micro/broker/broker.go
Vasiliy Tolstov eb107020c7 broker: replace Message.Body []byte slice to RawMessage
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-07-01 15:11:17 +03:00

71 lines
1.7 KiB
Go

// Package broker is an interface used for asynchronous messaging
package broker
import (
"context"
"errors"
"github.com/unistack-org/micro/v3/metadata"
)
// DefaultBroker default broker
var DefaultBroker Broker = NewBroker()
// Broker is an interface used for asynchronous messaging.
type Broker interface {
Name() string
Init(...Option) error
Options() Options
Address() string
Connect(context.Context) error
Disconnect(context.Context) error
Publish(context.Context, string, *Message, ...PublishOption) error
Subscribe(context.Context, string, Handler, ...SubscribeOption) (Subscriber, error)
String() string
}
// Handler is used to process messages via a subscription of a topic.
type Handler func(Event) error
// Event is given to a subscription handler for processing
type Event interface {
Topic() string
Message() *Message
Ack() error
Error() error
}
// RawMessage is a raw encoded JSON value.
// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
type RawMessage []byte
// MarshalJSON returns m as the JSON encoding of m.
func (m *RawMessage) MarshalJSON() ([]byte, error) {
if m == nil {
return nil, nil
}
return *m, nil
}
// UnmarshalJSON sets *m to a copy of data.
func (m *RawMessage) UnmarshalJSON(data []byte) error {
if m == nil {
return errors.New("RawMessage UnmarshalJSON on nil pointer")
}
*m = append((*m)[0:0], data...)
return nil
}
// Message is used to transfer data
type Message struct {
Header metadata.Metadata // contains message metadata
Body RawMessage // contains message body
}
// Subscriber is a convenience return type for the Subscribe method
type Subscriber interface {
Options() SubscribeOptions
Topic() string
Unsubscribe(context.Context) error
}