implement event count caching and background updates

.gitignore

@@ -1 +1 @@
-postgres/
+postgres**/

relay/main.go

@@ -8,12 +8,18 @@ import (
 	"strconv"
 	"time"
 
+	"git.highperfocused.tech/highperfocused/lumina-relay/relay/cache"
 	"git.highperfocused.tech/highperfocused/lumina-relay/relay/trending"
 	"github.com/fiatjaf/eventstore/postgresql"
 	"github.com/fiatjaf/khatru"
 	"github.com/fiatjaf/khatru/policies"
 )
 
+// Cache for storing generic data like event counts
+var dataCache = cache.New()
+const eventCountCacheKey = "total_event_count"
+const eventCountCacheDuration = 1 * time.Minute
+
 func getEnv(key, fallback string) string {
 	if value, ok := os.LookupEnv(key); ok {
 		return value
@@ -21,6 +27,43 @@ func getEnv(key, fallback string) string {
 	return fallback
 }
 
+// Gets total event count, using cache if available
+func getTotalEventCount(db *postgresql.PostgresBackend) (int, error) {
+	// Try getting from cache first
+	if cachedCount, ok := dataCache.Get(eventCountCacheKey); ok {
+		return cachedCount.(int), nil
+	}
+
+	// If not in cache, query the database
+	count := 0
+	row := db.DB.QueryRow("SELECT COUNT(*) FROM event")
+	if err := row.Scan(&count); err != nil {
+		return 0, err
+	}
+	
+	// Update the cache
+	dataCache.Set(eventCountCacheKey, count, eventCountCacheDuration)
+	return count, nil
+}
+
+// Updates event count in the background periodically
+func startEventCountUpdater(db *postgresql.PostgresBackend) {
+	go func() {
+		ticker := time.NewTicker(eventCountCacheDuration)
+		defer ticker.Stop()
+		for range ticker.C {
+			count := 0
+			row := db.DB.QueryRow("SELECT COUNT(*) FROM event")
+			if err := row.Scan(&count); err != nil {
+				fmt.Printf("Error updating event count: %v\n", err)
+				continue
+			}
+			dataCache.Set(eventCountCacheKey, count, eventCountCacheDuration)
+			fmt.Printf("Updated event count cache: %d events\n", count)
+		}
+	}()
+}
+
 func main() {
 	fmt.Print(`
 	LUMINA RELAY
@@ -55,6 +98,14 @@ func main() {
 		fmt.Printf("Warning: Error initializing trending system: %v\n", err)
 	}
 
+	// Initialize event count cache and start periodic updates
+	fmt.Println("Initializing event count cache...")
+	_, err := getTotalEventCount(&db)
+	if err != nil {
+		fmt.Printf("Warning: Error initializing event count cache: %v\n", err)
+	}
+	startEventCountUpdater(&db)
+
 	relay.StoreEvent = append(relay.StoreEvent, db.SaveEvent)
 	relay.QueryEvents = append(relay.QueryEvents, db.QueryEvents)
 	relay.DeleteEvent = append(relay.DeleteEvent, db.DeleteEvent)
@@ -73,11 +124,11 @@ func main() {
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("content-type", "text/html")
 
-		// Query the total number of events
-		count := 0
-		row := db.DB.QueryRow("SELECT COUNT(*) FROM event")
-		if err := row.Scan(&count); err != nil {
-			fmt.Printf("Error counting events: %v\n", err)
+			// Get event count from cache
+		count, err := getTotalEventCount(&db)
+		if err != nil {
+			fmt.Printf("Error getting event count: %v\n", err)
+			count = 0 // Fall back to zero if there's an error
 		}
 
 		// Improved HTML content with link to stats page
@@ -225,6 +276,13 @@ func main() {
 	mux.HandleFunc("/api/stats", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 
+			// Get total count from cache
+		totalCount, err := getTotalEventCount(&db)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("Error getting event count: %v", err), http.StatusInternalServerError)
+			return
+		}
+
 		// Query the number of events for each kind, sorted by kind
 		rows, err := db.DB.Query("SELECT kind, COUNT(*) FROM event GROUP BY kind ORDER BY kind")
 		if err != nil {
@@ -234,7 +292,6 @@ func main() {
 		defer rows.Close()
 
 		stats := make(map[string]int)
-		totalCount := 0
 		for rows.Next() {
 			var kind string
 			var count int
@@ -243,7 +300,6 @@ func main() {
 				return
 			}
 			stats[kind] = count
-			totalCount += count
 		}
 
 		// Add total count to the stats