hashfuncs.h

/*************************************************************************/
/*  hashfuncs.h                                                          */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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#ifndef HASHFUNCS_H
#define HASHFUNCS_H


#include "typedefs.h"

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;
    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