hexedit: smarter redraw

function                                             old     new   delta
format_line                                          197     209     +12
hexedit_main                                         930     924      -6
redraw_cur_line                                      104      94     -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 12/-16)             Total: -4 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/hexedit.c b/miscutils/hexedit.c
index cd4b3b1adc252038eba84ed8113df9a3c45d2f64..ac38978fd147e057a2bc597ec6b0d29cf4e98bbb 100644 (file)
--- a/miscutils/hexedit.c
+++ b/miscutils/hexedit.c
@@ -38,11 +38,27 @@ struct globals {
 /* Hopefully there aren't arches with PAGE_SIZE > 64k */
 #define G_mapsize (64*1024)
 
-static void format_line(char *hex, uint8_t *data, off_t offset)
+/* "12ef5670 (nn )*16 abcdef_1_3_5_7_9\n" */
+#define LINEBUF_SIZE (8 + 1 + 3*16 + 16 + 1 /*paranoia:*/ + 14)
+
+static int format_line(char *hex, uint8_t *data, off_t offset)
 {
-       char *text = hex + 16*3;
+       int ofs_pos;
+       char *text;
        uint8_t *end, *end1;
 
+#if 1
+       /* Can be more than 4Gb, thus >8 chars, thus use a variable - don't assume 8! */
+       ofs_pos = sprintf(hex, "%08"OFF_FMT"x ", offset);
+#else
+       if (offset <= 0xffff)
+               ofs_pos = sprintf(hex, "%04"OFF_FMT"x ", offset);
+       else
+               ofs_pos = sprintf(hex, "%08"OFF_FMT"x ", offset);
+#endif
+       hex += ofs_pos;
+
+       text = hex + 16*3;
        end1 = data + 15;
        if ((G.size - offset) > 0) {
                end = end1;
@@ -66,6 +82,8 @@ static void format_line(char *hex, uint8_t *data, off_t offset)
                data++;
        }
        *text = '\0';
+
+       return ofs_pos;
 }
 
 static void redraw(void)
@@ -78,11 +96,11 @@ static void redraw(void)
        offset = 0;
        i = 0;
        while (i < G.height) {
-               char buf[16*4 + 8];
+               char buf[LINEBUF_SIZE];
                format_line(buf, data, offset);
                printf(
-                       "\r\n%08"OFF_FMT"x %s" + (!i)*2, /* print \r\n only on 2nd line and later */
-                       offset, buf
+                       "\r\n%s" + (!i)*2, /* print \r\n only on 2nd line and later */
+                       buf
                );
                data += 16;
                offset += 16;
@@ -92,22 +110,22 @@ static void redraw(void)
 
 static void redraw_cur_line(void)
 {
-       off_t offset;
-       int len;
-       char buf[16*4 + 8];
+       char buf[LINEBUF_SIZE];
        uint8_t *data;
+       off_t offset;
+       int column;
 
-       len = (0xf & (uintptr_t)G.current_byte);
-       data = G.current_byte - len;
+       column = (0xf & (uintptr_t)G.current_byte);
+       data = G.current_byte - column;
        offset = G.offset + (data - G.addr);
-       format_line(buf, data, offset);
-       printf(
-               "\r%08"OFF_FMT"x %s",
-               offset, buf
-       );
-       printf(
-               "\r%08"OFF_FMT"x %.*s",
-               offset, (len*3 + G.half), buf
+
+       column = column*3 + G.half;
+       column += format_line(buf, data, offset);
+       printf("%s"
+               "\r"
+               "%.*s",
+               buf + column,
+               column, buf
        );
 }
 
@@ -216,7 +234,7 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
 
        printf(CLEAR);
        redraw();
-       printf(HOME "%08x ", 0);
+       printf(ESC"[1;10H"); /* position on 1st hex byte in first line */
 
 //TODO: //PgUp/PgDown; Home/End: start/end of line; '<'/'>': start/end of file
        //Backspace: undo
@@ -229,10 +247,6 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
 //TODO: detect window resize
 //TODO: read-only mode if open(O_RDWR) fails? hide cursor in this case?
 
-//TODO: smarter redraw: if down-arrow is pressed on last visible line,
-//emit LF, then print the tail of next line, then CR, then beginning -
-//which makes cursor end up exactly where it should be! Same for up-arrow.
-
        for (;;) {
                char read_key_buffer[KEYCODE_BUFFER_SIZE];
                int32_t key;
@@ -320,10 +334,11 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
                        }
                        if ((0xf & (uintptr_t)G.current_byte) == 0) {
                                /* leftmost pos, wrap to prev line */
-                               if (G.current_byte == G.addr)
+                               if (G.current_byte == G.addr) {
                                        move_mapping_lower();
-                               if ((G.current_byte - G.addr) < 16)
-                                       break; /* first line, don't do anything */
+                                       if (G.current_byte == G.addr)
+                                               break; /* first line, don't do anything */
+                               }
                                G.half = 1;
                                G.current_byte--;
                                printf(ESC"[46C"); /* cursor right 3*15 + 1 chars */