Fixed last songs displaying.

internal/radio/icecast.go

@@ -24,7 +24,6 @@ const (
 var (
 	lastPlayedCache      []Song
 	lastPlayedCacheMutex sync.Mutex
-	isJustStarted        bool = true
 )
 
 type IcecastStatusDTO struct {
@@ -79,15 +78,12 @@ func IcecastGetStatus(icecastURL string) (*IcecastStatus, error) {
 	}, nil
 }
 
-func IcecastLastPlayedSongs(lastNSongs int, playlistPath string) ([]Song, error) {
+func IcecastLastSongs(playlistPath string) ([]Song, error) {
 	lastPlayedCacheMutex.Lock()
 	defer lastPlayedCacheMutex.Unlock()
 	if lpcLen := len(lastPlayedCache); lpcLen > 0 {
-		if lastNSongs > lpcLen {
-			lastNSongs = lpcLen
-		}
-		var ret []Song = make([]Song, lastNSongs)
-		copy(ret[:], lastPlayedCache[lpcLen-lastNSongs:])
+		ret := make([]Song, 0, lpcLen)
+		ret = append(ret, lastPlayedCache...)
 		return ret, nil
 	}
 
@@ -104,7 +100,6 @@ func IcecastLastSong(playlistPath string) (*Song, error) {
 }
 
 func icecastLastPlayedSongs(playlistPath string, n int) ([]Song, error) {
-	songs := make([]Song, n)
 	var buf []byte
 	var offset int64 = 0
 
@@ -134,16 +129,18 @@ func icecastLastPlayedSongs(playlistPath string, n int) ([]Song, error) {
 
 	lines := bytes.Split(buf, []byte("\n"))
 
-	if len(lines) < 3 {
+	if len(lines) < 2 {
 		return nil, nil
 	}
 
-	lines = lines[:len(lines)-2]
+	lines = lines[:len(lines)-1]
 
 	if len(lines) > n {
 		lines = lines[len(lines)-n:]
 	}
 
+	songs := make([]Song, 0, len(lines))
+
 	for _, line := range lines {
 		fields := bytes.Split(line, []byte("|"))
 
@@ -184,27 +181,21 @@ func (pw *PlaylistLogWatcher) Watch(playlistPath string, n int) (err error) {
 
 	pw.watcher.WatchForMask(pw.changed, watcher.ModIgnMask)
 
+	lastPlayedCache, err = icecastLastPlayedSongs(playlistPath, n)
+	if err != nil {
+		return errors.Wrap(err, "cannot instantiate last played cache")
+	}
+
 	go func() {
 		for {
 			select {
 			case mask := <-pw.changed:
 				if mask&syscall.IN_MODIFY > 0 {
-					if isJustStarted {
-						isJustStarted = false
-					} else {
-						lastPlayedCacheMutex.Lock()
-						if lastPlayedCache == nil {
-							lastPlayedCache = make([]Song, n)
-						}
-						if songs, err := icecastLastPlayedSongs(playlistPath, 1); err == nil && len(songs) > 0 {
-							if len(lastPlayedCache) == n {
-								lastPlayedCache = append(lastPlayedCache[1:], songs...)
-							} else {
-								lastPlayedCache = append(lastPlayedCache, songs...)
-							}
-						}
-						lastPlayedCacheMutex.Unlock()
+					lastPlayedCacheMutex.Lock()
+					if songs, err := icecastLastPlayedSongs(playlistPath, n); err == nil && len(songs) > 0 {
+						lastPlayedCache = songs
 					}
+					lastPlayedCacheMutex.Unlock()
 				} else if mask&syscall.IN_IGNORED > 0 {
 					pw.Close()
 					pw.Watch(playlistPath, n)