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SongList struct was removed. A Song struct got UpdateMaxListeners() and IncListeners() methods. A mutex was Introduced for it. A Listeners field to store overall number of listeners during a song playing was introduced as well. A comment for the Song struct was removed.

This commit is contained in:
Alexander Andreev 2024-05-09 20:30:17 +04:00
parent ec5b6a028b
commit 9ef0771389
Signed by: Arav
GPG Key ID: 25969B23DCB5CA34

View File

@ -6,18 +6,35 @@ import (
"time"
)
// Song stores artist and title of a song, a timestamp of when it started, its
// duration, and a maximum number of listeners.
type Song struct {
mutex sync.Mutex
Artist string
Title string
Duration time.Duration
MaxListeners int
Listeners int64
MaxListeners int64
StartAt time.Time
}
func (s *Song) UpdateMaxListeners(listeners int64) {
s.mutex.Lock()
if listeners > s.MaxListeners {
s.MaxListeners = listeners
}
s.mutex.Unlock()
}
// IncListeners increments by one an overall amount of listeners of this song.
func (s *Song) IncListeners() {
s.mutex.Lock()
s.Listeners++
s.mutex.Unlock()
}
// DurationString returns song's duration as a string formatted as [H:]M:SS.
func (s *Song) DurationString() string {
s.mutex.Lock()
defer s.mutex.Unlock()
if s.Duration.Hours() >= 1 {
return time.UnixMilli(s.Duration.Milliseconds()).Format("3:4:05")
}
@ -25,85 +42,20 @@ func (s *Song) DurationString() string {
}
func (s *Song) MarshalJSON() ([]byte, error) {
s.mutex.Lock()
defer s.mutex.Unlock()
return json.Marshal(&struct {
Artist string `json:"artist"`
Title string `json:"title"`
DurationMill int64 `json:"duration_msec"`
MaxListeners int `json:"listeners"`
DurationMill int64 `json:"duration_msec,omitempty"`
Listeners int64 `json:"listeners"`
MaxListeners int64 `json:"max_listeners"`
StartAt string `json:"start_at"`
}{
Artist: s.Artist,
Title: s.Title,
DurationMill: s.Duration.Milliseconds(),
Listeners: s.Listeners,
MaxListeners: s.MaxListeners,
StartAt: s.StartAt.UTC().Format(time.RFC3339)})
}
// SongList holds a currently playing song and a list of previously played ones
// with a maximal length of maxLen.
type SongList struct {
mutex sync.RWMutex
current Song
lastSongs []Song
maxLen int
}
// NewSongList returns a new SongList with a maximal length set with maxLen.
func NewSongList(maxLen int) *SongList {
return &SongList{maxLen: maxLen, lastSongs: make([]Song, 0, maxLen)}
}
// Add a new song that is currently playing and update a list.
func (sl *SongList) Add(newSong Song) {
sl.mutex.Lock()
defer sl.mutex.Unlock()
if sl.current.StartAt.Year() == 1 {
sl.current = newSong
return
}
if len(sl.lastSongs) == sl.maxLen {
sl.lastSongs = append(sl.lastSongs[1:], sl.current)
} else {
sl.lastSongs = append(sl.lastSongs, sl.current)
}
sl.current = newSong
}
// Current returns a currently playing song or nil if it isn't set yet.
func (sl *SongList) Current() *Song {
sl.mutex.RLock()
defer sl.mutex.RUnlock()
if sl.current.StartAt.Year() == 1 {
return nil
}
return &Song{
Artist: sl.current.Artist,
Title: sl.current.Title,
Duration: sl.current.Duration,
MaxListeners: sl.current.MaxListeners,
StartAt: sl.current.StartAt}
}
// UpdateCurrentMaxListeners checks and updates a maximal number of listeners
// for a current song.
func (sl *SongList) UpdateCurrentMaxListeners(listeners int) {
sl.mutex.Lock()
defer sl.mutex.Unlock()
if listeners > sl.current.MaxListeners {
sl.current.MaxListeners = listeners
}
}
// List returns a list of lastly played songs.
func (sl *SongList) List() []Song {
sl.mutex.RLock()
defer sl.mutex.RUnlock()
return sl.lastSongs
}
// MaxLen returns a maximal length of a song list.
func (sl *SongList) MaxLen() int {
return sl.maxLen
}