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Comment:logstore: O(1) LRU eviction in PlaintextCache

Replace the pick-the-minimum-stamp linear scan with an intrusive doubly linked recency list; get/put/evict are all constant-time. The scan was invisible at small occupancy and dominant at full: a pkgsrc clone kept the cache pinned at max_entries and spent over half its client CPU sweeping the map once per stored artifact. Measured: clone 12:38 -> 8:39 wall, client CPU 694s -> 463s; cloned store verifies with 0 faults.

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SHA3-256: 0df83f350a2a7c8be8c01273a01effe7036fa96ce3440b058a4edb9978b51954
User & Date: dmestas on 2026-08-11 18:17:53.116
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Context
2026-08-11
19:07
repocache: persist the content log's scan index

The lazy content channel re-walked every frame header on each open — O(store) before the first byte of any comment, cat, or annotate. The scan's product (entries, hash index, shun rows, config cursor, tail key) now persists as .zit-cache/index, self-validating and LogKey-keyed: an exact tail adopts whole, a grown log resumes the walk over the tail alone, and anything else falls back to the authoritative scan (--no-cache never consults it). pkgsrc: info 1.7s -> 0.44s, timeline -n 5 4.3s -> 0.96s. check-in: f2bfd36e74 user: dmestas tags: sub-manifest

18:17
logstore: O(1) LRU eviction in PlaintextCache

Replace the pick-the-minimum-stamp linear scan with an intrusive doubly linked recency list; get/put/evict are all constant-time. The scan was invisible at small occupancy and dominant at full: a pkgsrc clone kept the cache pinned at max_entries and spent over half its client CPU sweeping the map once per stored artifact. Measured: clone 12:38 -> 8:39 wall, client CPU 694s -> 463s; cloned store verifies with 0 faults. check-in: 0df83f350a user: dmestas tags: sub-manifest

2026-08-10
23:48
Move the git-interop implementation into src/git/

Seven files relocate with unchanged basenames: git_fast_export(+test), git_import, git_import_impl, git_import_cli, git_import_verify, git_import_benchmark_support. The six standalone module roots (test, refs_test, cli_test, e2e, benchmark, pipe_helper) stay flat because a Zig module cannot import above its root file's directory — the same rule that keeps main/e2e/dst/smoke at src/. Future export-git files follow the same split: roots flat, implementation in src/git/. Path-string edits only; build.zig unchanged. check-in: ce3c87e25c user: dmestas tags: sub-manifest

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