incusd/network: Optimize UsedByInstanceDevices

Signed-off-by: Stéphane Graber <[email protected]>

internal/server/network/network_utils.go

@@ -79,30 +79,47 @@ func MACDevName(mac net.HardwareAddr) string {
 // UsedByInstanceDevices looks for instance NIC devices using the network and runs the supplied usageFunc for each.
 // Accepts optional filter arguments to specify a subset of instances.
 func UsedByInstanceDevices(s *state.State, networkProjectName string, networkName string, networkType string, usageFunc func(inst db.InstanceArgs, nicName string, nicConfig map[string]string) error, filters ...cluster.InstanceFilter) error {
-	return s.DB.Cluster.Transaction(context.TODO(), func(ctx context.Context, tx *db.ClusterTx) error {
+	// Get the instances.
+	projects := map[string]api.Project{}
+	instances := []db.InstanceArgs{}
+
+	err := s.DB.Cluster.Transaction(context.TODO(), func(ctx context.Context, tx *db.ClusterTx) error {
 		return tx.InstanceList(ctx, func(inst db.InstanceArgs, p api.Project) error {
-			// Get the instance's effective network project name.
-			instNetworkProject := project.NetworkProjectFromRecord(&p)
+			projects[inst.Project] = p
+			instances = append(instances, inst)
 
-			// Skip instances who's effective network project doesn't match this Network's project.
-			if instNetworkProject != networkProjectName {
-				return nil
-			}
+			return nil
+		}, filters...)
+	})
+	if err != nil {
+		return err
+	}
 
-			// Look for NIC devices using this network.
-			devices := db.ExpandInstanceDevices(inst.Devices.Clone(), inst.Profiles)
-			for devName, devConfig := range devices {
-				if isInUseByDevice(networkName, networkType, devConfig) {
-					err := usageFunc(inst, devName, devConfig)
-					if err != nil {
-						return err
-					}
+	// Go through the instances and run usageFunc.
+	for _, inst := range instances {
+		p := projects[inst.Project]
+
+		// Get the instance's effective network project name.
+		instNetworkProject := project.NetworkProjectFromRecord(&p)
+
+		// Skip instances who's effective network project doesn't match this Network's project.
+		if instNetworkProject != networkProjectName {
+			return nil
+		}
+
+		// Look for NIC devices using this network.
+		devices := db.ExpandInstanceDevices(inst.Devices.Clone(), inst.Profiles)
+		for devName, devConfig := range devices {
+			if isInUseByDevice(networkName, networkType, devConfig) {
+				err := usageFunc(inst, devName, devConfig)
+				if err != nil {
+					return err
 				}
 			}
+		}
+	}
 
-			return nil
-		}, filters...)
-	})
+	return nil
 }
 
 // UsedBy returns list of API resources using network. Accepts firstOnly argument to indicate that only the first