diff --git a/core/external_metadata.go b/core/external_metadata.go
index 8abef8279..6fc9de981 100644
--- a/core/external_metadata.go
+++ b/core/external_metadata.go
@@ -7,6 +7,8 @@ import (
"sync"
"time"
+ "github.com/navidrome/navidrome/utils"
+
"github.com/Masterminds/squirrel"
"github.com/microcosm-cc/bluemonday"
"github.com/navidrome/navidrome/conf"
@@ -133,7 +135,7 @@ func (e *externalMetadata) refreshArtistInfo(ctx context.Context, artist *auxArt
e.callGetBiography(ctx, allAgents, artist, wg)
e.callGetURL(ctx, allAgents, artist, wg)
e.callGetImage(ctx, allAgents, artist, wg)
- e.callGetSimilar(ctx, allAgents, artist, maxSimilarArtists, wg)
+ e.callGetSimilar(ctx, allAgents, artist, maxSimilarArtists, true, wg)
wg.Wait()
if isDone(ctx) {
@@ -159,7 +161,7 @@ func (e *externalMetadata) SimilarSongs(ctx context.Context, id string, count in
}
wg := &sync.WaitGroup{}
- e.callGetSimilar(ctx, allAgents, artist, count, wg)
+ e.callGetSimilar(ctx, allAgents, artist, 15, false, wg)
wg.Wait()
if isDone(ctx) {
@@ -167,33 +169,56 @@ func (e *externalMetadata) SimilarSongs(ctx context.Context, id string, count in
return nil, ctx.Err()
}
- if len(artist.SimilarArtists) == 0 {
- return nil, nil
- }
+ artists := model.Artists{artist.Artist}
+ artists = append(artists, artist.SimilarArtists...)
- var ids = []string{artist.ID}
- for _, a := range artist.SimilarArtists {
- if a.ID != unavailableArtistID {
- ids = append(ids, a.ID)
+ weightedSongs := utils.NewWeightedRandomChooser()
+ for _, a := range artists {
+ if isDone(ctx) {
+ log.Warn(ctx, "SimilarSongs call canceled", ctx.Err())
+ return nil, ctx.Err()
+ }
+
+ topCount := utils.MaxInt(count, 20)
+ topSongs, err := e.getMatchingTopSongs(ctx, allAgents, &auxArtist{Name: a.Name, Artist: a}, topCount)
+ if err != nil {
+ log.Warn(ctx, "Error getting artist's top songs", "artist", a.Name, err)
+ continue
+ }
+
+ weight := topCount * 4
+ for _, mf := range topSongs {
+ weightedSongs.Put(mf, weight)
+ weight -= 4
}
}
- return e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
- Filters: squirrel.Eq{"artist_id": ids},
- Max: count,
- Sort: "random()",
- })
+ var similarSongs model.MediaFiles
+ for len(similarSongs) < count && weightedSongs.Size() > 0 {
+ s, err := weightedSongs.GetAndRemove()
+ if err != nil {
+ log.Warn(ctx, "Error getting weighted song", err)
+ continue
+ }
+ similarSongs = append(similarSongs, s.(model.MediaFile))
+ }
+
+ return similarSongs, nil
}
func (e *externalMetadata) TopSongs(ctx context.Context, artistName string, count int) (model.MediaFiles, error) {
- allAgents := e.initAgents(ctx)
+ agents := e.initAgents(ctx)
artist, err := e.findArtistByName(ctx, artistName)
if err != nil {
log.Error(ctx, "Artist not found", "name", artistName, err)
return nil, nil
}
- songs, err := e.callGetTopSongs(ctx, allAgents, artist, count)
+ return e.getMatchingTopSongs(ctx, agents, artist, count)
+}
+
+func (e *externalMetadata) getMatchingTopSongs(ctx context.Context, allAgents []agents.Interface, artist *auxArtist, count int) (model.MediaFiles, error) {
+ songs, err := e.callGetTopSongs(ctx, allAgents, artist, 50)
if err != nil {
return nil, err
}
@@ -205,6 +230,9 @@ func (e *externalMetadata) TopSongs(ctx context.Context, artistName string, coun
continue
}
mfs = append(mfs, *mf)
+ if len(mfs) == count {
+ break
+ }
}
return mfs, nil
}
@@ -364,7 +392,7 @@ func (e *externalMetadata) callGetImage(ctx context.Context, allAgents []agents.
}()
}
-func (e *externalMetadata) callGetSimilar(ctx context.Context, allAgents []agents.Interface, artist *auxArtist, limit int, wg *sync.WaitGroup) {
+func (e *externalMetadata) callGetSimilar(ctx context.Context, allAgents []agents.Interface, artist *auxArtist, limit int, includeNotPresent bool, wg *sync.WaitGroup) {
wg.Add(1)
go func() {
defer wg.Done()
@@ -381,7 +409,7 @@ func (e *externalMetadata) callGetSimilar(ctx context.Context, allAgents []agent
if len(similar) == 0 || err != nil {
continue
}
- sa, err := e.mapSimilarArtists(ctx, similar, true)
+ sa, err := e.mapSimilarArtists(ctx, similar, includeNotPresent)
if err != nil {
continue
}
diff --git a/utils/weighted_random_chooser.go b/utils/weighted_random_chooser.go
new file mode 100644
index 000000000..387922240
--- /dev/null
+++ b/utils/weighted_random_chooser.go
@@ -0,0 +1,66 @@
+package utils
+
+import (
+ "errors"
+ "math/rand"
+ "time"
+)
+
+type weightedChooser struct {
+ entries []interface{}
+ weights []int
+ totalWeight int
+ rng *rand.Rand
+}
+
+func NewWeightedRandomChooser() *weightedChooser {
+ src := rand.NewSource(time.Now().UTC().UnixNano())
+
+ return &weightedChooser{
+ rng: rand.New(src), // nolint:gosec
+ }
+}
+
+func (w *weightedChooser) Put(value interface{}, weight int) {
+ w.entries = append(w.entries, value)
+ w.weights = append(w.weights, weight)
+ w.totalWeight += weight
+}
+
+// GetAndRemove choose a random entry based on their weights, and removes it from the list
+func (w *weightedChooser) GetAndRemove() (interface{}, error) {
+ i, err := w.weightedChoice()
+ if err != nil {
+ return nil, err
+ }
+ entry := w.entries[i]
+ w.Remove(i)
+ return entry, nil
+}
+
+// Based on https://eli.thegreenplace.net/2010/01/22/weighted-random-generation-in-python/
+func (w *weightedChooser) weightedChoice() (int, error) {
+ rnd := w.rng.Intn(w.totalWeight)
+ for i, weight := range w.weights {
+ rnd -= weight
+ if rnd < 0 {
+ return i, nil
+ }
+ }
+ return 0, errors.New("internal error - code should not reach this point")
+}
+
+func (w *weightedChooser) Remove(i int) {
+ w.totalWeight -= w.weights[i]
+
+ w.weights[i] = w.weights[len(w.weights)-1]
+ w.weights = w.weights[:len(w.weights)-1]
+
+ w.entries[i] = w.entries[len(w.entries)-1]
+ w.entries[len(w.entries)-1] = nil
+ w.entries = w.entries[:len(w.entries)-1]
+}
+
+func (w *weightedChooser) Size() int {
+ return len(w.entries)
+}