mirror of
https://github.com/nats-io/nats.go.git
synced 2025-09-27 04:46:01 +08:00
80 lines
2.2 KiB
Go
80 lines
2.2 KiB
Go
// Copyright 2022 The NATS Authors
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package micro
|
|
|
|
import (
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/nats-io/nats.go"
|
|
)
|
|
|
|
type (
|
|
Request struct {
|
|
*nats.Msg
|
|
}
|
|
|
|
// RequestHandler is a function used as a Handler for a service.
|
|
// It takes a request, which contains the data (payload and headers) of the request,
|
|
// as well as exposes methods to respond to the request.
|
|
//
|
|
// RequestHandler returns an error - if returned, the request will be accounted form in stats (in num_requests),
|
|
// and last_error will be set with the value.
|
|
RequestHandler func(*Request) error
|
|
)
|
|
|
|
var (
|
|
ErrRespond = errors.New("NATS error when sending response")
|
|
ErrMarshalResponse = errors.New("marshaling response")
|
|
ErrArgRequired = errors.New("argument required")
|
|
)
|
|
|
|
func (r *Request) Respond(response []byte) error {
|
|
if err := r.Msg.Respond(response); err != nil {
|
|
return fmt.Errorf("%w: %s", ErrRespond, err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (r *Request) RespondJSON(response interface{}) error {
|
|
resp, err := json.Marshal(response)
|
|
if err != nil {
|
|
return ErrMarshalResponse
|
|
}
|
|
|
|
return r.Respond(resp)
|
|
}
|
|
|
|
// Error prepares and publishes error response from a handler.
|
|
// A response error should be set containing an error code and description.
|
|
// Optionally, data can be set as response payload.
|
|
func (r *Request) Error(code, description string, data []byte) error {
|
|
if code == "" {
|
|
return fmt.Errorf("%w: error code", ErrArgRequired)
|
|
}
|
|
if description == "" {
|
|
return fmt.Errorf("%w: description", ErrArgRequired)
|
|
}
|
|
response := &nats.Msg{
|
|
Header: nats.Header{
|
|
ErrorHeader: []string{description},
|
|
ErrorCodeHeader: []string{code},
|
|
},
|
|
}
|
|
response.Data = data
|
|
return r.RespondMsg(response)
|
|
}
|