Beta task resuming

main.go

@@ -8,6 +8,7 @@ import (
 	"github.com/spf13/viper"
 	"github.com/terorie/od-database-crawler/fasturl"
 	"os"
+	"os/signal"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -61,8 +62,6 @@ func preRun(cmd *cobra.Command, args []string) error {
 	if err := os.MkdirAll("queue", 0755);
 		err != nil { panic(err) }
 
-	readConfig()
-
 	return nil
 }
 
@@ -75,25 +74,32 @@ func main() {
 }
 
 func cmdBase(_ *cobra.Command, _ []string) {
-	// TODO Graceful shutdown
-	appCtx := context.Background()
-	forceCtx := context.Background()
+	onlineMode = true
+	readConfig()
+
+	appCtx, soft := context.WithCancel(context.Background())
+	forceCtx, hard := context.WithCancel(context.Background())
+	go hardShutdown(forceCtx)
+	go listenCtrlC(soft, hard)
 
 	inRemotes := make(chan *OD)
-	go Schedule(forceCtx, inRemotes)
+	go LoadResumeTasks(inRemotes)
+	go Schedule(appCtx, inRemotes)
 
 	ticker := time.NewTicker(config.Recheck)
 	defer ticker.Stop()
 	for {
 		select {
 		case <-appCtx.Done():
-			return
+			goto shutdown
 		case <-ticker.C:
 			t, err := FetchTask()
 			if err != nil {
 				logrus.WithError(err).
 					Error("Failed to get new task")
-				time.Sleep(viper.GetDuration(ConfCooldown))
+				if !sleep(viper.GetDuration(ConfCooldown), appCtx) {
+					goto shutdown
+				}
 				continue
 			}
 			if t == nil {
@@ -126,9 +132,15 @@ func cmdBase(_ *cobra.Command, _ []string) {
 			ScheduleTask(inRemotes, t, &baseUri)
 		}
 	}
+
+	shutdown:
+	globalWait.Wait()
 }
 
 func cmdCrawler(_ *cobra.Command, args []string) error {
+	onlineMode = false
+	readConfig()
+
 	arg := args[0]
 	// https://github.com/golang/go/issues/19779
 	if !strings.Contains(arg, "://") {
@@ -161,3 +173,30 @@ func cmdCrawler(_ *cobra.Command, args []string) error {
 
 	return nil
 }
+
+func listenCtrlC(soft, hard context.CancelFunc) {
+	c := make(chan os.Signal)
+	signal.Notify(c, os.Interrupt)
+
+	<-c
+	logrus.Info(">>> Shutting down crawler... <<<")
+	soft()
+
+	<-c
+	logrus.Warning(">>> Force shutdown! <<<")
+	hard()
+}
+
+func hardShutdown(c context.Context) {
+	<-c.Done()
+	os.Exit(1)
+}
+
+func sleep(d time.Duration, c context.Context) bool {
+	select {
+	case <-time.After(d):
+		return true
+	case <-c.Done():
+		return false
+	}
+}