From 0e492a053ca6ddcf8d6f9f6111e5c954d6c9e577 Mon Sep 17 00:00:00 2001
From: Deluan <github@deluan.com>
Date: Sun, 6 Mar 2016 21:32:31 -0500
Subject: [PATCH] Only read tag when the track was changed

---
 scanner/importer.go       | 17 ++++++++++++++---
 scanner/itunes_scanner.go | 19 ++++++++++++++-----
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/scanner/importer.go b/scanner/importer.go
index 91ffbbd17..99067d77f 100644
--- a/scanner/importer.go
+++ b/scanner/importer.go
@@ -7,12 +7,13 @@ import (
 	"github.com/deluan/gosonic/domain"
 	"github.com/deluan/gosonic/persistence"
 	"github.com/deluan/gosonic/utils"
+	"strconv"
 	"strings"
 	"time"
 )
 
 type Scanner interface {
-	ScanLibrary(path string) (int, error)
+	ScanLibrary(lastModifiedSince time.Time, path string) (int, error)
 	MediaFiles() map[string]*domain.MediaFile
 	Albums() map[string]*domain.Album
 	Artists() map[string]*domain.Artist
@@ -47,7 +48,7 @@ type Importer struct {
 }
 
 func (i *Importer) Run() {
-	if total, err := i.scanner.ScanLibrary(i.mediaFolder); err != nil {
+	if total, err := i.scanner.ScanLibrary(i.lastModifiedSince(), i.mediaFolder); err != nil {
 		beego.Error("Error importing iTunes Library:", err)
 		return
 	} else {
@@ -62,6 +63,16 @@ func (i *Importer) Run() {
 	beego.Info("Finished importing tracks from iTunes Library")
 }
 
+func (i *Importer) lastModifiedSince() time.Time {
+	ms, err := i.propertyRepo.Get(consts.LastScan)
+	if err != nil {
+		beego.Warn("Couldn't read LastScan:", err)
+		return time.Time{}
+	}
+	s, _ := strconv.ParseInt(ms, 10, 64)
+	return time.Unix(0, s*int64(time.Millisecond))
+}
+
 func (i *Importer) importLibrary() (err error) {
 	indexGroups := utils.ParseIndexGroups(beego.AppConfig.String("indexGroups"))
 	artistIndex := make(map[string]tempIndex)
@@ -97,7 +108,7 @@ func (i *Importer) importLibrary() (err error) {
 	beego.Info("Total MediaFiles in database:", c)
 
 	if err == nil {
-		millis := time.Now().UnixNano() / 1000000
+		millis := time.Now().UnixNano() / int64(time.Millisecond)
 		i.propertyRepo.Put(consts.LastScan, fmt.Sprint(millis))
 		beego.Info("LastScan timestamp:", millis)
 	}
diff --git a/scanner/itunes_scanner.go b/scanner/itunes_scanner.go
index 7aebf03ee..2da9c87af 100644
--- a/scanner/itunes_scanner.go
+++ b/scanner/itunes_scanner.go
@@ -12,16 +12,19 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type ItunesScanner struct {
-	mediaFiles map[string]*domain.MediaFile
-	albums     map[string]*domain.Album
-	artists    map[string]*domain.Artist
+	mediaFiles        map[string]*domain.MediaFile
+	albums            map[string]*domain.Album
+	artists           map[string]*domain.Artist
+	lastModifiedSince time.Time
 }
 
-func (s *ItunesScanner) ScanLibrary(path string) (int, error) {
+func (s *ItunesScanner) ScanLibrary(lastModifiedSince time.Time, path string) (int, error) {
 	beego.Info("Starting iTunes import from:", path)
+	beego.Info("Checking for updates since", lastModifiedSince.String())
 	xml, _ := os.Open(path)
 	l, err := itl.ReadFromXML(xml)
 	if err != nil {
@@ -29,6 +32,7 @@ func (s *ItunesScanner) ScanLibrary(path string) (int, error) {
 	}
 	beego.Info("Loaded", len(l.Tracks), "tracks")
 
+	s.lastModifiedSince = lastModifiedSince
 	s.mediaFiles = make(map[string]*domain.MediaFile)
 	s.albums = make(map[string]*domain.Album)
 	s.artists = make(map[string]*domain.Artist)
@@ -39,6 +43,8 @@ func (s *ItunesScanner) ScanLibrary(path string) (int, error) {
 			ar := s.collectArtists(&t)
 			mf := s.collectMediaFiles(&t)
 			s.collectAlbums(&t, mf, ar)
+		} else {
+			beego.Trace("Skipped", t.Location, " - kind:", t.Kind)
 		}
 		i++
 		if i%1000 == 0 {
@@ -87,7 +93,10 @@ func (s *ItunesScanner) collectMediaFiles(t *itl.Track) *domain.MediaFile {
 	path = strings.TrimPrefix(unescape(path), "file://")
 	mf.Path = path
 	mf.Suffix = strings.TrimPrefix(filepath.Ext(path), ".")
-	mf.HasCoverArt = hasCoverArt(path)
+
+	if mf.UpdatedAt.After(s.lastModifiedSince) {
+		mf.HasCoverArt = hasCoverArt(path)
+	}
 
 	mf.CreatedAt = t.DateAdded
 	mf.UpdatedAt = t.DateModified