monitor

package
v1.0.6 Latest Latest
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 Go to latest Published: Jan 5, 2024 License: MIT Imports: 6 Imported by: 0

Documentation

Index

Constants

This section is empty.

Variables

View Source 
var (
	// DefaultCallbackBufferLen is the size of the internal buffer when using a callback-based subscription
	DefaultCallbackBufferLen = 8192

	// ErrSlowConsumer is returned when a subscriber does not keep up with the incoming messages
	ErrSlowConsumer = errors.New("slow consumer. messages may be dropped")
)

Functions

This section is empty.

Types

type DataChangeMessage 

type DataChangeMessage struct {
	*ua.DataValue
	Error  error
	NodeID *ua.NodeID
}

DataChangeMessage represents the changed DataValue from the server. It also includes a reference to the sending NodeID and error (if any)

type ErrHandler 

type ErrHandler func(*opcua.Client, *Subscription, error)

ErrHandler is a function that is called when there is an out of band issue with delivery

type Item 

type Item struct {
	// contains filtered or unexported fields
}

Item is a struct to manage Monitored Items

func (*Item) ID 

func (m *Item) ID() uint32

ID returns the MonitorItemID set by the server

func (*Item) NodeID 

func (m *Item) NodeID() *ua.NodeID

NodeID returns the NodeID for the Item

type MsgHandler 

type MsgHandler func(*Subscription, *DataChangeMessage)

MsgHandler is a function that is called for each new DataValue

type NodeMonitor 

type NodeMonitor struct {
	// contains filtered or unexported fields
}

NodeMonitor creates new subscriptions

func NewNodeMonitor 

func NewNodeMonitor(client *opcua.Client) (*NodeMonitor, error)

NewNodeMonitor creates a new NodeMonitor

func (*NodeMonitor) ChanSubscribe 

func (m *NodeMonitor) ChanSubscribe(ctx context.Context, params *opcua.SubscriptionParameters, ch chan<- *DataChangeMessage, nodes ...string) (*Subscription, error)

ChanSubscribe creates a new channel-based subscription and an optional list of nodes. The channel should be deep enough to allow some buffering, otherwise `ErrSlowConsumer` is sent via the monitor's `ErrHandler`. The caller must call `Unsubscribe` to stop and clean up resources. Canceling the context will also cause the subscription to stop, but `Unsubscribe` must still be called.

func (*NodeMonitor) SetErrorHandler 

func (m *NodeMonitor) SetErrorHandler(cb ErrHandler)

SetErrorHandler sets an optional callback for async errors

func (*NodeMonitor) Subscribe 

func (m *NodeMonitor) Subscribe(ctx context.Context, params *opcua.SubscriptionParameters, cb MsgHandler, nodes ...string) (*Subscription, error)

Subscribe creates a new callback-based subscription and an optional list of nodes. The caller must call `Unsubscribe` to stop and clean up resources. Canceling the context will also cause the subscription to stop, but `Unsubscribe` must still be called.

type Request 

type Request struct {
	NodeID               *ua.NodeID
	MonitoringMode       ua.MonitoringMode
	MonitoringParameters *ua.MonitoringParameters
	// contains filtered or unexported fields
}

Request is a struct to manage a request to monitor a node

type Subscription 

type Subscription struct {
	// contains filtered or unexported fields
}

Subscription is an instance of an active subscription. Nodes can be added and removed concurrently.

func (*Subscription) AddMonitorItems 

func (s *Subscription) AddMonitorItems(ctx context.Context, nodes ...Request) ([]Item, error)

AddMonitorItems adds nodes with monitoring parameters to the subscription

func (*Subscription) AddNodeIDs 

func (s *Subscription) AddNodeIDs(ctx context.Context, nodes ...*ua.NodeID) error

AddNodeIDs adds nodes

func (*Subscription) AddNodes 

func (s *Subscription) AddNodes(ctx context.Context, nodes ...string) error

AddNodes adds nodes defined by their string representation

func (*Subscription) Delivered 

func (s *Subscription) Delivered() uint64

Delivered returns the number of DataChangeMessages delivered

func (*Subscription) Dropped 

func (s *Subscription) Dropped() uint64

Dropped returns the number of DataChangeMessages dropped due to a slow consumer

func (*Subscription) RemoveMonitorItems 

func (s *Subscription) RemoveMonitorItems(ctx context.Context, items ...Item) error

RemoveMonitorItems removes nodes

func (*Subscription) RemoveNodeIDs 

func (s *Subscription) RemoveNodeIDs(ctx context.Context, nodes ...*ua.NodeID) error

RemoveNodeIDs removes nodes

func (*Subscription) RemoveNodes 

func (s *Subscription) RemoveNodes(ctx context.Context, nodes ...string) error

RemoveNodes removes nodes defined by their string representation

func (*Subscription) Stats 

func (s *Subscription) Stats(ctx context.Context) (*ua.SubscriptionDiagnosticsDataType, error)

Stats returns statistics for the subscription

func (*Subscription) Subscribed 

func (s *Subscription) Subscribed() int

Subscribed returns the number of currently subscribed to nodes

func (*Subscription) SubscriptionID 

func (s *Subscription) SubscriptionID() uint32

SubscriptionID returns the underlying subscription id

func (*Subscription) Unsubscribe 

func (s *Subscription) Unsubscribe(ctx context.Context) error

Unsubscribe removes the subscription interests and cleans up any resources

Source Files

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