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Tags and Properties for Check-in b224ffeb40

Context
2026-08-01
14:46 • Edit [b224ffeb40]: Mark "Closed". artifact: 0e20fa5a87 user: dmestas
2026-07-31
21:12 • Edit [b224ffeb40]: Edit check-in comment. artifact: df955ecee4 user: dmestas
21:12
logstore: openReadOnly scans header-only; verified_on_open is gone

The speedup reaches production. openReadOnly is the path every CLI verb takes -- Repository.open falls back to it, and Repository.logStore, the content channel behind cat, artifact, checkout and sync, calls it with no cache in front. It scanned every payload byte on every invocation:

10k frames 42 MB 42.2ms -> 10.3ms 10k frames 410 MB 298.0ms -> 12.3ms 100k frames 416 MB 511.9ms -> 115.4ms 100 frames 419 MB 321.4ms -> 0.10ms

Open cost is now a function of frame count, not repository size.

verified_on_open was the flag openReadOnly set to tell readFrameAt that the scan had already checked every frame, so reads could skip their own crc. With no scan doing that, the exemption had nothing left to rest on and the flag is deleted. readFrameAt now crc-checks unconditionally: it is the only thing standing between a rotted payload and a caller that believes it, and restoring any skip there means restoring the scan.

Detection is relocated, not removed. A payload bitflip no longer voids the open -- the rest of the repository stays usable -- and surfaces the first time anyone reads those bytes: "zit cat" and "zit artifact" both refuse with 'repository is corrupt', and "zit verify" names the artifact and the offset. That verb shipped first for exactly this reason.

openForVerify is deleted. It existed because openReadOnly both aborted on a damaged store and granted read-time trust, neither of which verify could accept; both properties are gone, it became byte-identical to openReadOnly, and its own doc comment said to remove it in this commit.

The DST prove-it-can-fail arm is inverted rather than deleted. It asserted that openReadOnly WOULD serve latent rot silently, across a seed range where at least one corpus lands a payload rot on a raw frame whose header survived. That hazard is gone, so the same range now asserts the opposite: the read path never serves rot as success. trust_on_read goes with it -- there are no longer two paths to select between. Losing the eager whole-log scan cost nothing here, because per-read verification is what was catching this all along.

Net -40 lines.

Verified: fmt clean, test 2327/2327, gate, e2e 671/671, dst 6 seeds x 1000 steps. The Slice 1 tripwire -- the assertion that openReadOnly still rejected eagerly, written to fail if the flag was deleted without an fsck verb -- fired on this commit, which is the one it was aimed at. closed check-in: b224ffeb40 user: dmestas tags: logstore-slice2