/
write_pubsub_message.go
111 lines (95 loc) · 2.63 KB
/
write_pubsub_message.go
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/*
Copyright 2021 The CloudEvents Authors
SPDX-License-Identifier: Apache-2.0
*/
package pubsub
import (
"bytes"
"context"
"io"
"cloud.google.com/go/pubsub"
"github.com/cloudevents/sdk-go/v2/binding"
"github.com/cloudevents/sdk-go/v2/binding/format"
"github.com/cloudevents/sdk-go/v2/binding/spec"
"github.com/cloudevents/sdk-go/v2/types"
)
// WritePubSubMessage fills the provided pubsubMessage with the message m.
// Using context you can tweak the encoding processing (more details on binding.Write documentation).
func WritePubSubMessage(ctx context.Context, m binding.Message, pubsubMessage *pubsub.Message, transformers ...binding.Transformer) error {
structuredWriter := (*pubsubMessagePublisher)(pubsubMessage)
binaryWriter := (*pubsubMessagePublisher)(pubsubMessage)
_, err := binding.Write(
ctx,
m,
structuredWriter,
binaryWriter,
transformers...,
)
return err
}
type pubsubMessagePublisher pubsub.Message
func (b *pubsubMessagePublisher) SetStructuredEvent(ctx context.Context, f format.Format, event io.Reader) error {
var buf bytes.Buffer
_, err := io.Copy(&buf, event)
if err != nil {
return err
}
b.Data = buf.Bytes()
return nil
}
func (b *pubsubMessagePublisher) Start(ctx context.Context) error {
return nil
}
func (b *pubsubMessagePublisher) End(ctx context.Context) error {
return nil
}
func (b *pubsubMessagePublisher) SetData(reader io.Reader) error {
buf, ok := reader.(*bytes.Buffer)
if !ok {
buf = new(bytes.Buffer)
_, err := io.Copy(buf, reader)
if err != nil {
return err
}
}
b.Data = buf.Bytes()
return nil
}
func (b *pubsubMessagePublisher) SetAttribute(attribute spec.Attribute, value interface{}) error {
if attribute.Kind() == spec.DataContentType {
if value == nil {
delete(b.Attributes, contentType)
}
// Everything is a string here
s, err := types.Format(value)
if err != nil {
return err
}
b.Attributes[contentType] = s
} else {
if value == nil {
delete(b.Attributes, prefix+attribute.Name())
}
// Everything is a string here
s, err := types.Format(value)
if err != nil {
return err
}
b.Attributes[prefix+attribute.Name()] = s
}
return nil
}
func (b *pubsubMessagePublisher) SetExtension(name string, value interface{}) error {
if value == nil {
delete(b.Attributes, prefix+name)
}
// Store extensions as string attrs as well
s, err := types.Format(value)
if err != nil {
return err
}
b.Attributes[prefix+name] = s
return nil
}
var _ binding.StructuredWriter = (*pubsubMessagePublisher)(nil) // Test it conforms to the interface
var _ binding.BinaryWriter = (*pubsubMessagePublisher)(nil) // Test it conforms to the interface