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Diffstat (limited to 'core/hashfuncs.h')
| -rw-r--r-- | core/hashfuncs.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/core/hashfuncs.h b/core/hashfuncs.h new file mode 100644 index 0000000000..6dae82bc55 --- /dev/null +++ b/core/hashfuncs.h @@ -0,0 +1,116 @@ +/*************************************************************************/ +/* hashfuncs.h */ +/*************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* http://www.godotengine.org */ +/*************************************************************************/ +/* Copyright (c) 2007-2014 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(uint8_t *p_buff, int p_len) { + + uint32_t hash = 5381; + + 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; + 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 |