engine: cleaned up around fRemoteMustSeeDevinf and mustSendDevInf()

The patch by Yong Wu revealed that the mechanism needed some
cleanup and better comments.

- mustSendDevinf() was *intended* for derived classes to force
  devInf sending originally (code from around 2001). However,
  it was not virtual so was pretty useless (and never used).
- fRemoteMustSeeDevinf was doing the same more or less
  independently.

Now both are unified. mustSendDevinf() is now the accessor
that must be called to check if devInf must be sent.

4 files changed, 12 insertions, 5 deletions

diff --git a/src/sysync/stdlogicds.cpp b/src/sysync/stdlogicds.cpp
index 8d43914..cbfafe2 100755
--- a/src/sysync/stdlogicds.cpp
+++ b/src/sysync/stdlogicds.cpp
@@ -125,7 +125,7 @@ localstatus TStdLogicDS::logicMakeAdminReady(cAppCharP aDataStoreURI, cAppCharP
     // - create this session's local anchor string from timestamp
     TimestampToISO8601Str(fNextLocalAnchor,fCurrentSyncTime,TCTX_UTC,false,false);
     // - check if config has changed since last sync
-    if (fSessionP->mustSendDevInf() || fFirstTimeSync || fPreviousSyncTime<=fSessionP->getRootConfig()->fConfigDate) {
+    if (fFirstTimeSync || fPreviousSyncTime<=fSessionP->getRootConfig()->fConfigDate) {
       // remote should see our (probably changed) devInf
       PDEBUGPRINTFX(DBG_PROTO,("First time sync or config changed since last sync -> remote should see our devinf"));
       fSessionP->remoteMustSeeDevinf();
diff --git a/src/sysync/syncclient.cpp b/src/sysync/syncclient.cpp
index 165277b..e581f33 100755
--- a/src/sysync/syncclient.cpp
+++ b/src/sysync/syncclient.cpp
@@ -905,8 +905,15 @@ localstatus TSyncClient::NextMessage(bool &aDone)
       if (localDS->fFirstTimeSync) anyfirstsyncs=true;
       if (localDS->fSlowSync) anyslowsyncs=true;
     }
-    // create Put command if any datastore is doing first time sync / slow sync or devinf Put is externally requested
-    if (fRemoteMustSeeDevinf || mustSendDevInf() || anyfirstsyncs || (anyslowsyncs && static_cast<TClientConfig *>(getRootConfig()->fAgentConfigP)->fPutDevInfAtSlowSync)) {
+    // send devinf in Put command right away with init message if either...
+    // - mustSendDevInf() returns true signalling an external condition that suggests sending devInf (like changed config)
+    // - any datastore is doing first time sync
+    // - fPutDevInfAtSlowSync is true and any datastore is doing slow sync
+    if (
+    	mustSendDevInf() ||
+      anyfirstsyncs ||
+      (anyslowsyncs && static_cast<TClientConfig *>(getRootConfig()->fAgentConfigP)->fPutDevInfAtSlowSync)
+    ) {
       TDevInfPutCommand *putcmdP = new TDevInfPutCommand(this);
       issueRootPtr(putcmdP);
     }
diff --git a/src/sysync/syncsession.cpp b/src/sysync/syncsession.cpp
index bb350a9..9d56efa 100644
--- a/src/sysync/syncsession.cpp
+++ b/src/sysync/syncsession.cpp
@@ -5098,7 +5098,7 @@ Ret_t TSyncSession::EndMessage(Boolean_t final)
   // Note: do it here because we have processed all commands (alerts) now but
   //       server response alerts are still in the fEndOfMessageCommands queue.
   //       This ensures that clients gets PUT before it gets ALERTs.
-  if (!fRemoteGotDevinf && fRemoteMustSeeDevinf) {
+  if (!fRemoteGotDevinf && mustSendDevInf()) {
     // remote has not got devinf and should see it
     if (!getRootConfig()->fNeverPutDevinf) {
       // PUT devinf now
diff --git a/src/sysync/syncsession.h b/src/sysync/syncsession.h
index a04399a..a1761af 100755
--- a/src/sysync/syncsession.h
+++ b/src/sysync/syncsession.h
@@ -505,7 +505,7 @@ public:
     TLocalEngineDS *aForDatastoreP
   );
   // access to session info from commands
-  bool mustSendDevInf(void) { return false; }; // can be overridden to force devinf sending (e.g if list of synced fields has changed since last sync)
+  bool mustSendDevInf(void) { return fRemoteMustSeeDevinf; };
   // - access DevInf (session owned)
   SmlItemPtr_t getLocalDevInfItem(bool aAlertedOnly, bool aWithoutCTCapProps);
   // - analyze devinf of remote party (can be derived to add client or server specific analysis)