Introduced flag for enabling Event Engine

Examples/Sources/MasterDetailTableViewController.swift

@@ -269,12 +269,12 @@ class MasterDetailTableViewController: UITableViewController {
           switch connectionChange {
           case .connected:
             print("Status connected!")
-          case .connectionError(let error):
-            print("Error while attempting to initialize connection: \(error)")
+          case .connectionError:
+            print("Error while attempting to initialize connection")
           case .disconnected:
             print("Status disconnected")
-          case .disconnectedUnexpectedly(let error):
-            print("Disconnected unexpectedly: \(error)")
+          case .disconnectedUnexpectedly:
+            print("Disconnected unexpectedly")
           }
         case let .presenceChanged(presenceChange):
           print("The channel \(presenceChange.channel) has an updated occupancy of \(presenceChange.occupancy)")

Podfile.lock

@@ -19,4 +19,4 @@ SPEC CHECKSUMS:
 
 PODFILE CHECKSUM: 61a40240486621bb01f596fdd5bc632504940fab
 
-COCOAPODS: 1.11.3
+COCOAPODS: 1.13.0

Sources/PubNub/EventEngine/Presence/Effects/DelayedHeartbeatEffect.swift

@@ -56,7 +56,7 @@ class DelayedHeartbeatEffect: DelayedEffectHandler {
     case 1:
       return 0.5 * Double(configuration.durationUntilTimeout)
     case 2:
-      return Double(configuration.durationUntilTimeout) - 1.0
+      return 0.5 * Double(configuration.durationUntilTimeout) - 1.0
     default:
       return nil
     }

Sources/PubNub/EventEngine/Presence/Helpers/PresenceHeartbeatRequest.swift

@@ -53,7 +53,7 @@ class PresenceHeartbeatRequest {
   func execute(completionBlock: @escaping (Result<Void, PubNubError>) -> Void) {
     request = session.request(with: PresenceRouter(
       .heartbeat(channels: channels, groups: groups, presenceTimeout: configuration.durationUntilTimeout),
-      configuration: configuration), requestOperator: nil
+      configuration: configuration, eventEngineEnabled: true), requestOperator: nil
     )
     request?.validate().response(on: sessionResponseQueue, decoder: GenericServiceResponseDecoder()) { result in
       switch result {

Sources/PubNub/EventEngine/Presence/Helpers/PresenceLeaveRequest.swift

@@ -53,7 +53,7 @@ class PresenceLeaveRequest {
   func execute(completionBlock: @escaping (Result<Void, PubNubError>) -> Void) {
     request = session.request(with: PresenceRouter(
       .leave(channels: channels, groups: groups),
-      configuration: configuration), requestOperator: nil
+      configuration: configuration, eventEngineEnabled: true), requestOperator: nil
     )
     request?.validate().response(on: sessionResponseQueue, decoder: GenericServiceResponseDecoder()) { result in
       switch result {

Sources/PubNub/EventEngine/Presence/PresenceTransition.swift

@@ -39,7 +39,7 @@ class PresenceTransition: TransitionProtocol {
     case .left(_,_):
       return !(state is Presence.HeartbeatInactive)
     case .heartbeatSuccess:
-      return state is Presence.Heartbeating
+      return state is Presence.Heartbeating || state is Presence.HeartbeatReconnecting
     case .heartbeatFailed(_):
       return state is Presence.Heartbeating || state is Presence.HeartbeatReconnecting
     case .heartbeatGiveUp(_):

Sources/PubNub/EventEngine/Subscribe/Helpers/SubscribeInput.swift

@@ -28,18 +28,15 @@
 import Foundation
 
 struct SubscribeInput: Equatable {
-  let channels: [String: PubNubChannel]
-  let groups: [String: PubNubChannel]
+  private let channels: [String: PubNubChannel]
+  private let groups: [String: PubNubChannel]
 
   init(channels: [PubNubChannel] = [], groups: [PubNubChannel] = []) {
     self.channels = channels.reduce(into: [String: PubNubChannel]()) { r, channel in _ = r.insert(channel) }
     self.groups = groups.reduce(into: [String: PubNubChannel]()) { r, channel in _ = r.insert(channel) }
   }
 
-  private init(
-    channels: [String: PubNubChannel],
-    groups: [String: PubNubChannel]
-  ) {
+  private init(channels: [String: PubNubChannel], groups: [String: PubNubChannel]) {
     self.channels = channels
     self.groups = groups
   }

Sources/PubNub/EventEngine/Subscribe/Helpers/SubscribeRequest.swift

@@ -86,7 +86,8 @@ class SubscribeRequest {
           timetoken: timetoken,
           region: region?.description ?? nil,
           heartbeat: configuration.durationUntilTimeout,
-          filter: configuration.filterExpression
+          filter: configuration.filterExpression,
+          eventEngineEnabled: true
         ), configuration: configuration
       ), requestOperator: nil
     )

Sources/PubNub/EventEngine/Subscribe/SubscribeTransition.swift

@@ -295,7 +295,7 @@ fileprivate extension SubscribeTransition {
       ), invocations: [
         .managed(.emitStatus(change: Subscribe.ConnectionStatusChange(
           oldStatus: state.connectionStatus,
-          newStatus: .connectionError(error.underlying),
+          newStatus: .connectionError,
           error: error
         )))
       ]
@@ -363,7 +363,7 @@ fileprivate extension SubscribeTransition {
       ), invocations: [
         .managed(.emitStatus(change: Subscribe.ConnectionStatusChange(
           oldStatus: state.connectionStatus,
-          newStatus: .disconnectedUnexpectedly(error.underlying),
+          newStatus: .disconnectedUnexpectedly,
           error: error
         )))
       ]

Sources/PubNub/Events/Subscription/SubscriptionStream.swift

@@ -27,6 +27,30 @@
 
 import Foundation
 
+/// A channel or group that has successfully been subscribed or unsubscribed
+public enum SubscriptionChangeEvent {
+  /// The channels or groups that have successfully been subscribed
+  case subscribed(channels: [PubNubChannel], groups: [PubNubChannel])
+  /// The response header for one or more subscription events
+  case responseHeader(
+    channels: [PubNubChannel], groups: [PubNubChannel], previous: SubscribeCursor?, next: SubscribeCursor?
+  )
+  /// The channels or groups that have successfully been unsubscribed
+  case unsubscribed(channels: [PubNubChannel], groups: [PubNubChannel])
+
+  /// Whether this event represents an actual change or contains no data
+  var didChange: Bool {
+    switch self {
+    case let .subscribed(channels, groups):
+      return !channels.isEmpty || !groups.isEmpty
+    case .responseHeader:
+      return false
+    case let .unsubscribed(channels, groups):
+      return !channels.isEmpty || !groups.isEmpty
+    }
+  }
+}
+
 /// Local events emitted from the Subscribe method
 public enum PubNubSubscribeEvent {
   /// The connection status of the PubNub subscription was changed
@@ -118,7 +142,6 @@ public final class CoreListener: BaseSubscriptionListener {
   public var didReceiveBatchSubscription: (([SubscriptionEvent]) -> Void)?
   /// Receiver for all subscription events
   public var didReceiveSubscription: ((SubscriptionEvent) -> Void)?
-
   /// Receiver for status (Connection & Error) events
   public var didReceiveStatus: ((StatusEvent) -> Void)?
   /// Receiver for presence events
@@ -215,12 +238,10 @@ public final class CoreListener: BaseSubscriptionListener {
         self?.didReceiveMessage?(message)
       case let .signalReceived(signal):
         self?.didReceiveSignal?(signal)
-
       case let .connectionStatusChanged(status):
         self?.didReceiveStatus?(.success(status))
       case let .presenceChanged(presence):
         self?.didReceivePresence?(presence)
-
       case let .uuidMetadataSet(metadata):
         self?.didReceiveObjectMetadataEvent?(.setUUID(metadata))
       case let .uuidMetadataRemoved(metadataId):
@@ -233,7 +254,6 @@ public final class CoreListener: BaseSubscriptionListener {
         self?.didReceiveObjectMetadataEvent?(.setMembership(membership))
       case let .membershipMetadataRemoved(membership):
         self?.didReceiveObjectMetadataEvent?(.removedMembership(membership))
-
       case let .messageActionAdded(action):
         self?.didReceiveMessageAction?(.added(action))
       case let .messageActionRemoved(action):

Sources/PubNub/Networking/HTTPRouter.swift

@@ -134,6 +134,7 @@ enum QueryKey: String {
   case filter
   case sort
   case descending = "desc"
+  case eventEngine = "ee"
 }
 
 /// The PubNub Key requirement for a given Endpoint

Sources/PubNub/Networking/Routers/PresenceRouter.swift

@@ -95,13 +95,15 @@ struct PresenceRouter: HTTPRouter {
   }
 
   // Init
-  init(_ endpoint: Endpoint, configuration: RouterConfiguration) {
+  init(_ endpoint: Endpoint, configuration: RouterConfiguration, eventEngineEnabled: Bool = false) {
     self.endpoint = endpoint
     self.configuration = configuration
+    self.eventEngineEnabled = eventEngineEnabled
   }
 
   var endpoint: Endpoint
   var configuration: RouterConfiguration
+  var eventEngineEnabled: Bool
 
   // Protocol Properties
   var service: PubNubService {
@@ -143,8 +145,14 @@ struct PresenceRouter: HTTPRouter {
     case let .heartbeat(_, groups, presenceTimeout):
       query.appendIfNotEmpty(key: .channelGroup, value: groups)
       query.appendIfPresent(key: .heartbeat, value: presenceTimeout?.description)
+      if eventEngineEnabled {
+        query.append(URLQueryItem(key: .eventEngine, value: nil))
+      }
     case let .leave(_, groups):
       query.appendIfNotEmpty(key: .channelGroup, value: groups)
+      if eventEngineEnabled {
+        query.append(URLQueryItem(key: .eventEngine, value: nil))
+      }
     case let .hereNow(_, groups, includeUUIDs, includeState):
       query.appendIfNotEmpty(key: .channelGroup, value: groups)
       query.append(URLQueryItem(key: .disableUUIDs, value: (!includeUUIDs).stringNumber))

Sources/PubNub/Networking/Routers/SubscribeRouter.swift

@@ -32,9 +32,11 @@ import Foundation
 struct SubscribeRouter: HTTPRouter {
   // Nested Endpoint
   enum Endpoint: CaseAccessible, CustomStringConvertible {
-    case subscribe(channels: [String], groups: [String],
-                   timetoken: Timetoken?, region: String?,
-                   heartbeat: UInt?, filter: String?)
+    case subscribe(
+      channels: [String], groups: [String],
+      timetoken: Timetoken?, region: String?,
+      heartbeat: UInt?, filter: String?, eventEngineEnabled: Bool
+    )
 
     var description: String {
       switch self {
@@ -66,7 +68,7 @@ struct SubscribeRouter: HTTPRouter {
     let path: String
 
     switch endpoint {
-    case let .subscribe(channels, _, _, _, _, _):
+    case let .subscribe(channels, _, _, _, _, _, _):
       path = "/v2/subscribe/\(subscribeKey)/\(channels.commaOrCSVString.urlEncodeSlash)/0"
     }
 
@@ -77,12 +79,16 @@ struct SubscribeRouter: HTTPRouter {
     var query = defaultQueryItems
 
     switch endpoint {
-    case let .subscribe(_, groups, timetoken, region, heartbeat, filter):
+    case let .subscribe(_, groups, timetoken, region, heartbeat, filter, eventEngineEnabled):
       query.appendIfNotEmpty(key: .channelGroup, value: groups)
       query.appendIfPresent(key: .timetokenShort, value: timetoken?.description)
       query.appendIfPresent(key: .regionShort, value: region?.description)
       query.appendIfPresent(key: .filterExpr, value: filter)
       query.appendIfPresent(key: .heartbeat, value: heartbeat?.description)
+
+      if eventEngineEnabled {
+        query.append(URLQueryItem(key: .eventEngine, value: nil))
+      }
     }
 
     return .success(query)
@@ -91,7 +97,7 @@ struct SubscribeRouter: HTTPRouter {
   // Validated
   var validationErrorDetail: String? {
     switch endpoint {
-    case let .subscribe(channels, groups, _, _, _, _):
+    case let .subscribe(channels, groups, _, _, _, _, _):
       return isInvalidForReason(
         (channels.isEmpty && groups.isEmpty, ErrorDescription.missingChannelsAnyGroups))
     }

Sources/PubNub/PubNubConfiguration.swift

@@ -104,7 +104,8 @@ public struct PubNubConfiguration: Hashable {
     heartbeatInterval: UInt = 0,
     supressLeaveEvents: Bool = false,
     requestMessageCountThreshold: UInt = 100,
-    filterExpression: String? = nil
+    filterExpression: String? = nil,
+    enableEventEngine: Bool = false
   ) {
     guard userId.trimmingCharacters(in: .whitespacesAndNewlines).count > 0 else {
       preconditionFailure("UserId should not be empty.")
@@ -127,6 +128,7 @@ public struct PubNubConfiguration: Hashable {
     self.supressLeaveEvents = supressLeaveEvents
     self.requestMessageCountThreshold = requestMessageCountThreshold
     self.filterExpression = filterExpression
+    self.enableEventEngine = enableEventEngine
   }
 
   // swiftlint:disable:next line_length
@@ -220,6 +222,8 @@ public struct PubNubConfiguration: Hashable {
   public var useInstanceId: Bool
   /// Whether a request identifier should be included on outgoing requests
   public var useRequestId: Bool
+  /// A flag describing whether to enable the new strategy for handling subscription loop
+  public var enableEventEngine: Bool = false
   /// Reconnection policy which will be used if/when a request fails
   public var automaticRetry: AutomaticRetry?
   /// URLSessionConfiguration used for URLSession network events

Sources/PubNub/Subscription/ConnectionStatus.swift

@@ -34,20 +34,16 @@ public enum ConnectionStatus: Equatable {
   /// Explicit disconnect from a remote system
   case disconnected
   /// Unexpected disconnect from a remote system
-  case disconnectedUnexpectedly(PubNubError)
+  case disconnectedUnexpectedly
   /// Unable to establish initial connection
-  case connectionError(PubNubError)
+  case connectionError
 
   /// If the connection is connected or attempting to connect
   public var isActive: Bool {
     switch self {
     case .connected:
       return true
-    case .disconnected:
-      return false
-    case .connectionError(_):
-      return false
-    case .disconnectedUnexpectedly(_):
+    default:
       return false
     }
   }
@@ -60,4 +56,19 @@ public enum ConnectionStatus: Equatable {
       return false
     }
   }
+
+  func canTransition(to state: ConnectionStatus) -> Bool {
+    switch (self, state) {
+    case (.connected, .disconnected):
+      return true
+    case (.disconnected, .connected):
+      return true
+    case (.connected, .disconnectedUnexpectedly):
+      return true
+    case (.disconnected, .connectionError):
+      return true
+    default:
+      return false
+    }
+  }
 }