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/*************************************************************************/
/* hashfuncs.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur. */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef HASHFUNCS_H
#define HASHFUNCS_H
#include "typedefs.h"
/**
* Hashing functions
*/
/**
* DJB2 Hash function
* @param C String
* @return 32-bits hashcode
*/
static inline uint32_t hash_djb2(const char *p_cstr) {
const unsigned char* chr=(const unsigned char*)p_cstr;
uint32_t hash = 5381;
uint32_t c;
while ((c = *chr++))
hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
return hash;
}
static inline uint32_t hash_djb2_buffer(const uint8_t *p_buff, int p_len,uint32_t p_prev=5381) {
uint32_t hash = p_prev;
for(int i=0;i<p_len;i++)
hash = ((hash << 5) + hash) + p_buff[i]; /* hash * 33 + c */
return hash;
}
static inline uint32_t hash_djb2_one_32(uint32_t p_in,uint32_t p_prev=5381) {
return ((p_prev<<5)+p_prev)+p_in;
}
static inline uint32_t hash_djb2_one_float(float p_in,uint32_t p_prev=5381) {
union {
float f;
uint32_t i;
} u;
// handle -0 case
if (p_in==0.0f) u.f=0.0f;
else u.f=p_in;
return ((p_prev<<5)+p_prev)+u.i;
}
template<class T>
static inline uint32_t make_uint32_t(T p_in) {
union {
T t;
uint32_t _u32;
} _u;
_u._u32=0;
_u.t=p_in;
return _u._u32;
}
static inline uint64_t hash_djb2_one_64(uint64_t p_in,uint64_t p_prev=5381) {
return ((p_prev<<5)+p_prev)+p_in;
}
template<class T>
static inline uint64_t make_uint64_t(T p_in) {
union {
T t;
uint64_t _u64;
} _u;
_u._u64=0; // in case p_in is smaller
_u.t=p_in;
return _u._u64;
}
#endif
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