Backend: Add mutex for location updates

Signed-off-by: Michael Mayer <michael@liquidbytes.net>

internal/entity/location.go

@@ -2,6 +2,7 @@ package entity
 
 import (
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/jinzhu/gorm"
@@ -10,6 +11,8 @@ import (
 	"github.com/photoprism/photoprism/internal/util"
 )
 
+var locationMutex = sync.Mutex{}
+
 // Photo location
 type Location struct {
 	ID          string `gorm:"type:varbinary(16);primary_key;auto_increment:false;"`
@@ -23,6 +26,16 @@ type Location struct {
 	UpdatedAt   time.Time
 }
 
+// Locks locations for updates
+func (Location) Lock() {
+	locationMutex.Lock()
+}
+
+// Unlock locations for updates
+func (Location) Unlock() {
+	locationMutex.Unlock()
+}
+
 func NewLocation(lat, lng float64) *Location {
 	result := &Location{}
 

internal/photoprism/index_mediafile.go

@@ -365,6 +365,9 @@ func (ind *Index) indexLocation(mediaFile *MediaFile, photo *entity.Photo, label
 	var keywords []string
 
 	if location, err := mediaFile.Location(); err == nil {
+		location.Lock()
+		defer location.Unlock()
+
 		err := location.Find(ind.db)
 
 		if err != nil {