lib, gapi: Next method of GAPI should generate first event

This puts the generation of the initial event into the Next method of
the GAPI. If it does not happen, then we will never get a graph. This is
important because this notifies the GAPI when we're actually ready to
try and generate a graph, rather than blocking on the Graph method if we
have a long compile for example.

This is also required for the etcd watch cleanup.

lib/main.go

@@ -65,7 +65,10 @@ type Main struct {
 	GAPI    gapi.GAPI // graph API interface struct
 	Remotes []string  // list of remote graph definitions to run
 
-	NoWatch          bool   // do not update graph on watched graph definition file changes
+	NoWatch       bool // do not change graph under any circumstances
+	NoConfigWatch bool // do not update graph due to config changes
+	NoStreamWatch bool // do not update graph due to stream changes
+
 	Noop             bool   // globally force all resources into no-op mode
 	Sema             int    // add a semaphore with this lock count to each resource
 	Graphviz         string // output file for graphviz data
@@ -112,6 +115,15 @@ func (obj *Main) Init() error {
 		return fmt.Errorf("choosing a prefix and the request for a tmp prefix is illogical")
 	}
 
+	// if we've turned off watching, then be explicit and disable them all!
+	// if all the watches are disabled, then it's equivalent to no watching
+	if obj.NoWatch {
+		obj.NoConfigWatch = true
+		obj.NoStreamWatch = true
+	} else if obj.NoConfigWatch && obj.NoStreamWatch {
+		obj.NoWatch = true
+	}
+
 	obj.idealClusterSize = uint16(obj.IdealClusterSize)
 	if obj.IdealClusterSize < 0 { // value is undefined, set to the default
 		obj.idealClusterSize = etcd.DefaultIdealClusterSize
@@ -361,11 +373,14 @@ func (obj *Main) Run() error {
 			Hostname: hostname,
 			World:    world,
 			Noop:     obj.Noop,
-			NoWatch:  obj.NoWatch,
+			//NoWatch:  obj.NoWatch,
+			NoConfigWatch: obj.NoConfigWatch,
+			NoStreamWatch: obj.NoStreamWatch,
 		}
 		if err := obj.GAPI.Init(data); err != nil {
 			obj.Exit(fmt.Errorf("Main: GAPI: Init failed: %v", err))
-		} else if !obj.NoWatch {
+		} else {
+			// this must generate at least one event for it to work
 			gapiChan = obj.GAPI.Next() // stream of graph switch events!
 		}
 	}
@@ -396,10 +411,6 @@ func (obj *Main) Run() error {
 					//obj.Exit(err) // trigger exit
 					continue // wait for exitchan or another event
 				}
-				if obj.NoWatch { // extra safety for bad GAPI's
-					log.Printf("Main: GAPI stream should be quiet with NoWatch!") // fix the GAPI!
-					continue                                                      // no stream events should be sent
-				}
 				// everything else passes through to cause a compile!
 
 			case <-exitchan:
@@ -509,7 +520,7 @@ func (obj *Main) Run() error {
 	configWatcher := recwatch.NewConfigWatcher()
 	configWatcher.Flags = recwatch.Flags{Debug: obj.Flags.Debug}
 	events := configWatcher.Events()
-	if !obj.NoWatch {
+	if !obj.NoWatch { // FIXME: fit this into a clean GAPI?
 		configWatcher.Add(obj.Remotes...) // add all the files...
 	} else {
 		events = nil // signal that no-watch is true