Move profile update handling from notes to the background

During profiling, I found that some large hangs were being caused by a
large number of `notify` calls (and their handling functions) keeping
the main thread overly busy.

We cannot move the `notify` mechanism to a background thread (It has to
be done on the main actor or else runtime warnings/errors appear), so
instead this commit removes a very large source of notify calls/handling around
NoteContentView, and replaces it with a background task that streams
for profile updates and only updates its view when a relevant profile is
updated.

Changelog-Changed: Improved performance around note content views to prevent hangs
Closes: https://github.com/damus-io/damus/issues/3439
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damus/Core/Networking/NostrNetworkManager/ProfilesManager.swift

@@ -101,10 +101,17 @@ extension NostrNetworkManager {
                     relevantStream.continuation.yield(profile)
                 }
             }
+        }
         
-            // Notify the rest of the app so views that rely on rendered text (like mention strings)
+        /// Manually trigger profile updates for a given pubkey
-            // can reload and pick up the freshly fetched profile metadata.
+        /// This is useful for local profile changes (e.g., nip05 validation, donation percentage updates)
-            notify(.profile_updated(.remote(pubkey: metadataEvent.pubkey)))
+        func notifyProfileUpdate(pubkey: Pubkey) {
+            if let relevantStreams = streams[pubkey] {
+                guard let profile = ndb.lookup_profile_and_copy(pubkey) else { return }
+                for relevantStream in relevantStreams.values {
+                    relevantStream.continuation.yield(profile)
+                }
+            }
         }
         
         
@@ -121,6 +128,29 @@ extension NostrNetworkManager {
             }
         }
         
+        func streamProfiles(pubkeys: Set<Pubkey>) -> AsyncStream<ProfileStreamItem> {
+            guard !pubkeys.isEmpty else {
+                return AsyncStream<ProfileStreamItem> { continuation in
+                    continuation.finish()
+                }
+            }
+            
+            return AsyncStream<ProfileStreamItem> { continuation in
+                let stream = ProfileStreamInfo(continuation: continuation)
+                for pubkey in pubkeys {
+                    self.add(pubkey: pubkey, stream: stream)
+                }
+                
+                continuation.onTermination = { @Sendable _ in
+                    Task {
+                        for pubkey in pubkeys {
+                            await self.removeStream(pubkey: pubkey, id: stream.id)
+                        }
+                    }
+                }
+            }
+        }
+        
         
         // MARK: - Stream management
         

damus/Features/Events/NoteContentView.swift

@@ -46,7 +46,6 @@ struct NoteContentView: View {
     let event: NostrEvent
     @State var blur_images: Bool
     @State var load_media: Bool = false
-    @State private var requestedMentionProfiles: Set<Pubkey> = []
     let size: EventViewKind
     let preview_height: CGFloat?
     let options: EventViewOptions
@@ -279,10 +278,12 @@ struct NoteContentView: View {
         .padding(.horizontal)
     }
     
-    func ensureMentionProfilesAreFetchingIfNeeded() {
+    @concurrent
+    func streamProfiles() async throws {
         var mentionPubkeys: Set<Pubkey> = []
-        try? NdbBlockGroup.borrowBlockGroup(event: event, using: damus_state.ndb, and: damus_state.keypair, borrow: { blockGroup in
+        let event = await self.event.clone()
-            let _: ()? = try? blockGroup.forEachBlock({ _, block in
+        try await NdbBlockGroup.borrowBlockGroup(event: event, using: damus_state.ndb, and: damus_state.keypair, borrow: { blockGroup in
+            blockGroup.forEachBlock({ _, block in
                 guard let pubkey = block.mentionPubkey(tags: event.tags) else {
                     return .loopContinue
                 }
@@ -291,32 +292,12 @@ struct NoteContentView: View {
             })
         })
         
-        guard !mentionPubkeys.isEmpty else { return }
+        if mentionPubkeys.isEmpty {
-
+            return
-        var toFetch: [Pubkey] = []
-        for pubkey in mentionPubkeys {
-            if requestedMentionProfiles.contains(pubkey) {
-                continue
-            }
-            requestedMentionProfiles.insert(pubkey)
-
-            if damus_state.profiles.has_fresh_profile(id: pubkey) {
-                continue
         }
 
-            toFetch.append(pubkey)
+        for await profile in await damus_state.nostrNetwork.profilesManager.streamProfiles(pubkeys: mentionPubkeys) {
-        }
+            await load(force_artifacts: true)
-
-        guard !toFetch.isEmpty else { return }
-
-        // Kick off metadata fetches for any missing mention profiles so their names can render once loaded.
-        for pubkey in toFetch {
-            Task {
-                for await _ in await damus_state.nostrNetwork.profilesManager.streamProfile(pubkey: pubkey) {
-                    // NO-OP, we will receive the update via `notify`
-                    break
-                }
-            }
         }
     }
 
@@ -325,8 +306,6 @@ struct NoteContentView: View {
             return
         }
         
-        ensureMentionProfilesAreFetchingIfNeeded()
-        
         // always reload artifacts on load
         let plan = get_preload_plan(evcache: damus_state.events, ev: event, our_keypair: damus_state.keypair, settings: damus_state.settings)
         
@@ -442,44 +421,13 @@ struct NoteContentView: View {
 
     var body: some View {
         ArtifactContent
-            .onReceive(handle_notify(.profile_updated)) { profile in
+            .task {
-                try? NdbBlockGroup.borrowBlockGroup(event: event, using: damus_state.ndb, and: damus_state.keypair, borrow: { blockGroup in
+                try? await streamProfiles()
-                    let _: Int? = blockGroup.forEachBlock { index, block in
-                        switch block {
-                        case .mention(let m):
-                            guard let typ = m.bech32_type else {
-                                return .loopContinue
-                            }
-                            switch typ {
-                            case .nprofile:
-                                if m.bech32.nprofile.matches_pubkey(pk: profile.pubkey) {
-                                    load(force_artifacts: true)
-                                }
-                            case .npub:
-                                if m.bech32.npub.matches_pubkey(pk: profile.pubkey) {
-                                    load(force_artifacts: true)
-                                }
-                            case .nevent: return .loopContinue
-                            case .nrelay: return .loopContinue
-                            case .nsec: return .loopContinue
-                            case .note: return .loopContinue
-                            case .naddr: return .loopContinue
-                            }
-                        case .text: return .loopContinue
-                        case .hashtag: return .loopContinue
-                        case .url: return .loopContinue
-                        case .invoice: return .loopContinue
-                        case .mention_index(_): return .loopContinue
-                        }
-                        return .loopContinue
-                    }
-                })
             }
             .onAppear {
                 load()
             }
     }
-    
 }
 
 class NoteArtifactsParts {

damus/Features/NIP05/Views/NIP05DomainTimelineView.swift

@@ -46,7 +46,7 @@ struct NIP05DomainTimelineView: View {
 
             if let pubkeys = model.filter.authors {
                 for pubkey in pubkeys {
-                    check_nip05_validity(pubkey: pubkey, profiles: damus_state.profiles)
+                    check_nip05_validity(pubkey: pubkey, damus_state: damus_state)
                 }
             }
         }

damus/Features/Profile/Views/EventProfileName.swift

@@ -17,7 +17,6 @@ struct EventProfileName: View {
     @State var nip05: NIP05?
     @State var donation: Int?
     @State var purple_account: DamusPurple.Account?
-    @StateObject private var profileObserver: ProfileObserver
 
     let size: EventViewKind
     
@@ -28,7 +27,6 @@ struct EventProfileName: View {
         let donation = damus.profiles.lookup(id: pubkey)?.damus_donation
         self._donation = State(wrappedValue: donation)
         self.purple_account = nil
-        self._profileObserver = StateObject.init(wrappedValue: ProfileObserver(pubkey: pubkey, damusState: damus))
     }
     
     var friend_type: FriendType? {
@@ -102,13 +100,8 @@ struct EventProfileName: View {
                 SupporterBadge(percent: self.supporter_percentage(), purple_account: self.purple_account, style: .compact)
             }
         }
-        .onReceive(handle_notify(.profile_updated)) { update in
+        .task {
-            if update.pubkey != pubkey {
+            for await profile in await damus_state.nostrNetwork.profilesManager.streamProfile(pubkey: pubkey) {
-                return
-            }
-
-            guard let profile = damus_state.profiles.lookup(id: update.pubkey) else { return }
-
                 let display_name = Profile.displayName(profile: profile, pubkey: pubkey)
                 if display_name != self.display_name {
                     self.display_name = display_name
@@ -124,6 +117,7 @@ struct EventProfileName: View {
                     donation = profile.damus_donation
                 }
             }
+        }
         .task {
             if damus_state.purple.enable_purple {
                 self.purple_account = try? await damus_state.purple.get_maybe_cached_account(pubkey: pubkey)

damus/Features/Profile/Views/ProfileName.swift

@@ -45,7 +45,6 @@ struct ProfileName: View {
     @State var donation: Int?
     @State var purple_account: DamusPurple.Account?
     @State var nip05_domain_favicon: FaviconURL?
-    @StateObject var profileObserver: ProfileObserver
 
     init(pubkey: Pubkey, prefix: String = "", damus: DamusState, show_nip5_domain: Bool = true, supporterBadgeStyle: SupporterBadge.Style = .compact) {
         self.pubkey = pubkey
@@ -54,7 +53,6 @@ struct ProfileName: View {
         self.show_nip5_domain = show_nip5_domain
         self.supporterBadgeStyle = supporterBadgeStyle
         self.purple_account = nil
-        self._profileObserver = StateObject.init(wrappedValue: ProfileObserver(pubkey: pubkey, damusState: damus))
     }
     
     var friend_type: FriendType? {
@@ -131,21 +129,10 @@ struct ProfileName: View {
                     .largest()
             }
         }
-        .onReceive(handle_notify(.profile_updated)) { update in
+        .task {
-            if update.pubkey != pubkey {
+            for await profile in await damus_state.nostrNetwork.profilesManager.streamProfile(pubkey: pubkey) {
-                return
+                handle_profile_update(profile: profile)
             }
-
-            switch update {
-            case .remote(let pubkey):
-                guard let prof = damus_state.profiles.lookup(id: pubkey) else {
-                    return
-                }
-                handle_profile_update(profile: prof)
-            case .manual(_, let prof):
-                handle_profile_update(profile: prof)
-            }
-
         }
     }
 

damus/Features/Profile/Views/ProfilePicView.swift

@@ -75,8 +75,7 @@ struct ProfilePicView: View {
     let privacy_sensitive: Bool
 
     @State var picture: String?
-    @StateObject private var profileObserver: ProfileObserver
+    let damusState: DamusState
-    @EnvironmentObject var damusState: DamusState
     
     init(pubkey: Pubkey, size: CGFloat, highlight: Highlight, profiles: Profiles, disable_animation: Bool, picture: String? = nil, show_zappability: Bool? = nil, privacy_sensitive: Bool = false, damusState: DamusState) {
         self.pubkey = pubkey
@@ -87,7 +86,7 @@ struct ProfilePicView: View {
         self.disable_animation = disable_animation
         self.zappability_indicator = show_zappability ?? false
         self.privacy_sensitive = privacy_sensitive
-        self._profileObserver = StateObject.init(wrappedValue: ProfileObserver(pubkey: pubkey, damusState: damusState))
+        self.damusState = damusState
     }
 
     var privacy_sensitive_pubkey: Pubkey {
@@ -110,23 +109,6 @@ struct ProfilePicView: View {
     var body: some View {
         ZStack (alignment: Alignment(horizontal: .trailing, vertical: .bottom)) {
             InnerProfilePicView(url: get_profile_url(picture: picture, pubkey: privacy_sensitive_pubkey, profiles: profiles), fallbackUrl: URL(string: robohash(privacy_sensitive_pubkey)), size: size, highlight: highlight, disable_animation: disable_animation)
-                .onReceive(handle_notify(.profile_updated)) { updated in
-                    guard updated.pubkey == self.pubkey else {
-                        return
-                    }
-                    
-                    switch updated {
-                        case .manual(_, let profile):
-                            if let pic = profile.picture {
-                                self.picture = pic
-                            }
-                        case .remote(pubkey: let pk):
-                            let profile = profiles.lookup(id: pk)
-                            if let pic = profile?.picture {
-                                self.picture = pic
-                            }
-                    }
-                }
             
             if self.zappability_indicator, let lnurl = self.get_lnurl(), lnurl != "" {
                 Image("zap.fill")
@@ -141,6 +123,13 @@ struct ProfilePicView: View {
                     .clipShape(Circle())
             }
         }
+        .task {
+            for await profile in await damusState.nostrNetwork.profilesManager.streamProfile(pubkey: pubkey) {
+                if let pic = profile.picture {
+                    self.picture = pic
+                }
+            }
+        }
     }
 }
 

damus/Features/Profile/Views/ProfileView.swift

@@ -144,7 +144,7 @@ struct ProfileView: View {
             return AnyView(
                 VStack(spacing: 0) {
                     ZStack {
-                        BannerImageView(pubkey: profile.pubkey, profiles: damus_state.profiles, disable_animation: damus_state.settings.disable_animation)
+                        BannerImageView(pubkey: profile.pubkey, profiles: damus_state.profiles, disable_animation: damus_state.settings.disable_animation, damusState: damus_state)
                             .aspectRatio(contentMode: .fill)
                             .frame(width: proxy.size.width, height: minY > 0 ? bannerHeight + minY : bannerHeight)
                             .clipped()
@@ -525,7 +525,7 @@ struct ProfileView: View {
                 dismiss()
             }
             .onAppear() {
-                check_nip05_validity(pubkey: self.profile.pubkey, profiles: self.damus_state.profiles)
+                check_nip05_validity(pubkey: self.profile.pubkey, damus_state: self.damus_state)
                 profile.subscribe()
                 //followers.subscribe()
             }
@@ -568,7 +568,8 @@ extension View {
 }
 
 @MainActor
-func check_nip05_validity(pubkey: Pubkey, profiles: Profiles) {
+func check_nip05_validity(pubkey: Pubkey, damus_state: DamusState) {
+    let profiles = damus_state.profiles
     let profile = profiles.lookup(id: pubkey)
 
     guard let nip05 = profile?.nip05,
@@ -586,7 +587,7 @@ func check_nip05_validity(pubkey: Pubkey, profiles: Profiles) {
         Task { @MainActor in
             profiles.set_validated(pubkey, nip05: validated)
             profiles.nip05_pubkey[nip05] = pubkey
-            notify(.profile_updated(.remote(pubkey: pubkey)))
+            await damus_state.nostrNetwork.profilesManager.notifyProfileUpdate(pubkey: pubkey)
         }
     }
 }

damus/Features/Wallet/Views/NWCSettings.swift

@@ -250,7 +250,9 @@ struct NWCSettings: View {
             
             let prof = Profile(name: profile.name, display_name: profile.display_name, about: profile.about, picture: profile.picture, banner: profile.banner, website: profile.website, lud06: profile.lud06, lud16: profile.lud16, nip05: profile.nip05, damus_donation: p, reactions: profile.reactions)
 
-            notify(.profile_updated(.manual(pubkey: self.damus_state.pubkey, profile: prof)))
+            Task {
+                await damus_state.nostrNetwork.profilesManager.notifyProfileUpdate(pubkey: self.damus_state.pubkey)
+            }
         }
         .onDisappear {
             

damus/Shared/Media/Images/BannerImageView.swift

@@ -90,30 +90,28 @@ struct BannerImageView: View {
     let disable_animation: Bool
     let pubkey: Pubkey
     let profiles: Profiles
+    let damusState: DamusState
     
     @State var banner: String?
     
-    init(pubkey: Pubkey, profiles: Profiles, disable_animation: Bool, banner: String? = nil) {
+    init(pubkey: Pubkey, profiles: Profiles, disable_animation: Bool, banner: String? = nil, damusState: DamusState) {
         self.pubkey = pubkey
         self.profiles = profiles
         self._banner = State(initialValue: banner)
         self.disable_animation = disable_animation
+        self.damusState = damusState
     }
     
     var body: some View {
         InnerBannerImageView(disable_animation: disable_animation, url: get_banner_url(banner: banner, pubkey: pubkey, profiles: profiles))
-            .onReceive(handle_notify(.profile_updated)) { updated in
+            .task {
-                guard updated.pubkey == self.pubkey,
+                for await profile in await damusState.nostrNetwork.profilesManager.streamProfile(pubkey: pubkey) {
-                      let profile = profiles.lookup(id: updated.pubkey)
-                else {
-                    return
-                }
-
                     if let bannerImage = profile.banner, bannerImage != self.banner {
                         self.banner = bannerImage
                     }
                 }
             }
+    }
 }
 
 func get_banner_url(banner: String?, pubkey: Pubkey, profiles: Profiles) -> URL? {
@@ -129,7 +127,8 @@ struct BannerImageView_Previews: PreviewProvider {
         BannerImageView(
             pubkey: test_pubkey,
             profiles: make_preview_profiles(test_pubkey),
-            disable_animation: false
+            disable_animation: false,
+            damusState: test_damus_state
         )
     }
 }