/usr/share/gocode/src/github.com/cenk/rpc2/jsonrpc/jsonrpc.go is in golang-github-cenk-rpc2-dev 0.0~git20160427.0.7ab76d2e88c7-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 | // Package jsonrpc implements a JSON-RPC ClientCodec and ServerCodec for the rpc2 package.
//
// Beside struct types, JSONCodec allows using positional arguments.
// Use []interface{} as the type of argument when sending and receiving methods.
//
// Positional arguments example:
// server.Handle("add", func(client *rpc2.Client, args []interface{}, result *float64) error {
// *result = args[0].(float64) + args[1].(float64)
// return nil
// })
//
// var result float64
// client.Call("add", []interface{}{1, 2}, &result)
//
package jsonrpc
import (
"encoding/json"
"errors"
"fmt"
"io"
"sync"
"github.com/cenk/rpc2"
)
type jsonCodec struct {
dec *json.Decoder // for reading JSON values
enc *json.Encoder // for writing JSON values
c io.Closer
// temporary work space
msg message
serverRequest serverRequest
clientResponse clientResponse
// JSON-RPC clients can use arbitrary json values as request IDs.
// Package rpc expects uint64 request IDs.
// We assign uint64 sequence numbers to incoming requests
// but save the original request ID in the pending map.
// When rpc responds, we use the sequence number in
// the response to find the original request ID.
mutex sync.Mutex // protects seq, pending
pending map[uint64]*json.RawMessage
seq uint64
}
// NewJSONCodec returns a new rpc2.Codec using JSON-RPC on conn.
func NewJSONCodec(conn io.ReadWriteCloser) rpc2.Codec {
return &jsonCodec{
dec: json.NewDecoder(conn),
enc: json.NewEncoder(conn),
c: conn,
pending: make(map[uint64]*json.RawMessage),
}
}
// serverRequest and clientResponse combined
type message struct {
Method string `json:"method"`
Params *json.RawMessage `json:"params"`
Id *json.RawMessage `json:"id"`
Result *json.RawMessage `json:"result"`
Error interface{} `json:"error"`
}
// Unmarshal to
type serverRequest struct {
Method string `json:"method"`
Params *json.RawMessage `json:"params"`
Id *json.RawMessage `json:"id"`
}
type clientResponse struct {
Id uint64 `json:"id"`
Result *json.RawMessage `json:"result"`
Error interface{} `json:"error"`
}
// to Marshal
type serverResponse struct {
Id *json.RawMessage `json:"id"`
Result interface{} `json:"result"`
Error interface{} `json:"error"`
}
type clientRequest struct {
Method string `json:"method"`
Params []interface{} `json:"params"`
Id *uint64 `json:"id"`
}
func (c *jsonCodec) ReadHeader(req *rpc2.Request, resp *rpc2.Response) error {
c.msg = message{}
if err := c.dec.Decode(&c.msg); err != nil {
return err
}
if c.msg.Method != "" {
// request comes to server
c.serverRequest.Id = c.msg.Id
c.serverRequest.Method = c.msg.Method
c.serverRequest.Params = c.msg.Params
req.Method = c.serverRequest.Method
// JSON request id can be any JSON value;
// RPC package expects uint64. Translate to
// internal uint64 and save JSON on the side.
if c.serverRequest.Id == nil {
// Notification
} else {
c.mutex.Lock()
c.seq++
c.pending[c.seq] = c.serverRequest.Id
c.serverRequest.Id = nil
req.Seq = c.seq
c.mutex.Unlock()
}
} else {
// response comes to client
err := json.Unmarshal(*c.msg.Id, &c.clientResponse.Id)
if err != nil {
return err
}
c.clientResponse.Result = c.msg.Result
c.clientResponse.Error = c.msg.Error
resp.Error = ""
resp.Seq = c.clientResponse.Id
if c.clientResponse.Error != nil || c.clientResponse.Result == nil {
x, ok := c.clientResponse.Error.(string)
if !ok {
return fmt.Errorf("invalid error %v", c.clientResponse.Error)
}
if x == "" {
x = "unspecified error"
}
resp.Error = x
}
}
return nil
}
var errMissingParams = errors.New("jsonrpc: request body missing params")
func (c *jsonCodec) ReadRequestBody(x interface{}) error {
if x == nil {
return nil
}
if c.serverRequest.Params == nil {
return errMissingParams
}
var params *[]interface{}
switch x := x.(type) {
case *[]interface{}:
params = x
default:
params = &[]interface{}{x}
}
return json.Unmarshal(*c.serverRequest.Params, params)
}
func (c *jsonCodec) ReadResponseBody(x interface{}) error {
if x == nil {
return nil
}
return json.Unmarshal(*c.clientResponse.Result, x)
}
func (c *jsonCodec) WriteRequest(r *rpc2.Request, param interface{}) error {
req := &clientRequest{Method: r.Method}
switch param := param.(type) {
case []interface{}:
req.Params = param
default:
req.Params = []interface{}{param}
}
if r.Seq == 0 {
// Notification
req.Id = nil
} else {
seq := r.Seq
req.Id = &seq
}
return c.enc.Encode(req)
}
var null = json.RawMessage([]byte("null"))
func (c *jsonCodec) WriteResponse(r *rpc2.Response, x interface{}) error {
c.mutex.Lock()
b, ok := c.pending[r.Seq]
if !ok {
c.mutex.Unlock()
return errors.New("invalid sequence number in response")
}
delete(c.pending, r.Seq)
c.mutex.Unlock()
if b == nil {
// Invalid request so no id. Use JSON null.
b = &null
}
resp := serverResponse{Id: b}
if r.Error == "" {
resp.Result = x
} else {
resp.Error = r.Error
}
return c.enc.Encode(resp)
}
func (c *jsonCodec) Close() error {
return c.c.Close()
}
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