Artifact Description [57403fd9a9]

Artifact 57403fd9a9b8bb1bb1616fa873bfccfdfec794a6647cf1effe616a4317668f38:

• File internal/content/sparse_horizon.go
  • 2026-10-23 02:24:20 — part of check-in [13f8021952] on branch feat/horizon-cones — perf(content): keep the trees a horizon's walk reads in the memo

    draft-fossil-horizon-00 §6.2 asks an origin to read each structural artifact's references once per store and classify every cone over that graph. The memo did so for kinds and P, B, S and A cards, but the F cards of a horizon's trees were walked from the store by the first classification of each horizon, so a second horizon under another C or rule re-read every tree it shared with the first.

    The memo now keeps, per store lineage, each manifest, baseline and node a walk read: its own F-card targets and its B and S references, so a delta manifest shares its baseline's entry. A view stages what it reads and the memo takes it on Publish, so a request that rolls back leaves nothing; a kept piece serves a view only when its rid is held at that view's prefix, and its size is charged as a read would charge it, so budgets fail where a fresh walk fails. Names are interned and the cache is capped at 64MiB with LRU eviction: fossil-scm's history names about 21M F entries, over 300MiB uncapped.

    On a copy of a 21k-check-in fossil repository, horizon B (2000 check-ins back) classified after horizon A (1000 back) took 2.5-3.0s and now 1.6s, reading 995 trees instead of 1995; A is unchanged at about 1.3-1.6s. (user: [email protected], size: 9529) [annotate] [blame] [check-ins using]

  • 2026-10-23 02:38:31 — part of check-in [479cbaad12] on branch feat/horizon-cones — Merge branch 'wip/hz-close-annotate' into feat/horizon-cones

    Annotate in a structural store marks the lines that reach the horizon and names the deepen that would show their origin (§5.5); the origin memo keeps the trees a horizon's walk reads in a bounded cache, so a second horizon over the same store reads only trees the first did not. (user: [email protected], size: 9529) [annotate] [blame] [check-ins using]