docs/vendor/github.com/cloudevents/sdk-go/v2/binding/event_message.go

91 lines
2.3 KiB
Go

package binding
import (
"bytes"
"context"
"github.com/cloudevents/sdk-go/v2/binding/format"
"github.com/cloudevents/sdk-go/v2/binding/spec"
"github.com/cloudevents/sdk-go/v2/event"
)
const (
FORMAT_EVENT_STRUCTURED = "FORMAT_EVENT_STRUCTURED"
)
// EventMessage type-converts a event.Event object to implement Message.
// This allows local event.Event objects to be sent directly via Sender.Send()
// s.Send(ctx, binding.EventMessage(e))
// When an event is wrapped into a EventMessage, the original event could be
// potentially mutated. If you need to use the Event again, after wrapping it into
// an Event message, you should copy it before
type EventMessage event.Event
func ToMessage(e *event.Event) Message {
return (*EventMessage)(e)
}
func (m *EventMessage) ReadEncoding() Encoding {
return EncodingEvent
}
func (m *EventMessage) ReadStructured(ctx context.Context, builder StructuredWriter) error {
f := GetOrDefaultFromCtx(ctx, FORMAT_EVENT_STRUCTURED, format.JSON).(format.Format)
b, err := f.Marshal((*event.Event)(m))
if err != nil {
return err
}
return builder.SetStructuredEvent(ctx, f, bytes.NewReader(b))
}
func (m *EventMessage) ReadBinary(ctx context.Context, b BinaryWriter) (err error) {
err = b.Start(ctx)
if err != nil {
return err
}
err = eventContextToBinaryWriter(m.Context, b)
if err != nil {
return err
}
// Pass the body
body := (*event.Event)(m).Data()
if len(body) > 0 {
err = b.SetData(bytes.NewReader(body))
if err != nil {
return err
}
}
return b.End(ctx)
}
func eventContextToBinaryWriter(c event.EventContext, b BinaryWriter) (err error) {
// Pass all attributes
sv := spec.VS.Version(c.GetSpecVersion())
for _, a := range sv.Attributes() {
value := a.Get(c)
if value != nil {
err = b.SetAttribute(a, value)
}
if err != nil {
return err
}
}
// Pass all extensions
for k, v := range c.GetExtensions() {
err = b.SetExtension(k, v)
if err != nil {
return err
}
}
return nil
}
func (*EventMessage) Finish(error) error { return nil }
var _ Message = (*EventMessage)(nil) // Test it conforms to the interface
// Configure which format to use when marshalling the event to structured mode
func UseFormatForEvent(ctx context.Context, f format.Format) context.Context {
return context.WithValue(ctx, FORMAT_EVENT_STRUCTURED, f)
}