conspy: code shrink

[platform/upstream/busybox.git] / miscutils / conspy.c

diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index 11105f0..6f2f025 100644 (file)
--- a/miscutils/conspy.c
+++ b/miscutils/conspy.c
@@ -56,31 +56,33 @@ struct globals {
        int size;
        int x, y;
        int kbd_fd;
-       unsigned width;
-       unsigned height;
-       unsigned col;
-       unsigned line;
+       int vcsa_fd;
        int ioerror_count;
        int key_count;
        int escape_count;
        int nokeys;
        int current;
-       int vcsa_fd;
-       uint16_t last_attr;
-       uint8_t last_bold;
-       uint8_t last_blink;
-       uint8_t last_fg;
-       uint8_t last_bg;
-       char attrbuf[sizeof("\033[0;1;5;30;40m")];
+       // cached local tty parameters
+       unsigned width;
+       unsigned height;
+       unsigned col;
+       unsigned line;
        smallint curoff;
+       uint8_t last_attr;
+       uint8_t force_attr_change;
+       char attrbuf[sizeof("\033[0;1;5;30;40m")];
+       // remote console
        struct screen_info remote;
+       // saved local tty terminfo
        struct termios term_orig;
 };
 
 #define G (*ptr_to_globals)
 #define INIT_G() do { \
        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
-       strcpy((char*)&G.last_attr, "\xff\xff\xff\xff\xff\xff" "\033["); \
+       G.attrbuf[0] = '\033'; \
+       G.attrbuf[1] = '['; \
+       G.force_attr_change = 0xff; \
 } while (0)
 
 enum {
@@ -100,7 +102,6 @@ static void screen_read_close(void)
        char *data = G.data + G.current;
 
        xread(G.vcsa_fd, data, G.size);
-       G.last_attr = 0;
        for (i = 0; i < G.remote.lines; i++) {
                for (j = 0; j < G.remote.cols; j++, NEXT(data)) {
                        unsigned x = j - G.x; // if will catch j < G.x too
@@ -117,9 +118,12 @@ static void screen_read_close(void)
 
 static void screen_char(char *data)
 {
-       uint8_t attr = ATTR(data);
+       if (!BW) {
+               uint8_t attr = ATTR(data);
+               //uint8_t attr = ATTR(data) >> 1; // for framebuffer console
+               uint8_t attr_diff = (G.last_attr ^ attr) | G.force_attr_change;
 
-       if (!BW && G.last_attr != attr) {
+               if (attr_diff) {
 // Attribute layout for VGA compatible text videobuffer:
 // blinking text
 // |red bkgd
@@ -143,51 +147,49 @@ static void screen_char(char *data)
 //      green text
 //       blue text
 //        text 8th bit
-               // converting RGB color bit triad to BGR:
-               static const char color[8] = "04261537";
-               char *ptr;
-               uint8_t fg, bold, bg, blink;
-
-               G.last_attr = attr;
-
-               //attr >>= 1; // for framebuffer console
-               ptr = G.attrbuf + sizeof("\033[")-1;
-               fg    = (attr & 0x07);
-               bold  = (attr & 0x08);
-               bg    = (attr & 0x70);
-               blink = (attr & 0x80);
-               if (G.last_bold > bold || G.last_blink > blink) {
-                       G.last_bold = G.last_blink = 0;
-                       G.last_bg = 0xff;
-                       *ptr++ = '0';
-                       *ptr++ = ';';
-               }
-               if (G.last_bold != bold) {
-                       G.last_bold = bold;
-                       *ptr++ = '1';
-                       *ptr++ = ';';
-               }
-               if (G.last_blink != blink) {
-                       G.last_blink = blink;
-                       *ptr++ = '5';
-                       *ptr++ = ';';
-               }
-               if (G.last_fg != fg) {
-                       G.last_fg = fg;
-                       *ptr++ = '3';
-                       *ptr++ = color[fg];
-                       *ptr++ = ';';
-               }
-               if (G.last_bg != bg) {
-                       G.last_bg = bg;
-                       *ptr++ = '4';
-                       *ptr++ = color[bg >> 4];
-                       *ptr++ = ';';
-               }
-               if (ptr != G.attrbuf + sizeof("\033[")-1) {
-                       ptr[-1] = 'm';
-                       *ptr = '\0';
-                       fputs(G.attrbuf, stdout);
+                       // converting RGB color bit triad to BGR:
+                       static const char color[8] = "04261537";
+                       const uint8_t fg_mask = 0x07, bold_mask  = 0x08;
+                       const uint8_t bg_mask = 0x70, blink_mask = 0x80;
+                       char *ptr;
+
+                       ptr = G.attrbuf + 2; /* skip "ESC [" */
+
+                       // (G.last_attr & ~attr) has 1 only where
+                       // G.last_attr has 1 but attr has 0.
+                       // Here we check whether we have transition
+                       // bold->non-bold or blink->non-blink:
+                       if ((G.last_attr & ~attr) & (bold_mask | blink_mask)) {
+                               *ptr++ = '0'; // "reset all attrs"
+                               *ptr++ = ';';
+                               // must set fg & bg, maybe need to set bold or blink:
+                               attr_diff = attr | ~(bold_mask | blink_mask);
+                       }
+                       G.force_attr_change = 0;
+                       G.last_attr = attr;
+                       if (attr_diff & bold_mask) {
+                               *ptr++ = '1';
+                               *ptr++ = ';';
+                       }
+                       if (attr_diff & blink_mask) {
+                               *ptr++ = '5';
+                               *ptr++ = ';';
+                       }
+                       if (attr_diff & fg_mask) {
+                               *ptr++ = '3';
+                               *ptr++ = color[attr & fg_mask];
+                               *ptr++ = ';';
+                       }
+                       if (attr_diff & bg_mask) {
+                               *ptr++ = '4';
+                               *ptr++ = color[(attr & bg_mask) >> 4];
+                               *ptr++ = ';';
+                       }
+                       if (ptr != G.attrbuf + 2) {
+                               ptr[-1] = 'm';
+                               *ptr = '\0';
+                               fputs(G.attrbuf, stdout);
+                       }
                }
        }
        putchar(CHAR(data));
@@ -402,6 +404,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
        termbuf.c_cc[VMIN] = 1;
        termbuf.c_cc[VTIME] = 0;
        tcsetattr(G.kbd_fd, TCSANOW, &termbuf);
+
        poll_timeout_ms = 250;
        while (1) {
                struct pollfd pfd;