Merge pull request #549 from gopcua/add-context-to-subscription

add context to subscription methods

client.go

@@ -423,7 +423,7 @@ func (c *Client) monitor(ctx context.Context) {
 
 						// try to transfer all subscriptions to the new session and
 						// recreate them all if that fails.
-						res, err := c.transferSubscriptions(subIDs)
+						res, err := c.transferSubscriptions(ctx, subIDs)
 						switch {
 						case err != nil:
 							dlog.Printf("transfer subscriptions failed. Recreating all subscriptions: %v", err)

client_sub.go

@@ -16,7 +16,15 @@ import (
 // Subscribe creates a Subscription with given parameters.
 // Parameters that have not been set are set to their default values.
 // See opcua.DefaultSubscription* constants
+//
+// Note: Starting with v0.5 this method will require a context
+// and the corresponding XXXWithContext(ctx) method will be removed.
 func (c *Client) Subscribe(params *SubscriptionParameters, notifyCh chan<- *PublishNotificationData) (*Subscription, error) {
+	return c.SubscribeWithContext(context.Background(), params, notifyCh)
+}
+
+// Note: Starting with v0.5 this method is superseded by the non 'WithContext' method.
+func (c *Client) SubscribeWithContext(ctx context.Context, params *SubscriptionParameters, notifyCh chan<- *PublishNotificationData) (*Subscription, error) {
 	stats.Client().Add("Subscribe", 1)
 
 	if params == nil {
@@ -34,7 +42,7 @@ func (c *Client) Subscribe(params *SubscriptionParameters, notifyCh chan<- *Publ
 	}
 
 	var res *ua.CreateSubscriptionResponse
-	err := c.Send(req, func(v interface{}) error {
+	err := c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 	if err != nil {
@@ -99,14 +107,14 @@ func (c *Client) recreateSubscription(ctx context.Context, id uint32) error {
 
 // transferSubscriptions ask the server to transfer the given subscriptions
 // of the previous session to the current one.
-func (c *Client) transferSubscriptions(ids []uint32) (*ua.TransferSubscriptionsResponse, error) {
+func (c *Client) transferSubscriptions(ctx context.Context, ids []uint32) (*ua.TransferSubscriptionsResponse, error) {
 	req := &ua.TransferSubscriptionsRequest{
 		SubscriptionIDs:   ids,
 		SendInitialValues: false,
 	}
 
 	var res *ua.TransferSubscriptionsResponse
-	err := c.Send(req, func(v interface{}) error {
+	err := c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 	return res, err

subscription.go

@@ -84,17 +84,17 @@ type PublishNotificationData struct {
 func (s *Subscription) Cancel(ctx context.Context) error {
 	stats.Subscription().Add("Cancel", 1)
 	s.c.forgetSubscription(ctx, s.SubscriptionID)
-	return s.delete()
+	return s.delete(ctx)
 }
 
 // delete removes the subscription from the server.
-func (s *Subscription) delete() error {
+func (s *Subscription) delete(ctx context.Context) error {
 	req := &ua.DeleteSubscriptionsRequest{
 		SubscriptionIDs: []uint32{s.SubscriptionID},
 	}
 
 	var res *ua.DeleteSubscriptionsResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 
@@ -111,7 +111,14 @@ func (s *Subscription) delete() error {
 	}
 }
 
+// Note: Starting with v0.5 this method will require a context
+// and the corresponding XXXWithContext(ctx) method will be removed.
 func (s *Subscription) Monitor(ts ua.TimestampsToReturn, items ...*ua.MonitoredItemCreateRequest) (*ua.CreateMonitoredItemsResponse, error) {
+	return s.MonitorWithContext(context.Background(), ts, items...)
+}
+
+// Note: Starting with v0.5 this method is superseded by the non 'WithContext' method.
+func (s *Subscription) MonitorWithContext(ctx context.Context, ts ua.TimestampsToReturn, items ...*ua.MonitoredItemCreateRequest) (*ua.CreateMonitoredItemsResponse, error) {
 	stats.Subscription().Add("Monitor", 1)
 	stats.Subscription().Add("MonitoredItems", int64(len(items)))
 
@@ -123,7 +130,7 @@ func (s *Subscription) Monitor(ts ua.TimestampsToReturn, items ...*ua.MonitoredI
 	}
 
 	var res *ua.CreateMonitoredItemsResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 
@@ -146,7 +153,14 @@ func (s *Subscription) Monitor(ts ua.TimestampsToReturn, items ...*ua.MonitoredI
 	return res, err
 }
 
+// Note: Starting with v0.5 this method will require a context
+// and the corresponding XXXWithContext(ctx) method will be removed.
 func (s *Subscription) Unmonitor(monitoredItemIDs ...uint32) (*ua.DeleteMonitoredItemsResponse, error) {
+	return s.UnmonitorWithContext(context.Background(), monitoredItemIDs...)
+}
+
+// Note: Starting with v0.5 this method is superseded by the non 'WithContext' method.
+func (s *Subscription) UnmonitorWithContext(ctx context.Context, monitoredItemIDs ...uint32) (*ua.DeleteMonitoredItemsResponse, error) {
 	stats.Subscription().Add("Unmonitor", 1)
 	stats.Subscription().Add("UnmonitoredItems", int64(len(monitoredItemIDs)))
 
@@ -156,7 +170,7 @@ func (s *Subscription) Unmonitor(monitoredItemIDs ...uint32) (*ua.DeleteMonitore
 	}
 
 	var res *ua.DeleteMonitoredItemsResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 
@@ -172,7 +186,14 @@ func (s *Subscription) Unmonitor(monitoredItemIDs ...uint32) (*ua.DeleteMonitore
 	return res, err
 }
 
+// Note: Starting with v0.5 this method will require a context
+// and the corresponding XXXWithContext(ctx) method will be removed.
 func (s *Subscription) ModifyMonitoredItems(ts ua.TimestampsToReturn, items ...*ua.MonitoredItemModifyRequest) (*ua.ModifyMonitoredItemsResponse, error) {
+	return s.ModifyMonitoredItemsWithContext(context.Background(), ts, items...)
+}
+
+// Note: Starting with v0.5 this method is superseded by the non 'WithContext' method.
+func (s *Subscription) ModifyMonitoredItemsWithContext(ctx context.Context, ts ua.TimestampsToReturn, items ...*ua.MonitoredItemModifyRequest) (*ua.ModifyMonitoredItemsResponse, error) {
 	stats.Subscription().Add("ModifyMonitoredItems", 1)
 	stats.Subscription().Add("ModifiedMonitoredItems", int64(len(items)))
 
@@ -191,7 +212,7 @@ func (s *Subscription) ModifyMonitoredItems(ts ua.TimestampsToReturn, items ...*
 		ItemsToModify:      items,
 	}
 	var res *ua.ModifyMonitoredItemsResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 	if err != nil {
@@ -222,7 +243,15 @@ func (s *Subscription) ModifyMonitoredItems(ts ua.TimestampsToReturn, items ...*
 // SetTriggering sends a request to the server to add and/or remove triggering links from a triggering item.
 // To add links from a triggering item to an item to report provide the server assigned ID(s) in the `add` argument.
 // To remove links from a triggering item to an item to report provide the server assigned ID(s) in the `remove` argument.
+//
+// Note: Starting with v0.5 this method will require a context
+// and the corresponding XXXWithContext(ctx) method will be removed.
 func (s *Subscription) SetTriggering(triggeringItemID uint32, add, remove []uint32) (*ua.SetTriggeringResponse, error) {
+	return s.SetTriggeringWithContext(context.Background(), triggeringItemID, add, remove)
+}
+
+// Note: Starting with v0.5 this method is superseded by the non 'WithContext' method.
+func (s *Subscription) SetTriggeringWithContext(ctx context.Context, triggeringItemID uint32, add, remove []uint32) (*ua.SetTriggeringResponse, error) {
 	stats.Subscription().Add("SetTriggering", 1)
 
 	// Part 4, 5.12.5.2 SetTriggering Service Parameters
@@ -234,7 +263,7 @@ func (s *Subscription) SetTriggering(triggeringItemID uint32, add, remove []uint
 	}
 
 	var res *ua.SetTriggeringResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 	return res, err
@@ -319,7 +348,7 @@ func (s *Subscription) recreate(ctx context.Context) error {
 			SubscriptionIDs: []uint32{s.SubscriptionID},
 		}
 		var res *ua.DeleteSubscriptionsResponse
-		_ = s.c.Send(req, func(v interface{}) error {
+		_ = s.c.SendWithContext(ctx, req, func(v interface{}) error {
 			return safeAssign(v, &res)
 		})
 		dlog.Print("subscription deleted")
@@ -336,7 +365,7 @@ func (s *Subscription) recreate(ctx context.Context) error {
 		Priority:                    params.Priority,
 	}
 	var res *ua.CreateSubscriptionResponse
-	err := s.c.Send(req, func(v interface{}) error {
+	err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 		return safeAssign(v, &res)
 	})
 	if err != nil {
@@ -379,7 +408,7 @@ func (s *Subscription) recreate(ctx context.Context) error {
 		}
 
 		var res *ua.CreateMonitoredItemsResponse
-		err := s.c.Send(req, func(v interface{}) error {
+		err := s.c.SendWithContext(ctx, req, func(v interface{}) error {
 			return safeAssign(v, &res)
 		})
 		if err != nil {