stream: switch to golang/x/tools lsp stream

Author: zchee

stream.go

@@ -5,11 +5,15 @@
 package jsonrpc2
 
 import (
+	"bufio"
 	"context"
+	"fmt"
 	"io"
+	"strconv"
+	"strings"
 	"sync"
 
-	"github.com/francoispqt/gojay"
+	"golang.org/x/xerrors"
 )
 
 // Stream abstracts the transport mechanics from the JSON RPC protocol.
@@ -20,31 +24,65 @@ type Stream interface {
 	Write(context.Context, []byte) error
 }
 
+type stream struct {
+	in  *bufio.Reader
+	out io.Writer
+	sync.Mutex
+}
+
 func NewStream(in io.Reader, out io.Writer) Stream {
 	return &stream{
-		in:  gojay.BorrowDecoder(in),
+		in:  bufio.NewReader(in),
 		out: out,
 	}
 }
 
-type stream struct {
-	in *gojay.Decoder
-	sync.Mutex
-	out io.Writer
-}
-
 func (s *stream) Read(ctx context.Context) ([]byte, error) {
 	select {
 	case <-ctx.Done():
 		return nil, ctx.Err()
 	default:
 	}
 
-	defer s.in.Release()
+	var length int64
+	for {
+		line, err := s.in.ReadString('\n')
+		if err != nil {
+			return nil, xerrors.Errorf("failed reading header line: %w", err)
+		}
 
-	var data []byte
-	if err := s.in.Decode(&data); err != nil {
-		return nil, err
+		line = strings.TrimSpace(line)
+		if line == "" { // check we have a header line
+			break
+		}
+
+		colon := strings.IndexRune(line, ':')
+		if colon < 0 {
+			return nil, xerrors.Errorf("invalid header line: %q", line)
+		}
+
+		name, value := line[:colon], strings.TrimSpace(line[colon+1:])
+		switch name {
+		case "Content-Length":
+			if length, err = strconv.ParseInt(value, 10, 32); err != nil {
+				return nil, xerrors.Errorf("failed parsing Content-Length: %v", value)
+			}
+
+			if length <= 0 {
+				return nil, xerrors.Errorf("invalid Content-Length: %v", length)
+			}
+		default:
+			// ignoring unknown headers
+		}
+	}
+
+	if length == 0 {
+		return nil, xerrors.New("missing Content-Length header")
+	}
+
+	data := make([]byte, length)
+	if _, err := io.ReadFull(s.in, data); err != nil {
+		return nil, xerrors.Errorf("failed reading data: %w", err)
 	}
 
 	return data, nil
@@ -56,8 +94,12 @@ func (s *stream) Write(ctx context.Context, data []byte) error {
 		return ctx.Err()
 	default:
 	}
+
 	s.Lock()
-	_, err := s.out.Write(data)
+	_, err := fmt.Fprintf(s.out, "Content-Length: %v\r\n\r\n", len(data))
+	if err == nil {
+		_, err = s.out.Write(data)
+	}
 	s.Unlock()
 
 	return err