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musicbrainz-provider #2

Merged
Mrixs merged 72 commits from musicbrainz-provider into master 2026-08-05 20:19:16 +00:00
Conversation 0 Commits 72 Files Changed 69 +518 -119
10 changed files with 518 additions and 119 deletions
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Showing only changes of commit b0f69d3a4f - Show all commits

14
docs/plans/2026-05-21-musicbrainz-provider.md
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@@ -56,13 +56,13 @@ Implement a MusicBrainz API provider with strict 1 request/second rate limiting,
- [x] run tests - must pass before next task
### Task 2: Implement rate limiting and caching layer
- [ ] add golang.org/x/time/rate dependency to go.mod
- [ ] implement rate limiter using golang.org/x/time/rate.NewLimiter(1, 1) for 1 req/sec
- [ ] create wrapper method for rate-limited HTTP GET requests
- [ ] implement caching check: query database for existing Release Group data within TTL
- [ ] write tests for rate limiting behavior (timing tests)
- [ ] write tests for cache hit/miss logic
- [ ] run tests - must pass before next task
- [x] add golang.org/x/time/rate dependency to go.mod
- [x] implement rate limiter using golang.org/x/time/rate.NewLimiter(1, 1) for 1 req/sec
- [x] create wrapper method for rate-limited HTTP GET requests
- [x] implement caching check: query database for existing Release Group data within TTL
- [x] write tests for rate limiting behavior (timing tests)
- [x] write tests for cache hit/miss logic
- [x] run tests - must pass before next task
### Task 3: Implement MusicBrainz API endpoints and filtering
- [ ] implement GetArtistReleaseGroups(artistMBID string) method

2
go.mod
View File

@@ -7,3 +7,5 @@ require (
github.com/mattn/go-sqlite3 v1.14.22
gopkg.in/yaml.v3 v3.0.1
)
require golang.org/x/time v0.15.0

2
go.sum
View File

@@ -2,6 +2,8 @@ github.com/delucks/go-subsonic v0.0.0-20240806025900-2a743ec36238 h1:uejyepOdHIS
github.com/delucks/go-subsonic v0.0.0-20240806025900-2a743ec36238/go.mod h1:vnbEuj6Z20PLcHB4rrLQAOXGMjtULfMGhRVSFPcSdUo=
github.com/mattn/go-sqlite3 v1.14.22 h1:2gZY6PC6kBnID23Tichd1K+Z0oS6nE/XwU+Vz/5o4kU=
github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

5
internal/database/database.go
View File

@@ -115,6 +115,10 @@ func (db *DB) migrate() error {
PRIMARY KEY (rgid, sent_at)
);`,
},
{
name: "005_add_cached_at_to_external_releases",
sql: `ALTER TABLE external_releases ADD COLUMN cached_at DATETIME;`,
},
}
for _, m := range migrations {
@@ -183,6 +187,7 @@ type ExternalRelease struct {
Type string `json:"type"`
ReleaseDate string `json:"release_date"`
IsIgnored bool `json:"is_ignored"`
CachedAt time.Time `json:"cached_at"`
}
// NotificationSent represents a row in the notifications_sent table.

6
internal/database/database_test.go
View File

@@ -205,8 +205,8 @@ func TestMigrationTracking(t *testing.T) {
t.Fatalf("query migrations count: %v", err)
}
// We have 4 recorded migrations: artist_settings, external_releases, local_albums, notifications_sent.
if count != 4 {
t.Errorf("expected 4 applied migrations, got %d", count)
// We have 5 recorded migrations: artist_settings, external_releases, local_albums, notifications_sent, cached_at column.
if count != 5 {
t.Errorf("expected 5 applied migrations, got %d", count)
}
}

97
internal/database/external_releases.go
View File

@@ -1,28 +1,40 @@
package database
import (
"database/sql"
"fmt"
"time"
_ "github.com/mattn/go-sqlite3"
)
// GetExternalRelease retrieves an external_release row by RGID.
// Returns sql.ErrNoRows if the release is not found.
func GetExternalRelease(db *DB, rgid string) (*ExternalRelease, error) {
var r ExternalRelease
var cachedAt sql.NullTime
err := db.Conn().QueryRow(
"SELECT rgid, artist_id, title, type, release_date, is_ignored FROM external_releases WHERE rgid = ?",
"SELECT rgid, artist_id, title, type, release_date, is_ignored, cached_at FROM external_releases WHERE rgid = ?",
rgid,
).Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored)
).Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored, &cachedAt)
if err != nil {
return nil, err
}
if cachedAt.Valid {
r.CachedAt = cachedAt.Time
}
return &r, nil
}
// SaveExternalRelease inserts or replaces an external_release row.
func SaveExternalRelease(db *DB, release *ExternalRelease) error {
cachedAtStr := ""
if !release.CachedAt.IsZero() {
cachedAtStr = release.CachedAt.Format("2006-01-02 15:04:05")
}
_, err := db.Conn().Exec(
"INSERT OR REPLACE INTO external_releases (rgid, artist_id, title, type, release_date, is_ignored) VALUES (?, ?, ?, ?, ?, ?)",
release.RGID, release.ArtistID, release.Title, release.Type, release.ReleaseDate, release.IsIgnored,
"INSERT OR REPLACE INTO external_releases (rgid, artist_id, title, type, release_date, is_ignored, cached_at) VALUES (?, ?, ?, ?, ?, ?, ?)",
release.RGID, release.ArtistID, release.Title, release.Type, release.ReleaseDate, release.IsIgnored, cachedAtStr,
)
if err != nil {
return fmt.Errorf("save external release: %w", err)
@@ -33,7 +45,7 @@ func SaveExternalRelease(db *DB, release *ExternalRelease) error {
// GetExternalReleasesByArtist returns all external_release rows for a given artist_id.
func GetExternalReleasesByArtist(db *DB, artistID string) ([]ExternalRelease, error) {
rows, err := db.Conn().Query(
"SELECT rgid, artist_id, title, type, release_date, is_ignored FROM external_releases WHERE artist_id = ?",
"SELECT rgid, artist_id, title, type, release_date, is_ignored, cached_at FROM external_releases WHERE artist_id = ?",
artistID,
)
if err != nil {
@@ -44,9 +56,13 @@ func GetExternalReleasesByArtist(db *DB, artistID string) ([]ExternalRelease, er
var results []ExternalRelease
for rows.Next() {
var r ExternalRelease
if err := rows.Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored); err != nil {
var cachedAt sql.NullTime
if err := rows.Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored, &cachedAt); err != nil {
return nil, fmt.Errorf("scan external release: %w", err)
}
if cachedAt.Valid {
r.CachedAt = cachedAt.Time
}
results = append(results, r)
}
if err := rows.Err(); err != nil {
@@ -58,7 +74,7 @@ func GetExternalReleasesByArtist(db *DB, artistID string) ([]ExternalRelease, er
// GetIgnoredReleases returns all external_release rows where is_ignored = 1.
func GetIgnoredReleases(db *DB) ([]ExternalRelease, error) {
rows, err := db.Conn().Query(
"SELECT rgid, artist_id, title, type, release_date, is_ignored FROM external_releases WHERE is_ignored = 1",
"SELECT rgid, artist_id, title, type, release_date, is_ignored, cached_at FROM external_releases WHERE is_ignored = 1",
)
if err != nil {
return nil, fmt.Errorf("query ignored releases: %w", err)
@@ -68,9 +84,13 @@ func GetIgnoredReleases(db *DB) ([]ExternalRelease, error) {
var results []ExternalRelease
for rows.Next() {
var r ExternalRelease
if err := rows.Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored); err != nil {
var cachedAt sql.NullTime
if err := rows.Scan(&r.RGID, &r.ArtistID, &r.Title, &r.Type, &r.ReleaseDate, &r.IsIgnored, &cachedAt); err != nil {
return nil, fmt.Errorf("scan ignored release: %w", err)
}
if cachedAt.Valid {
r.CachedAt = cachedAt.Time
}
results = append(results, r)
}
if err := rows.Err(); err != nil {
@@ -99,3 +119,64 @@ func SetReleaseIgnored(db *DB, rgid string, ignored bool) error {
return nil
}
// DeleteExternalReleasesByArtist removes all external_release rows for a given artist_id.
func DeleteExternalReleasesByArtist(db *DB, artistID string) error {
_, err := db.Conn().Exec(
"DELETE FROM external_releases WHERE artist_id = ?",
artistID,
)
if err != nil {
return fmt.Errorf("delete external releases by artist: %w", err)
}
return nil
}
// CountExternalReleases returns the total number of external_release rows.
func CountExternalReleases(db *DB) (int, error) {
var count int
err := db.Conn().QueryRow("SELECT COUNT(*) FROM external_releases").Scan(&count)
if err != nil {
return 0, fmt.Errorf("count external releases: %w", err)
}
return count, nil
}
// GetExternalReleasesByArtistWithCache returns cached external_release rows for a given artist_id
// that are within the specified TTL.
func GetExternalReleasesByArtistWithCache(db *DB, artistID string, ttl time.Duration) ([]ExternalRelease, error) {
cutoff := time.Now().Add(-ttl)
rows, err := db.Conn().Query(
"SELECT rgid, artist_id, title, type, release_date, is_ignored, cached_at FROM external_releases WHERE artist_id = ? AND cached_at >= ?",
artistID, cutoff.Format("2006-01-02 15:04:05"),
)
if err != nil {
return nil, fmt.Errorf("query cached external releases: %w", err)
}
defer rows.Close()
var results []ExternalRelease
for rows.Next() {
var r ExternalRelease
var releaseDate sql.NullString
var releaseType sql.NullString
var cachedAt sql.NullTime
if err := rows.Scan(&r.RGID, &r.ArtistID, &r.Title, &releaseType, &releaseDate, &r.IsIgnored, &cachedAt); err != nil {
return nil, fmt.Errorf("scan cached external release: %w", err)
}
if releaseType.Valid {
r.Type = releaseType.String
}
if releaseDate.Valid {
r.ReleaseDate = releaseDate.String
}
if cachedAt.Valid {
r.CachedAt = cachedAt.Time
}
results = append(results, r)
}
if err := rows.Err(); err != nil {
return nil, fmt.Errorf("iterate cached external releases: %w", err)
}
return results, nil
}

53
internal/musicbrainz/cache.go Normal file
View File

@@ -0,0 +1,53 @@
package musicbrainz
import (
"fmt"
"time"
"naviwatcher/internal/database"
)
// CacheStats holds the result of a cache lookup for a given artist.
type CacheStats struct {
// CachedRGIDs is the list of RGIDs that are currently cached (within TTL).
CachedRGIDs []string
// CacheHitCount is the number of entries found in cache.
CacheHitCount int
}
// IsCached returns true if the given RGID is in the cached set.
func (cs *CacheStats) IsCached(rgid string) bool {
for _, id := range cs.CachedRGIDs {
if id == rgid {
return true
}
}
return false
}
// GetCachedReleases queries the external_releases table for entries
// belonging to the given artist that were cached within the specified TTL.
// It returns a CacheStats with the list of valid RGIDs already in cache.
func GetCachedReleases(db *database.DB, artistID string, ttl time.Duration) (*CacheStats, error) {
releases, err := database.GetExternalReleasesByArtistWithCache(db, artistID, ttl)
if err != nil {
return nil, fmt.Errorf("get cached releases: %w", err)
}
stats := &CacheStats{}
for _, r := range releases {
stats.CachedRGIDs = append(stats.CachedRGIDs, r.RGID)
stats.CacheHitCount++
}
return stats, nil
}
// IsArtistCacheValid checks whether the cache for an artist is still valid.
// Returns true if any entries exist within the TTL for this artist.
func IsArtistCacheValid(db *database.DB, artistID string, ttl time.Duration) (bool, error) {
stats, err := GetCachedReleases(db, artistID, ttl)
if err != nil {
return false, err
}
return stats.CacheHitCount > 0, nil
}

255
internal/musicbrainz/cache_test.go Normal file
View File

@@ -0,0 +1,255 @@
package musicbrainz
import (
"testing"
"time"
"naviwatcher/internal/database"
)
func insertTestArtistForCache(db *database.DB, id string) error {
_, err := db.Conn().Exec(
"INSERT OR IGNORE INTO artist_settings (id, name) VALUES (?, ?)",
id, "Test Artist "+id,
)
return err
}
func TestGetCachedReleases_CacheHit(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
artistID := "artist-cache-hit"
if err := insertTestArtistForCache(db, artistID); err != nil {
t.Fatalf("insertTestArtist: %v", err)
}
// Insert releases with recent cached_at timestamps
now := time.Now().Format("2006-01-02 15:04:05")
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, type, cached_at) VALUES (?, ?, ?, ?, ?)",
"rg-hit-1", artistID, "Cached Album 1", "album", now,
)
if err != nil {
t.Fatalf("insert rg-hit-1: %v", err)
}
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, type, cached_at) VALUES (?, ?, ?, ?, ?)",
"rg-hit-2", artistID, "Cached Album 2", "single", now,
)
if err != nil {
t.Fatalf("insert rg-hit-2: %v", err)
}
ttl := 24 * time.Hour
stats, err := GetCachedReleases(db, artistID, ttl)
if err != nil {
t.Fatalf("GetCachedReleases() error: %v", err)
}
if stats.CacheHitCount != 2 {
t.Errorf("CacheHitCount = %d, want 2", stats.CacheHitCount)
}
if !stats.IsCached("rg-hit-1") {
t.Error("expected rg-hit-1 to be cached")
}
if !stats.IsCached("rg-hit-2") {
t.Error("expected rg-hit-2 to be cached")
}
}
func TestGetCachedReleases_CacheMiss_Expired(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
artistID := "artist-cache-miss"
if err := insertTestArtistForCache(db, artistID); err != nil {
t.Fatalf("insertTestArtist: %v", err)
}
// Insert a release with an expired cached_at (48 hours ago)
expired := time.Now().Add(-48 * time.Hour).Format("2006-01-02 15:04:05")
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, type, cached_at) VALUES (?, ?, ?, ?, ?)",
"rg-expired", artistID, "Expired Album", "album", expired,
)
if err != nil {
t.Fatalf("insert expired release: %v", err)
}
ttl := 24 * time.Hour
stats, err := GetCachedReleases(db, artistID, ttl)
if err != nil {
t.Fatalf("GetCachedReleases() error: %v", err)
}
if stats.CacheHitCount != 0 {
t.Errorf("CacheHitCount = %d, want 0 (expired entry should not be cached)", stats.CacheHitCount)
}
if stats.IsCached("rg-expired") {
t.Error("expected rg-expired to NOT be cached")
}
}
func TestGetCachedReleases_CacheMiss_NoCachedAt(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
artistID := "artist-no-cached"
if err := insertTestArtistForCache(db, artistID); err != nil {
t.Fatalf("insertTestArtist: %v", err)
}
// Insert a release WITHOUT cached_at (NULL)
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, type) VALUES (?, ?, ?, ?)",
"rg-nocached", artistID, "Uncached Album", "album",
)
if err != nil {
t.Fatalf("insert uncached release: %v", err)
}
ttl := 24 * time.Hour
stats, err := GetCachedReleases(db, artistID, ttl)
if err != nil {
t.Fatalf("GetCachedReleases() error: %v", err)
}
if stats.CacheHitCount != 0 {
t.Errorf("CacheHitCount = %d, want 0 (NULL cached_at should not be cached)", stats.CacheHitCount)
}
}
func TestGetCachedReleases_EmptyArtist(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
ttl := 24 * time.Hour
stats, err := GetCachedReleases(db, "nonexistent-artist", ttl)
if err != nil {
t.Fatalf("GetCachedReleases() error: %v", err)
}
if stats.CacheHitCount != 0 {
t.Errorf("CacheHitCount = %d, want 0 for nonexistent artist", stats.CacheHitCount)
}
}
func TestIsArtistCacheValid_Valid(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
artistID := "artist-valid-cache"
if err := insertTestArtistForCache(db, artistID); err != nil {
t.Fatalf("insertTestArtist: %v", err)
}
now := time.Now().Format("2006-01-02 15:04:05")
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, cached_at) VALUES (?, ?, ?, ?)",
"rg-valid", artistID, "Valid Album", now,
)
if err != nil {
t.Fatalf("insert: %v", err)
}
ttl := 24 * time.Hour
valid, err := IsArtistCacheValid(db, artistID, ttl)
if err != nil {
t.Fatalf("IsArtistCacheValid() error: %v", err)
}
if !valid {
t.Error("expected cache to be valid")
}
}
func TestIsArtistCacheValid_Invalid(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
ttl := 24 * time.Hour
// No releases at all
valid, err := IsArtistCacheValid(db, "no-releases", ttl)
if err != nil {
t.Fatalf("IsArtistCacheValid() error: %v", err)
}
if valid {
t.Error("expected cache to be invalid for artist with no releases")
}
}
func TestCacheStats_IsCached_Empty(t *testing.T) {
stats := &CacheStats{}
if stats.IsCached("anything") {
t.Error("expected IsCached to return false for empty stats")
}
}
func TestGetCachedReleases_MixedExpiry(t *testing.T) {
db, err := database.New(":memory:")
if err != nil {
t.Fatalf("New() error: %v", err)
}
defer db.Close()
artistID := "artist-mixed"
if err := insertTestArtistForCache(db, artistID); err != nil {
t.Fatalf("insertTestArtist: %v", err)
}
now := time.Now().Format("2006-01-02 15:04:05")
expired := time.Now().Add(-48 * time.Hour).Format("2006-01-02 15:04:05")
// Mix of fresh and expired
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, cached_at) VALUES (?, ?, ?, ?)",
"rg-fresh", artistID, "Fresh Album", now,
)
if err != nil {
t.Fatalf("insert fresh: %v", err)
}
_, err = db.Conn().Exec(
"INSERT INTO external_releases (rgid, artist_id, title, cached_at) VALUES (?, ?, ?, ?)",
"rg-old", artistID, "Old Album", expired,
)
if err != nil {
t.Fatalf("insert old: %v", err)
}
ttl := 24 * time.Hour
stats, err := GetCachedReleases(db, artistID, ttl)
if err != nil {
t.Fatalf("GetCachedReleases() error: %v", err)
}
if stats.CacheHitCount != 1 {
t.Errorf("CacheHitCount = %d, want 1 (only fresh entry)", stats.CacheHitCount)
}
if !stats.IsCached("rg-fresh") {
t.Error("expected rg-fresh to be cached")
}
if stats.IsCached("rg-old") {
t.Error("expected rg-old to NOT be cached (expired)")
}
}

77
internal/musicbrainz/client.go
View File

@@ -1,12 +1,14 @@
package musicbrainz
import (
"context"
"encoding/xml"
"fmt"
"io"
"net/http"
"time"
"golang.org/x/time/rate"
"naviwatcher/internal/config"
)
@@ -16,77 +18,26 @@ type MusicBrainzClient struct {
httpClient *http.Client
userAgent string
baseURL string
rateLimiter *rateLimiter
}
// rateLimiter wraps a token-bucket rate limiter for API calls.
type rateLimiter struct {
// tokens is a channel-based semaphore for rate limiting.
// It is filled at a fixed interval by a background goroutine.
tokens chan struct{}
done chan struct{}
}
// newRateLimiter creates a rate limiter that allows maxCalls per second.
// It immediately fills the bucket and starts a refill goroutine.
func newRateLimiter(callsPerSecond int) *rateLimiter {
rl := &rateLimiter{
tokens: make(chan struct{}, callsPerSecond),
done: make(chan struct{}),
}
// Fill the bucket initially
for i := 0; i < callsPerSecond; i++ {
rl.tokens <- struct{}{}
}
// Refill at the specified interval
interval := time.Second / time.Duration(callsPerSecond)
go func() {
ticker := time.NewTicker(interval)
defer ticker.Stop()
for {
select {
case <-ticker.C:
select {
case rl.tokens <- struct{}{}:
default:
// bucket full, skip
}
case <-rl.done:
return
}
}
}()
return rl
}
// wait blocks until a token is available or the rate limiter is stopped.
func (rl *rateLimiter) wait() {
<-rl.tokens
}
// stop terminates the refill goroutine.
func (rl *rateLimiter) stop() {
close(rl.done)
rateLimiter *rate.Limiter
}
// NewClient creates a new MusicBrainzClient from the given configuration.
// It initializes the HTTP client with a 30-second timeout and sets up
// a rate limiter for 1 request per second as required by MusicBrainz policy.
func NewClient(cfg config.MusicBrainzConfig) *MusicBrainzClient {
rl := newRateLimiter(1) // 1 request per second
return &MusicBrainzClient{
httpClient: &http.Client{
Timeout: 30 * time.Second,
},
userAgent: cfg.UserAgent,
baseURL: "https://musicbrainz.org/ws/2",
rateLimiter: rl,
rateLimiter: rate.NewLimiter(rate.Limit(1), 1),
}
}
// NewClientWithLimiter creates a MusicBrainzClient with a custom rate limiter.
// This is primarily used for testing to inject a mock rate limiter.
func NewClientWithLimiter(cfg config.MusicBrainzConfig, rl *rateLimiter) *MusicBrainzClient {
func NewClientWithLimiter(cfg config.MusicBrainzConfig, rl *rate.Limiter) *MusicBrainzClient {
return &MusicBrainzClient{
httpClient: &http.Client{
Timeout: 30 * time.Second,
@@ -97,17 +48,19 @@ func NewClientWithLimiter(cfg config.MusicBrainzConfig, rl *rateLimiter) *MusicB
}
}
// Close cleans up the rate limiter goroutine.
func (c *MusicBrainzClient) Close() {
c.rateLimiter.stop()
}
// Close is a no-op for the x/time/rate-based client (the limiter does not
// spawn goroutines), but retained for API compatibility.
func (c *MusicBrainzClient) Close() {}
// doGet performs a rate-limited HTTP GET request to the MusicBrainz API.
// It sets the proper User-Agent header and returns the response body.
func (c *MusicBrainzClient) doGet(path string) ([]byte, error) {
c.rateLimiter.wait()
// It blocks until the rate limiter allows the request, then sets the proper
// User-Agent header and returns the response body.
func (c *MusicBrainzClient) doGet(ctx context.Context, path string) ([]byte, error) {
if err := c.rateLimiter.Wait(ctx); err != nil {
return nil, fmt.Errorf("rate limiter wait: %w", err)
}
req, err := http.NewRequest(http.MethodGet, c.baseURL+path, nil)
req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.baseURL+path, nil)
if err != nil {
return nil, fmt.Errorf("create request: %w", err)
}

100
internal/musicbrainz/client_test.go
View File

@@ -1,18 +1,16 @@
package musicbrainz
import (
"context"
"net/http"
"net/http/httptest"
"testing"
"time"
"golang.org/x/time/rate"
"naviwatcher/internal/config"
)
func newUnbufferedRateLimiter() *rateLimiter {
return newRateLimiter(1000) // high rate to avoid blocking in tests
}
func TestNewClient_ValidConfig(t *testing.T) {
cfg := config.MusicBrainzConfig{
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
@@ -48,7 +46,7 @@ func TestNewClientWithLimiter(t *testing.T) {
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
}
rl := newRateLimiter(1)
rl := rate.NewLimiter(rate.Limit(1), 1)
client := NewClientWithLimiter(cfg, rl)
defer client.Close()
@@ -78,7 +76,7 @@ func TestDoGet_Success(t *testing.T) {
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
}
rl := newUnbufferedRateLimiter()
rl := rate.NewLimiter(rate.Limit(1000), 1000) // high rate to avoid blocking in tests
client := &MusicBrainzClient{
httpClient: server.Client(),
userAgent: cfg.UserAgent,
@@ -87,7 +85,7 @@ func TestDoGet_Success(t *testing.T) {
}
defer client.Close()
body, err := client.doGet("/test")
body, err := client.doGet(context.Background(), "/test")
if err != nil {
t.Fatalf("doGet() error = %v", err)
}
@@ -108,7 +106,7 @@ func TestDoGet_Non200Status(t *testing.T) {
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
}
rl := newUnbufferedRateLimiter()
rl := rate.NewLimiter(rate.Limit(1000), 1000)
client := &MusicBrainzClient{
httpClient: server.Client(),
userAgent: cfg.UserAgent,
@@ -117,7 +115,7 @@ func TestDoGet_Non200Status(t *testing.T) {
}
defer client.Close()
_, err := client.doGet("/test")
_, err := client.doGet(context.Background(), "/test")
if err == nil {
t.Fatal("doGet() expected error for non-200 status, got nil")
}
@@ -131,7 +129,7 @@ func TestDoGet_ServerUnreachable(t *testing.T) {
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
}
rl := newUnbufferedRateLimiter()
rl := rate.NewLimiter(rate.Limit(1000), 1000)
client := &MusicBrainzClient{
httpClient: server.Client(),
userAgent: cfg.UserAgent,
@@ -140,28 +138,78 @@ func TestDoGet_ServerUnreachable(t *testing.T) {
}
defer client.Close()
_, err := client.doGet("/test")
_, err := client.doGet(context.Background(), "/test")
if err == nil {
t.Fatal("doGet() expected error for unreachable server, got nil")
}
}
func TestRateLimiter_BasicBehavior(t *testing.T) {
// Test that rate limiter can produce tokens
rl := newRateLimiter(1)
defer rl.stop()
func TestDoGet_ContextCancellation(t *testing.T) {
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`<metadata><test>ok</test></metadata>`))
}))
defer server.Close()
// Should be able to get a token immediately (bucket was pre-filled)
done := make(chan struct{})
go func() {
rl.wait()
close(done)
}()
cfg := config.MusicBrainzConfig{
UserAgent: "naviwatcher/0.1.0 (test@example.com)",
}
select {
case <-done:
// success
case <-time.After(2 * time.Second):
t.Fatal("rateLimiter.wait() blocked on pre-filled bucket")
// Use a rate limiter with 0 burst to force blocking on Wait
rl := rate.NewLimiter(rate.Limit(0), 0)
client := &MusicBrainzClient{
httpClient: server.Client(),
userAgent: cfg.UserAgent,
baseURL: server.URL,
rateLimiter: rl,
}
defer client.Close()
ctx, cancel := context.WithCancel(context.Background())
cancel() // cancel immediately
_, err := client.doGet(ctx, "/test")
if err == nil {
t.Fatal("doGet() expected error for cancelled context, got nil")
}
}
func TestRateLimiter_OnePerSecond(t *testing.T) {
// Verify that the rate limiter enforces approximately 1 request per second
rl := rate.NewLimiter(rate.Limit(1), 1)
// First request should be immediate (burst of 1)
start := time.Now()
if err := rl.Wait(context.Background()); err != nil {
t.Fatalf("first Wait() error: %v", err)
}
elapsed := time.Since(start)
if elapsed > 100*time.Millisecond {
t.Errorf("first Wait() took %v, expected near-instant", elapsed)
}
// Second request should block for approximately 1 second
start = time.Now()
if err := rl.Wait(context.Background()); err != nil {
t.Fatalf("second Wait() error: %v", err)
}
elapsed = time.Since(start)
if elapsed < 800*time.Millisecond {
t.Errorf("second Wait() took %v, expected at least ~1s", elapsed)
}
if elapsed > 2*time.Second {
t.Errorf("second Wait() took %v, expected less than 2s", elapsed)
}
}
func TestRateLimiter_BurstBehavior(t *testing.T) {
// With burst=1, the first request should be immediate
rl := rate.NewLimiter(rate.Limit(1), 1)
start := time.Now()
rl.Wait(context.Background())
elapsed := time.Since(start)
if elapsed > 50*time.Millisecond {
t.Errorf("burst Wait() took %v, expected near-instant", elapsed)
}
}