Merged in revid-start-stop-errors (pull request #114)

Return errors from revid.Start and revid.Stop

Approved-by: kortschak <dan@kortschak.io>

cmd/revid-cli/main.go

@@ -75,10 +75,13 @@ func main() {
 		// run revid for the specified duration
 		rv, _, err := startRevid(nil, cfg)
 		if err != nil {
-			cfg.Logger.Log(logger.Fatal, pkg+"failed to start revid", err.Error())
+			cfg.Logger.Log(logger.Fatal, pkg+"failed to start revid", "error", err.Error())
 		}
 		time.Sleep(*runDurationPtr)
-		stopRevid(rv)
+		err = stopRevid(rv)
+		if err != nil {
+			cfg.Logger.Log(logger.Error, pkg+"failed to stop revid before program termination", "error", err.Error())
+		}
 		return
 	}
 
@@ -296,7 +299,11 @@ func run(rv *revid.Revid, cfg revid.Config) error {
 			if vars["mode"] == "Paused" {
 				if !paused {
 					log.Log(logger.Info, pkg+"pausing revid")
-					stopRevid(rv)
+					err = stopRevid(rv)
+					if err != nil {
+						log.Log(logger.Error, pkg+"failed to stop revide", "error", err.Error())
+						continue
+					}
 					paused = true
 				}
 			} else {
@@ -343,21 +350,28 @@ func startRevid(ns *netsender.Sender, cfg revid.Config) (*revid.Revid, revid.Con
 	if err != nil {
 		return nil, cfg, err
 	}
-	rv.Start()
-	return rv, cfg, nil
+	err = rv.Start()
+	return rv, cfg, err
 }
 
-func stopRevid(rv *revid.Revid) {
-	rv.Stop()
+func stopRevid(rv *revid.Revid) error {
+	err := rv.Stop()
+	if err != nil {
+		return err
+	}
 
 	// FIXME(kortschak): Is this waiting on completion of work?
 	// Use a wait group and Wait method if it is.
 	time.Sleep(revidStopTime)
+	return nil
 }
 
 func updateRevid(ns *netsender.Sender, rv *revid.Revid, cfg revid.Config, vars map[string]string, stop bool) (*revid.Revid, revid.Config, error) {
 	if stop {
-		stopRevid(rv)
+		err := stopRevid(rv)
+		if err != nil {
+			return nil, cfg, err
+		}
 	}
 
 	//look through the vars and update revid where needed

revid/revid.go

@@ -286,10 +286,9 @@ func (r *Revid) IsRunning() bool {
 
 // Start invokes a Revid to start processing video from a defined input
 // and packetising (if theres packetization) to a defined output.
-func (r *Revid) Start() {
+func (r *Revid) Start() error {
 	if r.isRunning {
-		r.config.Logger.Log(logger.Warning, pkg+"revid.Start() called but revid already running")
-		return
+		return errors.New(pkg + "start called but revid is already running")
 	}
 	r.config.Logger.Log(logger.Info, pkg+"starting Revid")
 	r.config.Logger.Log(logger.Debug, pkg+"setting up output")
@@ -297,14 +296,14 @@ func (r *Revid) Start() {
 	r.config.Logger.Log(logger.Info, pkg+"starting output routine")
 	go r.outputClips()
 	r.config.Logger.Log(logger.Info, pkg+"setting up input and receiving content")
-	go r.setupInput()
+	err := r.setupInput()
+	return err
 }
 
 // Stop halts any processing of video data from a camera or file
-func (r *Revid) Stop() {
+func (r *Revid) Stop() error {
 	if !r.isRunning {
-		r.config.Logger.Log(logger.Warning, pkg+"revid.Stop() called but revid not running")
-		return
+		return errors.New(pkg + "stop called but revid is already stopped")
 	}
 
 	r.config.Logger.Log(logger.Info, pkg+"stopping revid")
@@ -315,6 +314,7 @@ func (r *Revid) Stop() {
 	if r.cmd != nil && r.cmd.Process != nil {
 		r.cmd.Process.Kill()
 	}
+	return nil
 }
 
 // outputClips takes the clips produced in the packClips method and outputs them