langserver: support Changed files

x/jsonrpc2/conn.go

@@ -287,7 +287,7 @@ func (c *Connection) Notify(ctx context.Context, method string, params interface
 	}()
 
 	if debugCall {
-		log.Println("==> Connection.Notify", method, "params:", params)
+		log.Println("Notify", method, "params:", params)
 	}
 
 	c.updateInFlight(func(s *inFlightState) {
@@ -315,7 +315,7 @@ func (c *Connection) Notify(ctx context.Context, method string, params interface
 
 	err = c.write(ctx, notify)
 	if debugCall {
-		log.Println("==> Connection.write:", notify.Method, err)
+		log.Println("Connection.write", notify.Method, err)
 	}
 	return
 }
@@ -327,7 +327,7 @@ func (c *Connection) Notify(ctx context.Context, method string, params interface
 // If sending the call failed, the response will be ready and have the error in it.
 func (c *Connection) Call(ctx context.Context, method string, params interface{}) *AsyncCall {
 	if debugCall {
-		log.Println("==> Connection.Call", method, "params:", params)
+		log.Println("Call", method, "params:", params)
 	}
 	// Generate a new request identifier.
 	id := Int64ID(atomic.AddInt64(&c.seq, 1))
@@ -362,7 +362,7 @@ func (c *Connection) Call(ctx context.Context, method string, params interface{}
 
 	err = c.write(ctx, call)
 	if debugCall {
-		log.Println("==> Connection.write:", call.ID, call.Method, err)
+		log.Println("Connection.write", call.ID, call.Method, err)
 	}
 	if err != nil {
 		// Sending failed. We will never get a response, so deliver a fake one if it
@@ -693,7 +693,11 @@ func (c *Connection) handleAsync() {
 
 		if debugCall {
 			req := req.Request
-			log.Println("==> handleAsync", req.ID, req.Method, string(req.Params))
+			id := req.ID
+			if !id.IsValid() {
+				id = StringID("")
+			}
+			log.Println("handleAsync", id, req.Method, string(req.Params))
 		}
 		result, err := c.handler.Handle(req.ctx, req.Request)
 		c.processResult(c.handler, req, result, err)
@@ -721,7 +725,7 @@ func (c *Connection) processResult(from interface{}, req *incomingRequest, resul
 	if req.IsCall() {
 		response, respErr := NewResponse(req.ID, result, err)
 		if debugCall {
-			log.Println("==> processResult", response.ID, string(response.Result), response.Error)
+			log.Println("processResult", response.ID, string(response.Result), response.Error)
 		}
 
 		// The caller could theoretically reuse the request's ID as soon as we've

x/langserver/serve_dial.go

@@ -19,9 +19,13 @@ package langserver
 import (
 	"context"
 	"io"
+	"io/fs"
 	"log"
 	"os"
 	"os/exec"
+	"strconv"
+	"strings"
+	"time"
 
 	"github.com/goplus/gop/x/jsonrpc2/stdio"
 )
@@ -34,43 +38,93 @@ func fatal(err error) {
 
 // ServeAndDialConfig represents the configuration of ServeAndDial.
 type ServeAndDialConfig struct {
-	// LogFile is where the LangServer application log saves to (optional).
-	// Default is ~/.gop/serve.log
-	LogFile string
-
 	// OnError is to customize how to process errors (optional).
 	// It should panic in any case.
 	OnError func(err error)
 }
 
+const (
+	logPrefix = "serve-"
+	logSuffix = ".log"
+)
+
+func logFileOf(gopDir string, pid int) string {
+	return gopDir + logPrefix + strconv.Itoa(pid) + logSuffix
+}
+
+func isLog(fname string) bool {
+	return strings.HasSuffix(fname, logSuffix) && strings.HasPrefix(fname, logPrefix)
+}
+
+func pidByName(fname string) int {
+	pidText := fname[len(logPrefix) : len(fname)-len(logSuffix)]
+	if ret, err := strconv.ParseInt(pidText, 10, 0); err == nil {
+		return int(ret)
+	}
+	return -1
+}
+
+func killByPid(pid int) {
+	if pid < 0 {
+		return
+	}
+	if proc, err := os.FindProcess(pid); err == nil {
+		proc.Kill()
+	}
+}
+
+func tooOld(d fs.DirEntry) bool {
+	if fi, e := d.Info(); e == nil {
+		lastHour := time.Now().Add(-time.Hour)
+		return fi.ModTime().Before(lastHour)
+	}
+	return false
+}
+
 // ServeAndDial executes a command as a LangServer, makes a new connection to it
 // and returns a client of the LangServer based on the connection.
-func ServeAndDial(conf *ServeAndDialConfig, cmd string, args ...string) Client {
+func ServeAndDial(conf *ServeAndDialConfig, gopCmd string, args ...string) Client {
 	if conf == nil {
 		conf = new(ServeAndDialConfig)
 	}
 	onErr := conf.OnError
 	if onErr == nil {
 		onErr = fatal
 	}
-	logFile := conf.LogFile
-	if logFile == "" {
-		home, err := os.UserHomeDir()
-		if err != nil {
-			onErr(err)
-		}
-		gopDir := home + "/.gop"
-		err = os.MkdirAll(gopDir, 0755)
-		if err != nil {
-			onErr(err)
-		}
-		logFile = gopDir + "/serve.log"
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		onErr(err)
 	}
+	gopDir := home + "/.gop/"
+	err = os.MkdirAll(gopDir, 0755)
+	if err != nil {
+		onErr(err)
+	}
+
+	// logFile is where the LangServer application log saves to.
+	// default is ~/.gop/serve-{pid}.log
+	logFile := logFileOf(gopDir, os.Getpid())
+
+	// clean too old logfiles, and kill old LangServer processes
+	go func() {
+		if fis, e := os.ReadDir(gopDir); e == nil {
+			for _, fi := range fis {
+				if fi.IsDir() {
+					continue
+				}
+				if fname := fi.Name(); isLog(fname) && tooOld(fi) {
+					os.Remove(gopDir + fname)
+					killByPid(pidByName(fname))
+				}
+			}
+		}
+	}()
 
 	in, w := io.Pipe()
 	r, out := io.Pipe()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	var cmd *exec.Cmd
 	go func() {
 		defer r.Close()
 		defer w.Close()
@@ -81,14 +135,30 @@ func ServeAndDial(conf *ServeAndDialConfig, cmd string, args ...string) Client {
 		}
 		defer f.Close()
 
-		cmd := exec.CommandContext(ctx, cmd, args...)
+		cmd = exec.Command(gopCmd, args...)
 		cmd.Stdin = r
 		cmd.Stdout = w
 		cmd.Stderr = f
-		cmd.Run()
+		err = cmd.Start()
+		if err != nil {
+			onErr(err)
+		}
+
+		newLogFile := logFileOf(gopDir, cmd.Process.Pid)
+		os.Rename(logFile, newLogFile)
+
+		cmd.Wait()
 	}()
 
-	c, err := Open(ctx, stdio.Dialer(in, out), cancel)
+	c, err := Open(context.Background(), stdio.Dialer(in, out), func() {
+		if cmd == nil {
+			return
+		}
+		if proc := cmd.Process; proc != nil {
+			log.Println("==> ServeAndDial: kill", proc.Pid, gopCmd, args)
+			proc.Kill()
+		}
+	})
 	if err != nil {
 		onErr(err)
 	}

x/langserver/server.go

@@ -19,7 +19,9 @@ package langserver
 import (
 	"context"
 	"encoding/json"
-	"log"
+	"path/filepath"
+	"sync"
+	"time"
 
 	"github.com/goplus/gop"
 	"github.com/goplus/gop/x/gopprojs"
@@ -43,32 +45,72 @@ type Config struct {
 
 // NewServer creates a new LangServer and returns it.
 func NewServer(ctx context.Context, listener Listener, conf *Config) (ret *Server) {
-	h := new(handler)
+	h := newHandle()
 	ret = jsonrpc2.NewServer(ctx, listener, jsonrpc2.BinderFunc(
 		func(ctx context.Context, c *jsonrpc2.Connection) (ret jsonrpc2.ConnectionOptions) {
 			if conf != nil {
 				ret.Framer = conf.Framer
 			}
 			ret.Handler = h
-			ret.OnInternalError = h.OnInternalError
+			// ret.OnInternalError = h.OnInternalError
 			return
 		}))
 	h.server = ret
+	go h.runLoop()
 	return
 }
 
 // -----------------------------------------------------------------------------
 
+type none = struct{}
+
 type handler struct {
+	mutex sync.Mutex
+	dirty map[string]none
+
 	server *Server
 }
 
+func newHandle() *handler {
+	return &handler{
+		dirty: make(map[string]none),
+	}
+}
+
+/*
 func (p *handler) OnInternalError(err error) {
 	panic("jsonrpc2: " + err.Error())
 }
+*/
+
+func (p *handler) runLoop() {
+	const (
+		duration = time.Second / 100
+	)
+	for {
+		var dir string
+		p.mutex.Lock()
+		for dir = range p.dirty {
+			delete(p.dirty, dir)
+			break
+		}
+		p.mutex.Unlock()
+		if dir == "" {
+			time.Sleep(duration)
+			continue
+		}
+		gop.GenGoEx(dir, nil, true, gop.GenFlagPrompt)
+	}
+}
 
 func (p *handler) Changed(files []string) {
-	log.Println("Changed:", files)
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+
+	for _, file := range files {
+		dir := filepath.Dir(file)
+		p.dirty[dir] = none{}
+	}
 }
 
 func (p *handler) Handle(ctx context.Context, req *jsonrpc2.Request) (result interface{}, err error) {