navidrome/server/jellyfin/lyrics_test.go
Deluan Quintão 756df9decf
fix: dedupe and cap concurrent lyrics plugin fetches (#5792)
* fix: dedupe and cap concurrent lyrics plugin fetches

Clients like Finamp prefetch lyrics for several queue tracks at once. The
resulting burst of concurrent plugin calls can rate-limit the primary
lyrics provider into a timeout, making the plugin fall back to a lower
quality source and cache the bad result.

SimpleCache.GetWithLoader now deduplicates concurrent loads of the same
key via singleflight, with every waiter receiving the winner's result or
error. The Jellyfin lyrics loader is detached from the request context so
one cancelled request cannot fail the load for all waiters, and the
lyrics adapter caps in-flight plugin calls at 2 per plugin, queueing the
rest. As a side effect, the cached HTTP client used by the Last.fm,
Deezer and ListenBrainz agents also collapses identical concurrent
requests into a single upstream call.

* fix: harden lyrics concurrency fixes per review

Replace the stringified singleflight keys with a per-cache flight map
keyed by the cache key type itself, eliminating potential key collisions
for non-string keys, the nil-interface assertion panic, and the
stringification overhead. Release the lyrics semaphore slot via defer so
a panicking plugin call cannot leak it, and bound the detached lyrics
load with a one-minute timeout so a hung plugin cannot pin its
singleflight and semaphore slot indefinitely.
2026-07-16 20:10:35 -04:00

156 lines
4.9 KiB
Go

package jellyfin
import (
"context"
"encoding/json"
"net/http"
"net/http/httptest"
"github.com/navidrome/navidrome/model"
"github.com/navidrome/navidrome/model/request"
"github.com/navidrome/navidrome/server/jellyfin/dto"
"github.com/navidrome/navidrome/tests"
"github.com/navidrome/navidrome/utils/cache"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
)
// fakeLyricsService returns canned lyrics per media-file ID and counts calls.
type fakeLyricsService struct {
lyrics map[string]model.LyricList
err error
calls int
hadDeadline bool
}
func (f *fakeLyricsService) GetLyrics(ctx context.Context, mf *model.MediaFile) (model.LyricList, error) {
f.calls++
_, f.hadDeadline = ctx.Deadline()
if err := ctx.Err(); err != nil {
return nil, err
}
if f.err != nil {
return nil, f.err
}
return f.lyrics[mf.ID], nil
}
func (f *fakeLyricsService) GetLyricsByArtistTitle(context.Context, string, string) (model.LyricList, error) {
return nil, nil
}
func p(ms int64) *int64 { return &ms }
func newTestLyricsCache() cache.SimpleCache[string, model.LyricList] {
return cache.NewSimpleCache[string, model.LyricList](cache.Options{SizeLimit: 1000})
}
var _ = Describe("getLyrics", func() {
var api *Router
var ds *tests.MockDataStore
var fake *fakeLyricsService
BeforeEach(func() {
ds = &tests.MockDataStore{}
ds.MediaFile(context.Background()).(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
{ID: "s1", Title: "Song", LibraryID: 1},
{ID: "s2", Title: "Silent Song", LibraryID: 1},
})
fake = &fakeLyricsService{lyrics: map[string]model.LyricList{}}
api = &Router{
ds: ds,
lyrics: fake,
lyricsCache: newTestLyricsCache(),
}
})
doRequest := func(id string) *httptest.ResponseRecorder {
w := httptest.NewRecorder()
ctx := request.WithUser(context.Background(), model.User{ID: "u1", Libraries: model.Libraries{{ID: 1}}})
// Clients send hex-encoded ids (matching real traffic and the other handler tests).
enc := dto.EncodeID(id)
r := httptest.NewRequest("GET", "/Audio/"+enc+"/Lyrics", nil).WithContext(ctx)
r = withChiURLParam(r, "itemId", enc)
invoke(api.getLyrics, w, r)
return w
}
It("returns 200 with a LyricDto for a track with synced lyrics", func() {
fake.lyrics["s1"] = model.LyricList{
{Kind: "main", Synced: true, Line: []model.Line{{Start: p(1000), Value: "hello"}}},
}
w := doRequest("s1")
Expect(w.Code).To(Equal(http.StatusOK))
var res dto.LyricDto
Expect(json.Unmarshal(w.Body.Bytes(), &res)).To(Succeed())
Expect(res.Lyrics).To(HaveLen(1))
Expect(res.Lyrics[0].Text).To(Equal("hello"))
Expect(res.Lyrics[0].Start).ToNot(BeNil())
Expect(*res.Lyrics[0].Start).To(Equal(int64(10000000)))
})
It("serves the main-kind lyric when a translation is also present", func() {
fake.lyrics["s1"] = model.LyricList{
{Kind: "translation", Synced: true, Line: []model.Line{{Start: p(1000), Value: "bonjour"}}},
{Kind: "main", Synced: true, Line: []model.Line{{Start: p(1000), Value: "hello"}}},
}
w := doRequest("s1")
Expect(w.Code).To(Equal(http.StatusOK))
var res dto.LyricDto
Expect(json.Unmarshal(w.Body.Bytes(), &res)).To(Succeed())
Expect(res.Lyrics).To(HaveLen(1))
Expect(res.Lyrics[0].Text).To(Equal("hello"))
})
It("returns 404 when the service returns no lyrics", func() {
w := doRequest("s2")
Expect(w.Code).To(Equal(http.StatusNotFound))
})
It("returns 404 when the main lyric has no lines", func() {
fake.lyrics["s1"] = model.LyricList{{Kind: "main", Lang: "eng"}}
w := doRequest("s1")
Expect(w.Code).To(Equal(http.StatusNotFound))
})
It("returns 404 for an unknown item id", func() {
w := doRequest("unknown")
Expect(w.Code).To(Equal(http.StatusNotFound))
})
It("caches results so a second request doesn't re-invoke the service", func() {
fake.lyrics["s1"] = model.LyricList{
{Kind: "main", Synced: true, Line: []model.Line{{Start: p(1000), Value: "hello"}}},
}
Expect(doRequest("s1").Code).To(Equal(http.StatusOK))
Expect(doRequest("s1").Code).To(Equal(http.StatusOK))
Expect(fake.calls).To(Equal(1))
})
It("caches empty results too", func() {
Expect(doRequest("s2").Code).To(Equal(http.StatusNotFound))
Expect(doRequest("s2").Code).To(Equal(http.StatusNotFound))
Expect(fake.calls).To(Equal(1))
})
It("completes and caches the fetch even when the request context is cancelled", func() {
fake.lyrics["s1"] = model.LyricList{
{Kind: "main", Synced: true, Line: []model.Line{{Start: p(1000), Value: "hello"}}},
}
ctx, cancel := context.WithCancel(context.Background())
cancel()
list := api.cachedLyrics(ctx, &model.MediaFile{ID: "s1"})
Expect(list).ToNot(BeEmpty())
Expect(doRequest("s1").Code).To(Equal(http.StatusOK))
Expect(fake.calls).To(Equal(1))
})
It("bounds the detached fetch with a timeout", func() {
Expect(doRequest("s2").Code).To(Equal(http.StatusNotFound))
Expect(fake.hadDeadline).To(BeTrue())
})
})