Updated spec for connection resume/recover

textile/features.textile

@@ -505,13 +505,14 @@ h3(#realtime-connection). Connection
 ** @(RTN15g)@ Connection state is only maintained server-side for a brief period, given by the @connectionStateTtl@ in the @connectionDetails@, see "CD2f":#CD2f. If a client has been disconnected for longer than the @connectionStateTtl@, it should not attempt to resume. Instead, it should clear the local connection state, and any connection attempts should be made as for a fresh connection
 *** @(RTN15g1)@ This check should be made before each connection attempt. It is generally not sufficient to merely clear the connection state when moving to @SUSPENDED@ state (though that may be done too), since the device may have been sleeping / suspended, in which case it may have been many hours since it was last actually connected, even though, having been in the @CONNECTED@ state when it was put to sleep, it has only moved out of that state very recently (after waking up and noticing it's no longer connected)
 *** @(RTN15g2)@ Another consequence of that is that the measure of whether the client been disconnected for too long (for the purpose of this check) cannot just be whether the client left the @CONNECTED@ state more than @connectionStateTtl@ ago. Instead, it should be whether the difference between the current time and the last activity time is greater than the sum of the @connectionStateTtl@ and the @maxIdleInterval@, where the last activity time is the time of the last known actual sign of activity from Ably per "RTN23a":#RTN23a
-*** @(RTN15g3)@ When a connection attempt succeeds after the connection state has been cleared in this way, channels that were previously @ATTACHED@, @ATTACHING@, or @SUSPENDED@ must be automatically reattached, just as if the connection was a resume attempt which failed per "RTN15c7":#RTN15c7
+*** @(RTN15g3)@ When a connection attempt succeeds after the connection state has been cleared in this way, channels that were previously @ATTACHED@, @ATTACHING@, or @SUSPENDED@ must be automatically reattached, just as if the connection was a resume attempt which failed per "RTN15c8":#RTN15c8
 ** @(RTN15b)@ In order for a connection to be resumed and connection state to be recovered, the client must have received a @CONNECTED@ ProtocolMessage which will include a private connection key. To resume that connection, the library reconnects to the "websocket":https://ably.com/topic/websockets endpoint with an additional querystring param:
 *** @(RTN15b1)@ @resume@ is the @ProtocolMessage#connectionKey@ from the most recent @CONNECTED@ @ProtocolMessage@ received
 *** @(RTN15b2)@ This clause has been deleted. It was valid up to and including specification version @1.2@.
-** @(RTN15c)@ The system's response to a resume request will be one of the following:
-**** @(RTN15c6)@ A @CONNECTED@ @ProtocolMessage@ with the same @connectionId@ as the current client (and no @error@ property). This indicates that the resume attempt was valid. The client library should move all channels that were in the @ATTACHING@, @ATTACHED@, or @SUSPENDED@ states to the @ATTACHING@ state, and initiate an @RTL4c@ attach sequence for each. The connection should also process any messages queued per @RTL6c2@ (there is no need to wait for the attaches to finish before processing queued messages).
-**** @(RTN15c7)@ @CONNECTED@ @ProtocolMessage@ with a new @connectionId@ and an @ErrorInfo@ in the @error@ field. In this case, the resume was invalid, and the error indicates the cause. The @error@ should be set as the @reason@ in the @CONNECTED@ event, and as the @Connection#errorReason@. The internal @msgSerial@ counter should be reset so that the first message published to Ably will contain a @msgSerial@ of @0@. The rest of the process is the same as for @RTN16c6@: The client library should move all channels that were in the @ATTACHING@, @ATTACHED@, or @SUSPENDED@ states to the @ATTACHING@ state, and initiate an @RTL4c@ attach sequence for each. The connection should also process any messages queued per @RTL6c2@.
+** @(RTN15c)@ The system's response to a resume request (with a non-empty connectionKey) will be one of the following:
+**** @(RTN15c6)@ A @CONNECTED@ @ProtocolMessage@ with the same @connectionId@ as the current client (and no @error@ property). This indicates that the resume attempt was valid.
+**** @(RTN15c7)@ @CONNECTED@ @ProtocolMessage@ with a new @connectionId@ and an @ErrorInfo@ in the @error@ field. In this case, the resume was invalid, and the error indicates the cause. The @error@ should be set as the @reason@ in the @CONNECTED@ event, and as the @Connection#errorReason@. The internal @msgSerial@ counter should be reset so that the first message published to Ably will contain a @msgSerial@ of @0@.
+**** @(RTN15c8)@ Irrespective of success/failure for a resume request, the client library should move all channels that were in the @ATTACHING@, @ATTACHED@, or @SUSPENDED@ states to the @ATTACHING@ state, and initiate an @RTL4c@ attach sequence for each. The connection should also process any messages queued per @RTL6c2@ (there is no need to wait for the attaches to finish before processing queued messages).
 **** @(RTN15c5)@ @ERROR@ @ProtocolMessage@ indicating a failure to authenticate as a result of a token error (see "RTN15h":#RTN15h). The transport will be closed by the server. The spec described in "RTN15h":#RTN15h must be followed for a connection being resumed with a token error
 **** @(RTN15c4)@ Any other @ERROR@ @ProtocolMessage@ indicating a fatal error in the connection. The server will close the transport immediately after. The client should transition to the @FAILED@ state triggering all attached channels to transition to the @FAILED@ state as well. Additionally the @Connection#errorReason@ will be set should be set with the error received from Ably
 **** @(RTN15c1)@ This clause has been replaced by "@RTN15c6@":#RTN15c6. It was valid up to and including specification version @1.2@.
@@ -535,7 +536,7 @@ h3(#realtime-connection). Connection
 ** @(RTN16d)@ The library may wish to test that after a connection has been successfully recovered, the @Connection#id@ should be identical to the @id@ of the connection that was recovered, and @Connection#key@ should have been updated to the @ConnectionDetails#connectionKey@ provided in the @CONNECTED@ @ProtocolMessage@.
 ** @(RTN16m)@ @Connection#recoveryKey@ is a deprecated property that, when read, contains the same value that would be returned by calling @Connection#createRecoveryKey@. If the implementation languague allows, it should be implemented in a way that does not require that it be recalculated on every message. If this is not possible, it should be recalculated on every incoming message.
 *** @(RTN16m1)@ @Connection#recoveryKey@ must be removed on the next major release of the SDK.
-** @(RTN16l)@ Recovery failures should be handled identically to resume failures, per "RTN15c7":#RTN15c7, "RTN15c5":#RTN15c5, and "RTN15c4":#RTN15c4.
+** @(RTN16l)@ Recovery success/failures should be handled identically to resume, per "RTN15c8":#RTN15c8, "RTN15c5":#RTN15c5, and "RTN15c4":#RTN15c4.
 ** @(RTN16a)@ This clause has been replaced by "@RTN16i@":#RTN16i. It was valid up to and including specification version @1.2@.
 ** @(RTN16b)@ This clause has been replaced by "@RTN16g@":#RTN16g and "@RTN16m@":#RTN16m. It was valid up to and including specification version @1.2@.
 ** @(RTN16c)@ This clause has been replaced by "@RTN16g2@":#RTN16g2. It was valid up to and including specification version @1.2@.
@@ -554,7 +555,7 @@ h3(#realtime-connection). Connection
 * @(RTN19)@ Transport state side effects - when a transport is disconnected for any reason:
 ** @(RTN19a)@ Any @ProtocolMessage@ that is awaiting an @ACK@/@NACK@ on the old transport will not receive the @ACK@/@NACK@ on the new transport. The client library must therefore resend any @ProtocolMessage@ that is awaiting a @ACK@/@NACK@ to Ably in order to receive the expected @ACK@/@NACK@ for that message (subject to @RTN7c@/@RTN7d@). The Ably service is responsible for keeping track of messages, ignoring duplicates and responding with suitable @ACK@/@NACK@ messages
 *** @(RTN19a1)@ One possible implementation of this requirement would be to add any in-flight messages to the @RTL6c2@ connection-wide queue of messages that will be sent once the connection next becomes @CONNECTED@
-*** @(RTN19a2)@ In the case of an @RTN15c6@ successful resume, the @msgSerial@ of the reattempted @ProtocolMessage@s should remain the same as for the original attempt. In the case of an @RTN15c7@ failed resume, the message must be assigned a new @msgSerial@ from the SDK's internal counter.
+*** @(RTN19a2)@ In the case of an @RTN15c6@ successful resume, the @msgSerial@ of the reattempted @ProtocolMessage@s should remain the same as for the original attempt. In the case of an @RTN15c7@ failed resume, the message must be assigned a new @msgSerial@ from the SDK's internal counter ( need clarification).
 ** @(RTN19b)@ If there are any pending channels i.e. in the @ATTACHING@ or @DETACHING@ state, the respective @ATTACH@ or @DETACH@ message should be resent to Ably
 * @(RTN23)@ Heartbeats
 ** @(RTN23a)@ If a transport does not receive any indication of activity on a transport for a period greater than the sum of the @maxIdleInterval@ (which will be sent in the @connectionDetails@ of the most recent @CONNECTED@ message received on that transport) and the @realtimeRequestTimeout@, that transport should be disconnected. Any message (or non-message indicator, see @RTN23b@) received counts as an indication of activity and should reset the timer, not merely heartbeat messages. However, it must be received (that is, sent from the server to the client); client-sent data does not count.