Initial QSfera import

Server/vendor/go-micro.dev/v4/events/events.go

@@ -0,0 +1,92 @@
+// Package events is for event streaming and storage
+package events
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+)
+
+var (
+	// DefaultStream is the default events stream implementation.
+	DefaultStream Stream
+	// DefaultStore is the default events store implementation.
+	DefaultStore Store
+)
+
+var (
+	// ErrMissingTopic is returned if a blank topic was provided to publish.
+	ErrMissingTopic = errors.New("Missing topic")
+	// ErrEncodingMessage is returned from publish if there was an error encoding the message option.
+	ErrEncodingMessage = errors.New("Error encoding message")
+)
+
+// Stream is an event streaming interface.
+type Stream interface {
+	Publish(topic string, msg interface{}, opts ...PublishOption) error
+	Consume(topic string, opts ...ConsumeOption) (<-chan Event, error)
+}
+
+// Store is an event store interface.
+type Store interface {
+	Read(topic string, opts ...ReadOption) ([]*Event, error)
+	Write(event *Event, opts ...WriteOption) error
+}
+
+type AckFunc func() error
+type NackFunc func() error
+
+// Event is the object returned by the broker when you subscribe to a topic.
+type Event struct {
+	// Timestamp of the event
+	Timestamp time.Time
+	// Metadata contains the values the event was indexed by
+	Metadata map[string]string
+
+	ackFunc  AckFunc
+	nackFunc NackFunc
+	// ID to uniquely identify the event
+	ID string
+	// Topic of event, e.g. "registry.service.created"
+	Topic string
+	// Payload contains the encoded message
+	Payload []byte
+}
+
+// Unmarshal the events message into an object.
+func (e *Event) Unmarshal(v interface{}) error {
+	return json.Unmarshal(e.Payload, v)
+}
+
+// Ack acknowledges successful processing of the event in ManualAck mode.
+func (e *Event) Ack() error {
+	return e.ackFunc()
+}
+
+func (e *Event) SetAckFunc(f AckFunc) {
+	e.ackFunc = f
+}
+
+// Nack negatively acknowledges processing of the event (i.e. failure) in ManualAck mode.
+func (e *Event) Nack() error {
+	return e.nackFunc()
+}
+
+func (e *Event) SetNackFunc(f NackFunc) {
+	e.nackFunc = f
+}
+
+// Publish an event to a topic.
+func Publish(topic string, msg interface{}, opts ...PublishOption) error {
+	return DefaultStream.Publish(topic, msg, opts...)
+}
+
+// Consume to events.
+func Consume(topic string, opts ...ConsumeOption) (<-chan Event, error) {
+	return DefaultStream.Consume(topic, opts...)
+}
+
+// Read events for a topic.
+func Read(topic string, opts ...ReadOption) ([]*Event, error) {
+	return DefaultStore.Read(topic, opts...)
+}