Fix preferences

Library/Database/SharedPreferences+Database.swift

@@ -0,0 +1,112 @@
+import BinaryCodable
+import Foundation
+import GRDB
+
+extension SharedPreferences {
+    public class Preference<T: Codable> {
+        let name: String
+        private let defaultValue: T
+
+        init(_ name: String, defaultValue: T) {
+            self.name = name
+            self.defaultValue = defaultValue
+        }
+
+        public nonisolated func get() async -> T {
+            do {
+                return try await SharedPreferences.read(name) ?? defaultValue
+            } catch {
+                NSLog("read preferences error: \(error)")
+                return defaultValue
+            }
+        }
+
+        public func getBlocking() -> T {
+            runBlocking { [self] in
+                await get()
+            }
+        }
+
+        public nonisolated func set(_ newValue: T?) async {
+            do {
+                try await SharedPreferences.write(name, newValue)
+            } catch {
+                NSLog("write preferences error: \(error)")
+            }
+        }
+    }
+
+    private nonisolated static func read<T: Codable>(_ name: String) async throws -> T? {
+        guard let item = try await (Database.sharedWriter.read { db in
+            try Item.fetchOne(db, id: name)
+        })
+        else {
+            return nil
+        }
+        if T.self == String.self {
+            return String(data: item.data, encoding: .utf8) as? T
+        } else {
+            return try BinaryDecoder().decode(from: item.data)
+        }
+    }
+
+    private nonisolated static func write(_ name: String, _ value: (some Codable)?) async throws {
+        if value == nil {
+            _ = try await Database.sharedWriter.write { db in
+                try Item.deleteOne(db, id: name)
+            }
+        } else {
+            let data: Data
+            if let stringValue = value as? String {
+                data = stringValue.data(using: .utf8)!
+            } else {
+                data = try BinaryEncoder().encode(value)
+            }
+            try await Database.sharedWriter.write { db in
+                try Item(name: name, data: data).save(db)
+            }
+        }
+    }
+
+    nonisolated static func batchDelete(_ names: [String]) async throws {
+        try await Database.sharedWriter.write { db in
+            for name in names {
+                try Item.deleteOne(db, id: name)
+            }
+        }
+    }
+}
+
+private class Item: Record, Identifiable {
+    var id: String {
+        name
+    }
+
+    var name: String
+    var data: Data
+
+    init(name: String, data: Data) {
+        self.name = name
+        self.data = data
+        super.init()
+    }
+
+    override class var databaseTableName: String {
+        "preferences"
+    }
+
+    enum Columns: String, ColumnExpression {
+        case name, data
+    }
+
+    required init(row: Row) throws {
+        name = row[Columns.name]
+        data = row[Columns.data]
+        try super.init(row: row)
+    }
+
+    override func encode(to container: inout PersistenceContainer) throws {
+        container[Columns.name] = name
+        container[Columns.data] = data
+    }
+}