From 8838c6d53ecf9491d862ee090c9bf1579fa64eed Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 14 Sep 2017 11:01:37 +0200 Subject: hexdump: code shrink 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 --- miscutils/hexedit.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/miscutils/hexedit.c b/miscutils/hexedit.c index eaf4ba57b..bdb7683f2 100644 --- a/miscutils/hexedit.c +++ b/miscutils/hexedit.c @@ -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) 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 */ 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 pagesize; 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 */ pos = G.current_byte - G.baseaddr; @@ -205,16 +207,17 @@ static void move_mapping_further(void) } 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 pagesize; if (G.offset == 0) - return; /* we are at 0 already */ + return 0; /* we are at 0 already */ pagesize = getpagesize(); /* constant on most arches */ pos = G.current_byte - G.baseaddr; @@ -229,7 +232,7 @@ static void move_mapping_lower(void) } pos -= pagesize; - remap(pos); + return remap(pos); } //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 '5': case '6': case '7': case '8': case '9': if (G.current_byte == G.eof_byte) { - move_mapping_further(); - if (G.current_byte == G.eof_byte) { - /* extend the file */ + if (!move_mapping_further()) { + /* already at EOF; extend the file */ if (++G.size <= 0 /* overflow? */ || 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) { move_mapping_further(); if (G.current_byte > G.eof_byte) { - /* eof - don't allow going past it */ + /* _after_ eof - don't allow this */ G.current_byte -= 16; break; } @@ -368,8 +370,7 @@ 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.baseaddr) { - move_mapping_lower(); - if (G.current_byte == G.baseaddr) + if (!move_mapping_lower()) break; /* first line, don't do anything */ } G.half = 1; @@ -386,9 +387,8 @@ int hexedit_main(int argc UNUSED_PARAM, char **argv) case KEYCODE_UP: k_up: if ((G.current_byte - G.baseaddr) < 16) { - move_mapping_lower(); - if ((G.current_byte - G.baseaddr) < 16) - break; + if (!move_mapping_lower()) + break; /* already at 0, stop */ } G.current_byte -= 16; up: -- cgit v1.2.3