Parents and children of check-in [1a4b74f2d5]
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2026-08-10
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| 01:23 |
repocache: extend across appends; import warms at completion
The derived-state cache was all-or-nothing: any log append was a total miss, and the next read re-derived the whole store. On a real 1M-artifact pkgsrc store that was 352s per cold read, re-paid after every commit. Repository.open's miss path now distinguishes growth from rewrite. On growth it replays the cached record body (parse-free), folds only the tail frames through the same crosslink fold a cold derive uses, and rewrites the cache: every append healed by the next read at O(tail). Measured on pkgsrc: 352.31s cold, 2.40s after a commit, output byte-identical to a forced full re-derive. Sound because extension refuses whenever the fold could be wrong rather than stale: validatePrefix proves the old tail frame still verifies at its offset (a rewritten log cannot extend), and a shun fingerprint in the cache header forces the full derive on any shun-table change, since the body was distilled under the old mask. Cache format v2; a v1 cache misses once and rebuilds. import-git now warms the cache at completion, after the atomic rename, against the published store -- clone has done this since warmCacheFromLog existed, so an import-built store no longer defers the whole derive onto its first reader. Tests: extension equals cold derive with a fork and control tag in the tail; a forged-cache canary proving the fold starts from the stored body; shun change takes the full derive with the mask applied. Also backs out 1a4b74f2d5 (parallel staging): measured ~3% on a corpus where staging is ~5s of 149s -- threading complexity the number never justified. Closes #51. check-in: 84d3fe8f32 user: dmestas tags: sub-manifest | |
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2026-08-09
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| 16:32 |
update: stage plan entries in parallel
Staging reconstructs and writes every file in a plan -- one decompress, delta-chain application and hash verification each -- and on a wide repository that is tens of thousands of files for a single open or update. The work is per-file independent, and the store's read path is offset-addressed pread over an index immutable for the duration, so it parallelises without coordination. The one thing that cannot be written concurrently is last_stage_fault, a module global. Workers keep their own and the winner is chosen by ENTRY INDEX, which is exactly the fault sequential order would have raised, so this is observationally identical to the loop it replaces including which failure gets reported. Below 64 entries it stays sequential, and a thread that fails to spawn is not an error -- its share drains off the same cursor. Measured 2:33.5 to 2:28.8 on a 299 MB sqlite store, about 3%, with CPU never leaving 101%. So staging is NOT the dominant term there: the flatten's per-node reconstruction is, which this does not touch. Committed so it can be measured at pkgsrc scale, where the file count is 27x higher and the size distribution is different. If it does not move that number either, revert it -- it buys complexity for 3%. check-in: 1a4b74f2d5 user: dmestas tags: sub-manifest | |
| 04:46 |
import-git: sub-manifest mode drops on the pair proof, not on reproduction
A POLICY CHANGE, not a bug fix. Gates 5 to 7 prove the mirror's manifest is byte-reproducible from the check-in this import builds. Flat mode claims that; sub-manifest mode restructures the file set behind S cards, so its check-in is a different artifact by construction and claims nothing of the kind. Refusing to release the metadata because a mode failed to reproduce something it never promised is a category error. What makes the drop safe is gate 3 -- the bytes hash to the name a sibling manifest.uuid records, which a project file merely called 'manifest' cannot satisfy. That gate is untouched and still catches the look-alike. Gate 8 still guards the tags member. The B-card and S-card shape checks move with gates 5 to 7: a delta manifest is a real check-in, and refusing it only ever mattered because gate 5 needs a complete F run to compare against. On a sound source the win is small: bench measures 180 retained on sqlite, and this takes that to about 1. The win is on sources holding shunned or phantom content, where the origin's manifests name bytes the origin no longer has and no export can reproduce them -- permanent stranding today. libfossil goes from 293 of 3819 commits validated to 3817, and its store from 35.0 MB to 30.2 MB. Costs, stated rather than discovered later: this retires the only signal that a source repository is incomplete, and it leaves mirrorTreeMatches's tree arm unreachable from classification, annotated in place with the condition for deleting it. check-in: 063a66e4c5 user: dmestas tags: sub-manifest | |