vweb: continue after bad http client connection; performance fixes

* Enable compiling vweb with -prod (by supressing 'declared and not used' warning about 'reset') .

* Fix http responses (now wrk is happy and shows no errors) by adding a Content-Length header.

* Fix -g compilation for urllib.v .

* vweb: println action= only in debug mode.

* vweb: max request headers counting fix.

* Make vweb.html get a 'ctx mut Context' param, just like the other methods.

* vweb: simplify add_header.

* Use a string builder for the most common html case so that the response http text can be send in one go.

* vweb: reduce _STR/string interpolation usage in the most common html response case.

* vweb: refactor common http response formatting into Context.send_response_to_client/2 method.

examples/vweb/vweb_example.v

@@ -22,7 +22,7 @@ pub fn (app mut App) init() {
 	app.vweb.handle_static('.')
 }
 
-pub fn (app & App) json_endpoint() {
+pub fn (app mut App) json_endpoint() {
 	app.vweb.json('{"a": 3}')
 }
 

vlib/compiler/comptime.v

@@ -178,7 +178,7 @@ fn (p mut Parser) comp_time() {
 		p.genln('/////////////////// tmpl end')
 		receiver := p.cur_fn.args[0]
 		dot := if receiver.is_mut || receiver.ptr || receiver.typ.ends_with('*') { '->' } else { '.' }
-		p.genln('vweb__Context_html($receiver.name /*!*/$dot vweb, tmpl_res)')
+		p.genln('vweb__Context_html( & $receiver.name /*!*/$dot vweb, tmpl_res)')
 	}
 	else {
 		p.error('bad comptime expr')

vlib/compiler/fn.v

@@ -627,7 +627,7 @@ fn (p mut Parser) check_unused_and_mut_vars() {
 			break
 		}
 		if !var.is_used && !p.pref.is_repl &&  !var.is_arg &&
-			!p.pref.translated && var.name != 'tmpl_res'
+			!p.pref.translated && var.name != 'tmpl_res' && p.mod != 'vweb'
 		{
 			p.production_error_with_token_index('`$var.name` declared and not used', var.token_idx )
 		}

vlib/net/socket.v

@@ -202,13 +202,23 @@ pub fn dial(address string, port int) ?Socket {
 	return s
 }
 
-// send string data to socket
+// send data to socket (when you have a memory buffer)
 pub fn (s Socket) send(buf byteptr, len int) ?int {
-	res := C.send(s.sockfd, buf, len, MSG_NOSIGNAL)
+	mut dptr := buf
-	if res < 0 {
+	mut dlen := len
-		return error('net.send: failed with $res')
+	for {
+		sbytes := C.send(s.sockfd, dptr, dlen, MSG_NOSIGNAL)
+		if sbytes < 0 { return error('net.send: failed with $sbytes') }
+		dlen -= sbytes
+		if dlen <= 0 { break }
+		dptr += sbytes
 	}
-	return res
+	return len
+}
+
+// send string data to socket (when you have a v string)
+pub fn (s Socket) send_string(sdata string) ?int {
+	return s.send( sdata.str, sdata.len )
 }
 
 // receive string data from socket

vlib/net/urllib/urllib.v

@@ -518,8 +518,8 @@ fn parse_url(rawurl string, via_request bool) ?URL {
 		// RFC 3986, §3.3:
 		// In addition, a URI reference (Section 4.1) may be a relative-path reference,
 		// in which case the first path segment cannot contain a colon (':') character.
-		colon := rest.index(':') or { -1 }
+		colon := rest.index(':') or { return error('there should be a : in the URL') }
-		slash := rest.index('/') or { -1 }
+		slash := rest.index('/') or { return error('there should be a / in the URL') }
 		if colon >= 0 && (slash < 0 || colon < slash) {
 			// First path segment has colon. Not allowed in relative URL.
 			return error(error_msg('parse_url: first path segment in URL cannot contain colon', ''))
@@ -553,7 +553,7 @@ struct ParseAuthorityRes {
 fn parse_authority(authority string) ?ParseAuthorityRes {
 	i := authority.last_index('@')
 	mut host := ''
-	mut user := user('')
+	mut zuser := user('')
 	if i < 0 {
 		h := parse_host(authority) or {
 			return error(err)
@@ -566,7 +566,7 @@ fn parse_authority(authority string) ?ParseAuthorityRes {
 		host = h
 	}
 	if i < 0 {
-		return ParseAuthorityRes{host: host, user: user}
+		return ParseAuthorityRes{host: host, user: zuser}
 	}
 	mut userinfo := authority[..i]
 	if !valid_userinfo(userinfo) {
@@ -577,7 +577,7 @@ fn parse_authority(authority string) ?ParseAuthorityRes {
 			return error(err)
 		}
 		userinfo = u
-		user = user(userinfo)
+		zuser = user(userinfo)
 	} else {
 		mut username, mut password := split(userinfo, `:`, true)
 		u := unescape(username, .encode_user_password) or {
@@ -588,10 +588,10 @@ fn parse_authority(authority string) ?ParseAuthorityRes {
 			return error(err)
 		}
 		password = p
-		user = user_password(username, password)
+		zuser = user_password(username, password)
 	}
 	return ParseAuthorityRes{
-		user: user
+		user: zuser
 		host: host
 	}
 }

vlib/strings/builder_c.v

@@ -9,11 +9,13 @@ mut:
 	buf []byte
 pub:
 	len int
+	initial_size int = 1
 }
 
 pub fn new_builder(initial_size int) Builder {
 	return Builder {
 		buf: make(0, initial_size, 1)
+		initial_size: initial_size
 	}
 }
 
@@ -48,6 +50,6 @@ pub fn (b mut Builder) str() string {
 
 pub fn (b mut Builder) free() {
 	unsafe{ free(b.buf.data) }
-	b.buf = make(0, 1, 1)
+	b.buf = make(0, b.initial_size, 1)
 	b.len = 0
 }

vlib/strings/builder_js.v

@@ -9,11 +9,13 @@ mut:
 	buf []byte
 pub:
 	len int
+	initial_size int = 1
 }
 
 pub fn new_builder(initial_size int) Builder {
 	return Builder {
 		buf: make(0, initial_size, sizeof(byte))
+		initial_size: initial_size
 	}
 }
 
@@ -44,4 +46,6 @@ pub fn (b mut Builder) cut(n int) {
 }
 
 pub fn (b mut Builder) free() {
+	b.buf = make(0, b.initial_size, 1)
+	b.len = 0
 }

vlib/vweb/vweb.v

@@ -9,13 +9,16 @@ import (
 	net
 	http
 	net.urllib
+	strings
 )
 
 const (
 	methods_with_form = ['POST', 'PUT', 'PATCH']
-	HEADER_SERVER = 'Server: VWeb\r\n' // TODO add to the headers
+	HEADER_SERVER = 'Server: VWeb\r\n'
-	HTTP_404 = 'HTTP/1.1 404 Not Found\r\nContent-Type: text/plain\r\n\r\n404 Not Found'
+	HEADER_CONNECTION_CLOSE = 'Connection: close\r\n'
-	HTTP_500 = 'HTTP/1.1 500 Internal Server Error\r\nContent-Type: text/plain\r\n\r\n500 Internal Server Error'
+	HEADERS_CLOSE = '${HEADER_SERVER}${HEADER_CONNECTION_CLOSE}\r\n'
+	HTTP_404 = 'HTTP/1.1 404 Not Found\r\nContent-Type: text/plain\r\n${HEADERS_CLOSE}404 Not Found'
+	HTTP_500 = 'HTTP/1.1 500 Internal Server Error\r\nContent-Type: text/plain\r\n${HEADERS_CLOSE}500 Internal Server Error'
 	mime_types = {
 		'.css': 'text/css; charset=utf-8',
 		'.gif': 'image/gif',
@@ -44,37 +47,49 @@ mut:
 	done bool
 }
 
-pub fn (ctx Context) html(html string) {
+fn (ctx mut Context) send_response_to_client(mimetype string, res string) bool {
-	if ctx.done { return }
+	if ctx.done { return false }
-	//println('HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n$ctx.headers\r\n\r\n$html')
+	ctx.done = true
-	ctx.conn.write('HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n$ctx.headers\r\n\r\n$html') or { panic(err) }
+	mut sb := strings.new_builder(1024)
+	sb.write('HTTP/1.1 200 OK\r\nContent-Type: ') sb.write(mimetype)
+	sb.write('\r\nContent-Length: ')              sb.write(res.len.str())
+	sb.write(ctx.headers)
+	sb.write('\r\n')
+	sb.write(HEADERS_CLOSE)
+	sb.write(res)
+	ctx.conn.send_string(sb.str()) or { return false }
+	sb.free()
+	return true
+}
+
+pub fn (ctx mut Context) html(s string) {
+	ctx.send_response_to_client('text/html', s)
 }
 
 pub fn (ctx mut Context) text(s string) {
+	ctx.send_response_to_client('text/plain', s)
+}
+
+pub fn (ctx mut Context) json(s string) {
+	ctx.send_response_to_client('application/json', s)
+}
+
+pub fn (ctx mut Context) redirect(url string) {
 	if ctx.done { return }
-	ctx.conn.write('HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\n' +
-		'$ctx.headers\r\n$s') or { panic(err) }
 	ctx.done = true
+	ctx.conn.send_string('HTTP/1.1 302 Found\r\nLocation: ${url}${ctx.headers}\r\n${HEADERS_CLOSE}') or { return }
 }
 
-pub fn (ctx Context) json(s string) {
+pub fn (ctx mut Context) not_found(s string) {
 	if ctx.done { return }
-	ctx.conn.write('HTTP/1.1 200 OK\r\nContent-Type: application/json\r\n$ctx.headers\r\n\r\n$s') or { panic(err) }
+	ctx.done = true
+	ctx.conn.send_string(HTTP_404) or { return }
 }
 
-pub fn (ctx Context) redirect(url string) {
+pub fn (ctx mut Context) set_cookie(key, val string) {
-	if ctx.done { return }
+	// TODO support directives, escape cookie value (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie)
-	ctx.conn.write('HTTP/1.1 302 Found\r\nLocation: $url\r\n$ctx.headers\r\n\r\n') or { panic(err) }
-}
-
-pub fn (ctx Context) not_found(s string) {
-	if ctx.done { return }
-	ctx.conn.write(HTTP_404) or { panic(err) }
-}
-
-pub fn (ctx mut Context) set_cookie(key, val string) { // TODO support directives, escape cookie value (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie)
 	//println('Set-Cookie $key=$val')
-	ctx.add_header('Set-Cookie', '$key=$val;  Secure; HttpOnly')
+	ctx.add_header('Set-Cookie', '${key}=${val};  Secure; HttpOnly')
 }
 
 pub fn (ctx &Context) get_cookie(key string) ?string { // TODO refactor
@@ -92,8 +107,7 @@ pub fn (ctx &Context) get_cookie(key string) ?string { // TODO refactor
 
 fn (ctx mut Context) add_header(key, val string) {
 	//println('add_header($key, $val)')
-	ctx.headers = ctx.headers +
+	ctx.headers = ctx.headers + '\r\n$key: $val'
-		if ctx.headers == '' { '$key: $val' } else { '\r\n$key: $val' }
 	//println(ctx.headers)
 }
 
@@ -108,16 +122,14 @@ pub fn run<T>(app mut T, port int) {
 	//mut app := T{}
 	app.init()
 	for {
-		conn := l.accept() or {
+		conn := l.accept() or { panic('accept() failed') }
-			panic('accept() failed')
-		}
 		//foobar<T>()
 		// TODO move this to handle_conn<T>(conn, app)
 		first_line:= conn.read_line()
 		if first_line == '' {
-			conn.write(HTTP_500) or {}
+			conn.send_string(HTTP_500) or {}
 			conn.close() or {}
-			return
+			continue
 		}
 		// Parse the first line
 		// "GET / HTTP/1.1"
@@ -125,18 +137,17 @@ pub fn run<T>(app mut T, port int) {
 		vals := first_line.split(' ')
 		if vals.len < 2 {
 			println('no vals for http')
-			conn.write(HTTP_500) or {}
+			conn.send_string(HTTP_500) or {}
 			conn.close() or {}
-			return
+			continue
 		}
 		mut headers := []string
-		for _ in 0..30 {
+		for {
+			if headers.len >= 30 { break }
 			header := conn.read_line()
 			headers << header
 			//println('header="$header" len = ' + header.len.str())
-			if header.len <= 2 {
+			if header.len <= 2 { break }
-				break
-			}
 		}
 		mut action := vals[1][1..].all_before('/')
 		if action.contains('?') {
@@ -196,9 +207,11 @@ pub fn run<T>(app mut T, port int) {
 		// }
 
 		// Call the right action
-		println('action=$action')
+		$if debug {
+			println('action=$action')
+		}
 		app.$action() or {
-			conn.write(HTTP_404) or {}
+			conn.send_string(HTTP_404) or {}
 		}
 		conn.close() or {}
 		reset := 'reset'
@@ -267,6 +280,7 @@ fn (ctx mut Context) scan_static_directory(directory_path, mount_path string) {
 }
 
 pub fn (ctx mut Context) handle_static(directory_path string) bool {
+	if ctx.done { return false }
 	ctx.scan_static_directory(directory_path, '')
 
 	static_file := ctx.static_files[ctx.req.url]
@@ -274,8 +288,7 @@ pub fn (ctx mut Context) handle_static(directory_path string) bool {
 
 	if static_file != '' {
 		data := os.read_file(static_file) or { return false }
-		ctx.conn.write('HTTP/1.1 200 OK\r\nContent-Type: $mime_type\r\n\r\n$data') or { panic(err) }
+		return ctx.send_response_to_client(mime_type, data)
-		return true
 	}
 	return false
 }