Files
lmxopcua/tests/Server
Joseph Doherty 7e8941fbdc test(historian): paged-vs-unpaged raw-cap fuzz, MaxReturnDataValues advertisement, cap floor of 3
- NodeManagerHistoryReadRawCapFuzzTests: 10k seeds (env OTOPCUA_PAGING_FUZZ_ITERATIONS)
  through a real SDK node manager against wire-faithful fakes of SqlServer / QuestDB /
  Gateway that enforce the backend half of the cap; random series with ties, random
  windows (empty, on/past a tie, between samples, forward/reverse/end-only, bounds),
  N in {0,1,2,small,huge}, cap in {off,3..1000}, tie budget {3,8,65536}. Pages must
  concatenate to the cap-off one-shot answer (checked against the series), terminate
  within values + 2 (+ one empty step per oversized boundary cluster), never exceed
  the cap, never ask the backend for 0 / over-cap; refusals only past the budget.
- HistoryPaging.AdvertiseMaxReturnDataValues writes HistoryServerCapabilities/
  MaxReturnDataValues (i=11273), read back through the SDK master node manager.
- MinMaxRawValuesPerRead raised to 3: at 2 a resumed page has no room (value + its
  boundary tie + lookahead) and every value cost an empty page + CP (seed 15).
- RawPageLimit rows pin the default-cap arithmetic (9 999 first page, 9 998 resumed).

Fuzz findings recorded as follow-ups: a bounded read whose data fits one page
returns cap + 1 (end bound fitted against N, not the cap; node manager, F2);
the Gateway walk-back's cost on a sparse series under a tiny tie budget is
pre-existing (seed 320: 82 reads uncapped, 93 capped).

Refs #736

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
2026-10-22 10:15:21 -04:00
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