| 1 | // Copyright 2018 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package jsonrpc2 |
| 6 | |
| 7 | import ( |
| 8 | "encoding/json" |
| 9 | "errors" |
| 10 | "fmt" |
| 11 | ) |
| 12 | |
| 13 | // Message is the interface to all jsonrpc2 message types. |
| 14 | // They share no common functionality, but are a closed set of concrete types |
| 15 | // that are allowed to implement this interface. The message types are *Call, |
| 16 | // *Notification and *Response. |
| 17 | type Message interface { |
| 18 | // isJSONRPC2Message is used to make the set of message implementations a |
| 19 | // closed set. |
| 20 | isJSONRPC2Message() |
| 21 | } |
| 22 | |
| 23 | // Request is the shared interface to jsonrpc2 messages that request |
| 24 | // a method be invoked. |
| 25 | // The request types are a closed set of *Call and *Notification. |
| 26 | type Request interface { |
| 27 | Message |
| 28 | // Method is a string containing the method name to invoke. |
| 29 | Method() string |
| 30 | // Params is either a struct or an array with the parameters of the method. |
| 31 | Params() json.RawMessage |
| 32 | // isJSONRPC2Request is used to make the set of request implementations closed. |
| 33 | isJSONRPC2Request() |
| 34 | } |
| 35 | |
| 36 | // Notification is a request for which a response cannot occur, and as such |
| 37 | // it has not ID. |
| 38 | type Notification struct { |
| 39 | // Method is a string containing the method name to invoke. |
| 40 | method string |
| 41 | params json.RawMessage |
| 42 | } |
| 43 | |
| 44 | // Call is a request that expects a response. |
| 45 | // The response will have a matching ID. |
| 46 | type Call struct { |
| 47 | // Method is a string containing the method name to invoke. |
| 48 | method string |
| 49 | // Params is either a struct or an array with the parameters of the method. |
| 50 | params json.RawMessage |
| 51 | // id of this request, used to tie the Response back to the request. |
| 52 | id ID |
| 53 | } |
| 54 | |
| 55 | // Response is a reply to a Call. |
| 56 | // It will have the same ID as the call it is a response to. |
| 57 | type Response struct { |
| 58 | // result is the content of the response. |
| 59 | result json.RawMessage |
| 60 | // err is set only if the call failed. |
| 61 | err error |
| 62 | // ID of the request this is a response to. |
| 63 | id ID |
| 64 | } |
| 65 | |
| 66 | // NewNotification constructs a new Notification message for the supplied |
| 67 | // method and parameters. |
| 68 | func NewNotification(method string, params interface{}) (*Notification, error) { |
| 69 | p, merr := marshalToRaw(params) |
| 70 | return &Notification{method: method, params: p}, merr |
| 71 | } |
| 72 | |
| 73 | func (msg *Notification) Method() string { return msg.method } |
| 74 | func (msg *Notification) Params() json.RawMessage { return msg.params } |
| 75 | func (msg *Notification) isJSONRPC2Message() {} |
| 76 | func (msg *Notification) isJSONRPC2Request() {} |
| 77 | |
| 78 | func (n *Notification) MarshalJSON() ([]byte, error) { |
| 79 | msg := wireRequest{Method: n.method, Params: &n.params} |
| 80 | data, err := json.Marshal(msg) |
| 81 | if err != nil { |
| 82 | return data, fmt.Errorf("marshaling notification: %w", err) |
| 83 | } |
| 84 | return data, nil |
| 85 | } |
| 86 | |
| 87 | func (n *Notification) UnmarshalJSON(data []byte) error { |
| 88 | msg := wireRequest{} |
| 89 | if err := json.Unmarshal(data, &msg); err != nil { |
| 90 | return fmt.Errorf("unmarshaling notification: %w", err) |
| 91 | } |
| 92 | n.method = msg.Method |
| 93 | if msg.Params != nil { |
| 94 | n.params = *msg.Params |
| 95 | } |
| 96 | return nil |
| 97 | } |
| 98 | |
| 99 | // NewCall constructs a new Call message for the supplied ID, method and |
| 100 | // parameters. |
| 101 | func NewCall(id ID, method string, params interface{}) (*Call, error) { |
| 102 | p, merr := marshalToRaw(params) |
| 103 | return &Call{id: id, method: method, params: p}, merr |
| 104 | } |
| 105 | |
| 106 | func (msg *Call) Method() string { return msg.method } |
| 107 | func (msg *Call) Params() json.RawMessage { return msg.params } |
| 108 | func (msg *Call) ID() ID { return msg.id } |
| 109 | func (msg *Call) isJSONRPC2Message() {} |
| 110 | func (msg *Call) isJSONRPC2Request() {} |
| 111 | |
| 112 | func (c *Call) MarshalJSON() ([]byte, error) { |
| 113 | msg := wireRequest{Method: c.method, Params: &c.params, ID: &c.id} |
| 114 | data, err := json.Marshal(msg) |
| 115 | if err != nil { |
| 116 | return data, fmt.Errorf("marshaling call: %w", err) |
| 117 | } |
| 118 | return data, nil |
| 119 | } |
| 120 | |
| 121 | func (c *Call) UnmarshalJSON(data []byte) error { |
| 122 | msg := wireRequest{} |
| 123 | if err := json.Unmarshal(data, &msg); err != nil { |
| 124 | return fmt.Errorf("unmarshaling call: %w", err) |
| 125 | } |
| 126 | c.method = msg.Method |
| 127 | if msg.Params != nil { |
| 128 | c.params = *msg.Params |
| 129 | } |
| 130 | if msg.ID != nil { |
| 131 | c.id = *msg.ID |
| 132 | } |
| 133 | return nil |
| 134 | } |
| 135 | |
| 136 | // NewResponse constructs a new Response message that is a reply to the |
| 137 | // supplied. If err is set result may be ignored. |
| 138 | func NewResponse(id ID, result interface{}, err error) (*Response, error) { |
| 139 | r, merr := marshalToRaw(result) |
| 140 | return &Response{id: id, result: r, err: err}, merr |
| 141 | } |
| 142 | |
| 143 | func (msg *Response) ID() ID { return msg.id } |
| 144 | func (msg *Response) Result() json.RawMessage { return msg.result } |
| 145 | func (msg *Response) Err() error { return msg.err } |
| 146 | func (msg *Response) isJSONRPC2Message() {} |
| 147 | |
| 148 | func (r *Response) MarshalJSON() ([]byte, error) { |
| 149 | msg := &wireResponse{Error: toWireError(r.err), ID: &r.id} |
| 150 | if msg.Error == nil { |
| 151 | msg.Result = &r.result |
| 152 | } |
| 153 | data, err := json.Marshal(msg) |
| 154 | if err != nil { |
| 155 | return data, fmt.Errorf("marshaling notification: %w", err) |
| 156 | } |
| 157 | return data, nil |
| 158 | } |
| 159 | |
| 160 | func toWireError(err error) *wireError { |
| 161 | if err == nil { |
| 162 | // no error, the response is complete |
| 163 | return nil |
| 164 | } |
| 165 | if err, ok := err.(*wireError); ok { |
| 166 | // already a wire error, just use it |
| 167 | return err |
| 168 | } |
| 169 | result := &wireError{Message: err.Error()} |
| 170 | var wrapped *wireError |
| 171 | if errors.As(err, &wrapped) { |
| 172 | // if we wrapped a wire error, keep the code from the wrapped error |
| 173 | // but the message from the outer error |
| 174 | result.Code = wrapped.Code |
| 175 | } |
| 176 | return result |
| 177 | } |
| 178 | |
| 179 | func (r *Response) UnmarshalJSON(data []byte) error { |
| 180 | msg := wireResponse{} |
| 181 | if err := json.Unmarshal(data, &msg); err != nil { |
| 182 | return fmt.Errorf("unmarshaling jsonrpc response: %w", err) |
| 183 | } |
| 184 | if msg.Result != nil { |
| 185 | r.result = *msg.Result |
| 186 | } |
| 187 | if msg.Error != nil { |
| 188 | r.err = msg.Error |
| 189 | } |
| 190 | if msg.ID != nil { |
| 191 | r.id = *msg.ID |
| 192 | } |
| 193 | return nil |
| 194 | } |
| 195 | |
| 196 | func DecodeMessage(data []byte) (Message, error) { |
| 197 | msg := wireCombined{} |
| 198 | if err := json.Unmarshal(data, &msg); err != nil { |
| 199 | return nil, fmt.Errorf("unmarshaling jsonrpc message: %w", err) |
| 200 | } |
| 201 | if msg.Method == "" { |
| 202 | // no method, should be a response |
| 203 | if msg.ID == nil { |
| 204 | return nil, ErrInvalidRequest |
| 205 | } |
| 206 | response := &Response{id: *msg.ID} |
| 207 | if msg.Error != nil { |
| 208 | response.err = msg.Error |
| 209 | } |
| 210 | if msg.Result != nil { |
| 211 | response.result = *msg.Result |
| 212 | } |
| 213 | return response, nil |
| 214 | } |
| 215 | // has a method, must be a request |
| 216 | if msg.ID == nil { |
| 217 | // request with no ID is a notify |
| 218 | notify := &Notification{method: msg.Method} |
| 219 | if msg.Params != nil { |
| 220 | notify.params = *msg.Params |
| 221 | } |
| 222 | return notify, nil |
| 223 | } |
| 224 | // request with an ID, must be a call |
| 225 | call := &Call{method: msg.Method, id: *msg.ID} |
| 226 | if msg.Params != nil { |
| 227 | call.params = *msg.Params |
| 228 | } |
| 229 | return call, nil |
| 230 | } |
| 231 | |
| 232 | func marshalToRaw(obj interface{}) (json.RawMessage, error) { |
| 233 | data, err := json.Marshal(obj) |
| 234 | if err != nil { |
| 235 | return json.RawMessage{}, err |
| 236 | } |
| 237 | return json.RawMessage(data), nil |
| 238 | } |
| 239 |
Members