godot/core/hashfuncs.h
Rémi Verschelde a7f49ac9a1 Update copyright statements to 2020
Happy new year to the wonderful Godot community!

We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.

Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
2020-01-01 11:16:22 +01:00

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/*************************************************************************/
/* hashfuncs.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 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/node_path.h"
#include "core/string_name.h"
#include "core/typedefs.h"
#include "core/ustring.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_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 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 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