z_listsentbyaddress re-walks the whole wallet when there's no usable
watermark, which the daemon does under cs_main for every send -- hundreds
of seconds, 400+ s and ~19 GB RSS on a large wallet. The watermark lived
only in memory, so every relaunch, reconnect or daemon restart paid for a
full sweep. This persists it so those cases run a bounded windowed sweep
([z, 0, 2, tip - W + margin]) instead (SENT-HISTORY-SWEEP Part 1).
- The watermark (W = last swept tip), its anchor (A = W - margin) and anchor
hash (H_A = getblockhash(A)), plus the enrichment backlog and the full-
sweep backoff, ride in the encrypted history snapshot as an optional
`sent_sweep` object (schema stays v1; a missing/inconsistent one reads as
"no watermark" = today's behaviour, so older builds and payloads are safe).
- Before the first windowed sweep after a load, the anchor is verified
(getblockhash(A) == H_A). A match means any fork is inside the window; a
mismatch (reorg deeper than the margin, different chain/datadir) or an
inability to check drops the watermark and sweeps the whole wallet.
- The first sweep after a load uses a bigger margin (absorbs notifier lag),
and a watermark older than 2400 blocks uses the long timeout (callLong).
- The backlog is persisted WITH W: a pure z->z send's txid lives only in a
sweep result and would be lost if the window moved past an un-enriched one.
- Watermark changes reach disk (folded into the store signature), and every
hard case still forces a full sweep: reorg (anchor verify), GUI rescan /
zap / import / address change, restoreOriginalWallet, and disconnect.
Deferred (follow-ups, each only turns a correct-but-slow case faster, never a
correctness risk): the banded full sweep for seeding on a pre-note-cache
daemon, the external-import tripwire, and the weekly safety-net re-sweep.
Part 2 (the daemon's decrypt cost) is already on the daemon's
perf/sapling-note-cache branch.
Pure helpers + cache round-trip + anchor-verify/large-window covered by
tests; the getblockhash-after-sweep updates the pinned RPC sequences.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Every history refresh, address refresh, connect and lock-state check
rewrote the encrypted tx-history snapshot on the UI thread: a JSON
document of every row, its encryption, then INSERT OR REPLACE and a
prune, an estimated 40-120 ms on a 5k-transaction wallet, even when
nothing had changed.
Now a signature of what would be stored (about 1 ms on 5k rows)
decides whether to write. Confirmations count only by the thresholds
the UI reads (conflicted, pending, 1-9, 10-99, 100+); per-address scan
heights, exact confirmations and the tip drift every block and form a
separate part.
- Routine refreshes write a content change at most every 20 s (a
deferred one is released from the update loop) and the per-block
drift at most every 10 min. Nothing changed means no write.
- A mining-address relabel, a passphrase change, a rescan, a
disconnect, a wallet lock and exit write whatever is not on disk yet,
at once.
- The UI thread only copies the rows and the key into a job; a single
background writer (newest job wins) builds, encrypts and stores it. A
failed write is retried.
- Exit queues the final write so it overlaps the daemon stop, then
waits up to 3 s for the writer; a disk that hangs past that keeps the
previous snapshot.
- A loaded snapshot counts as stored, so the first identical refresh
doesn't rewrite it. An address refresh re-keys the snapshot only when
the address set changed.
After a hard kill the snapshot can now be up to ~20 s behind for rows
and 10 min for scan heights, exact confirmations and the tip (it was
one refresh); the first refresh replaces it either way. Lite builds,
which never read this cache, no longer write it on Refresh or a mining
relabel, and the screenshot capture mode's demo rows never reach it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>