sift/docs/implementer-log.md

Implementer log

One row per task session that ends in a commit. Newest last.

Task	Date	Status	Sessions	Gate	Deviations	Summary
p5a/01-kind-fetch	2026-09-25	done	resumed	gate: ok	none	Implemented Kind/application/pdf recognition, PDF body cap (100 MB) and deadline (120 s), and FetchIf with If-None-Match/If-Modified-Since via shared doFetch. Previous session could not pass TestFetchIf only because the given test held its mutex across the handler (deadlock); owner fixed the test. Session resumed after that fix — did not rewrite fetch code, only verified rules and ran gate.
p5a/02-pdftext	2026-09-25	done	1	gate: ok	none	Built the child-extraction package: Extract (reader.Open with ErrWrongPassword→ErrEncrypted, per-page recover, trailer /Info /Title, rule-3 UTF-16BE/Latin-1 decode), outline.go (/Dest and /GoTo /A dests, 10k-item and no-double-visit bounds, never-nil outline), Runner (re-exec'd child, env-isolated via empty env, 60 s deadline, 64 MiB output cap, 200 MiB stdin cap, stderr capped at 4 KiB, exit-code→error mapping, Doc parse plus ErrNoText), and the sift pdftext case in main.go. Removed the tools.go module pin; go.mod/go.sum/vendor/modules.txt confirmed unchanged. All 10 given tests pass under -race -count=3 including the deadline-kill test; make gate ok; given files byte-identical; `printf nope
p5a/03-dcache	2026-09-25	done	1	gate: ok	evict() tie-break	Added the pdf_doc/pdf_page tables, PDFEntry/PDFKey/PutPDF/GetPDF/TouchPDF (one-tx write deleting old pages first, page-ordered read, 304 touch moves only fetched_at), PDFH/PDFM counters, Size() including pdf_doc nbytes. One deviation: extended the eviction union with pdf_doc and added rowid ASC to the ORDER BY so same-second puts evict in insertion order (deterministic whole-document eviction); without it TestPDFEviction is order-dependent. Left Stats() signature unchanged for task 07. Given test byte-identical.
p5a/04-pdfpool	2026-09-25	done	1	gate: ok	none	Implemented the generic scheduler. Pool holds one mutex, a jobs map (key→in-flight job), a callerJobs map (caller→their job), and a FIFO waiters line. Do applies the six rules in order: join (counted in Waiting, no slot, allowed while the caller holds another job, fn may be nil), caller-busy, then slot/queue/refuse. A job's result is broadcast to every sharer via a done channel; results are not cached (key forgotten on finish). fn runs under context.WithoutCancel so the flight outlives a caller that leaves. Panic in fn is recovered into an error, freed the slot and caller. One implementation finding (not a plan deviation): queued jobs must not be counted in Running(), so startLocked only registers a job and a separate takeSlotLocked/grant increments the slot count — abandoning a queued starter (abandon) releases sharers without touching the slot. Given test byte-identical.
p5a/05-pdfdoc	2026-09-25	done	1	gate: ok	none	Implemented the render package with no I/O on a *pdftext.Doc. Marker/Full print each extracted page as --- page N ---, text trimmed, joined by a blank line. Render dispatches grep → page range → whole. Whole fits in OutCap runes, else a map: title (or Untitled PDF)/pages/~tokens line with pages 1-E extracted only when fewer extracted than Pages, a cuttable ## Outline (two-space indent per level below 1, cut before the header/instruction), the instruction line, and whole leading pages within OutCap/4 (at least page 1, cut to fit). Range parses a-b/a/a-, wraps out-of-range in ErrBadPages with pages out of range (1-E), clamps b, caps at 100 pages and OutCap runes, and notes the rest as pages="k-b". Grep is RE2 with smart-case (?i) prefix, 200-byte cap, per-line matches with previous/next page context in p. P-/p. P: form, first 100 shown, total counted; RE2 keeps the (a+)+$ test linear. Every length is in runes. Given test byte-identical; make gate ok.