From e52da5570eb93d6cb2950e55c48bd22edb5a9f18 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 9 Oct 2015 17:59:56 +0200 Subject: [PATCH] libbb: auto_string() for efficient handling of temporary malloced stirngs Use it in libiproute: get rid of one static string buffer. function old new delta auto_string - 51 +51 ll_index_to_name 10 49 +39 buffer_fill_and_print 169 178 +9 scan_recursive 378 380 +2 decode_one_format 732 734 +2 cmdputs 334 332 -2 static.cur_saved 4 1 -3 static.nbuf 16 - -16 printable_string 94 57 -37 ll_idx_n2a 53 - -53 ------------------------------------------------------------------------------ (add/remove: 2/2 grow/shrink: 4/3 up/down: 103/-111) Total: -8 bytes text data bss dec hex filename 939880 992 17496 958368 e9fa0 busybox_old 939880 992 17480 958352 e9f90 busybox_unstripped Signed-off-by: Denys Vlasenko --- include/libbb.h | 1 + libbb/auto_string.c | 23 +++++++++++++++++++++++ libbb/printable_string.c | 10 +--------- networking/libiproute/ll_map.c | 13 +++++++------ networking/libiproute/ll_map.h | 2 +- 5 files changed, 33 insertions(+), 16 deletions(-) create mode 100644 libbb/auto_string.c diff --git a/include/libbb.h b/include/libbb.h index 2f24ecbc3..a8ceb449c 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -692,6 +692,7 @@ int bb_putchar(int ch) FAST_FUNC; /* Note: does not use stdio, writes to fd 2 directly */ int bb_putchar_stderr(char ch) FAST_FUNC; char *xasprintf(const char *format, ...) __attribute__ ((format(printf, 1, 2))) FAST_FUNC RETURNS_MALLOC; +char *auto_string(char *str) FAST_FUNC; // gcc-4.1.1 still isn't good enough at optimizing it // (+200 bytes compared to macro) //static ALWAYS_INLINE diff --git a/libbb/auto_string.c b/libbb/auto_string.c new file mode 100644 index 000000000..ae940069a --- /dev/null +++ b/libbb/auto_string.c @@ -0,0 +1,23 @@ +/* vi: set sw=4 ts=4: */ +/* + * Utility routines. + * + * Copyright (C) 2015 Denys Vlasenko + * + * Licensed under GPLv2, see file LICENSE in this source tree. + */ +//kbuild:lib-y += auto_string.o + +#include "libbb.h" + +char* FAST_FUNC auto_string(char *str) +{ + static char *saved[4]; + static uint8_t cur_saved; /* = 0 */ + + free(saved[cur_saved]); + saved[cur_saved] = str; + cur_saved = (cur_saved + 1) & (ARRAY_SIZE(saved)-1); + + return str; +} diff --git a/libbb/printable_string.c b/libbb/printable_string.c index a316f60de..077d58d32 100644 --- a/libbb/printable_string.c +++ b/libbb/printable_string.c @@ -11,9 +11,6 @@ const char* FAST_FUNC printable_string(uni_stat_t *stats, const char *str) { - static char *saved[4]; - static unsigned cur_saved; /* = 0 */ - char *dst; const char *s; @@ -56,10 +53,5 @@ const char* FAST_FUNC printable_string(uni_stat_t *stats, const char *str) } } #endif - - free(saved[cur_saved]); - saved[cur_saved] = dst; - cur_saved = (cur_saved + 1) & (ARRAY_SIZE(saved)-1); - - return dst; + return auto_string(dst); } diff --git a/networking/libiproute/ll_map.c b/networking/libiproute/ll_map.c index feb6e8d22..e2b85fc7b 100644 --- a/networking/libiproute/ll_map.c +++ b/networking/libiproute/ll_map.c @@ -86,7 +86,8 @@ int FAST_FUNC ll_remember_index(const struct sockaddr_nl *who UNUSED_PARAM, return 0; } -const char FAST_FUNC *ll_idx_n2a(int idx, char *buf) +static +const char FAST_FUNC *ll_idx_n2a(int idx/*, char *buf*/) { struct idxmap *im; @@ -95,15 +96,15 @@ const char FAST_FUNC *ll_idx_n2a(int idx, char *buf) im = find_by_index(idx); if (im) return im->name; - snprintf(buf, 16, "if%d", idx); - return buf; + //snprintf(buf, 16, "if%d", idx); + //return buf; + return auto_string(xasprintf("if%d", idx)); } const char FAST_FUNC *ll_index_to_name(int idx) { - static char nbuf[16]; - - return ll_idx_n2a(idx, nbuf); + //static char nbuf[16]; + return ll_idx_n2a(idx/*, nbuf*/); } #ifdef UNUSED diff --git a/networking/libiproute/ll_map.h b/networking/libiproute/ll_map.h index c5d383422..7ea383c81 100644 --- a/networking/libiproute/ll_map.h +++ b/networking/libiproute/ll_map.h @@ -7,8 +7,8 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN int ll_remember_index(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg) FAST_FUNC; int ll_init_map(struct rtnl_handle *rth) FAST_FUNC; int xll_name_to_index(const char *name) FAST_FUNC; +//static: const char *ll_idx_n2a(int idx, char *buf) FAST_FUNC; const char *ll_index_to_name(int idx) FAST_FUNC; -const char *ll_idx_n2a(int idx, char *buf) FAST_FUNC; /* int ll_index_to_type(int idx); */ unsigned ll_index_to_flags(int idx) FAST_FUNC;