micro/codec/jsonrpc/server.go
2015-11-28 18:54:38 +00:00

112 lines
2.0 KiB
Go

package jsonrpc
import (
"encoding/json"
"errors"
"io"
"sync"
"github.com/micro/go-micro/codec"
)
type serverCodec struct {
dec *json.Decoder // for reading JSON values
enc *json.Encoder // for writing JSON values
c io.Closer
// temporary work space
req serverRequest
resp serverResponse
sync.Mutex
seq uint64
pending map[uint64]*json.RawMessage
}
type serverRequest struct {
Method string `json:"method"`
Params *json.RawMessage `json:"params"`
ID *json.RawMessage `json:"id"`
}
type serverResponse struct {
ID *json.RawMessage `json:"id"`
Result interface{} `json:"result"`
Error interface{} `json:"error"`
}
func newServerCodec(conn io.ReadWriteCloser) *serverCodec {
return &serverCodec{
dec: json.NewDecoder(conn),
enc: json.NewEncoder(conn),
c: conn,
pending: make(map[uint64]*json.RawMessage),
}
}
func (r *serverRequest) reset() {
r.Method = ""
if r.Params != nil {
*r.Params = (*r.Params)[0:0]
}
if r.ID != nil {
*r.ID = (*r.ID)[0:0]
}
}
func (c *serverCodec) ReadHeader(m *codec.Message) error {
c.req.reset()
if err := c.dec.Decode(&c.req); err != nil {
return err
}
m.Method = c.req.Method
c.Lock()
c.seq++
c.pending[c.seq] = c.req.ID
c.req.ID = nil
m.Id = c.seq
c.Unlock()
return nil
}
func (c *serverCodec) ReadBody(x interface{}) error {
if x == nil {
return nil
}
var params [1]interface{}
params[0] = x
return json.Unmarshal(*c.req.Params, &params)
}
var null = json.RawMessage([]byte("null"))
func (c *serverCodec) Write(m *codec.Message, x interface{}) error {
var resp serverResponse
c.Lock()
b, ok := c.pending[m.Id]
if !ok {
c.Unlock()
return errors.New("invalid sequence number in response")
}
c.Unlock()
if b == nil {
// Invalid request so no id. Use JSON null.
b = &null
}
resp.ID = b
resp.Result = x
if m.Error == "" {
resp.Error = nil
} else {
resp.Error = m.Error
}
return c.enc.Encode(resp)
}
func (c *serverCodec) Close() error {
return c.c.Close()
}