Thread Caching

Changelog-Added: Threads now load instantly and are cached

damus/Util/EventCache.swift

@@ -9,6 +9,64 @@ import Foundation
 
 class EventCache {
     private var events: [String: NostrEvent]
+    private var replies: ReplyMap = ReplyMap()
+    
+    //private var thread_latest: [String: Int64]
+    
+    init() {
+        self.events = [:]
+        self.replies = ReplyMap()
+    }
+    
+    func parent_events(event: NostrEvent) -> [NostrEvent] {
+        var parents: [NostrEvent] = []
+        
+        var ev = event
+        
+        while true {
+            guard let direct_reply = ev.direct_replies(nil).first else {
+                break
+            }
+            
+            guard let next_ev = lookup(direct_reply.ref_id), next_ev != ev else {
+                break
+            }
+            
+            parents.append(next_ev)
+            ev = next_ev
+        }
+        
+        return parents.reversed()
+    }
+    
+    func add_replies(ev: NostrEvent) {
+        for reply in ev.direct_replies(nil) {
+            replies.add(id: reply.ref_id, reply_id: ev.id)
+        }
+    }
+    
+    func child_events(event: NostrEvent) -> [NostrEvent] {
+        guard let xs = replies.lookup(event.id) else {
+            return []
+        }
+        let evs: [NostrEvent] = xs.reduce(into: [], { evs, evid in
+            guard let ev = self.lookup(evid) else {
+                return
+            }
+            
+            evs.append(ev)
+        }).sorted(by: { $0.created_at < $1.created_at })
+        return evs
+    }
+    
+    func upsert(_ ev: NostrEvent) -> NostrEvent {
+        if let found = lookup(ev.id) {
+            return found
+        }
+        
+        insert(ev)
+        return ev
+    }
     
     func lookup(_ evid: String) -> NostrEvent? {
         return events[evid]
@@ -21,7 +79,4 @@ class EventCache {
         events[ev.id] = ev
     }
     
-    init() {
-        self.events = [:]
-    }
 }