Timeline

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

Both consumers live in their own build roots and cannot reach crc32.zig by path, so the export is forced. Adds the differential fuzz lane against std — the only coverage that can see a self-consistent but numerically shifted implementation, which would orphan every existing .zit file.

The implementation brief prohibited this export, citing repocache as the precedent for unexported leaf modules. That precedent does not apply: repocache has no out-of-module consumer. storestat and repoimage, which do, are both exported. Overridden deliberately. closed check-in: c57c16c5cd user: dmestas tags: logstore-index

The other three on-disk formats defined in terms of this checksum: the cache image self-checksum, the bisect session trailer, the undo journal trailer. Same swap, same values. check-in: 55d6e7c7bb user: dmestas tags: logstore-index

The four frame checksums plus the file header. The open-time scan CRCs every payload byte, so this is ~93% of a cold open: 416 MB goes 1.22s to 292ms. No format change — the values are identical by construction. check-in: dd71dd3006 user: dmestas tags: logstore-index

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

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