server progress events: report stable sync mode

In a client, PEV_ALERTED was reported to the app with the final sync
mode. On the server, that was missing, partly because the
determination of the final sync mode has to be delayed a bit.

This patch moves the progress event into the one place that is called
in all cases: TLocalEngineDS::changeState() for aNewState ==
dssta_syncmodestable. There it is executed for client and server.

2 files changed, 37 insertions, 11 deletions

diff --git a/src/sysync/localengineds.cpp b/src/sysync/localengineds.cpp
index bb4ecfe..b8289c6 100644
--- a/src/sysync/localengineds.cpp
+++ b/src/sysync/localengineds.cpp
@@ -2730,16 +2730,6 @@ TAlertCommand *TLocalEngineDS::engProcessSyncAlert(
           fSlowSync ? "slow" : "normal",
           fFirstTimeSync ? " first time" : ""
         ));
-        #ifdef PROGRESS_EVENTS
-        // - progress event
-        DB_PROGRESS_EVENT(
-          this,
-          pev_alerted,
-          fSlowSync ? (fFirstTimeSync ? 2 : 1) : 0,
-          fResuming ? 1 : 0,
-          fSyncMode
-        );
-        #endif // PROGRESS_EVENTS
       } // client Case
       #endif // SYSYNC_CLIENT
     }
@@ -4189,6 +4179,32 @@ localstatus TLocalEngineDS::changeState(TLocalEngineDSState aNewState, bool aFor
   if (!aForceOnError && err1) goto endchange;
   // switch state
   fLocalDSState = aNewState;
+
+  if (aNewState == dssta_syncmodestable) {
+    // There are multiple places where the sync mode is frozen.  Ensure
+    // that this change is reported in all of them by putting the code
+    // here.
+    PDEBUGPRINTFX(DBG_HOT,(
+                         "executing %s%s%s Sync%s",
+                         fResuming ? "resumed " : "",
+                         fSlowSync ? "slow" : "normal",
+                         fFirstTimeSync ? " first time" : "",
+                         fSyncMode == smo_twoway ? ", two-way" :
+                         fSyncMode == smo_fromclient ? " from client" :
+                         fSyncMode == smo_fromserver ? " from server" :
+                         " in unknown direction?!"
+                           ));
+#ifdef PROGRESS_EVENTS
+    // progress event
+    DB_PROGRESS_EVENT(this,
+                      pev_alerted,
+                      fSlowSync ? (fFirstTimeSync ? 2 : 1) : 0,
+                      fResuming ? 1 : 0,
+                      fSyncMode
+                      );
+#endif // PROGRESS_EVENTS
+  }
+
   // now give logic opportunity to react again
   err2 = dsAfterStateChange(oldState,aNewState);
 endchange:
diff --git a/src/sysync_SDK/Sources/engine_defs.h b/src/sysync_SDK/Sources/engine_defs.h
index 3b0246b..5dabfb0 100644
--- a/src/sysync_SDK/Sources/engine_defs.h
+++ b/src/sysync_SDK/Sources/engine_defs.h
@@ -367,7 +367,17 @@ enum TProgressEventEnum {
   /** deleting (zapping datastore), extra1=progress, extra2=total */
   PEV_DELETING = 18,
   /** datastore alerted (extra1=0 for normal, 1 for slow, 2 for first time slow,
-      extra2=1 for resumed session, extra3=syncmode: 0=twoway, 1=fromserver, 2=fromclient) */
+      extra2=1 for resumed session, extra3=syncmode: 0=twoway, 1=fromserver, 2=fromclient)
+      
+      This used to be reported only in client mode, directly after receiving and checking
+      the ALERT command from the server. Now this event is also reported in server mode
+      at that point in time where the final sync mode is known (in other words, after
+      the client acknowledged the alerted sync mode).
+
+      Note that a server cannot reliably distinguish between "refresh-from-server" and
+      "slow" sync. A client might delete all its data and then do a "slow" sync - the
+      Synthesis engine itself does that.
+  */
   PEV_ALERTED = 19,
   /** sync started */
   PEV_SYNCSTART = 20,