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Diffstat (limited to 'core/templates/hashfuncs.h')
| -rw-r--r-- | core/templates/hashfuncs.h | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/core/templates/hashfuncs.h b/core/templates/hashfuncs.h new file mode 100644 index 0000000000..4572b269cf --- /dev/null +++ b/core/templates/hashfuncs.h @@ -0,0 +1,192 @@ +/*************************************************************************/ +/* 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; +} + +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 (int)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 = Math_NAN; + } else { + u.d = p_in; + } + + return ((p_prev << 5) + p_prev) + hash_one_uint64(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_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 = Math_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 <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; +} + +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 <typename T> +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 |