ab user: dmestas tags: cli

An adversarial review found zit annotate could charge a line to the too-recent CHILD when a parent and child check-in share an identical (or non-monotone) event mtime — the chain was ordered (mtime asc, hash). Fossil orders its annotate walk by pure topology (generation number, descendants.c/diff.c), so a parent is ALWAYS processed before its child. Match that.

New repostate.ancestryLinearized runs Kahn's over the reversed (child->parent) ancestry edges within the file's ancestor set, emitting newest->oldest with a (mtime desc, hash) ready-queue among topologically-INCOMPARABLE nodes, then reverses to the engine's oldest-first order — topology is now the PRIMARY key, mtime/hash only orders incomparable versions. annotateFile consumes it in place of the old sort; the attribute engine (primary-parent pass-through, oldest origin, binary refusal, layout) is unchanged. Amends the RESOLVED annotate-attribution rule. Linear/monotone history is byte-identical (degenerates to mtime-ascending); new tests (same-mtime parent-first, non-monotone, merge primary-parent) fail against the old order. 1678 unit + 376 e2e green. check-in: ff9662dfee user: dmestas tags: cli

fossil-style best-of-N delta base selection (pickBase, plan §5) plus a `zit pack` re-deltification pass with a monotonic-shrink guard (§6.1) and same-path candidates (§6.2). At-rest only: all four RFCs conformant, wire interop preserved, every repacked frame hash-verified against the log.

Measured (whole-file, index-inclusive): sqlite: 207.3 MB -> 174.4 MB (1.40x -> 1.18x vs fossil 147.7 MB) fossil-scm: 117.5 MB -> 108.1 MB (1.63x -> 1.50x vs fossil 72.2 MB)

The monotonic-shrink guard (keep the smaller of {existing frame, re-encoding}) is what turned re-deltifying a clone of fossil-quality wire deltas into a net win instead of a +33% regression. check-in: bab9303056 user: dmestas tags: trunk

zit addremove [--dry-run] — checkout-layer convenience (fossil/hg parity; git add -A). ONE scan via the shipped extras.sweep (the exact untracked/exclusion walk zit extras and zit clean use) is the ADD set; every managed file absent from disk (no-follow stat, as status checks) is the REMOVE set. Both mutate the managed set through the shipped ManagedSet.insert/remove/write (write-temp + fsync + rename) — no second walker, no ad-hoc mutation. A present-but-modified file is never touched; control/never-tracked names are never added. --dry-run leaves .zit-managed byte-identical and prints the same report (ADDED block then REMOVED block, each ascending, root-relative). 1675 unit + 374 e2e green. check-in: f0dc5f4e2a user: dmestas tags: cli