sources

Documentation

Index

• type Heartbeat
• type HeartbeatEventSource
  • func NewHeartbeatEventSource(tracerProvider trace.TracerProvider, logger *log.Logger) *HeartbeatEventSource
  • func (source *HeartbeatEventSource) GetChannel() chan event.Event
  • func (source *HeartbeatEventSource) Start(ctx context.Context) error
  • func (source *HeartbeatEventSource) Stop(ctx context.Context) error

Types

type Heartbeat

type Heartbeat struct {
	// Unix (seconds) timestamp when heartbeat has been published.
	Timestamp int64 `json:"timestamp"`
}

Data of a heartbeat

type HeartbeatEventSource

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

Event source which emits heartbeat events

func NewHeartbeatEventSource

func NewHeartbeatEventSource(tracerProvider trace.TracerProvider, logger *log.Logger) *HeartbeatEventSource

Description

Build and return a non-started heartbeat event source

Inputs

• tracerProvider: Provider to use to get a tracer. If nil, global tracer provider is used.
• logger: Logger to use to publish debug logs. If nil, debug logs will be discarded.

Return

A new, non-started heartbeat event source.

func (*HeartbeatEventSource) GetChannel

func (source *HeartbeatEventSource) GetChannel() chan event.Event

Description

Provide the channel used by the event source to publish its events.

Implementation requirements & hints

• The method must return the same channel instance to all callers.
• The source must provide its publication channel even if it has not been started yet.
• The source must continue providing the same channel even if the source has been stopped.
• To achieve end to end event traceability, events are expected to embed tracing data as described in the following documentation: https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/extensions/distributed-tracing.md

Return

The channel used by this source to publish its events.

func (*HeartbeatEventSource) Start

func (source *HeartbeatEventSource) Start(ctx context.Context) error

Description

Start the event source that will start publishing events on its publication channel.

Implementation requirements & hints

• The method must return an error if the source has already been started.
• The method must return an error if the provided context has been canceled or has expired.
• The method must return an error if the source has been stopped (no restart).
• The method must close the publication channel.

Inputs

• ctx: Context used for tracing purpose.

Return

An error if the event source could not be started.

func (*HeartbeatEventSource) Stop

func (source *HeartbeatEventSource) Stop(ctx context.Context) error

Description

Stop the event source and close the publication channel.

Implementation requirements & hints

• The method must return an error if the source has not been started.
• The method must return an error if the source has already been stopped.
• The method must close the publication channel even if the underlying event source could not properly closed.
• The closed publication channel must be kept: source must not be restarted (stale source).

Inputs

• ctx: Context used for tracing purpose.

Return

An error if the event source could not be closed.