refactor and cleanup [skip ci]

submodules/Postbox/Sources/PeerChatInterfaceStateTable.swift

@@ -0,0 +1,78 @@
+import Foundation
+
+final class PeerChatInterfaceStateTable: Table {
+    static func tableSpec(_ id: Int32) -> ValueBoxTable {
+        return ValueBoxTable(id: id, keyType: .int64, compactValuesOnCreation: false)
+    }
+    
+    private var states: [PeerId: PeerChatInterfaceState?] = [:]
+    private var peerIdsWithUpdatedStates = Set<PeerId>()
+    
+    private let sharedKey = ValueBoxKey(length: 8)
+    
+    private func key(_ peerId: PeerId, sharedKey: ValueBoxKey = ValueBoxKey(length: 8)) -> ValueBoxKey {
+        sharedKey.setInt64(0, value: peerId.toInt64())
+        return sharedKey
+    }
+    
+    func get(_ peerId: PeerId) -> PeerChatInterfaceState? {
+        if let cachedValue = self.states[peerId] {
+            return cachedValue
+        } else if let value = self.valueBox.get(self.table, key: self.key(peerId, sharedKey: self.sharedKey)), let state = PostboxDecoder(buffer: value).decodeRootObject() as? PeerChatInterfaceState {
+            self.states[peerId] = state
+            return state
+        } else {
+            self.states[peerId] = nil
+            return nil
+        }
+    }
+    
+    func set(_ peerId: PeerId, state: PeerChatInterfaceState?) -> (updated: Bool, updatedEmbeddedState: Bool) {
+        let currentState = self.get(peerId)
+        var updated = false
+        var updatedEmbeddedState = false
+        if let currentState = currentState, let state = state {
+            if !currentState.isEqual(to: state) {
+                updated = true
+                if let currentEmbeddedState = currentState.chatListEmbeddedState, let embeddedState = state.chatListEmbeddedState {
+                    if !currentEmbeddedState.isEqual(to: embeddedState) {
+                        updatedEmbeddedState = true
+                    }
+                } else if (currentState.chatListEmbeddedState != nil) != (state.chatListEmbeddedState != nil) {
+                    updatedEmbeddedState = true
+                }
+            }
+        } else if (currentState != nil) != (state != nil) {
+            updated = true
+            updatedEmbeddedState = true
+        }
+        if updated {
+            self.states[peerId] = state
+            self.peerIdsWithUpdatedStates.insert(peerId)
+        }
+        return (updated, updatedEmbeddedState)
+    }
+    
+    override func clearMemoryCache() {
+        self.states.removeAll()
+        self.peerIdsWithUpdatedStates.removeAll()
+    }
+    
+    override func beforeCommit() {
+        if !self.peerIdsWithUpdatedStates.isEmpty {
+            let sharedEncoder = PostboxEncoder()
+            for peerId in self.peerIdsWithUpdatedStates {
+                if let state = self.states[peerId] {
+                    if let state = state {
+                    sharedEncoder.reset()
+                    sharedEncoder.encodeRootObject(state)
+                    self.valueBox.set(self.table, key: self.key(peerId, sharedKey: self.sharedKey), value: sharedEncoder.readBufferNoCopy())
+                    } else {
+                        self.valueBox.remove(self.table, key: self.key(peerId, sharedKey: self.sharedKey), secure: false)
+                    }
+                }
+            }
+            self.peerIdsWithUpdatedStates.removeAll()
+        }
+    }
+}