Use lastPoll time as cutoff on subsequent polls

cmd/scheduled-feed/main.go

@@ -22,10 +22,12 @@ type FeedHandler struct {
 	scheduler *scheduler.Scheduler
 	pub       publisher.Publisher
 	delta     time.Duration
+	lastPoll  time.Time
 }
 
 func (handler *FeedHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	cutoff := time.Now().UTC().Add(-handler.delta)
+	cutoff := handler.getCutoff()
+	handler.lastPoll = time.Now().UTC()
 	pkgs, errs := handler.scheduler.Poll(cutoff)
 	if len(errs) > 0 {
 		for _, err := range errs {
@@ -59,6 +61,16 @@ func (handler *FeedHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte(fmt.Sprintf("%d packages processed", processed)))
 }
 
+func (handler FeedHandler) getCutoff() time.Time {
+	var cutoff time.Time
+	if handler.lastPoll.IsZero() {
+		cutoff = time.Now().UTC().Add(-handler.delta)
+	} else {
+		cutoff = handler.lastPoll
+	}
+	return cutoff
+}
+
 func main() {
 	configPath, useConfig := os.LookupEnv("PACKAGE_FEEDS_CONFIG_PATH")
 	var err error