Swift 6 concurrency support (#33)

Author: aashishpatil-g

Sources/BaseOperationRef.swift

@@ -15,24 +15,24 @@
 import Foundation
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public struct OperationResult<ResultData: Decodable> {
+public struct OperationResult<ResultData: Decodable & Sendable>: Sendable {
   public var data: ResultData
 }
 
 // notional protocol that denotes a variable.
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public protocol OperationVariable: Encodable, Hashable, Equatable {}
+public protocol OperationVariable: Encodable, Hashable, Equatable, Sendable {}
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-protocol OperationRequest: Hashable, Equatable {
+protocol OperationRequest: Hashable, Equatable, Sendable {
   associatedtype Variable: OperationVariable
   var operationName: String { get } // Name within Connector definition
   var variables: Variable? { get }
 }
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
 public protocol OperationRef {
-  associatedtype ResultData: Decodable
+  associatedtype ResultData: Decodable & Sendable
 
   func execute() async throws -> OperationResult<ResultData>
 }

Sources/ConnectorConfig.swift

@@ -15,7 +15,7 @@
 import Foundation
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public struct ConnectorConfig: Hashable, Equatable {
+public struct ConnectorConfig: Hashable, Equatable, Sendable {
   public private(set) var serviceId: String
   public private(set) var location: String
   public private(set) var connector: String

Sources/DataConnect.swift

@@ -14,9 +14,9 @@
 
 import Foundation
 
-import FirebaseAppCheck
-import FirebaseAuth
-import FirebaseCore
+@preconcurrency import FirebaseAppCheck
+@preconcurrency import FirebaseAuth
+@preconcurrency import FirebaseCore
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
 public class DataConnect {
@@ -29,7 +29,17 @@ public class DataConnect {
 
   private var callerSDKType: CallerSDKType = .base
 
-  private static var instanceStore = InstanceStore()
+  private let accessQueue = DispatchQueue(
+    label: "com.google.firebase.dataConnect.instanceAccessQueue",
+    autoreleaseFrequency: .workItem
+  )
+
+  // Instance store uses an internal queue to protect mutable state.
+  #if compiler(>=6)
+    private nonisolated(unsafe) static let instanceStore = InstanceStore()
+  #else
+    private static let instanceStore = InstanceStore()
+  #endif
 
   public enum EmulatorDefaults {
     public static let host = "127.0.0.1"
@@ -62,26 +72,26 @@ public class DataConnect {
 
   public func useEmulator(host: String = EmulatorDefaults.host,
                           port: Int = EmulatorDefaults.port) {
-    settings = DataConnectSettings(host: host, port: port, sslEnabled: false)
+    accessQueue.sync {
+      settings = DataConnectSettings(host: host, port: port, sslEnabled: false)
 
-    // TODO: - shutdown grpc client
-    // self.grpcClient.close
-    // self.operations.close
+      // TODO: - shutdown grpc client
+      // self.grpcClient.close
+      // self.operations.close
 
-    guard app.options.projectID != nil else {
-      fatalError("Firebase DataConnect requires the projectID to be set in the app options")
-    }
+      guard app.options.projectID != nil else {
+        fatalError("Firebase DataConnect requires the projectID to be set in the app options")
+      }
 
-    grpcClient = GrpcClient(
-      app: app,
-      settings: settings,
-      connectorConfig: connectorConfig,
-      auth: Auth.auth(app: app),
-      appCheck: AppCheck.appCheck(app: app),
-      callerSDKType: callerSDKType
-    )
+      grpcClient = GrpcClient(
+        app: app,
+        settings: settings,
+        connectorConfig: connectorConfig,
+        callerSDKType: callerSDKType
+      )
 
-    operationsManager = OperationsManager(grpcClient: grpcClient)
+      operationsManager = OperationsManager(grpcClient: grpcClient)
+    }
   }
 
   // MARK: Init
@@ -101,8 +111,6 @@ public class DataConnect {
       app: self.app,
       settings: settings,
       connectorConfig: connectorConfig,
-      auth: Auth.auth(app: app),
-      appCheck: AppCheck.appCheck(app: app),
       callerSDKType: self.callerSDKType
     )
     operationsManager = OperationsManager(grpcClient: grpcClient)
@@ -111,33 +119,37 @@ public class DataConnect {
   // MARK: Operations
 
   /// Returns a query ref matching the name and variables.
-  public func query<ResultData: Decodable,
+  public func query<ResultData: Decodable & Sendable,
     Variable: OperationVariable>(name: String,
                                  variables: Variable,
                                  resultsDataType: ResultData
                                    .Type,
                                  publisher: ResultsPublisherType = .observableObject)
     -> any ObservableQueryRef {
-    let request = QueryRequest(operationName: name, variables: variables)
-    return operationsManager.queryRef(for: request, with: resultsDataType, publisher: publisher)
+    accessQueue.sync {
+      let request = QueryRequest(operationName: name, variables: variables)
+      return operationsManager.queryRef(for: request, with: resultsDataType, publisher: publisher)
+    }
   }
 
   /// Returns a Mutation Ref matching the name and specified variables.
-  public func mutation<ResultData: Decodable,
+  public func mutation<ResultData: Decodable & Sendable,
     Variable: OperationVariable>(name: String,
                                  variables: Variable,
                                  resultsDataType: ResultData
                                    .Type)
     -> MutationRef<ResultData,
       Variable> {
-    let request = MutationRequest(operationName: name, variables: variables)
-    return operationsManager.mutationRef(for: request, with: resultsDataType)
+    accessQueue.sync {
+      let request = MutationRequest(operationName: name, variables: variables)
+      return operationsManager.mutationRef(for: request, with: resultsDataType)
+    }
   }
 }
 
 // This enum is public so the gen sdk can access it
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public enum CallerSDKType {
+public enum CallerSDKType: Sendable {
   case base // base sdk is directly used
   case generated // generated sdk is calling the base
 }
@@ -170,7 +182,7 @@ private class InstanceStore {
     autoreleaseFrequency: .workItem
   )
 
-  var instances = [InstanceKey: DataConnect]()
+  private var instances = [InstanceKey: DataConnect]()
 
   func instance(for app: FirebaseApp, config: ConnectorConfig,
                 settings: DataConnectSettings, callerSDKType: CallerSDKType) -> DataConnect {

Sources/DataConnectSettings.swift

@@ -15,7 +15,7 @@
 import Foundation
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public struct DataConnectSettings: Hashable, Equatable {
+public struct DataConnectSettings: Hashable, Equatable, Sendable {
   public private(set) var host: String
   public private(set) var port: Int
   public private(set) var sslEnabled: Bool

Sources/Internal/GrpcClient.swift

@@ -14,8 +14,8 @@
 
 import Foundation
 
-import FirebaseAppCheck
-import FirebaseAuth
+@preconcurrency import FirebaseAppCheck
+@preconcurrency import FirebaseAuth
 import FirebaseCore
 import GRPC
 import NIOCore
@@ -108,8 +108,6 @@ actor GrpcClient: CustomStringConvertible {
   }()
 
   init(app: FirebaseApp, settings: DataConnectSettings, connectorConfig: ConnectorConfig,
-       auth: Auth,
-       appCheck: AppCheck?,
        callerSDKType: CallerSDKType) {
     self.app = app
 
@@ -120,8 +118,8 @@ actor GrpcClient: CustomStringConvertible {
 
     serverSettings = settings
     self.connectorConfig = connectorConfig
-    self.auth = auth
-    self.appCheck = appCheck
+    auth = Auth.auth(app: app)
+    appCheck = AppCheck.appCheck(app: app)
     self.callerSDKType = callerSDKType
 
     connectorName =

Sources/Internal/OperationsManager.swift

@@ -34,7 +34,7 @@ class OperationsManager {
     self.grpcClient = grpcClient
   }
 
-  func queryRef<ResultDataType: Decodable,
+  func queryRef<ResultDataType: Decodable & Sendable,
     VariableType: OperationVariable>(for request: QueryRequest<VariableType>,
                                      with resultType: ResultDataType
                                        .Type,

Sources/MutationRef.swift

@@ -27,7 +27,10 @@ struct MutationRequest<Variable: OperationVariable>: OperationRequest {
 
 /// Represents a predefined graphql mutation identified by name and variables.
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public class MutationRef<ResultData: Decodable, Variable: OperationVariable>: OperationRef {
+public class MutationRef<
+  ResultData: Decodable & Sendable,
+  Variable: OperationVariable
+>: OperationRef {
   private var request: any OperationRequest
 
   private var grpcClient: GrpcClient

Sources/QueryRef.swift

@@ -14,7 +14,7 @@
 
 import Foundation
 
-import Combine
+@preconcurrency import Combine
 import Observation
 
 /// The type of publisher to use for the Query Ref
@@ -75,13 +75,13 @@ public protocol QueryRef: OperationRef {
 }
 
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-actor GenericQueryRef<ResultData: Decodable, Variable: OperationVariable>: QueryRef {
-  private var resultsPublisher = PassthroughSubject<Result<ResultData, DataConnectError>,
+actor GenericQueryRef<ResultData: Decodable & Sendable, Variable: OperationVariable>: QueryRef {
+  private let resultsPublisher = PassthroughSubject<Result<ResultData, DataConnectError>,
     Never>()
 
-  private var request: QueryRequest<Variable>
+  private let request: QueryRequest<Variable>
 
-  private var grpcClient: GrpcClient
+  private let grpcClient: GrpcClient
 
   init(request: QueryRequest<Variable>, grpcClient: GrpcClient) {
     self.request = request
@@ -143,7 +143,7 @@ public protocol ObservableQueryRef: QueryRef {
 ///            If last fetch was successful, this variable is cleared
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
 public class QueryRefObservableObject<
-  ResultData: Decodable,
+  ResultData: Decodable & Sendable,
   Variable: OperationVariable
 >: ObservableObject, ObservableQueryRef {
   private var request: QueryRequest<Variable>
@@ -216,7 +216,7 @@ public class QueryRefObservableObject<
 @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
 @Observable
 public class QueryRefObservation<
-  ResultData: Decodable,
+  ResultData: Decodable & Sendable,
   Variable: OperationVariable
 >: ObservableQueryRef {
   @ObservationIgnored

Sources/Scalars/AnyValue.swift

@@ -62,3 +62,6 @@ extension AnyValue: Hashable {
     hasher.combine(value)
   }
 }
+
+@available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
+extension AnyValue: Sendable {}

Sources/Scalars/LocalDate.swift

@@ -20,7 +20,7 @@ import Foundation
  Essentially represents: https://the-guild.dev/graphql/scalars/docs/scalars/local-date
  */
 @available(iOS 15.0, macOS 12.0, tvOS 15.0, watchOS 8.0, *)
-public struct LocalDate: Codable, Equatable, Comparable, CustomStringConvertible {
+public struct LocalDate: Codable, Comparable, CustomStringConvertible, Equatable, Sendable {
   private var calendar = Calendar(identifier: .gregorian)
   private var dateFormatter = DateFormatter()
   private var date = Date()