Bumping k8s dependencies to 1.13

vendor/golang.org/x/tools/internal/jsonrpc2/stream.go

@@ -0,0 +1,146 @@
+// Copyright 2018 The Go 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 (
+	"bufio"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// Stream abstracts the transport mechanics from the JSON RPC protocol.
+// A Conn reads and writes messages using the stream it was provided on
+// construction, and assumes that each call to Read or Write fully transfers
+// a single message, or returns an error.
+type Stream interface {
+	// Read gets the next message from the stream.
+	// It is never called concurrently.
+	Read(context.Context) ([]byte, error)
+	// Write sends a message to the stream.
+	// It must be safe for concurrent use.
+	Write(context.Context, []byte) error
+}
+
+// NewStream returns a Stream built on top of an io.Reader and io.Writer
+// The messages are sent with no wrapping, and rely on json decode consistency
+// to determine message boundaries.
+func NewStream(in io.Reader, out io.Writer) Stream {
+	return &plainStream{
+		in:  json.NewDecoder(in),
+		out: out,
+	}
+}
+
+type plainStream struct {
+	in    *json.Decoder
+	outMu sync.Mutex
+	out   io.Writer
+}
+
+func (s *plainStream) Read(ctx context.Context) ([]byte, error) {
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	default:
+	}
+	var raw json.RawMessage
+	if err := s.in.Decode(&raw); err != nil {
+		return nil, err
+	}
+	return raw, nil
+}
+
+func (s *plainStream) Write(ctx context.Context, data []byte) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+	s.outMu.Lock()
+	_, err := s.out.Write(data)
+	s.outMu.Unlock()
+	return err
+}
+
+// NewHeaderStream returns a Stream built on top of an io.Reader and io.Writer
+// The messages are sent with HTTP content length and MIME type headers.
+// This is the format used by LSP and others.
+func NewHeaderStream(in io.Reader, out io.Writer) Stream {
+	return &headerStream{
+		in:  bufio.NewReader(in),
+		out: out,
+	}
+}
+
+type headerStream struct {
+	in    *bufio.Reader
+	outMu sync.Mutex
+	out   io.Writer
+}
+
+func (s *headerStream) Read(ctx context.Context) ([]byte, error) {
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	default:
+	}
+	var length int64
+	// read the header, stop on the first empty line
+	for {
+		line, err := s.in.ReadString('\n')
+		if err != nil {
+			return nil, fmt.Errorf("failed reading header line %q", err)
+		}
+		line = strings.TrimSpace(line)
+		// check we have a header line
+		if line == "" {
+			break
+		}
+		colon := strings.IndexRune(line, ':')
+		if colon < 0 {
+			return nil, fmt.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, fmt.Errorf("failed parsing Content-Length: %v", value)
+			}
+			if length <= 0 {
+				return nil, fmt.Errorf("invalid Content-Length: %v", length)
+			}
+		default:
+			// ignoring unknown headers
+		}
+	}
+	if length == 0 {
+		return nil, fmt.Errorf("missing Content-Length header")
+	}
+	data := make([]byte, length)
+	if _, err := io.ReadFull(s.in, data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func (s *headerStream) Write(ctx context.Context, data []byte) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+	s.outMu.Lock()
+	_, err := fmt.Fprintf(s.out, "Content-Length: %v\r\n\r\n", len(data))
+	if err == nil {
+		_, err = s.out.Write(data)
+	}
+	s.outMu.Unlock()
+	return err
+}