Setup periodic scan background runner

api/graphql/resolvers/scanner.go

@@ -2,6 +2,7 @@ package resolvers
 
 import (
 	"context"
+	"time"
 
 	"github.com/pkg/errors"
 	"github.com/viktorstrate/photoview/api/graphql/models"
@@ -57,5 +58,7 @@ func (r *mutationResolver) SetPeriodicScanInterval(ctx context.Context, interval
 		return 0, err
 	}
 
+	scanner.ChangePeriodicScanInterval(time.Duration(dbInterval) * time.Second)
+
 	return dbInterval, nil
 }

api/scanner/periodic_scanner.go

@@ -0,0 +1,90 @@
+package scanner
+
+import (
+	"database/sql"
+	"log"
+	"sync"
+	"time"
+)
+
+type periodicScanner struct {
+	ticker         *time.Ticker
+	ticker_changed chan bool
+	mutex          *sync.Mutex
+	db             *sql.DB
+}
+
+var mainPeriodicScanner *periodicScanner = nil
+
+func getPeriodicScanInterval(db *sql.DB) (time.Duration, error) {
+	row := db.QueryRow("SELECT periodic_scan_interval FROM site_info")
+	var intervalSeconds int
+
+	if err := row.Scan(&intervalSeconds); err != nil {
+		return 0, err
+	}
+
+	return time.Duration(intervalSeconds) * time.Second, nil
+}
+
+func InitializePeriodicScanner(db *sql.DB) error {
+	if mainPeriodicScanner != nil {
+		panic("periodic scanner has already been initialized")
+	}
+
+	scanInterval, err := getPeriodicScanInterval(db)
+	if err != nil {
+		return err
+	}
+
+	mainPeriodicScanner = &periodicScanner{
+		db:             db,
+		ticker_changed: make(chan bool),
+		mutex:          &sync.Mutex{},
+	}
+
+	go scanIntervalRunner()
+
+	ChangePeriodicScanInterval(scanInterval)
+	return nil
+}
+
+func ChangePeriodicScanInterval(duration time.Duration) {
+	var new_ticker *time.Ticker = nil
+	if duration > 0 {
+		new_ticker = time.NewTicker(duration)
+		log.Printf("Periodic scan interval changed: %s", duration.String())
+	} else {
+		log.Print("Periodic scan interval changed: disabled")
+	}
+
+	{
+		mainPeriodicScanner.mutex.Lock()
+		defer mainPeriodicScanner.mutex.Unlock()
+
+		if mainPeriodicScanner.ticker != nil {
+			mainPeriodicScanner.ticker.Stop()
+		}
+
+		mainPeriodicScanner.ticker = new_ticker
+		mainPeriodicScanner.ticker_changed <- true
+	}
+}
+
+func scanIntervalRunner() {
+	for {
+		log.Print("Scan interval runner: Waiting for signal")
+		if mainPeriodicScanner.ticker != nil {
+			select {
+			case <-mainPeriodicScanner.ticker_changed:
+				log.Print("Scan interval runner: New ticker detected")
+			case <-mainPeriodicScanner.ticker.C:
+				log.Print("Scan interval runner: Starting periodic scan")
+				AddAllToQueue()
+			}
+		} else {
+			<-mainPeriodicScanner.ticker_changed
+			log.Print("Scan interval runner: New ticker detected")
+		}
+	}
+}

api/server.go

@@ -42,6 +42,7 @@ func main() {
 	}
 
 	scanner.InitializeScannerQueue(db)
+	scanner.InitializePeriodicScanner(db)
 
 	rootRouter := mux.NewRouter()
 

ui/src/Pages/SettingsPage/ScannerSection.js

@@ -75,7 +75,10 @@ const convertToAppropriateUnit = ({ value, unit }) => {
 
   let resultingUnit = timeUnits.first
   for (const unit of timeUnits) {
-    if (seconds / unit.multiplier >= 1) {
+    if (
+      seconds / unit.multiplier >= 1 &&
+      (seconds / unit.multiplier) % 1 == 0
+    ) {
       resultingUnit = unit
     } else {
       break