General code optimisations. (#16)

* General code optimisations.

events.go

@@ -5,70 +5,76 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
 	libpack_logger "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
 )
 
-func enableHasuraEventCleaner() {
-	if cfg.HasuraEventCleaner.Enable {
-		if cfg.HasuraEventCleaner.EventMetadataDb == "" {
-			cfg.Logger.Warning(&libpack_logger.LogMessage{
-				Message: "Event metadata db URL not specified, event cleaner not active",
-				Pairs:   nil,
-			})
-			return
-		}
+const (
+	initialDelay    = 60 * time.Second
+	cleanupInterval = 1 * time.Hour
+)
 
-		ticker := time.NewTicker(1 * time.Hour)
-		defer ticker.Stop()
-		cfg.Logger.Info(&libpack_logger.LogMessage{
-			Message: "Event cleaner enabled",
-			Pairs:   map[string]interface{}{"interval_in_days": cfg.HasuraEventCleaner.ClearOlderThan},
-		})
-
-		time.Sleep(60 * time.Second) // wait for everything to start and settle down
-		cfg.Logger.Info(&libpack_logger.LogMessage{
-			Message: "Initial cleanup of old events",
-			Pairs:   nil,
-		})
-		cleanEvents()
-
-		for {
-			select {
-			case <-ticker.C:
-				cfg.Logger.Info(&libpack_logger.LogMessage{
-					Message: "Cleaning up old events",
-					Pairs:   nil,
-				})
-				cleanEvents()
-			}
-		}
-	}
+var delQueries = []string{
+	"DELETE FROM hdb_catalog.event_invocation_logs WHERE created_at < now() - interval '%d days';",
+	"DELETE FROM hdb_catalog.event_log WHERE created_at < now() - interval '%d days';",
+	"DELETE FROM hdb_catalog.hdb_action_log WHERE created_at < NOW() - INTERVAL '%d days';",
+	"DELETE FROM hdb_catalog.hdb_cron_event_invocation_logs WHERE created_at < NOW() - INTERVAL '%d days';",
+	"DELETE FROM hdb_catalog.hdb_scheduled_event_invocation_logs WHERE created_at < NOW() - INTERVAL '%d days';",
 }
 
-func cleanEvents() {
-	conn, err := pgx.Connect(context.Background(), cfg.HasuraEventCleaner.EventMetadataDb)
+func enableHasuraEventCleaner() {
+	if !cfg.HasuraEventCleaner.Enable {
+		return
+	}
+
+	if cfg.HasuraEventCleaner.EventMetadataDb == "" {
+		cfg.Logger.Warning(&libpack_logger.LogMessage{
+			Message: "Event metadata db URL not specified, event cleaner not active",
+		})
+		return
+	}
+
+	cfg.Logger.Info(&libpack_logger.LogMessage{
+		Message: "Event cleaner enabled",
+		Pairs:   map[string]interface{}{"interval_in_days": cfg.HasuraEventCleaner.ClearOlderThan},
+	})
+
+	pool, err := pgxpool.New(context.Background(), cfg.HasuraEventCleaner.EventMetadataDb)
 	if err != nil {
 		cfg.Logger.Error(&libpack_logger.LogMessage{
-			Message: "Failed to connect to event metadata db",
+			Message: "Failed to create connection pool",
 			Pairs:   map[string]interface{}{"error": err},
 		})
 		return
 	}
-	defer conn.Close(context.Background())
+	defer pool.Close()
 
-	delQueries := []string{
-		fmt.Sprintf("DELETE FROM hdb_catalog.event_invocation_logs WHERE created_at < now() - interval '%d days';", cfg.HasuraEventCleaner.ClearOlderThan),
-		fmt.Sprintf("DELETE FROM hdb_catalog.event_log WHERE created_at < now() - interval '%d days';", cfg.HasuraEventCleaner.ClearOlderThan),
-		fmt.Sprintf("DELETE FROM hdb_catalog.hdb_action_log WHERE created_at < NOW() - INTERVAL '%d days';", cfg.HasuraEventCleaner.ClearOlderThan),
-		fmt.Sprintf("DELETE FROM hdb_catalog.hdb_cron_event_invocation_logs WHERE created_at < NOW() - INTERVAL '%d days';", cfg.HasuraEventCleaner.ClearOlderThan),
-		fmt.Sprintf("DELETE FROM hdb_catalog.hdb_scheduled_event_invocation_logs WHERE created_at < NOW() - INTERVAL '%d days';", cfg.HasuraEventCleaner.ClearOlderThan),
-	}
+	go func() {
+		time.Sleep(initialDelay)
 
+		cfg.Logger.Info(&libpack_logger.LogMessage{
+			Message: "Initial cleanup of old events",
+		})
+		cleanEvents(pool)
+
+		ticker := time.NewTicker(cleanupInterval)
+		defer ticker.Stop()
+
+		for range ticker.C {
+			cfg.Logger.Info(&libpack_logger.LogMessage{
+				Message: "Cleaning up old events",
+			})
+			cleanEvents(pool)
+		}
+	}()
+}
+
+func cleanEvents(pool *pgxpool.Pool) {
+	ctx := context.Background()
 	for _, query := range delQueries {
-		_, err := conn.Exec(context.Background(), query)
+		_, err := pool.Exec(ctx, fmt.Sprintf(query, cfg.HasuraEventCleaner.ClearOlderThan))
 		if err != nil {
-			cfg.Logger.Debug(&libpack_logger.LogMessage{
+			cfg.Logger.Error(&libpack_logger.LogMessage{
 				Message: "Failed to execute query",
 				Pairs:   map[string]interface{}{"query": query, "error": err},
 			})