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/*
* Copyright 2011, Ben Langmead <langmea@cs.jhu.edu>
*
* This file is part of Bowtie 2.
*
* Bowtie 2 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Bowtie 2 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Bowtie 2. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef STR_UTIL_H_
#define STR_UTIL_H_
#include <stdint.h>
#include <string>
/**
* Given a string, return an int hash for it.
*/
static inline int
hash_string(const std::string& s) {
int ret = 0;
int a = 63689;
int b = 378551;
for(size_t i = 0; i < s.length(); i++) {
ret = (ret * a) + (int)s[i];
if(a == 0) {
a += b;
} else {
a *= b;
}
if(a == 0) {
a += b;
}
}
return ret;
}
/*
* Implementation of the FNV-1a hash function.
* https://tools.etf.org/html/draft/eastlake-fnv-03
*/
static inline uint32_t hash_str(const char *str) {
int c;
const uint32_t FNV_PRIME = 0x010000193;
uint32_t hash = 0x811C9Dc5;
while ((c = *str++) != '\0')
hash = (hash ^ c) * FNV_PRIME;
return hash;
}
#endif /* STR_UTIL_H_ */
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