From 8521c9e02b2bcb9f6437a111cba3f395236f8e22 Mon Sep 17 00:00:00 2001 From: Charles Date: Thu, 13 Feb 2020 03:13:57 +0100 Subject: Added ft_memmem and ft_memset_pattern4, not tested --- src/mem/ft_memmem.c | 54 ++++++++++++++++++++++++++++++++++++++++++++ src/mem/ft_memset_pattern4.c | 25 ++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 src/mem/ft_memmem.c create mode 100644 src/mem/ft_memset_pattern4.c (limited to 'src/mem') diff --git a/src/mem/ft_memmem.c b/src/mem/ft_memmem.c new file mode 100644 index 0000000..b69efa0 --- /dev/null +++ b/src/mem/ft_memmem.c @@ -0,0 +1,54 @@ +/* ************************************************************************** */ +/* */ +/* ::: :::::::: */ +/* ft_memmem.c :+: :+: :+: */ +/* +:+ +:+ +:+ */ +/* By: cacharle +#+ +:+ +#+ */ +/* +#+#+#+#+#+ +#+ */ +/* Created: 2020/02/13 01:54:55 by cacharle #+# #+# */ +/* Updated: 2020/02/13 03:13:23 by cacharle ### ########.fr */ +/* */ +/* ************************************************************************** */ + +#include "libft_mem.h" + +#define BAD_TABLE_SIZE 256 + +static void st_bad_table_init(size_t bad_table[BAD_TABLE_SIZE], + const char *little, size_t little_len) +{ + size_t i; + + ft_memset_pattern4(bad_table, &little_len, 4 * BAD_TABLE_SIZE); + i = 0; + while (i < little_len) + { + bad_table[(int)little[i]] = little_len - i - 1; + i++; + } +} + +static t_ftbool st_memcmp_end(const void *s1, const void *s2, size_t n) +{ + while (n-- > 0) + if (((t_ftbyte*)s1)[n] != ((t_ftbyte*)s2)[n]) + return (FALSE); + return (TRUE); +} + +void *ft_memmem(const void *big, size_t big_len, + const void *little, size_t little_len) +{ + size_t i; + size_t bad_table[BAD_TABLE_SIZE]; + + st_bad_table_init(bad_table, little, little_len); + i = 0; + while (i < big_len - little_len) + { + if (st_memcmp_end((t_ftbyte*)big + i, little, little_len)) + return ((t_ftbyte*)big + i); + i += bad_table[(int)(((t_ftbyte*)big)[i + big_len] - 1)]; + } + return (NULL); +} diff --git a/src/mem/ft_memset_pattern4.c b/src/mem/ft_memset_pattern4.c new file mode 100644 index 0000000..d16f420 --- /dev/null +++ b/src/mem/ft_memset_pattern4.c @@ -0,0 +1,25 @@ +/* ************************************************************************** */ +/* */ +/* ::: :::::::: */ +/* ft_memset_pattern4.c :+: :+: :+: */ +/* +:+ +:+ +:+ */ +/* By: cacharle +#+ +:+ +#+ */ +/* +#+#+#+#+#+ +#+ */ +/* Created: 2020/02/13 03:06:41 by cacharle #+# #+# */ +/* Updated: 2020/02/13 03:10:42 by cacharle ### ########.fr */ +/* */ +/* ************************************************************************** */ + +#include "libft_mem.h" + +void ft_memset_pattern4(void *b, const void *pattern4, size_t len) +{ + int i; + + i = len / 4; + while (i-- > 0) + ((int*)b)[i] = *(int*)pattern4; + i = len % 4; + while (i-- > 0) + ((int*)b)[len / 4 + i] = ((t_ftbyte*)pattern4)[i]; +} -- cgit