- Aggregation backfill walks build into a STAGING map and swap in atomically
on completion. A mid-walk failure drops the staging map — the previous live
state keeps serving, the aggregate stays flagged pending, and the storage
error surfaces to the failing query. Previously the walk wiped live state
before a scan that could throw, never cleared the pending flag on failure,
and re-ran a full walk on every subsequent query: a silent wipe/walk/throw
loop at the caller's retry rate.
- Failed walks are latched: retries within a 30s cooldown rethrow the recorded
error instantly instead of re-walking, so a tight caller-side retry loop
costs one loud error per query, never a full store walk per query.
- Persisted aggregation state is stamped with the store's committed generation
at flush; reopen adoption requires stamp equality. Stale state (unclean
shutdown) or over-counting state (a log truncation on a copied store pulled
the watermark back) triggers exactly one loud rescan, never a silent adopt.
- The backfill/adoption path narrates: adoption decisions, walk start/finish
with counts and duration, and failures all log by default.
- getNouns/getVerbs refuse a supplied-but-undecodable pagination cursor with a
loud error instead of silently restarting the walk at offset 0 (which
re-served page 1 forever to any while(hasMore) caller).
- The graph cold-load verb walk aborts loudly on a missing or non-advancing
cursor with hasMore=true.
- A versioned index provider whose generation is AHEAD of the committed
watermark (torn copy / crash-recovery truncation) is now named loudly at
open, alongside the existing behind-direction message.
getVerbsWithPagination was offset-only: it re-scanned from shard 0 on every page
and early-terminated at offset+limit, so a full edge walk was O(N²) (a consumer
measured ~19k edges → 27s paging at 900/page). It now accepts an opaque resume
token (cv1:<shard>:<verbId>) that resumes the shard walk immediately AFTER the
last returned verb — O(N) total at any page size, no scale cliff.
- Stable within-shard order (sort by verb id); ids come from the path so verbs
skipped by the cursor are never read.
- Cursor supersedes offset when present; offset path preserved for back-compat,
and offset callers now get a usable nextCursor so they can switch to cursor
paging. Foreign/malformed tokens decode to null → offset fallback (no throw).
- The relationships stream generator now uses cursor (was offset → O(N²)).
- Parity with the noun side (getNounsWithPagination already cursored).
Test: tests/unit/storage/verb-cursor-pagination.test.ts — a full cursored walk
visits every edge exactly once (no dup, no skip), matches the offset walk's set,
and a foreign cursor falls back gracefully.
