89 lines
2.1 KiB
Go
89 lines
2.1 KiB
Go
package radio
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import (
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"bytes"
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"errors"
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"strconv"
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"time"
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)
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const MostListenedDateFormat = "02 January 2006"
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var mlsChanged = false
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type MostListenedSong struct {
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Listeners int
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Date time.Time
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Song string
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}
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func (mls *MostListenedSong) DateString() string {
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return mls.Date.Format(MostListenedDateFormat)
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}
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var mostListened MostListenedSong
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// CheckAndUpdateMostListenedSong compares current most played song with
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// provided `cur`rent song's listeners, and if it is larger, then it takes
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// `prev`ious song's name.
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//
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// Why we take a previous song's name? Experimentally I noticed that Icecast
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// writes amount of listeners that was by the very start of a next song. So
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// it means that it was actually amount of listeners by the end of
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// the previous song.
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//
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// So it would be fairer to give these listeners back to a song they was
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// listening to.
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func CheckAndUpdateMostListenedSong(cur, prev *Song) {
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if prev.Song == "" {
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return
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}
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l, _ := strconv.Atoi(cur.Listeners)
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if l > mostListened.Listeners {
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mostListened = MostListenedSong{
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Listeners: l,
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Date: time.Now().UTC(),
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Song: prev.Song}
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}
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mlsChanged = true
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}
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// MostListened returns song that currently is the song with most simultaneous
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// listeners.
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func MostListened() *MostListenedSong {
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return &mostListened
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}
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func LoadMostListenedSong(data []byte) (err error) {
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lines := bytes.Split(data, []byte{'\n'})
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if len(lines) != 3 {
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return errors.New("lines count mismatch, should be 3")
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}
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mostListened = MostListenedSong{}
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if mostListened.Date, err = time.Parse(time.RFC3339, string(lines[0])); err != nil {
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return err
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}
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if mostListened.Listeners, err = strconv.Atoi(string(lines[1])); err != nil {
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return err
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}
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mostListened.Song = string(lines[2])
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return nil
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}
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func StoreMostListenedSong() []byte {
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if !mlsChanged {
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return nil
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}
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buf := make([]byte, 0, 30+len(mostListened.Song))
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b := bytes.NewBuffer(buf)
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b.WriteString(mostListened.Date.Format(time.RFC3339))
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b.WriteByte('\n')
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b.WriteString(strconv.Itoa(mostListened.Listeners))
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b.WriteByte('\n')
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b.WriteString(mostListened.Song)
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return b.Bytes()
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}
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