nats

Documentation

Overview

Package nats contains utilties for reading/writing data using NATS.

Index

• func DecodeEdgePointsMsg(msg *natsgo.Msg) (string, string, []data.Point, error)
• func DecodeNodePointsMsg(msg *natsgo.Msg) (string, []data.Point, error)
• func Dump(nc *natsgo.Conn, msg *natsgo.Msg) error
• func EdgeConnect(eo EdgeOptions) (*nats.Conn, error)
• func ExpBackoff(attempts int, max time.Duration) time.Duration
• func GetNode(nc *natsgo.Conn, id, parent string) (data.NodeEdge, error)
• func GetNodeChildren(nc *natsgo.Conn, id, typ string, includeDel bool) ([]data.NodeEdge, error)
• func ListenForFile(nc *nats.Conn, dir, deviceID string, callback func(path string)) error
• func SendEdgePoint(nc *natsgo.Conn, nodeID, parentID string, point data.Point, ack bool) error
• func SendEdgePoints(nc *natsgo.Conn, nodeID, parentID string, points data.Points, ack bool) error
• func SendFile(nc *nats.Conn, deviceID string, reader io.Reader, name string, ...) error
• func SendNode(src, dest *natsgo.Conn, node data.NodeEdge) error
• func SendNodePoint(nc *natsgo.Conn, nodeID string, point data.Point, ack bool) error
• func SendNodePointCreate(nc *natsgo.Conn, nodeID string, point data.Point, ack bool) error
• func SendNodePoints(nc *natsgo.Conn, nodeID string, points data.Points, ack bool) error
• func SendNodePointsCreate(nc *natsgo.Conn, nodeID string, points data.Points, ack bool) error
• func String(nc *natsgo.Conn, msg *natsgo.Msg) (string, error)
• func SubjectEdgeAllPoints() string
• func SubjectEdgePoints(nodeID, parentID string) string
• func SubjectNodeAllPoints() string
• func SubjectNodePoints(nodeID string) string
• type EdgeOptions
• type Metric
  • func NewMetric(nc *natsgo.Conn, nodeID, pointType string, reportPeriod time.Duration) *Metric
  • func (m *Metric) AddSample(s float64) error
  • func (m *Metric) SetNodeID(id string)

Functions

func DecodeEdgePointsMsg

func DecodeEdgePointsMsg(msg *natsgo.Msg) (string, string, []data.Point, error)

DecodeEdgePointsMsg decodes NATS message into node ID and points

func DecodeNodePointsMsg

func DecodeNodePointsMsg(msg *natsgo.Msg) (string, []data.Point, error)

DecodeNodePointsMsg decodes NATS message into node ID and points

func Dump

func Dump(nc *natsgo.Conn, msg *natsgo.Msg) error

Dump converts displays a NATS message

func EdgeConnect

func EdgeConnect(eo EdgeOptions) (*nats.Conn, error)

EdgeConnect is a function that attempts connections for edge devices with appropriate timeouts, backups, etc. Currently set to disconnect if we don't have a connection after 6m, and then exp backup to try to connect every 6m after that.

func ExpBackoff

func ExpBackoff(attempts int, max time.Duration) time.Duration

ExpBackoff calculates an exponential time backup to max duration + a random fraction of 1s

func GetNode

func GetNode(nc *natsgo.Conn, id, parent string) (data.NodeEdge, error)

GetNode over NATS. If id is "root", the root node is fetched. If parent is set to "skip", the edge details are not included and the hash is calculated without the edge points. returns data.ErrDocumentNotFound if node is not found.

func GetNodeChildren

func GetNodeChildren(nc *natsgo.Conn, id, typ string, includeDel bool) ([]data.NodeEdge, error)

GetNodeChildren over NATS (immediate children only, not recursive) deleted nodes are skipped unless includeDel is set to true. typ can be used to limit nodes to a particular type, otherwise, all nodes are returned.

func ListenForFile

func ListenForFile(nc *nats.Conn, dir, deviceID string, callback func(path string)) error

ListenForFile listens for a file sent from server. dir is the directly to place downloaded files.

func SendEdgePoint

func SendEdgePoint(nc *natsgo.Conn, nodeID, parentID string, point data.Point, ack bool) error

SendEdgePoint sends a edge point using the nats protocol

func SendEdgePoints

func SendEdgePoints(nc *natsgo.Conn, nodeID, parentID string, points data.Points, ack bool) error

SendEdgePoints sends points using the nats protocol

func SendFile

func SendFile(nc *nats.Conn, deviceID string, reader io.Reader, name string, callback func(int)) error

SendFile can be used to send a file to a device. Callback provides bytes transfered.

func SendNode

func SendNode(src, dest *natsgo.Conn, node data.NodeEdge) error

SendNode is used to recursively send a node and children over nats

func SendNodePoint

func SendNodePoint(nc *natsgo.Conn, nodeID string, point data.Point, ack bool) error

SendNodePoint sends a node point using the nats protocol

func SendNodePointCreate

func SendNodePointCreate(nc *natsgo.Conn, nodeID string, point data.Point, ack bool) error

SendNodePointCreate sends a node point using the nats protocol and creates the node if it does not already exist

func SendNodePoints

func SendNodePoints(nc *natsgo.Conn, nodeID string, points data.Points, ack bool) error

SendNodePoints sends node points using the nats protocol

func SendNodePointsCreate

func SendNodePointsCreate(nc *natsgo.Conn, nodeID string, points data.Points, ack bool) error

SendNodePointsCreate sends a node point using the nats protocol and creates the node if it does not already exist

func String

func String(nc *natsgo.Conn, msg *natsgo.Msg) (string, error)

String converts a NATS message to a string

func SubjectEdgeAllPoints

func SubjectEdgeAllPoints() string

SubjectEdgeAllPoints provides subject for all edge points for any node

func SubjectEdgePoints

func SubjectEdgePoints(nodeID, parentID string) string

SubjectEdgePoints constructs a NATS subject for edge points

func SubjectNodeAllPoints

func SubjectNodeAllPoints() string

SubjectNodeAllPoints provides subject for all points for any node

func SubjectNodePoints

func SubjectNodePoints(nodeID string) string

SubjectNodePoints constructs a NATS subject for node points

Types

type EdgeOptions

type EdgeOptions struct {
	Server       string
	AuthToken    string
	NoEcho       bool
	Disconnected func()
	Reconnected  func()
	Closed       func()
}

EdgeOptions describes options for connecting edge devices

type Metric

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

Metric is a type that can be used to track metrics and periodically report them to a node point. Data is queued and averaged and then the average is sent out as a point.

func NewMetric

func NewMetric(nc *natsgo.Conn, nodeID, pointType string, reportPeriod time.Duration) *Metric

NewMetric creates a new metric

func (*Metric) AddSample

func (m *Metric) AddSample(s float64) error

AddSample adds a sample and reports it if reportPeriod has expired

func (*Metric) SetNodeID

func (m *Metric) SetNodeID(id string)

SetNodeID -- this is a bit of a hack to get around some init issues