Second half of the Theseus-lag investigation. 0.27.1 removed the 7.4 MB
store; this removes the two things that produced it and the latency that
came with it.
Measured on this profile's own cache: 6,981 transactions, 7.38 MB, and one
consolidation with 400 inputs (median 2).
- loadHistory() awaited getTx() per displayed transaction and then again per
INPUT, strictly one at a time. The 400-input row alone cost 400 serial
round trips. Both waves are now prefetched with bounded parallelism
(getTxMany, 12 at a time). Against a simulated 10 ms link the same 473
fetches take 771 ms instead of ~4,730 ms; on a real 30-50 ms link the
serial version was 15-25 seconds per refresh, per wallet.
- Parent transactions were persisted forever. They exist only to compute a
delta for the 25 rows on screen, and keeping every one ever seen is what
grew the file. Only the displayed window is written now — 25 entries,
16.4 KB in the harness — while parents stay in a process-lifetime map
bounded at 20,000, seeded from the window so a restart does not refetch
what is already visible. A second refresh issues zero fetches.
TX_CACHE_VERSION 4 discards v3 caches. The v3 cap of 400 was also exactly
the wrong number for this data: a 400-input transaction needs 401 entries,
so it would have evicted and refetched on every single refresh.