f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
86 lines
2.9 KiB
C
86 lines
2.9 KiB
C
/* $NetBSD: wcscspn_bloom.h,v 1.4 2011/11/25 17:48:22 joerg Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2011 Joerg Sonnenberger,
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* Bloom filter for fast test if a given character is part of the reject set.
|
|
* The test may have false positives, but doesn't have false negatives.
|
|
* The first hash function is designed to be very fast to evaluate.
|
|
* It is collision free if the input is part of the same European language
|
|
* and shouldn't be too bad even other input. The second hash function
|
|
* tries to provide a much better mixing, but involves the slower
|
|
* multiplication.
|
|
*/
|
|
|
|
#include <limits.h>
|
|
|
|
#define BLOOM_SIZE 64
|
|
#define BLOOM_ARRAY_SIZE (BLOOM_SIZE / sizeof(size_t))
|
|
#define BLOOM_BITS (BLOOM_SIZE * CHAR_BIT)
|
|
#define BLOOM_DIV (sizeof(size_t) * CHAR_BIT)
|
|
|
|
static inline size_t
|
|
wcscspn_bloom1(size_t x)
|
|
{
|
|
return x % BLOOM_BITS;
|
|
}
|
|
|
|
static inline size_t
|
|
wcscspn_bloom2(size_t x)
|
|
{
|
|
return (size_t)((uint32_t)(x * 2654435761U) /
|
|
(0x100000000ULL / BLOOM_BITS));
|
|
}
|
|
|
|
static inline void
|
|
wcsspn_bloom_init(size_t *bloom, const wchar_t *charset)
|
|
{
|
|
size_t val;
|
|
|
|
memset(bloom, 0, BLOOM_SIZE);
|
|
do {
|
|
val = wcscspn_bloom1((size_t)*charset);
|
|
bloom[val / BLOOM_DIV] |= (size_t)1 << (val % BLOOM_DIV);
|
|
val = wcscspn_bloom2((size_t)*charset);
|
|
bloom[val / BLOOM_DIV] |= (size_t)1 << (val % BLOOM_DIV);
|
|
}
|
|
while (*++charset);
|
|
}
|
|
|
|
static inline int
|
|
wcsspn_in_bloom(const size_t *bloom, wchar_t ch)
|
|
{
|
|
size_t val;
|
|
|
|
val = wcscspn_bloom1((size_t)ch);
|
|
if (bloom[val / BLOOM_DIV] & ((size_t)1 << (val % BLOOM_DIV)))
|
|
return 1;
|
|
val = wcscspn_bloom2((size_t)ch);
|
|
if (bloom[val / BLOOM_DIV] & ((size_t)1 << (val % BLOOM_DIV)))
|
|
return 1;
|
|
return 0;
|
|
}
|