perf(api): cache sitemap pages

api/server.go

@@ -158,6 +158,14 @@ func NewApiServer(config config.Config) *ApiServer {
 		panic(err)
 	}
 
+	sitemapPageCache, err := otter.MustBuilder[string, []byte](256).
+		WithTTL(sitemapPageCacheTTL).
+		CollectStats().
+		Build()
+	if err != nil {
+		panic(err)
+	}
+
 	privateKey, err := crypto.HexToECDSA(config.DelegatePrivateKey)
 	if err != nil {
 		panic(err)
@@ -268,6 +276,7 @@ func NewApiServer(config config.Config) *ApiServer {
 		oauthTokenCache:         &oauthTokenCache,
 		qualifiedPlaylistsCache: &qualifiedPlaylistsCache,
 		relatedUsersCache:       &relatedUsersCache,
+		sitemapPageCache:        &sitemapPageCache,
 		requestValidator:        requestValidator,
 		rewardAttester:          rewardAttester,
 		transactionSender:       transactionSender,
@@ -822,6 +831,7 @@ type ApiServer struct {
 	oauthTokenCache         *otter.Cache[string, oauthTokenCacheEntry]
 	qualifiedPlaylistsCache *otter.Cache[string, []int32]
 	relatedUsersCache       *otter.Cache[string, []int32]
+	sitemapPageCache        *otter.Cache[string, []byte]
 	requestValidator        *RequestValidator
 	rewardManagerClient     *reward_manager.RewardManagerClient
 	claimableTokensClient   *claimable_tokens.ClaimableTokensClient

api/v1_sitemaps.go

@@ -18,6 +18,7 @@ import (
 
 const sitemapLimit = 40_000
 const sitemapCountCacheTTL = 1 * time.Hour
+const sitemapPageCacheTTL = 1 * time.Hour
 
 var sitemapPageRegex = regexp.MustCompile(`^(\d+)\.xml$`)
 
@@ -266,6 +267,12 @@ func (app *ApiServer) sitemapTypePage(c *fiber.Ctx) error {
 		return fiber.NewError(400, "Page number must be >= 1")
 	}
 
+	cacheKey := entityType + ":" + fileName
+	if data, ok := app.sitemapPageCache.Get(cacheKey); ok {
+		c.Set("Content-Type", "text/xml")
+		return c.Send(data)
+	}
+
 	offset := int32((pageNumber - 1) * sitemapLimit)
 	ctx := c.Context()
 	baseURL := app.audiusAppUrl
@@ -328,6 +335,7 @@ func (app *ApiServer) sitemapTypePage(c *fiber.Ctx) error {
 	if err != nil {
 		return err
 	}
+	app.sitemapPageCache.Set(cacheKey, data)
 	c.Set("Content-Type", "text/xml")
 	return c.Send(data)
 }

api/v1_sitemaps_test.go

@@ -112,6 +112,17 @@ func TestSitemapTrackPage(t *testing.T) {
 	assert.NotContains(t, xml, "%2F")
 }
 
+func TestSitemapTrackPageCache(t *testing.T) {
+	app := sitemapTestApp(t)
+
+	cached := []byte(`<?xml version="1.0" encoding="UTF-8"?><urlset><url><loc>cached-track-page</loc></url></urlset>`)
+	require.True(t, app.sitemapPageCache.Set("track:1.xml", cached))
+
+	status, body := testGet(t, app, "/sitemaps/track/1.xml")
+	require.Equal(t, 200, status)
+	assert.Contains(t, string(body), "cached-track-page")
+}
+
 func TestSitemapPlaylistPage(t *testing.T) {
 	app := sitemapTestApp(t)
 	status, body := testGet(t, app, "/sitemaps/playlist/1.xml")