This adds a sync mechanism in Ndb.swift to coordinate certain usage of
nostrdb.c calls and the need to close nostrdb due to app lifecycle
requirements. Furthermore, it fixes the order of operations when
re-opening NostrDB, to avoid race conditions where a query uses an older
Ndb generation.
This sync mechanism allows multiple queries to happen simultaneously
(from the Swift-side), while preventing ndb from simultaneously closing
during such usages. It also does that while keeping the Ndb interface
sync and nonisolated, which keeps the API easy to use from
Swift/SwiftUI and allows for parallel operations to occur.
If Swift Actors were to be used (e.g. creating an NdbActor), the Ndb.swift
interface would change in such a way that it would propagate the need for
several changes throughout the codebase, including loading logic in
some ViewModels. Furthermore, it would likely decrease performance by
forcing Ndb.swift operations to run sequentially when they could run in
parallel.
Changelog-Fixed: Fixed crashes that happened when the app went into background mode
Closes: https://github.com/damus-io/damus/issues/3245
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
When a view subscribes to profile updates via streamProfile() or
streamProfiles(), the stream now immediately yields any existing
profile data from NostrDB before waiting for network updates.
Previously, subscribers had to wait up to ~1 second for the
subscriptionSwitcherTask to restart the profile listener before
receiving any data. During this window, views would display
abbreviated pubkeys (e.g., "npub1abc...") or robohash placeholders
instead of the cached profile name and picture.
The fix adds a simple NDB lookup when creating the stream. This has
negligible performance impact since:
- It's a one-time operation per subscription (not per update)
- The same lookup was already happening in view bodies anyway
- NDB lookups are fast local queries
A new `yieldCached` parameter (default: true) allows callers to opt
out of the initial cached emission. NoteContentView uses this to
avoid redundant artifact re-renders — it only needs network updates
since its initial render already uses cached profile data.
Furthermore, when a profile has no metadata, the display name now shows
"npub1yrse...q9ye" instead of "1yrsedhw:8q0pq9ye" for a better UX.
Closes: https://github.com/damus-io/damus/issues/3454
Closes: https://github.com/damus-io/damus/issues/3455
Changelog-Changed: Changed abbreviated pubkey format to npub1...xyz for better readability
Changelog-Fixed: Fixed instances where a profile would not display profile name and picture for a few seconds
Signed-off-by: alltheseas <64376233+alltheseas@users.noreply.github.com>
Co-authored-by: Daniel D’Aquino <daniel@daquino.me>
