perf(api): cache total wallets metric

api/server.go

@@ -158,6 +158,14 @@ func NewApiServer(config config.Config) *ApiServer {
 		panic(err)
 	}
 
+	totalWalletsCache, err := otter.MustBuilder[string, int64](16).
+		WithTTL(totalWalletsCacheTTL).
+		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,
+		totalWalletsCache:       &totalWalletsCache,
 		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]
+	totalWalletsCache       *otter.Cache[string, int64]
 	requestValidator        *RequestValidator
 	rewardManagerClient     *reward_manager.RewardManagerClient
 	claimableTokensClient   *claimable_tokens.ClaimableTokensClient

api/v1_metrics_total_wallets.go

@@ -1,10 +1,19 @@
 package api
 
 import (
+	"time"
+
 	"github.com/gofiber/fiber/v2"
 )
 
+const totalWalletsCacheTTL = 5 * time.Minute
+const totalWalletsCacheKey = "total"
+
 func (app *ApiServer) v1MetricsTotalWallets(c *fiber.Ctx) error {
+	if total, ok := app.totalWalletsCache.Get(totalWalletsCacheKey); ok {
+		return c.JSON(fiber.Map{"data": map[string]int64{"total": total}})
+	}
+
 	var total int64
 	if err := app.pool.QueryRow(c.Context(), `
 		SELECT SUM(count)::bigint AS total
@@ -17,5 +26,6 @@ func (app *ApiServer) v1MetricsTotalWallets(c *fiber.Ctx) error {
 		return err
 	}
 
+	app.totalWalletsCache.Set(totalWalletsCacheKey, total)
 	return c.JSON(fiber.Map{"data": map[string]int64{"total": total}})
 }

api/v1_metrics_total_wallets_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"api.audius.co/database"
+	"github.com/stretchr/testify/require"
 )
 
 func TestMetricsTotalWallets_Empty(t *testing.T) {
@@ -46,3 +47,18 @@ func TestMetricsTotalWallets_WithFixtures(t *testing.T) {
 		"data.total": 7,
 	})
 }
+
+func TestMetricsTotalWallets_Cache(t *testing.T) {
+	app := emptyTestApp(t)
+
+	_, ok := app.totalWalletsCache.Get(totalWalletsCacheKey)
+	require.False(t, ok)
+
+	app.totalWalletsCache.Set(totalWalletsCacheKey, 42)
+
+	status, body := testGet(t, app, "/v1/metrics/total_wallets")
+	require.Equal(t, 200, status)
+	jsonAssert(t, body, map[string]any{
+		"data.total": 42,
+	})
+}