Parents and children of check-in [cc996c1af2]
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2026-08-18
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| 14:12 |
build: how to measure this project without being lied to
Every rule was paid for by a wrong answer that looked convincing: an issue filed against this repository proposed an architectural change on the strength of a 58s figure that was a bare-zig-build Debug number; the ~25x pack figure this file carried came from a --release=fast that was quietly building ReleaseSafe; a single run reported a 20% regression for a change that was a 3.7x improvement; and an optimization that won by 50x was erroring out on the first artifact and printing nothing. It sits beside the build rather than in the wiki because each rule is only true of THIS build script -- bare zig build means Debug because of the line above it, and every --release resolves to the preference for the same reason. A page elsewhere would rot the day one of those changes and nothing would fail. check-in: 4e355fbfd1 user: dmestas tags: trunk | |
| 13:34 |
log: walk the derived adjacency, the way fossil does
The default listing prints an ID per check-in and reads nothing else, yet it reconstructed and re-parsed every reachable manifest to find P cards. On a repository whose manifests inline the whole file set -- sqlite's are 2,219 F cards and 186KB each -- that is 6GB of text decompressed and parsed to answer a question that reads none of it. Fossil does not do this. manifest_crosslink parses a manifest once and writes the edge to a persistent table: CREATE TABLE plink(pid, cid, isprim, mtime, baseid, UNIQUE(pid,cid)); CREATE INDEX plink_i2 ON plink(cid,pid); Every later traversal is an indexed read of it -- timeline.c's ancestor walk is a recursive CTE over plink and touches no manifest. The tell is fossil's parsed-manifest cache: MX_MANIFEST_CACHE is 6, and its comment says it exists for rebuild. Nothing on the read path needed more. zit's derive holds the same relation, with the is_primary flag plink's isprim carries, and since #98 the zero-parse image carries it too, so this walk reads no artifact content at all. --long still needs D/U/C, so it stays on the reading walk. log tip, min of repeated runs, warm, ReleaseFast: libfossil 1.28s -> 0.02s libspatialite 4.81s -> 0.00s fossil 20.40s -> 0.11s tcl 40.05s -> 0.65s sqlite 62.90s -> 0.51s Output byte-identical across all seven corpora. WHAT MOVED: the reading walk re-hashed and re-validated every reachable artifact, so log doubled as an integrity check. It no longer does -- which is fossil's split, where validation happens at crosslink and test-integrity re-checks. zit verify is that verb, and the wrong-full-ID test now asserts verify catches what log stopped catching, so the coverage cannot go missing unnoticed. check-in: cc996c1af2 user: dmestas tags: trunk | |
| 13:07 |
info reads the warm image too: §5.2 overrides, resolved (#98)
info was the last of the three verbs held on the record-body rung, and it was held by one thing: amend --comment stores its override as a tag, and tagxref is empty on an image backing, so the fast path printed the manifest's original comment. On tcl that cost 58s to print one check-in. The image carries the three display overrides now -- comment, user, date -- RESOLVED. The derive has already applied the cancel rule and mtime precedence by the time they are written, so the image stores the answer and never re-judges it, the same trade branch_id already makes with the §6.1 fallback. That is also what fossil does: tagxref holds one row per (rid, tag) with propagation flattened in by tag_propagate at write time, so its readers do group-bys rather than precedence. activeTagValue now asserts derived backing instead of answering null there. It returned null for a caller that had a tag, which is the silent shape of wrong this whole issue is about; displayOverride is the image-safe door for the subset the image actually carries. check-in: 8c3abc36c7 user: dmestas tags: trunk | |