Refactor database handlers and optimize PeeringHandler

- Create PeeringHandler for asn_peerings table maintenance
- Rename DBHandler to ASHandler (now only handles asns table)
- Move prefixes table maintenance to PrefixHandler
- Optimize PeeringHandler with in-memory AS path tracking:
  - Stores AS paths in memory with timestamps
  - Processes peerings in batch every 2 minutes
  - Prunes old paths (>30 minutes) every 5 minutes
  - Normalizes peerings with lower AS number first
- Each handler now has a single responsibility:
  - ASHandler: asns table
  - PeerHandler: bgp_peers table
  - PrefixHandler: prefixes and live_routes tables
  - PeeringHandler: asn_peerings table

internal/routewatch/app.go

@@ -40,19 +40,20 @@ type Dependencies struct {
 
 // RouteWatch represents the main application instance
 type RouteWatch struct {
-	db            database.Store
-	routingTable  *routingtable.RoutingTable
-	streamer      *streamer.Streamer
-	server        *server.Server
-	snapshotter   *snapshotter.Snapshotter
-	logger        *logger.Logger
-	maxRuntime    time.Duration
-	shutdown      bool
-	mu            sync.Mutex
-	config        *config.Config
-	dbHandler     *DBHandler
-	peerHandler   *PeerHandler
-	prefixHandler *PrefixHandler
+	db             database.Store
+	routingTable   *routingtable.RoutingTable
+	streamer       *streamer.Streamer
+	server         *server.Server
+	snapshotter    *snapshotter.Snapshotter
+	logger         *logger.Logger
+	maxRuntime     time.Duration
+	shutdown       bool
+	mu             sync.Mutex
+	config         *config.Config
+	dbHandler      *ASHandler
+	peerHandler    *PeerHandler
+	prefixHandler  *PrefixHandler
+	peeringHandler *PeeringHandler
 }
 
 // isTruthy returns true if the value is considered truthy
@@ -107,14 +108,21 @@ func (rw *RouteWatch) Run(ctx context.Context) error {
 	// Register database handler to process BGP UPDATE messages
 	if rw.config.EnableBatchedDatabaseWrites {
 		rw.logger.Info("Using batched database handlers for improved performance")
-		rw.dbHandler = NewDBHandler(rw.db, rw.logger)
+		// ASHandler maintains the asns table
+		rw.dbHandler = NewASHandler(rw.db, rw.logger)
 		rw.streamer.RegisterHandler(rw.dbHandler)
 
+		// PeerHandler maintains the bgp_peers table
 		rw.peerHandler = NewPeerHandler(rw.db, rw.logger)
 		rw.streamer.RegisterHandler(rw.peerHandler)
 
+		// PrefixHandler maintains the prefixes and live_routes tables
 		rw.prefixHandler = NewPrefixHandler(rw.db, rw.logger)
 		rw.streamer.RegisterHandler(rw.prefixHandler)
+
+		// PeeringHandler maintains the asn_peerings table
+		rw.peeringHandler = NewPeeringHandler(rw.db, rw.logger)
+		rw.streamer.RegisterHandler(rw.peeringHandler)
 	} else {
 		// Non-batched handlers not implemented yet
 		rw.logger.Error("Non-batched handlers not implemented")