optimize utf8 check tests into state bit

Considering we go through it once per incoming char, the tests to see if we
should be checking utf-8 are too expensive... move them to a bit that lives
in the wsi and set them once per frame (except for CLOSE who has to update
after the close code has been skipped).

Signed-off-by: Andy Green <andy.green@linaro.org>

diff --git a/lib/client-parser.c b/lib/client-parser.c
index 72e19f6..ec35e13 100644 (file)
--- a/lib/client-parser.c
+++ b/lib/client-parser.c
@@ -31,18 +31,25 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
 
        switch (wsi->lws_rx_parse_state) {
        case LWS_RXPS_NEW:
+               /* control frames (PING) may interrupt checkable sequences */
+               wsi->u.ws.defeat_check_utf8 = 0;
 
                switch (wsi->ietf_spec_revision) {
-
                case 13:
                        wsi->u.ws.opcode = c & 0xf;
                        /* revisit if an extension wants them... */
                        switch (wsi->u.ws.opcode) {
                        case LWSWSOPC_TEXT_FRAME:
-                       case LWSWSOPC_BINARY_FRAME:
                                wsi->u.ws.continuation_possible = 1;
+                               wsi->u.ws.check_utf8 =
+                                       !!(wsi->context->options &
+                                          LWS_SERVER_OPTION_VALIDATE_UTF8);
                                wsi->u.ws.utf8 = 0;
                                break;
+                       case LWSWSOPC_BINARY_FRAME:
+                               wsi->u.ws.check_utf8 = 0;
+                               wsi->u.ws.continuation_possible = 1;
+                               break;
                        case LWSWSOPC_CONTINUATION:
                                if (!wsi->u.ws.continuation_possible) {
                                        lwsl_info("disordered continuation\n");
@@ -50,6 +57,7 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                                }
                                break;
                        case LWSWSOPC_CLOSE:
+                               wsi->u.ws.check_utf8 = 0;
                                wsi->u.ws.utf8 = 0;
                                break;
                        case 3:
@@ -65,6 +73,7 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                                lwsl_info("illegal opcode\n");
                                return -1;
                        default:
+                               wsi->u.ws.defeat_check_utf8 = 1;
                                break;
                        }
                        wsi->u.ws.rsv = (c & 0x70);
@@ -94,9 +103,9 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                                lwsl_info("control message cannot be fragmented\n");
                                return -1;
                        }
-                       if (!wsi->u.ws.final) {
+                       if (!wsi->u.ws.final)
                                wsi->u.ws.owed_a_fin = 1;
-                       }
+
                        switch (wsi->u.ws.opcode) {
                        case LWSWSOPC_TEXT_FRAME:
                        case LWSWSOPC_BINARY_FRAME:
@@ -282,12 +291,13 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                        c ^= wsi->u.ws.mask_nonce[
                                            (wsi->u.ws.frame_mask_index++) & 3];
 
-               if ((wsi->context->options & LWS_SERVER_OPTION_VALIDATE_UTF8) &&
-                   ((!wsi->u.ws.frame_is_binary &&
-                     (wsi->u.ws.opcode == LWSWSOPC_CONTINUATION ||
-                      wsi->u.ws.opcode == LWSWSOPC_TEXT_FRAME)) ||
-                    (wsi->u.ws.opcode == LWSWSOPC_CLOSE &&
-                     wsi->u.ws.rx_user_buffer_head > 2))) {
+               /* if we skipped the 2-byte code at the start, UTF-8 after */
+               if (wsi->u.ws.opcode == LWSWSOPC_CLOSE &&
+                   wsi->u.ws.rx_user_buffer_head == 2)
+                       wsi->u.ws.check_utf8 = !!(wsi->context->options &
+                                              LWS_SERVER_OPTION_VALIDATE_UTF8);
+
+               if (wsi->u.ws.check_utf8 && !wsi->u.ws.defeat_check_utf8) {
                        static const unsigned char e0f4[] = {
                                0xa0 | ((2 - 1) << 2) | 1, /* e0 */
                                0x80 | ((4 - 1) << 2) | 1, /* e1 */
@@ -335,8 +345,7 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                        }
 
                        /* we are ending partway through utf-8 character? */
-                       if (wsi->u.ws.final &&
-                           wsi->u.ws.rx_packet_length == 1 &&
+                       if (wsi->u.ws.final && wsi->u.ws.rx_packet_length == 1 &&
                            wsi->u.ws.utf8) {
 utf8_fail:                     lwsl_info("utf8 error\n");
                                return -1;
@@ -344,7 +353,7 @@ utf8_fail:                  lwsl_info("utf8 error\n");
                }
 
                wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
-                              (wsi->u.ws.rx_user_buffer_head++)] = c;
+                                        (wsi->u.ws.rx_user_buffer_head++)] = c;
 
                if (--wsi->u.ws.rx_packet_length == 0) {
                        /* spill because we have the whole frame */
@@ -358,13 +367,11 @@ utf8_fail:                        lwsl_info("utf8 error\n");
                 */
 
                if (!wsi->protocol->rx_buffer_size &&
-                                       wsi->u.ws.rx_user_buffer_head !=
-                                                         LWS_MAX_SOCKET_IO_BUF)
+                   wsi->u.ws.rx_user_buffer_head != LWS_MAX_SOCKET_IO_BUF)
                        break;
-               else
-                       if (wsi->protocol->rx_buffer_size &&
-                                       wsi->u.ws.rx_user_buffer_head !=
-                                                 wsi->protocol->rx_buffer_size)
+
+               if (wsi->protocol->rx_buffer_size &&
+                   wsi->u.ws.rx_user_buffer_head != wsi->protocol->rx_buffer_size)
                        break;
 
                /* spill because we filled our rx buffer */

diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index d6b5175..3ef7a52 100644 (file)
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -859,6 +859,8 @@ struct _lws_websocket_related {
        unsigned int ping_pending_flag:1;
        unsigned int continuation_possible:1;
        unsigned int owed_a_fin:1;
+       unsigned int check_utf8:1;
+       unsigned int defeat_check_utf8:1;
 };
 
 struct lws {