internal/lsp/cmd/serve.go - tools - Git at Google

 // 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 cmd

 import (
 	"context"
 	"encoding/json"
 	"flag"
 	"fmt"
 	"io"
 	"log"
 	"net"
 	"os"
 	"path/filepath"
 	"strings"
 	"time"

 	"golang.org/x/tools/internal/jsonrpc2"
 	"golang.org/x/tools/internal/lsp"
 	"golang.org/x/tools/internal/lsp/debug"
 	"golang.org/x/tools/internal/lsp/telemetry"
 	"golang.org/x/tools/internal/lsp/telemetry/tag"
 	"golang.org/x/tools/internal/lsp/telemetry/trace"
 	"golang.org/x/tools/internal/tool"
 )

 // Serve is a struct that exposes the configurable parts of the LSP server as
 // flags, in the right form for tool.Main to consume.
 type Serve struct {
 	Logfile string `flag:"logfile" help:"filename to log to. if value is \"auto\", then logging to a default output file is enabled"`
 	Mode    string `flag:"mode" help:"no effect"`
 	Port    int    `flag:"port" help:"port on which to run gopls for debugging purposes"`
 	Address string `flag:"listen" help:"address on which to listen for remote connections"`
 	Trace   bool   `flag:"rpc.trace" help:"Print the full rpc trace in lsp inspector format"`
 	Debug   string `flag:"debug" help:"Serve debug information on the supplied address"`

 	app *Application
 }

 func (s *Serve) Name() string  { return "serve" }
 func (s *Serve) Usage() string { return "" }
 func (s *Serve) ShortHelp() string {
 	return "run a server for Go code using the Language Server Protocol"
 }
 func (s *Serve) DetailedHelp(f *flag.FlagSet) {
 	fmt.Fprint(f.Output(), `
 The server communicates using JSONRPC2 on stdin and stdout, and is intended to be run directly as
 a child of an editor process.

 gopls server flags are:
 `)
 	f.PrintDefaults()
 }

 // Run configures a server based on the flags, and then runs it.
 // It blocks until the server shuts down.
 func (s *Serve) Run(ctx context.Context, args ...string) error {
 	if len(args) > 0 {
 		return tool.CommandLineErrorf("server does not take arguments, got %v", args)
 	}
 	out := os.Stderr
 	if s.Logfile != "" {
 		filename := s.Logfile
 		if filename == "auto" {
 			filename = filepath.Join(os.TempDir(), fmt.Sprintf("gopls-%d.log", os.Getpid()))
 		}
 		f, err := os.Create(filename)
 		if err != nil {
 			return fmt.Errorf("Unable to create log file: %v", err)
 		}
 		defer f.Close()
 		log.SetOutput(io.MultiWriter(os.Stderr, f))
 		out = f
 	}

 	debug.Serve(ctx, s.Debug)

 	if s.app.Remote != "" {
 		return s.forward()
 	}

 	// For debugging purposes only.
 	run := func(ctx context.Context, srv *lsp.Server) {
 		srv.Conn.AddHandler(&handler{loggingRPCs: s.Trace, out: out})
 		go srv.Run(ctx)
 	}
 	if s.Address != "" {
 		return lsp.RunServerOnAddress(ctx, s.app.cache, s.Address, run)
 	}
 	if s.Port != 0 {
 		return lsp.RunServerOnPort(ctx, s.app.cache, s.Port, run)
 	}
 	stream := jsonrpc2.NewHeaderStream(os.Stdin, os.Stdout)
 	ctx, srv := lsp.NewServer(ctx, s.app.cache, stream)
 	srv.Conn.AddHandler(&handler{loggingRPCs: s.Trace, out: out})
 	return srv.Run(ctx)
 }

 func (s *Serve) forward() error {
 	conn, err := net.Dial("tcp", s.app.Remote)
 	if err != nil {
 		return err
 	}
 	errc := make(chan error)

 	go func(conn net.Conn) {
 		_, err := io.Copy(conn, os.Stdin)
 		errc <- err
 	}(conn)

 	go func(conn net.Conn) {
 		_, err := io.Copy(os.Stdout, conn)
 		errc <- err
 	}(conn)

 	return <-errc
 }

 type handler struct {
 	loggingRPCs bool
 	out         io.Writer
 }

 type rpcStats struct {
 	method     string
 	direction  jsonrpc2.Direction
 	id         *jsonrpc2.ID
 	payload    *json.RawMessage
 	start      time.Time
 	delivering func()
 	close      func()
 }

 type statsKeyType int

 const statsKey = statsKeyType(0)

 func (h *handler) Deliver(ctx context.Context, r *jsonrpc2.Request, delivered bool) bool {
 	stats := h.getStats(ctx)
 	if stats != nil {
 		stats.delivering()
 	}
 	return false
 }

 func (h *handler) Cancel(ctx context.Context, conn *jsonrpc2.Conn, id jsonrpc2.ID, cancelled bool) bool {
 	return false
 }

 func (h *handler) Request(ctx context.Context, direction jsonrpc2.Direction, r *jsonrpc2.WireRequest) context.Context {
 	if r.Method == "" {
 		panic("no method in rpc stats")
 	}
 	stats := &rpcStats{
 		method:    r.Method,
 		start:     time.Now(),
 		direction: direction,
 		payload:   r.Params,
 	}
 	ctx = context.WithValue(ctx, statsKey, stats)
 	mode := telemetry.Outbound
 	if direction == jsonrpc2.Receive {
 		mode = telemetry.Inbound
 	}
 	ctx, stats.close = trace.StartSpan(ctx, r.Method,
 		tag.Tag{Key: telemetry.Method, Value: r.Method},
 		tag.Tag{Key: telemetry.RPCDirection, Value: mode},
 		tag.Tag{Key: telemetry.RPCID, Value: r.ID},
 	)
 	telemetry.Started.Record(ctx, 1)
 	_, stats.delivering = trace.StartSpan(ctx, "queued")
 	return ctx
 }

 func (h *handler) Response(ctx context.Context, direction jsonrpc2.Direction, r *jsonrpc2.WireResponse) context.Context {
 	stats := h.getStats(ctx)
 	h.logRPC(direction, r.ID, 0, stats.method, r.Result, nil)
 	return ctx
 }

 func (h *handler) Done(ctx context.Context, err error) {
 	stats := h.getStats(ctx)
 	h.logRPC(stats.direction, stats.id, time.Since(stats.start), stats.method, stats.payload, err)
 	if err != nil {
 		ctx = telemetry.StatusCode.With(ctx, "ERROR")
 	} else {
 		ctx = telemetry.StatusCode.With(ctx, "OK")
 	}
 	elapsedTime := time.Since(stats.start)
 	latencyMillis := float64(elapsedTime) / float64(time.Millisecond)
 	telemetry.Latency.Record(ctx, latencyMillis)
 	stats.close()
 }

 func (h *handler) Read(ctx context.Context, bytes int64) context.Context {
 	telemetry.SentBytes.Record(ctx, bytes)
 	return ctx
 }

 func (h *handler) Wrote(ctx context.Context, bytes int64) context.Context {
 	telemetry.ReceivedBytes.Record(ctx, bytes)
 	return ctx
 }

 const eol = "\r\n\r\n\r\n"

 func (h *handler) Error(ctx context.Context, err error) {
 	stats := h.getStats(ctx)
 	h.logRPC(stats.direction, stats.id, 0, stats.method, nil, err)
 }

 func (h *handler) getStats(ctx context.Context) *rpcStats {
 	stats, ok := ctx.Value(statsKey).(*rpcStats)
 	if !ok || stats == nil {
 		method, ok := ctx.Value(telemetry.Method).(string)
 		if !ok {
 			method = "???"
 		}
 		stats = &rpcStats{
 			method: method,
 			close:  func() {},
 		}
 	}
 	return stats
 }

 func (h *handler) logRPC(direction jsonrpc2.Direction, id *jsonrpc2.ID, elapsed time.Duration, method string, payload *json.RawMessage, err error) {
 	if !h.loggingRPCs {
 		return
 	}
 	const eol = "\r\n\r\n\r\n"
 	if err != nil {
 		fmt.Fprintf(h.out, "[Error - %v] %s %s%s %v%s", time.Now().Format("3:04:05 PM"),
 			direction, method, id, err, eol)
 		return
 	}
 	outx := new(strings.Builder)
 	fmt.Fprintf(outx, "[Trace - %v] ", time.Now().Format("3:04:05 PM"))
 	switch direction {
 	case jsonrpc2.Send:
 		fmt.Fprint(outx, "Received ")
 	case jsonrpc2.Receive:
 		fmt.Fprint(outx, "Sending ")
 	}
 	switch {
 	case id == nil:
 		fmt.Fprint(outx, "notification ")
 	case elapsed >= 0:
 		fmt.Fprint(outx, "response ")
 	default:
 		fmt.Fprint(outx, "request ")
 	}
 	fmt.Fprintf(outx, "'%s", method)
 	switch {
 	case id == nil:
 		// do nothing
 	case id.Name != "":
 		fmt.Fprintf(outx, " - (%s)", id.Name)
 	default:
 		fmt.Fprintf(outx, " - (%d)", id.Number)
 	}
 	fmt.Fprint(outx, "'")
 	if elapsed >= 0 {
 		msec := int(elapsed.Round(time.Millisecond) / time.Millisecond)
 		fmt.Fprintf(outx, " in %dms", msec)
 	}
 	params := "null"
 	if payload != nil {
 		params = string(*payload)
 	}
 	if params == "null" {
 		params = "{}"
 	}
 	fmt.Fprintf(outx, ".\r\nParams: %s%s", params, eol)
 	fmt.Fprintf(h.out, "%s", outx.String())
 }
	// 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 cmd

	import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"log"
	"net"
	"os"
	"path/filepath"
	"strings"
	"time"

	"golang.org/x/tools/internal/jsonrpc2"
	"golang.org/x/tools/internal/lsp"
	"golang.org/x/tools/internal/lsp/debug"
	"golang.org/x/tools/internal/lsp/telemetry"
	"golang.org/x/tools/internal/lsp/telemetry/tag"
	"golang.org/x/tools/internal/lsp/telemetry/trace"
	"golang.org/x/tools/internal/tool"
	)

	// Serve is a struct that exposes the configurable parts of the LSP server as
	// flags, in the right form for tool.Main to consume.
	type Serve struct {
	Logfile string `flag:"logfile" help:"filename to log to. if value is \"auto\", then logging to a default output file is enabled"`
	Mode string `flag:"mode" help:"no effect"`
	Port int `flag:"port" help:"port on which to run gopls for debugging purposes"`
	Address string `flag:"listen" help:"address on which to listen for remote connections"`
	Trace bool `flag:"rpc.trace" help:"Print the full rpc trace in lsp inspector format"`
	Debug string `flag:"debug" help:"Serve debug information on the supplied address"`

	app *Application
	}

	func (s *Serve) Name() string { return "serve" }
	func (s *Serve) Usage() string { return "" }
	func (s *Serve) ShortHelp() string {
	return "run a server for Go code using the Language Server Protocol"
	}
	func (s Serve) DetailedHelp(f flag.FlagSet) {
	fmt.Fprint(f.Output(), `
	The server communicates using JSONRPC2 on stdin and stdout, and is intended to be run directly as
	a child of an editor process.

	gopls server flags are:
	`)
	f.PrintDefaults()
	}

	// Run configures a server based on the flags, and then runs it.
	// It blocks until the server shuts down.
	func (s *Serve) Run(ctx context.Context, args ...string) error {
	if len(args) > 0 {
	return tool.CommandLineErrorf("server does not take arguments, got %v", args)
	}
	out := os.Stderr
	if s.Logfile != "" {
	filename := s.Logfile
	if filename == "auto" {
	filename = filepath.Join(os.TempDir(), fmt.Sprintf("gopls-%d.log", os.Getpid()))
	}
	f, err := os.Create(filename)
	if err != nil {
	return fmt.Errorf("Unable to create log file: %v", err)
	}
	defer f.Close()
	log.SetOutput(io.MultiWriter(os.Stderr, f))
	out = f
	}

	debug.Serve(ctx, s.Debug)

	if s.app.Remote != "" {
	return s.forward()
	}

	// For debugging purposes only.
	run := func(ctx context.Context, srv *lsp.Server) {
	srv.Conn.AddHandler(&handler{loggingRPCs: s.Trace, out: out})
	go srv.Run(ctx)
	}
	if s.Address != "" {
	return lsp.RunServerOnAddress(ctx, s.app.cache, s.Address, run)
	}
	if s.Port != 0 {
	return lsp.RunServerOnPort(ctx, s.app.cache, s.Port, run)
	}
	stream := jsonrpc2.NewHeaderStream(os.Stdin, os.Stdout)
	ctx, srv := lsp.NewServer(ctx, s.app.cache, stream)
	srv.Conn.AddHandler(&handler{loggingRPCs: s.Trace, out: out})
	return srv.Run(ctx)
	}

	func (s *Serve) forward() error {
	conn, err := net.Dial("tcp", s.app.Remote)
	if err != nil {
	return err
	}
	errc := make(chan error)

	go func(conn net.Conn) {
	_, err := io.Copy(conn, os.Stdin)
	errc <- err
	}(conn)

	go func(conn net.Conn) {
	_, err := io.Copy(os.Stdout, conn)
	errc <- err
	}(conn)

	return <-errc
	}

	type handler struct {
	loggingRPCs bool
	out io.Writer
	}

	type rpcStats struct {
	method string
	direction jsonrpc2.Direction
	id *jsonrpc2.ID
	payload *json.RawMessage
	start time.Time
	delivering func()
	close func()
	}

	type statsKeyType int

	const statsKey = statsKeyType(0)

	func (h handler) Deliver(ctx context.Context, r jsonrpc2.Request, delivered bool) bool {
	stats := h.getStats(ctx)
	if stats != nil {
	stats.delivering()
	}
	return false
	}

	func (h handler) Cancel(ctx context.Context, conn jsonrpc2.Conn, id jsonrpc2.ID, cancelled bool) bool {
	return false
	}

	func (h handler) Request(ctx context.Context, direction jsonrpc2.Direction, r jsonrpc2.WireRequest) context.Context {
	if r.Method == "" {
	panic("no method in rpc stats")
	}
	stats := &rpcStats{
	method: r.Method,
	start: time.Now(),
	direction: direction,
	payload: r.Params,
	}
	ctx = context.WithValue(ctx, statsKey, stats)
	mode := telemetry.Outbound
	if direction == jsonrpc2.Receive {
	mode = telemetry.Inbound
	}
	ctx, stats.close = trace.StartSpan(ctx, r.Method,
	tag.Tag{Key: telemetry.Method, Value: r.Method},
	tag.Tag{Key: telemetry.RPCDirection, Value: mode},
	tag.Tag{Key: telemetry.RPCID, Value: r.ID},
	)
	telemetry.Started.Record(ctx, 1)
	_, stats.delivering = trace.StartSpan(ctx, "queued")
	return ctx
	}

	func (h handler) Response(ctx context.Context, direction jsonrpc2.Direction, r jsonrpc2.WireResponse) context.Context {
	stats := h.getStats(ctx)
	h.logRPC(direction, r.ID, 0, stats.method, r.Result, nil)
	return ctx
	}

	func (h *handler) Done(ctx context.Context, err error) {
	stats := h.getStats(ctx)
	h.logRPC(stats.direction, stats.id, time.Since(stats.start), stats.method, stats.payload, err)
	if err != nil {
	ctx = telemetry.StatusCode.With(ctx, "ERROR")
	} else {
	ctx = telemetry.StatusCode.With(ctx, "OK")
	}
	elapsedTime := time.Since(stats.start)
	latencyMillis := float64(elapsedTime) / float64(time.Millisecond)
	telemetry.Latency.Record(ctx, latencyMillis)
	stats.close()
	}

	func (h *handler) Read(ctx context.Context, bytes int64) context.Context {
	telemetry.SentBytes.Record(ctx, bytes)
	return ctx
	}

	func (h *handler) Wrote(ctx context.Context, bytes int64) context.Context {
	telemetry.ReceivedBytes.Record(ctx, bytes)
	return ctx
	}

	const eol = "\r\n\r\n\r\n"

	func (h *handler) Error(ctx context.Context, err error) {
	stats := h.getStats(ctx)
	h.logRPC(stats.direction, stats.id, 0, stats.method, nil, err)
	}

	func (h handler) getStats(ctx context.Context) rpcStats {
	stats, ok := ctx.Value(statsKey).(*rpcStats)
	if !ok \|\| stats == nil {
	method, ok := ctx.Value(telemetry.Method).(string)
	if !ok {
	method = "???"
	}
	stats = &rpcStats{
	method: method,
	close: func() {},
	}
	}
	return stats
	}

	func (h handler) logRPC(direction jsonrpc2.Direction, id jsonrpc2.ID, elapsed time.Duration, method string, payload *json.RawMessage, err error) {
	if !h.loggingRPCs {
	return
	}
	const eol = "\r\n\r\n\r\n"
	if err != nil {
	fmt.Fprintf(h.out, "[Error - %v] %s %s%s %v%s", time.Now().Format("3:04:05 PM"),
	direction, method, id, err, eol)
	return
	}
	outx := new(strings.Builder)
	fmt.Fprintf(outx, "[Trace - %v] ", time.Now().Format("3:04:05 PM"))
	switch direction {
	case jsonrpc2.Send:
	fmt.Fprint(outx, "Received ")
	case jsonrpc2.Receive:
	fmt.Fprint(outx, "Sending ")
	}
	switch {
	case id == nil:
	fmt.Fprint(outx, "notification ")
	case elapsed >= 0:
	fmt.Fprint(outx, "response ")
	default:
	fmt.Fprint(outx, "request ")
	}
	fmt.Fprintf(outx, "'%s", method)
	switch {
	case id == nil:
	// do nothing
	case id.Name != "":
	fmt.Fprintf(outx, " - (%s)", id.Name)
	default:
	fmt.Fprintf(outx, " - (%d)", id.Number)
	}
	fmt.Fprint(outx, "'")
	if elapsed >= 0 {
	msec := int(elapsed.Round(time.Millisecond) / time.Millisecond)
	fmt.Fprintf(outx, " in %dms", msec)
	}
	params := "null"
	if payload != nil {
	params = string(*payload)
	}
	if params == "null" {
	params = "{}"
	}
	fmt.Fprintf(outx, ".\r\nParams: %s%s", params, eol)
	fmt.Fprintf(h.out, "%s", outx.String())
	}