stream: add stream.go

Author: zchee

stream.go

@@ -0,0 +1,64 @@
+// Copyright 2019 The go-language-server Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package jsonrpc2
+
+import (
+	"context"
+	"io"
+	"sync"
+
+	"github.com/francoispqt/gojay"
+)
+
+// Stream abstracts the transport mechanics from the JSON RPC protocol.
+type Stream interface {
+	// Read gets the next message from the stream.
+	Read(context.Context) ([]byte, error)
+	// Write sends a message to the stream.
+	Write(context.Context, []byte) error
+}
+
+func NewStream(in io.Reader, out io.Writer) Stream {
+	return &stream{
+		in:  gojay.BorrowDecoder(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 data []byte
+	if err := s.in.Decode(&data); err != nil {
+		return nil, err
+	}
+
+	return data, nil
+}
+
+func (s *stream) Write(ctx context.Context, data []byte) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+	s.Lock()
+	_, err := s.out.Write(data)
+	s.Unlock()
+
+	return err
+}