[693388e] | 1 | /* hash.c */ |
---|
| 2 | /* String hashing function */ |
---|
[e1b99fc] | 3 | /* Copyright (C) 1995-2002 Olly Betts |
---|
[693388e] | 4 | * |
---|
| 5 | * This program is free software; you can redistribute it and/or modify |
---|
| 6 | * it under the terms of the GNU General Public License as published by |
---|
| 7 | * the Free Software Foundation; either version 2 of the License, or |
---|
| 8 | * (at your option) any later version. |
---|
| 9 | * |
---|
| 10 | * This program is distributed in the hope that it will be useful, |
---|
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
| 13 | * GNU General Public License for more details. |
---|
| 14 | * |
---|
| 15 | * You should have received a copy of the GNU General Public License |
---|
| 16 | * along with this program; if not, write to the Free Software |
---|
[ecbc6c18] | 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
---|
[693388e] | 18 | */ |
---|
| 19 | |
---|
[a258036] | 20 | #include <config.h> |
---|
| 21 | |
---|
[693388e] | 22 | #include <ctype.h> |
---|
| 23 | |
---|
[63dc4eb] | 24 | #include "debug.h" |
---|
[693388e] | 25 | #include "hash.h" |
---|
| 26 | |
---|
| 27 | /* some (preferably prime) number for the hashing function */ |
---|
| 28 | #define HASH_PRIME 29363 |
---|
| 29 | |
---|
[30ec602] | 30 | #ifdef __clang__ |
---|
[ed953f1] | 31 | __attribute__((no_sanitize("unsigned-integer-overflow"))) |
---|
[30ec602] | 32 | #endif |
---|
[693388e] | 33 | int |
---|
| 34 | hash_string(const char *p) |
---|
| 35 | { |
---|
| 36 | int hash; |
---|
[4c07c51] | 37 | SVX_ASSERT(p); |
---|
[693388e] | 38 | for (hash = 0; *p; p++) |
---|
| 39 | hash = (hash * HASH_PRIME + *(const unsigned char*)p) & 0x7fff; |
---|
| 40 | return hash; |
---|
| 41 | } |
---|
| 42 | |
---|
[30ec602] | 43 | #ifdef __clang__ |
---|
[ed953f1] | 44 | __attribute__((no_sanitize("unsigned-integer-overflow"))) |
---|
[30ec602] | 45 | #endif |
---|
[693388e] | 46 | int |
---|
| 47 | hash_lc_string(const char *p) |
---|
| 48 | { |
---|
| 49 | int hash; |
---|
[4c07c51] | 50 | SVX_ASSERT(p); |
---|
[693388e] | 51 | for (hash = 0; *p; p++) |
---|
| 52 | hash = (hash * HASH_PRIME + tolower(*(const unsigned char*)p)) & 0x7fff; |
---|
| 53 | return hash; |
---|
| 54 | } |
---|
[e1b99fc] | 55 | |
---|
[30ec602] | 56 | #ifdef __clang__ |
---|
[ed953f1] | 57 | __attribute__((no_sanitize("unsigned-integer-overflow"))) |
---|
[30ec602] | 58 | #endif |
---|
[e1b99fc] | 59 | int |
---|
| 60 | hash_data(const char *p, size_t len) |
---|
| 61 | { |
---|
| 62 | int hash; |
---|
[4c07c51] | 63 | SVX_ASSERT(p); |
---|
[e1b99fc] | 64 | for (hash = 0; len--; p++) |
---|
| 65 | hash = (hash * HASH_PRIME + *(const unsigned char*)p) & 0x7fff; |
---|
| 66 | return hash; |
---|
| 67 | } |
---|