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hexdump: code shrink

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function                                             old     new   delta
remap                                                173     178      +5
move_mapping_lower                                   107     109      +2
move_mapping_further                                 141     143      +2
hexedit_main                                        1191    1176     -15
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 9/-15)              Total: -6 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-09-14 11:01:37 +02:00
parent d54f58d487
commit 8838c6d53e
1 changed files with 16 additions and 16 deletions
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32
miscutils/hexedit.c
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@ -159,7 +159,8 @@ static void redraw_cur_line(void)
); );
} }
static void remap(unsigned cur_pos) /* if remappers return 0, no change was done */
static int remap(unsigned cur_pos)
{ {
if (G.baseaddr) if (G.baseaddr)
munmap(G.baseaddr, G_mapsize); munmap(G.baseaddr, G_mapsize);
@ -184,14 +185,15 @@ static void remap(unsigned cur_pos)
/* we do have a mapped byte which is past eof */ /* we do have a mapped byte which is past eof */
G.eof_byte = G.baseaddr + (G.size - G.offset); G.eof_byte = G.baseaddr + (G.size - G.offset);
} }
return 1;
} }
static void move_mapping_further(void) static int move_mapping_further(void)
{ {
unsigned pos; unsigned pos;
unsigned pagesize; unsigned pagesize;
if ((G.size - G.offset) < G_mapsize) if ((G.size - G.offset) < G_mapsize)
return; /* can't move mapping even further, it's at the end already */ return 0; /* can't move mapping even further, it's at the end already */
pagesize = getpagesize(); /* constant on most arches */ pagesize = getpagesize(); /* constant on most arches */
pos = G.current_byte - G.baseaddr; pos = G.current_byte - G.baseaddr;
@ -205,16 +207,17 @@ static void move_mapping_further(void)
} }
pos -= pagesize; pos -= pagesize;
} while (pos >= pagesize); } while (pos >= pagesize);
remap(pos); return remap(pos);
} }
return 0;
} }
static void move_mapping_lower(void) static int move_mapping_lower(void)
{ {
unsigned pos; unsigned pos;
unsigned pagesize; unsigned pagesize;
if (G.offset == 0) if (G.offset == 0)
return; /* we are at 0 already */ return 0; /* we are at 0 already */
pagesize = getpagesize(); /* constant on most arches */ pagesize = getpagesize(); /* constant on most arches */
pos = G.current_byte - G.baseaddr; pos = G.current_byte - G.baseaddr;
@ -229,7 +232,7 @@ static void move_mapping_lower(void)
} }
pos -= pagesize; pos -= pagesize;
remap(pos); return remap(pos);
} }
//usage:#define hexedit_trivial_usage //usage:#define hexedit_trivial_usage
@ -292,9 +295,8 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
case '0': case '1': case '2': case '3': case '4': case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9': case '5': case '6': case '7': case '8': case '9':
if (G.current_byte == G.eof_byte) { if (G.current_byte == G.eof_byte) {
move_mapping_further(); if (!move_mapping_further()) {
if (G.current_byte == G.eof_byte) { /* already at EOF; extend the file */
/* extend the file */
if (++G.size <= 0 /* overflow? */ if (++G.size <= 0 /* overflow? */
|| ftruncate(G.fd, G.size) != 0 /* error extending? (e.g. block dev) */ || ftruncate(G.fd, G.size) != 0 /* error extending? (e.g. block dev) */
) { ) {
@ -343,7 +345,7 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
if (G.current_byte >= G.eof_byte) { if (G.current_byte >= G.eof_byte) {
move_mapping_further(); move_mapping_further();
if (G.current_byte > G.eof_byte) { if (G.current_byte > G.eof_byte) {
/* eof - don't allow going past it */ /* _after_ eof - don't allow this */
G.current_byte -= 16; G.current_byte -= 16;
break; break;
} }
@ -368,8 +370,7 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
if ((0xf & (uintptr_t)G.current_byte) == 0) { if ((0xf & (uintptr_t)G.current_byte) == 0) {
/* leftmost pos, wrap to prev line */ /* leftmost pos, wrap to prev line */
if (G.current_byte == G.baseaddr) { if (G.current_byte == G.baseaddr) {
move_mapping_lower(); if (!move_mapping_lower())
if (G.current_byte == G.baseaddr)
break; /* first line, don't do anything */ break; /* first line, don't do anything */
} }
G.half = 1; G.half = 1;
@ -386,9 +387,8 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv)
case KEYCODE_UP: case KEYCODE_UP:
k_up: k_up:
if ((G.current_byte - G.baseaddr) < 16) { if ((G.current_byte - G.baseaddr) < 16) {
move_mapping_lower(); if (!move_mapping_lower())
if ((G.current_byte - G.baseaddr) < 16) break; /* already at 0, stop */
break;
} }
G.current_byte -= 16; G.current_byte -= 16;
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