implemented HTTP 1.0/1.1 server

internal/server/Server.go

@@ -1,59 +1,139 @@
 package server
 
 import (
+	"errors"
+	"io"
 	"net"
+	"os"
+	"serveg/internal/http"
 	"serveg/internal/log"
 	"strconv"
+	"sync"
+	"syscall"
 	"time"
 )
 
-func Serve(conf *Config) error {
-	logger := log.LoggerContext{Name: "server"}
-	addr := net.JoinHostPort(conf.Ip.String(), strconv.Itoa(int(conf.Port)))
+type Server struct {
+	Conf     *Config
+	listener net.Listener
+	logger   log.LoggerContext
+	wg       sync.WaitGroup
+}
 
-	logger.Info("listening at", addr)
-	srv, err := net.Listen("tcp", addr)
-	if err != nil {
-		return err
+func (srv *Server) StartGoroutine() (err error) {
+	srv.logger = log.LoggerContext{Name: "server"}
+	srv.logger.Info("listening at ", srv.Conf.Addr)
+	srv.listener, err = net.Listen("tcp", srv.Conf.Addr)
+	if err == nil {
+		srv.wg.Go(srv.serve)
 	}
-	defer func() { _ = srv.Close() }()
+	return
+}
 
+func (srv *Server) serve() {
+	srv.logger.Info("server started")
 	for i := int64(0); ; i++ {
-		conn, err := srv.Accept()
+		conn, err := srv.listener.Accept()
 		if err != nil {
-			logger.Warn(err)
+			if errors.Is(err, net.ErrClosed) {
+				srv.logger.Info("listener socket closed")
+				return
+			}
+			srv.logger.Warn(err)
 			continue
 		}
-		go handleConnection(conn, i)
+		// TODO: add connection to map. SetDeadline(Now()) in Stop().
+		// srv.wg.Go(func() { handleConnection(conn.(*net.TCPConn), i) })
+		go handleConnection(conn.(*net.TCPConn), i)
 	}
 }
 
-func handleConnection(conn net.Conn, n int64) {
+func (srv *Server) Stop() {
+	srv.logger.Info("stopping server")
+	_ = srv.listener.Close()
+	srv.wg.Wait()
+}
+
+func handleConnection(socket *net.TCPConn, n int64) {
 	logger := log.LoggerContext{Name: "conn-" + strconv.FormatInt(n, 10)}
 	defer func() {
 		if r := recover(); r != nil {
 			logger.Error("panic: ", r)
 		}
-		_ = conn.Close()
+		_ = socket.Close()
+		logger.Info("connection closed")
 	}()
 
-	buf := make([]byte, 4096)
-
+	conn := http.NewConnection(socket)
 	for {
-		if err := conn.SetDeadline(time.Now().Add(30 * time.Second)); err != nil {
-			logger.Warn(err)
-			break
-		}
-		n, err := conn.Read(buf)
+		err := socket.SetDeadline(time.Now().Add(30 * time.Second))
 		if err != nil {
 			logger.Warn(err)
-			break
+			return
 		}
-		msgBytes := buf[:n]
-		logger.Info("msg: `", string(msgBytes), "`")
-		if _, err := conn.Write(msgBytes); err != nil {
-			logger.Warn(err)
-			break
+
+		req, err := conn.ReadRequest()
+		if err != nil {
+			logConnError(logger, err)
+
+			if httpErr, ok := errors.AsType[*http.HttpError](err); ok {
+				// return error code to client
+				logger.Info("sending error response")
+				// req is partially parsed, may use fields
+				if err = conn.SendErrorResponse(httpErr, req, true); err != nil {
+					logger.Warn("can't send error response")
+					return
+				}
+			}
+			// close the connection
+			logger.Info("lingering close")
+			lingeringClose(socket)
+			return
+		}
+		logger.Info(req.Method, " ", req.Path, " ", req.Protocol,
+			"\nHeaders: ", req.Headers)
+
+		resBody := "Hi\n" + time.Now().Format(time.DateTime)
+
+		res := conn.CreateResponse(http.StatusOK, req, false)
+		res.AttachBodySmallStr(resBody, http.TextPlain)
+		logger.Info("sending response: ", res.Status,
+			"\nHeaders: ", res.Headers)
+		err = conn.SendResponse(res)
+		if err != nil {
+			logConnError(logger, err)
+			return
+		}
+
+		// it is set by CreateResponse
+		if res.Headers["connection"] == "close" {
+			logger.Info("lingering close")
+			lingeringClose(socket)
+			return
 		}
 	}
 }
+
+func logConnError(logger log.LoggerContext, err error) {
+	if errors.Is(err, os.ErrDeadlineExceeded) {
+		logger.Info("time out")
+	} else if errors.Is(err, io.EOF) ||
+		errors.Is(err, syscall.EPIPE) ||
+		errors.Is(err, syscall.ECONNRESET) {
+
+		logger.Info("closed by client")
+	} else {
+		logger.Warn(err)
+	}
+}
+
+// lingeringClose: shut down our side, then drain the client's unread data,
+// so close() doesn't send RST and destroy the response before it's read.
+// Limits: 500 ms, 32 KB
+func lingeringClose(socket *net.TCPConn) {
+	if socket.CloseWrite() != nil {
+		return
+	}
+	_ = socket.SetReadDeadline(time.Now().Add(500 * time.Millisecond))
+	_, _ = io.Copy(io.Discard, io.LimitReader(socket, 32*1024))
+}