image cache

Signed-off-by: William Casarin <jb55@jb55.com>

damus.xcodeproj/project.pbxproj

@@ -14,6 +14,7 @@
 		4C0A3F95280F6C78000448DE /* ReplyQuoteView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C0A3F94280F6C78000448DE /* ReplyQuoteView.swift */; };
 		4C0A3F97280F8E02000448DE /* ThreadView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C0A3F96280F8E02000448DE /* ThreadView.swift */; };
 		4C363A8428233689006E126D /* Parser.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C363A8328233689006E126D /* Parser.swift */; };
+		4C363A8628234FDE006E126D /* ImageCache.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C363A8528234FDE006E126D /* ImageCache.swift */; };
 		4C3BEFD22819DB9B00B3DE84 /* ProfileModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C3BEFD12819DB9B00B3DE84 /* ProfileModel.swift */; };
 		4C3BEFD42819DE8F00B3DE84 /* NostrKind.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C3BEFD32819DE8F00B3DE84 /* NostrKind.swift */; };
 		4C3BEFD6281D995700B3DE84 /* ActionBarModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C3BEFD5281D995700B3DE84 /* ActionBarModel.swift */; };
@@ -81,6 +82,7 @@
 		4C0A3F94280F6C78000448DE /* ReplyQuoteView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReplyQuoteView.swift; sourceTree = "<group>"; };
 		4C0A3F96280F8E02000448DE /* ThreadView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ThreadView.swift; sourceTree = "<group>"; };
 		4C363A8328233689006E126D /* Parser.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Parser.swift; sourceTree = "<group>"; };
+		4C363A8528234FDE006E126D /* ImageCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ImageCache.swift; sourceTree = "<group>"; };
 		4C3BEFD12819DB9B00B3DE84 /* ProfileModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ProfileModel.swift; sourceTree = "<group>"; };
 		4C3BEFD32819DE8F00B3DE84 /* NostrKind.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NostrKind.swift; sourceTree = "<group>"; };
 		4C3BEFD5281D995700B3DE84 /* ActionBarModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ActionBarModel.swift; sourceTree = "<group>"; };
@@ -213,6 +215,7 @@
 			isa = PBXGroup;
 			children = (
 				4C363A8328233689006E126D /* Parser.swift */,
+				4C363A8528234FDE006E126D /* ImageCache.swift */,
 			);
 			path = Util;
 			sourceTree = "<group>";
@@ -428,6 +431,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				4CE4F8CD281352B30009DFBB /* Notifications.swift in Sources */,
+				4C363A8628234FDE006E126D /* ImageCache.swift in Sources */,
 				4C75EFB728049D990006080F /* RelayPool.swift in Sources */,
 				4CE6DEE927F7A08100C66700 /* ContentView.swift in Sources */,
 				4CEE2AF5280B29E600AB5EEF /* TimeAgo.swift in Sources */,

damus/ContentView.swift

@@ -303,7 +303,9 @@ struct ContentView: View {
 
         self.damus = DamusState(pool: pool, pubkey: pubkey,
                                 likes: EventCounter(our_pubkey: pubkey),
-                                boosts: EventCounter(our_pubkey: pubkey))
+                                boosts: EventCounter(our_pubkey: pubkey),
+                                image_cache: ImageCache()
+        )
         pool.connect()
     }
 

damus/Models/DamusState.swift

@@ -12,5 +12,6 @@ struct DamusState {
     let pubkey: String
     let likes: EventCounter
     let boosts: EventCounter
+    let image_cache: ImageCache
     
 }

damus/Nostr/Profiles.swift

@@ -6,7 +6,65 @@
 //
 
 import Foundation
+import UIKit
+import Combine
 
+class ImageCache {
+    private let lock = NSLock()
+    
+    lazy var cache: NSCache<AnyObject, AnyObject> = {
+        let cache = NSCache<AnyObject, AnyObject>()
+        cache.totalCostLimit = 1024 * 1024 * 100 // 100MB
+        return cache
+    }()
+    
+    func lookup(for url: URL) -> UIImage? {
+        lock.lock(); defer { lock.unlock() }
+        
+        if let decoded = cache.object(forKey: url as AnyObject) as? UIImage {
+            return decoded
+        }
+        
+        return nil
+    }
+    
+    func remove(for url: URL) {
+        lock.lock(); defer { lock.unlock() }
+        cache.removeObject(forKey: url as AnyObject)
+    }
+    
+    func insert(_ image: UIImage?, for url: URL) {
+        guard let image = image else { return remove(for: url) }
+        let decodedImage = image.decodedImage(Int(PFP_SIZE!))
+        lock.lock(); defer { lock.unlock() }
+        cache.setObject(decodedImage, forKey: url as AnyObject)
+    }
+    
+    subscript(_ key: URL) -> UIImage? {
+        get {
+            return lookup(for: key)
+        }
+        set {
+            return insert(newValue, for: key)
+        }
+    }
+}
+
+func load_image(cache: ImageCache, from url: URL) -> AnyPublisher<UIImage?, Never> {
+    if let image = cache[url] {
+        return Just(image).eraseToAnyPublisher()
+    }
+    return URLSession.shared.dataTaskPublisher(for: url)
+        .map { (data, response) -> UIImage? in return UIImage(data: data) }
+        .catch { error in return Just(nil) }
+        .handleEvents(receiveOutput: { image in
+            guard let image = image else { return }
+            cache[url] = image
+        })
+        .subscribe(on: DispatchQueue.global(qos: .background))
+        .receive(on: RunLoop.main)
+        .eraseToAnyPublisher()
+}
 
 class Profiles: ObservableObject {
     @Published var profiles: [String: TimestampedProfile] = [:]

damus/Util/ImageCache.swift

@@ -0,0 +1,28 @@
+//
+//  ImageCache.swift
+//  damus
+//
+//  Created by William Casarin on 2022-05-04.
+//
+
+import Foundation
+import SwiftUI
+
+extension UIImage {
+    func decodedImage(_ size: Int) -> UIImage {
+        guard let cgImage = cgImage else { return self }
+        let scale = UIScreen.main.scale
+        let pix_size = CGFloat(size) * scale
+        let colorSpace = CGColorSpaceCreateDeviceRGB()
+        //let cgsize = CGSize(width: size, height: size)
+        
+        let context = CGContext(data: nil, width: Int(pix_size), height: Int(pix_size), bitsPerComponent: 8, bytesPerRow: cgImage.bytesPerRow, space: colorSpace, bitmapInfo: CGImageAlphaInfo.noneSkipFirst.rawValue)
+        
+        //UIGraphicsBeginImageContextWithOptions(cgsize, true, 0)
+        context?.draw(cgImage, in: CGRect(x: 0, y: 0, width: pix_size, height: pix_size))
+        //UIGraphicsEndImageContext()
+
+        guard let decodedImage = context?.makeImage() else { return self }
+        return UIImage(cgImage: decodedImage, scale: scale, orientation: .up)
+    }
+}

damus/Views/ChatView.swift

@@ -12,8 +12,7 @@ struct ChatView: View {
     let prev_ev: NostrEvent?
     let next_ev: NostrEvent?
     
-    let likes: EventCounter
-    let our_pubkey: String
+    let damus: DamusState
     
     @EnvironmentObject var profiles: Profiles
     @EnvironmentObject var thread: ThreadModel
@@ -91,7 +90,7 @@ struct ChatView: View {
                 
                 VStack {
                     if is_active || just_started {
-                        ProfilePicView(picture: profile?.picture, size: 32, highlight: is_active ? .main : .none)
+                        ProfilePicView(picture: profile?.picture, size: 32, highlight: is_active ? .main : .none, image_cache: damus.image_cache)
                     }
                     /*
                     if just_started {
@@ -122,7 +121,7 @@ struct ChatView: View {
                 
                     if let ref_id = thread.replies.lookup(event.id) {
                         if !is_reply_to_prev() {
-                            ReplyQuoteView(quoter: event, event_id: ref_id)
+                            ReplyQuoteView(quoter: event, event_id: ref_id, image_cache: damus.image_cache)
                                 .environmentObject(thread)
                                 .environmentObject(profiles)
                             ReplyDescription
@@ -133,7 +132,10 @@ struct ChatView: View {
                         .textSelection(.enabled)
                     
                     if is_active || next_ev == nil || next_ev!.pubkey != event.pubkey {
-                        EventActionBar(event: event, our_pubkey: our_pubkey, bar: make_actionbar_model(ev: event, counter: likes))
+                        EventActionBar(event: event,
+                                       our_pubkey: damus.pubkey,
+                                       bar: make_actionbar_model(ev: event, counter: damus.likes)
+                        )
                             .environmentObject(profiles)
                     }
 

damus/Views/ChatroomView.swift

@@ -10,8 +10,7 @@ import SwiftUI
 struct ChatroomView: View {
     @EnvironmentObject var thread: ThreadModel
     @Environment(\.dismiss) var dismiss
-    let likes: EventCounter
-    let our_pubkey: String
+    let damus: DamusState
     
     var body: some View {
         ScrollViewReader { scroller in
@@ -22,8 +21,7 @@ struct ChatroomView: View {
                         ChatView(event: thread.events[ind],
                                  prev_ev: ind > 0 ? thread.events[ind-1] : nil,
                                  next_ev: ind == count-1 ? nil : thread.events[ind+1],
-                                 likes: likes,
-                                 our_pubkey: our_pubkey
+                                 damus: damus
                         )
                         .onTapGesture {
                             if thread.event.id == ev.id {

damus/Views/EventView.swift

@@ -53,7 +53,7 @@ struct EventView: View {
                     .environmentObject(profiles)
                 
                 NavigationLink(destination: pv) {
-                    ProfilePicView(picture: profile?.picture, size: PFP_SIZE!, highlight: highlight)
+                    ProfilePicView(picture: profile?.picture, size: PFP_SIZE!, highlight: highlight, image_cache: damus.image_cache)
                 }
 
                 Spacer()

damus/Views/ProfilePicView.swift

@@ -36,27 +36,46 @@ struct ProfilePicView: View {
     let picture: String?
     let size: CGFloat
     let highlight: Highlight
+    let image_cache: ImageCache
+    
+    @State var img: Image? = nil
+    
+    @EnvironmentObject var profiles: Profiles
     
     var Placeholder: some View {
         Color.purple.opacity(0.2)
+            .frame(width: size, height: size)
+            .cornerRadius(CORNER_RADIUS)
+            .overlay(Circle().stroke(highlight_color(highlight), lineWidth: pfp_line_width(highlight)))
+            .padding(2)
+    }
+    
+    func ProfilePic(_ url: URL) -> some View {
+        let pub = load_image(cache: image_cache, from: url)
+        return Group {
+            if let img = self.img {
+                img
+                    .frame(width: size, height: size)
+                    .clipShape(Circle())
+                    .overlay(Circle().stroke(highlight_color(highlight), lineWidth: pfp_line_width(highlight)))
+                    .padding(2)
+            } else {
+                Placeholder
+            }
+        }
+        .onReceive(pub) { mimg in
+            if let img = mimg {
+                self.img = Image(uiImage: img)
+            }
+        }
     }
     
     var MainContent: some View {
         Group {
-            if let pic = picture.flatMap({ URL(string: $0) }) {
-                AsyncImage(url: pic) { img in
-                    img.resizable()
-                } placeholder: { Placeholder }
-                .frame(width: size, height: size)
-                .clipShape(Circle())
-                .overlay(Circle().stroke(highlight_color(highlight), lineWidth: pfp_line_width(highlight)))
-                .padding(2)
+            if let pic_url = picture.flatMap { URL(string: $0) } {
+                ProfilePic(pic_url)
             } else {
                 Placeholder
-                    .frame(width: size, height: size)
-                    .cornerRadius(CORNER_RADIUS)
-                    .overlay(Circle().stroke(highlight_color(highlight), lineWidth: pfp_line_width(highlight)))
-                    .padding(2)
             }
         }
     }
@@ -66,11 +85,13 @@ struct ProfilePicView: View {
     }
 }
 
+/*
 struct ProfilePicView_Previews: PreviewProvider {
     static var previews: some View {
         ProfilePicView(picture: "http://cdn.jb55.com/img/red-me.jpg", size: 64, highlight: .none)
     }
 }
+ */
     
 
 func hex_to_rgb(_ hex: String) -> Color {

damus/Views/ProfileView.swift

@@ -24,7 +24,7 @@ struct ProfileView: View {
     var TopSection: some View {
         HStack(alignment: .top) {
             let data = profiles.lookup(id: profile.pubkey)
-            ProfilePicView(picture: data?.picture, size: 64, highlight: .custom(Color.black, 4))
+            ProfilePicView(picture: data?.picture, size: 64, highlight: .custom(Color.black, 4), image_cache: damus.image_cache)
                 //.border(Color.blue)
             VStack(alignment: .leading) {
                 if let pubkey = profile.pubkey {

damus/Views/ReplyQuoteView.swift

@@ -10,6 +10,7 @@ import SwiftUI
 struct ReplyQuoteView: View {
     let quoter: NostrEvent
     let event_id: String
+    let image_cache: ImageCache
     
     @EnvironmentObject var profiles: Profiles
     @EnvironmentObject var thread: ThreadModel
@@ -22,7 +23,7 @@ struct ReplyQuoteView: View {
             
             VStack(alignment: .leading) {
                 HStack(alignment: .top) {
-                    ProfilePicView(picture: profiles.lookup(id: event.pubkey)?.picture, size: 16, highlight: .reply)
+                    ProfilePicView(picture: profiles.lookup(id: event.pubkey)?.picture, size: 16, highlight: .reply, image_cache: image_cache)
                     Text(Profile.displayName(profile: profiles.lookup(id: event.pubkey), pubkey: event.pubkey))
                         .foregroundColor(.accentColor)
                     Text("\(format_relative_time(event.created_at))")

damus/Views/ThreadView.swift

@@ -19,7 +19,7 @@ struct ThreadView: View {
     var body: some View {
         Group {
             if is_chatroom {
-                ChatroomView(likes: damus.likes, our_pubkey: damus.pubkey)
+                ChatroomView(damus: damus)
                     .navigationBarTitle("Chat")
                     .environmentObject(profiles)
                     .environmentObject(thread)