Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/Postbox/Sources/StoryExpirationTimeItemsView.swift

@@ -0,0 +1,63 @@
+import Foundation
+
+public struct StoryExpirationTimeEntry: Equatable {
+    public var id: StoryId
+    public var expirationTimestamp: Int32
+
+    init(id: StoryId, expirationTimestamp: Int32) {
+        self.id = id
+        self.expirationTimestamp = expirationTimestamp
+    }
+}
+
+final class MutableStoryExpirationTimeItemsView: MutablePostboxView {
+    var topEntry: StoryExpirationTimeEntry?
+
+    init(postbox: PostboxImpl) {
+        let _ = self.refreshDueToExternalTransaction(postbox: postbox)
+    }
+    
+    func replay(postbox: PostboxImpl, transaction: PostboxTransaction) -> Bool {
+        var updated = false
+        if !transaction.storyItemsEvents.isEmpty {
+            var refresh = false
+            loop: for event in transaction.storyItemsEvents {
+                switch event {
+                case .replace:
+                    refresh = true
+                    break loop
+                }
+            }
+            if refresh {
+                updated = self.refreshDueToExternalTransaction(postbox: postbox)
+            }
+        }
+        
+        return updated
+    }
+
+    func refreshDueToExternalTransaction(postbox: PostboxImpl) -> Bool {
+        var topEntry: StoryExpirationTimeEntry?
+        if let item = postbox.storyItemsTable.getMinExpirationTimestamp() {
+            topEntry = StoryExpirationTimeEntry(id: item.0, expirationTimestamp: item.1)
+        }
+        if self.topEntry != topEntry {
+            self.topEntry = topEntry
+            return true
+        } else {
+            return false
+        }
+    }
+    
+    func immutableView() -> PostboxView {
+        return StoryExpirationTimeItemsView(self)
+    }
+}
+
+public final class StoryExpirationTimeItemsView: PostboxView {
+    public let topEntry: StoryExpirationTimeEntry?
+    
+    init(_ view: MutableStoryExpirationTimeItemsView) {
+        self.topEntry = view.topEntry
+    }
+}