initial commit

jsonrpc/jsonrpc.go

@@ -0,0 +1,145 @@
+/*
+Simple implementation of JSONRPC 2.0.
+*/
+package jsonrpc
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"sync/atomic"
+
+	"github.com/rs/zerolog/log"
+	"golang.org/x/net/websocket"
+)
+
+var MsgID int64 = 0
+
+type Msg struct {
+	ID      int64           `json:"id"`
+	Jsonrpc string          `json:"jsonrpc"`
+	Method  string          `json:"method"`
+	Params  json.RawMessage `json:"params"`
+}
+
+type Result struct {
+	ID       int64       `json:"id"`
+	Jsonrpc  string      `json:"jsonrpc"`
+	Result   interface{} `json:"result"`
+	Encoding string      `json:"encoding,omitempty"`
+}
+
+type Error struct {
+	ID      int64  `json:"id"`
+	Jsonrpc string `json:"jsonrpc"`
+	Error   string `json:"error"`
+}
+
+func NewMsg(method string, params interface{}) Msg {
+	buff, err := json.Marshal(params)
+	if err != nil {
+		panic(err)
+	}
+	return Msg{
+		ID:      atomic.AddInt64(&MsgID, 1),
+		Jsonrpc: "2.0",
+		Method:  method,
+		Params:  json.RawMessage(buff),
+	}
+}
+
+func (m Msg) RespondBytes(buf []byte) Result {
+	return Result{
+		ID:       m.ID,
+		Jsonrpc:  "2.0",
+		Encoding: "base64",
+		Result:   base64.StdEncoding.EncodeToString(buf),
+	}
+}
+
+func (m Msg) Respond(data interface{}) Result {
+	return Result{
+		ID:      m.ID,
+		Jsonrpc: "2.0",
+		Result:  data,
+	}
+}
+
+func (m Msg) Error(err string) Error {
+	return Error{
+		ID:      m.ID,
+		Jsonrpc: "2.0",
+		Error:   err,
+	}
+}
+
+func (m Msg) DebugParams() map[string]interface{} {
+	var out map[string]interface{}
+	err := json.Unmarshal(m.Params, &out)
+	if err != nil {
+		panic(err)
+	}
+	return out
+}
+
+func WsSend[T Msg | Error | Result](c *websocket.Conn, data T) error {
+	buff, err := json.Marshal(data)
+	if err != nil {
+		panic(err)
+	}
+
+	_, err = c.Write(buff)
+	if err != nil {
+		return fmt.Errorf("ws write error: %w", err)
+	}
+
+	return nil
+}
+
+func WsReadLoop(c *websocket.Conn) <-chan Msg {
+	out := make(chan Msg, 100)
+
+	go func() {
+		defer close(out)
+		for {
+			msg, err := wsRead(c)
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			if err != nil {
+				log.Warn().Err(err).Msg("read loop error, ignore")
+				return
+			}
+			out <- msg
+		}
+	}()
+
+	return out
+}
+
+func wsRead(c *websocket.Conn) (Msg, error) {
+	buff := make([]byte, 512)
+	var msg Msg
+	for {
+		n, err := c.Read(buff)
+		if err != nil {
+			return msg, fmt.Errorf("ws read: %w", err)
+		}
+		if n >= 512 {
+			panic("too big")
+		}
+
+		err = json.Unmarshal(buff[:n], &msg)
+		if err != nil {
+			return msg, fmt.Errorf("ws read error: %w", err)
+		}
+		if len(msg.Method) == 0 {
+			// ignore response messages
+			continue
+		}
+
+		return msg, nil
+	}
+}