Implements NowPlayingRepository as an in-memory only struct

persistence/nowplaying_repository.go

@@ -0,0 +1,75 @@
+package persistence
+
+import (
+	"container/list"
+	"sync"
+
+	"github.com/cloudsonic/sonic-server/domain"
+)
+
+var playerMap = sync.Map{}
+
+type nowPlayingRepository struct{}
+
+// TODO Make it persistent
+func NewNowPlayingRepository() domain.NowPlayingRepository {
+	r := &nowPlayingRepository{}
+	return r
+}
+
+func (r *nowPlayingRepository) getList(id int) *list.List {
+	l, _ := playerMap.LoadOrStore(id, list.New())
+	return l.(*list.List)
+}
+
+func (r *nowPlayingRepository) Enqueue(info *domain.NowPlayingInfo) error {
+	l := r.getList(info.PlayerId)
+	l.PushFront(info)
+	return nil
+}
+
+func (r *nowPlayingRepository) Dequeue(playerId int) (*domain.NowPlayingInfo, error) {
+	l := r.getList(playerId)
+	e := l.Back()
+	if e == nil {
+		return nil, nil
+	}
+	l.Remove(e)
+	return e.Value.(*domain.NowPlayingInfo), nil
+}
+
+func (r *nowPlayingRepository) Head(playerId int) (*domain.NowPlayingInfo, error) {
+	l := r.getList(playerId)
+	e := l.Front()
+	if e == nil {
+		return nil, nil
+	}
+	return e.Value.(*domain.NowPlayingInfo), nil
+}
+
+func (r *nowPlayingRepository) Tail(playerId int) (*domain.NowPlayingInfo, error) {
+	l := r.getList(playerId)
+	e := l.Back()
+	if e == nil {
+		return nil, nil
+	}
+	return e.Value.(*domain.NowPlayingInfo), nil
+}
+
+func (r *nowPlayingRepository) Count(playerId int) (int64, error) {
+	l := r.getList(playerId)
+	return int64(l.Len()), nil
+}
+
+func (r *nowPlayingRepository) GetAll() ([]*domain.NowPlayingInfo, error) {
+	var all []*domain.NowPlayingInfo
+	playerMap.Range(func(playerId, l interface{}) bool {
+		ll := l.(*list.List)
+		e := ll.Front()
+		all = append(all, e.Value.(*domain.NowPlayingInfo))
+		return true
+	})
+	return all, nil
+}
+
+var _ domain.NowPlayingRepository = (*nowPlayingRepository)(nil)