Skip to content
zit Timeline
Login

Timeline

Parents and children of check-in [a469147254]

2026-07-29
14:19
merge logstore-index: checksum the store through a vendored crc32

std.hash.Crc32 is byte-at-a-time over one table (~350 MB/s here) and the open-time scan CRCs every payload byte, so it was ~93% of a cold open. Slicing-by-8 in its place: a 416 MB store opens in 292ms against 1.22s, warm reads run 3.3x, the write path 1.5x. Bit-identical by construction, so no format changes and no repository is affected. check-in: 602c2459f2 user: dmestas tags: trunk

13:16
crc32: vendored slicing-by-8 CRC-32/ISO-HDLC

Bit-identical to std.hash.Crc32, which every on-disk checksum in the store is already defined in terms of. std's is byte-at-a-time over one table (~350 MB/s here); this folds eight bytes per step. Nothing uses it yet. check-in: aef8f539b5 user: dmestas tags: logstore-index

2026-07-27
19:29
Sub-manifest: card alphabet, artifact type, and the specification's vectors

Adds S as the twenty-second card letter and SUBMANIFEST as the ninth artifact type, per draft-fossil-submanifests-00 sections 3 and 4. Type determination reassigns after the card scan rather than during it, so no type is committed while cards are still being read (section 9.1). Reading and classification only: no tree walk, no emission.

The draft's seven appendix vectors ship alongside, each named by the SHA3-256 the draft states and checked by a test that recomputes it. check-in: 9b8bad477a user: dmestas tags: sub-manifest

2026-07-25
14:51
Release zit 0.1.3

A serving release over 0.1.2. Where 0.1.2 made a large repository cloneable, 0.1.3 makes serving one fast and lean.

A server against a large repository comes up immediately: the listener opens before the repository is read, so a client queues in the accept backlog while the server primes rather than being refused during a startup a large store made long. A push no longer stalls inside its own reply deadline; the snapshot rebuild it triggers now runs between connections. Serving reads the repository through an on-demand log-offset index rather than a resident copy, so peak memory to serve a 67,499-artifact repository fell from about 157 MB to about 32 MB, with clones byte-identical to before.

Also: the end-to-end suite is safe to run concurrently with itself (fresh loopback ports), and the unclassifiable-artifact tolerance rule is now covered by deterministic simulation and an end-to-end scenario. check-in: a469147254 user: dmestas tags: trunk, version-0.1.3

13:39
update: cover the unclassifiable-artifact rule with a DST sweep and an e2e

The rule that lets state assembly skip a stored artifact it cannot classify — when the artifact's bytes verify against the name it is stored under — shipped with the fix but was pinned only by two unit tests over hand-built logs, and by a manual clone of the real fossil repository. Neither the simulator nor the end-to-end suite exercised it, so a regression could pass every automated gate.

Deterministic simulation grows an artifact-level generator (src/sim/ assembly_sweep.zig): it emits artifacts whose card sets sit in and around the required-card table — some verifying against their stored name, some stored under a wrong one — and asserts the split directly, that assembly completes iff every unclassifiable artifact verifies, derives no state from one, and stays fatal on a single artifact whose bytes do not match its name. It runs every seed. assembleState is made public for it to drive; its body is unchanged.

The e2e suite gains a scenario that clones a served store carrying an anonymous wiki artifact (cards D L W Z, no U — the shape that first surfaced this) and asserts update tolerates it, with the read verbs and assembly agreeing on the same store. Reverting the verify-then-skip arm to an unconditional failure reddens the sweep, the e2e scenario, and both unit tests. check-in: c2851f933e user: dmestas tags: trunk