/*************************************************************************/ /* hashfuncs.h */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* 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 "core/math/math_defs.h" #include "core/math/math_funcs.h" #include "core/object/object_id.h" #include "core/string/node_path.h" #include "core/string/string_name.h" #include "core/string/ustring.h" #include "core/templates/rid.h" #include "core/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; } /** * Thomas Wang's 64-bit to 32-bit Hash function: * https://web.archive.org/web/20071223173210/https:/www.concentric.net/~Ttwang/tech/inthash.htm * * @param p_int - 64-bit unsigned integer key to be hashed * @return unsigned 32-bit value representing hashcode */ static inline uint32_t hash_one_uint64(const uint64_t p_int) { uint64_t v = p_int; v = (~v) + (v << 18); // v = (v << 18) - v - 1; v = v ^ (v >> 31); v = v * 21; // v = (v + (v << 2)) + (v << 4); v = v ^ (v >> 11); v = v + (v << 6); v = v ^ (v >> 22); return uint32_t(v); } static inline uint32_t hash_djb2_one_float(double p_in, uint32_t p_prev = 5381) { union { double d; uint64_t i; } u; // Normalize +/- 0.0 and NaN values so they hash the same. if (p_in == 0.0f) { u.d = 0.0; } else if (Math::is_nan(p_in)) { u.d = NAN; } else { u.d = p_in; } return ((p_prev << 5) + p_prev) + hash_one_uint64(u.i); } template 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_float_64(double p_in, uint64_t p_prev = 5381) { union { double d; uint64_t i; } u; // Normalize +/- 0.0 and NaN values so they hash the same. if (p_in == 0.0f) { u.d = 0.0; } else if (Math::is_nan(p_in)) { u.d = NAN; } else { u.d = p_in; } return ((p_prev << 5) + p_prev) + u.i; } 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 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; } struct HashMapHasherDefault { static _FORCE_INLINE_ uint32_t hash(const String &p_string) { return p_string.hash(); } static _FORCE_INLINE_ uint32_t hash(const char *p_cstr) { return hash_djb2(p_cstr); } static _FORCE_INLINE_ uint32_t hash(const uint64_t p_int) { return hash_one_uint64(p_int); } static _FORCE_INLINE_ uint32_t hash(const ObjectID &p_id) { return hash_one_uint64(p_id); } static _FORCE_INLINE_ uint32_t hash(const int64_t p_int) { return hash(uint64_t(p_int)); } static _FORCE_INLINE_ uint32_t hash(const float p_float) { return hash_djb2_one_float(p_float); } static _FORCE_INLINE_ uint32_t hash(const double p_double) { return hash_djb2_one_float(p_double); } static _FORCE_INLINE_ uint32_t hash(const uint32_t p_int) { return p_int; } static _FORCE_INLINE_ uint32_t hash(const int32_t p_int) { return (uint32_t)p_int; } static _FORCE_INLINE_ uint32_t hash(const uint16_t p_int) { return p_int; } static _FORCE_INLINE_ uint32_t hash(const int16_t p_int) { return (uint32_t)p_int; } static _FORCE_INLINE_ uint32_t hash(const uint8_t p_int) { return p_int; } static _FORCE_INLINE_ uint32_t hash(const int8_t p_int) { return (uint32_t)p_int; } static _FORCE_INLINE_ uint32_t hash(const wchar_t p_wchar) { return (uint32_t)p_wchar; } static _FORCE_INLINE_ uint32_t hash(const char16_t p_uchar) { return (uint32_t)p_uchar; } static _FORCE_INLINE_ uint32_t hash(const char32_t p_uchar) { return (uint32_t)p_uchar; } static _FORCE_INLINE_ uint32_t hash(const RID &p_rid) { return hash_one_uint64(p_rid.get_id()); } static _FORCE_INLINE_ uint32_t hash(const StringName &p_string_name) { return p_string_name.hash(); } static _FORCE_INLINE_ uint32_t hash(const NodePath &p_path) { return p_path.hash(); } //static _FORCE_INLINE_ uint32_t hash(const void* p_ptr) { return uint32_t(uint64_t(p_ptr))*(0x9e3779b1L); } }; template struct HashMapComparatorDefault { static bool compare(const T &p_lhs, const T &p_rhs) { return p_lhs == p_rhs; } bool compare(const float &p_lhs, const float &p_rhs) { return (p_lhs == p_rhs) || (Math::is_nan(p_lhs) && Math::is_nan(p_rhs)); } bool compare(const double &p_lhs, const double &p_rhs) { return (p_lhs == p_rhs) || (Math::is_nan(p_lhs) && Math::is_nan(p_rhs)); } }; #endif // HASHFUNCS_H