quintodrome/server/subsonic/media_retrieval_test.go
Deluan Quintão 5f0245ea84
fix(server): prevent artwork throttle token starvation on slow clients (#5472)
* fix(server): prevent artwork throttle token starvation on slow clients

Replace Chi's ThrottleBacklog middleware for artwork endpoints with a
custom RequestThrottle that releases processing tokens before writing
the HTTP response. Previously, a slow or stalled client could hold a
throttle token indefinitely during io.Copy, exhausting all 2-4 slots
and blocking artwork requests for all users (reported after 15+ days
uptime).

The new approach buffers artwork into memory while holding the token,
releases it immediately, then writes the buffered response. A 30-second
per-request write deadline (SetWriteTimeout) prevents stalled writes
from blocking indefinitely. Throttle exhaustion is now logged with
context for operator visibility.

* refactor(server): simplify throttle to middleware with same API as Chi

Restructure RequestThrottle from a DI-injected type into a drop-in
middleware function with the same signature as Chi's ThrottleBacklog.
Handlers are reverted to their original simple form (no throttle
awareness), and the middleware is applied at route definition time
just like before. This eliminates the DI dependency, removes the
artworkThrottle field from both Router structs, and consolidates
SetWriteTimeout into the throttle file. When limit <= 0, the
middleware returns a passthrough so callers don't need a guard.

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(server): add opt-out flag for buffered artwork throttle

Add DevArtworkThrottleBuffered config (default true) that controls
whether the new buffered ThrottleBacklog middleware is used. When set
to false, it falls back to Chi's original middleware, giving users a
safety valve in case the buffered implementation causes issues.

Signed-off-by: Deluan <deluan@navidrome.org>

* test(server): clean up throttle tests for clarity and speed

Consolidate duplicate router setup into runTwoRequests() and
slowClientTest() helpers. Replace time.Sleep-based token holding with
channel synchronization, reducing suite time from ~7s to ~1.5s.
Remove redundant test, fix duplicate comment block, and add comment
explaining why slowTestWriter can't embed httptest.ResponseRecorder.

* fix: release artwork throttle tokens on panic

Defer the buffered artwork throttle release inside the handler closure so tokens are returned even when a downstream handler panics before response flushing. Document that the middleware buffers full responses in memory and add a regression test covering recovery after a panic.

* fix: align buffered throttle response behavior

Keep only the first status code written to the buffered artwork throttle response writer so it matches net/http semantics. Strengthen the opt-out test to verify DevArtworkThrottleBuffered=false uses Chi's original slow-client behavior instead of only checking shared 429 handling.

* refactor(server): remove setWriteTimeout from throttle middleware

SetWriteDeadline only constrains the server's Write syscall, not how
fast the client reads from the TCP buffer. For artwork-sized responses
(up to ~500KB), the kernel accepts the entire write immediately even
over real network interfaces due to TCP buffer auto-tuning. Verified
by testing with a stalled client over both loopback and en0 — the
deadline never triggers. The actual protection comes from buffering +
early token release, which is already in place.

---------

Signed-off-by: Deluan <deluan@navidrome.org>
2026-05-06 00:12:50 -04:00

372 lines
11 KiB
Go

package subsonic
import (
"bytes"
"cmp"
"context"
"encoding/json"
"errors"
"io"
"net/http/httptest"
"slices"
"time"
"github.com/navidrome/navidrome/conf"
"github.com/navidrome/navidrome/conf/configtest"
"github.com/navidrome/navidrome/core/artwork"
"github.com/navidrome/navidrome/core/lyrics"
"github.com/navidrome/navidrome/model"
"github.com/navidrome/navidrome/server/subsonic/responses"
"github.com/navidrome/navidrome/tests"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
)
var _ = Describe("MediaRetrievalController", func() {
var router *Router
var ds model.DataStore
mockRepo := &mockedMediaFile{MockMediaFileRepo: tests.MockMediaFileRepo{}}
var artwork *fakeArtwork
var w *httptest.ResponseRecorder
BeforeEach(func() {
ds = &tests.MockDataStore{
MockedMediaFile: mockRepo,
}
artwork = &fakeArtwork{data: "image data"}
router = New(ds, artwork, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, lyrics.NewLyrics(nil), nil, nil)
w = httptest.NewRecorder()
DeferCleanup(configtest.SetupConfig())
conf.Server.LyricsPriority = "embedded,.lrc"
})
Describe("GetCoverArt", func() {
It("should return data for that id", func() {
r := newGetRequest("id=34", "size=128", "square=true")
_, err := router.GetCoverArt(w, r)
Expect(err).ToNot(HaveOccurred())
Expect(artwork.recvSize).To(Equal(128))
Expect(artwork.recvSquare).To(BeTrue())
Expect(w.Body.String()).To(Equal(artwork.data))
})
It("should return placeholder if id parameter is missing (mimicking Subsonic)", func() {
r := newGetRequest() // No id parameter
_, err := router.GetCoverArt(w, r)
Expect(err).To(BeNil())
Expect(artwork.recvId).To(BeEmpty())
Expect(w.Body.String()).To(Equal(artwork.data))
})
It("should fail when the file is not found", func() {
artwork.err = model.ErrNotFound
r := newGetRequest("id=34", "size=128", "square=true")
_, err := router.GetCoverArt(w, r)
Expect(err).To(MatchError("Artwork not found"))
})
It("should fail when there is an unknown error", func() {
artwork.err = errors.New("weird error")
r := newGetRequest("id=34", "size=128")
_, err := router.GetCoverArt(w, r)
Expect(err).To(MatchError("weird error"))
})
When("client disconnects (context is cancelled)", func() {
It("should not call the service if cancelled before the call", func() {
ctx, cancel := context.WithCancel(context.Background())
r := newGetRequest("id=34", "size=128", "square=true")
r = r.WithContext(ctx)
cancel()
_, err := router.GetCoverArt(w, r)
Expect(err).ToNot(HaveOccurred())
Expect(artwork.recvId).To(Equal(""))
Expect(artwork.recvSize).To(Equal(0))
Expect(artwork.recvSquare).To(BeFalse())
Expect(w.Body.String()).To(BeEmpty())
})
It("should not return data if cancelled during the call", func() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
r := newGetRequest("id=34", "size=128", "square=true")
r = r.WithContext(ctx)
artwork.ctxCancelFunc = cancel
_, err := router.GetCoverArt(w, r)
Expect(err).ToNot(HaveOccurred())
Expect(artwork.recvId).To(Equal("34"))
Expect(artwork.recvSize).To(Equal(128))
Expect(artwork.recvSquare).To(BeTrue())
Expect(w.Body.String()).To(BeEmpty())
})
})
})
Describe("GetLyrics", func() {
It("should return data for given artist & title", func() {
r := newGetRequest("artist=Rick+Astley", "title=Never+Gonna+Give+You+Up")
lyrics, _ := model.ToLyrics("eng", "[00:18.80]We're no strangers to love\n[00:22.80]You know the rules and so do I")
lyricsJson, err := json.Marshal(model.LyricList{
*lyrics,
})
Expect(err).ToNot(HaveOccurred())
baseTime := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
mockRepo.SetData(model.MediaFiles{
{
ID: "2",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
Lyrics: "[]",
UpdatedAt: baseTime.Add(2 * time.Hour), // No lyrics, newer
},
{
ID: "1",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
Lyrics: string(lyricsJson),
UpdatedAt: baseTime.Add(1 * time.Hour), // Has lyrics, older
},
{
ID: "3",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
Lyrics: "[]",
UpdatedAt: baseTime.Add(3 * time.Hour), // No lyrics, newest
},
})
response, err := router.GetLyrics(r)
Expect(err).ToNot(HaveOccurred())
Expect(response.Lyrics.Artist).To(Equal("Rick Astley"))
Expect(response.Lyrics.Title).To(Equal("Never Gonna Give You Up"))
Expect(response.Lyrics.Value).To(Equal("We're no strangers to love\nYou know the rules and so do I\n"))
})
It("should return empty subsonic response if the record corresponding to the given artist & title is not found", func() {
r := newGetRequest("artist=Dheeraj", "title=Rinkiya+Ke+Papa")
mockRepo.SetData(model.MediaFiles{})
response, err := router.GetLyrics(r)
Expect(err).ToNot(HaveOccurred())
Expect(response.Lyrics.Artist).To(Equal(""))
Expect(response.Lyrics.Title).To(Equal(""))
Expect(response.Lyrics.Value).To(Equal(""))
})
It("should return lyric file when finding mediafile with no embedded lyrics but present on filesystem", func() {
r := newGetRequest("artist=Rick+Astley", "title=Never+Gonna+Give+You+Up")
mockRepo.SetData(model.MediaFiles{
{
Path: "tests/fixtures/test.mp3",
ID: "1",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
},
{
Path: "tests/fixtures/test.mp3",
ID: "2",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
},
})
response, err := router.GetLyrics(r)
Expect(err).ToNot(HaveOccurred())
Expect(response.Lyrics.Artist).To(Equal("Rick Astley"))
Expect(response.Lyrics.Title).To(Equal("Never Gonna Give You Up"))
Expect(response.Lyrics.Value).To(Equal("We're no strangers to love\nYou know the rules and so do I\n"))
})
})
Describe("GetLyricsBySongId", func() {
const syncedLyrics = "[00:18.80]We're no strangers to love\n[00:22.801]You know the rules and so do I"
const unsyncedLyrics = "We're no strangers to love\nYou know the rules and so do I"
const metadata = "[ar:Rick Astley]\n[ti:That one song]\n[offset:-100]"
var times = []int64{18800, 22801}
compareResponses := func(actual *responses.LyricsList, expected responses.LyricsList) {
Expect(actual).ToNot(BeNil())
Expect(actual.StructuredLyrics).To(HaveLen(len(expected.StructuredLyrics)))
for i, realLyric := range actual.StructuredLyrics {
expectedLyric := expected.StructuredLyrics[i]
Expect(realLyric.DisplayArtist).To(Equal(expectedLyric.DisplayArtist))
Expect(realLyric.DisplayTitle).To(Equal(expectedLyric.DisplayTitle))
Expect(realLyric.Lang).To(Equal(expectedLyric.Lang))
Expect(realLyric.Synced).To(Equal(expectedLyric.Synced))
if expectedLyric.Offset == nil {
Expect(realLyric.Offset).To(BeNil())
} else {
Expect(*realLyric.Offset).To(Equal(*expectedLyric.Offset))
}
Expect(realLyric.Line).To(HaveLen(len(expectedLyric.Line)))
for j, realLine := range realLyric.Line {
expectedLine := expectedLyric.Line[j]
Expect(realLine.Value).To(Equal(expectedLine.Value))
if expectedLine.Start == nil {
Expect(realLine.Start).To(BeNil())
} else {
Expect(*realLine.Start).To(Equal(*expectedLine.Start))
}
}
}
}
It("should return mixed lyrics", func() {
r := newGetRequest("id=1")
synced, _ := model.ToLyrics("eng", syncedLyrics)
unsynced, _ := model.ToLyrics("xxx", unsyncedLyrics)
lyricsJson, err := json.Marshal(model.LyricList{
*synced, *unsynced,
})
Expect(err).ToNot(HaveOccurred())
mockRepo.SetData(model.MediaFiles{
{
ID: "1",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
Lyrics: string(lyricsJson),
},
})
response, err := router.GetLyricsBySongId(r)
Expect(err).ToNot(HaveOccurred())
compareResponses(response.LyricsList, responses.LyricsList{
StructuredLyrics: responses.StructuredLyrics{
{
Lang: "eng",
DisplayArtist: "Rick Astley",
DisplayTitle: "Never Gonna Give You Up",
Synced: true,
Line: []responses.Line{
{
Start: &times[0],
Value: "We're no strangers to love",
},
{
Start: &times[1],
Value: "You know the rules and so do I",
},
},
},
{
Lang: "xxx",
DisplayArtist: "Rick Astley",
DisplayTitle: "Never Gonna Give You Up",
Synced: false,
Line: []responses.Line{
{
Value: "We're no strangers to love",
},
{
Value: "You know the rules and so do I",
},
},
},
},
})
})
It("should parse lrc metadata", func() {
r := newGetRequest("id=1")
synced, _ := model.ToLyrics("eng", metadata+"\n"+syncedLyrics)
lyricsJson, err := json.Marshal(model.LyricList{
*synced,
})
Expect(err).ToNot(HaveOccurred())
mockRepo.SetData(model.MediaFiles{
{
ID: "1",
Artist: "Rick Astley",
Title: "Never Gonna Give You Up",
Lyrics: string(lyricsJson),
},
})
response, err := router.GetLyricsBySongId(r)
Expect(err).ToNot(HaveOccurred())
offset := int64(-100)
compareResponses(response.LyricsList, responses.LyricsList{
StructuredLyrics: responses.StructuredLyrics{
{
DisplayArtist: "Rick Astley",
DisplayTitle: "That one song",
Lang: "eng",
Synced: true,
Line: []responses.Line{
{
Start: &times[0],
Value: "We're no strangers to love",
},
{
Start: &times[1],
Value: "You know the rules and so do I",
},
},
Offset: &offset,
},
},
})
})
})
})
type fakeArtwork struct {
artwork.Artwork
data string
err error
ctxCancelFunc func()
recvId string
recvSize int
recvSquare bool
}
func (c *fakeArtwork) GetOrPlaceholder(_ context.Context, id string, size int, square bool) (io.ReadCloser, time.Time, error) {
if c.err != nil {
return nil, time.Time{}, c.err
}
c.recvId = id
c.recvSize = size
c.recvSquare = square
if c.ctxCancelFunc != nil {
c.ctxCancelFunc()
return nil, time.Time{}, context.Canceled
}
return io.NopCloser(bytes.NewReader([]byte(c.data))), time.Time{}, nil
}
type mockedMediaFile struct {
tests.MockMediaFileRepo
}
func (m *mockedMediaFile) GetAll(opts ...model.QueryOptions) (model.MediaFiles, error) {
data, err := m.MockMediaFileRepo.GetAll(opts...)
if err != nil {
return nil, err
}
if len(opts) == 0 || opts[0].Sort != "lyrics, updated_at" {
return data, nil
}
result := slices.Clone(data)
slices.SortFunc(result, func(a, b model.MediaFile) int {
diff := cmp.Or(
cmp.Compare(a.Lyrics, b.Lyrics),
cmp.Compare(a.UpdatedAt.Unix(), b.UpdatedAt.Unix()),
)
if opts[0].Order == "desc" {
return -diff
}
return diff
})
return result, nil
}