hash.h File Reference

This file contains different utilities for hashing. The ideas of algorithms were borrowed from the boost library. http://www.boost.org/doc/libs/1_64_0/boost/functional/hash/hash.hpp http://www.boost.org/doc/libs/1_64_0/boost/functional/hash/detail/hash_float.hpp. More...

#include <cdcontainers/casts.h>
#include <float.h>
#include <limits.h>
#include <stddef.h>
#include <string.h>

Go to the source code of this file.

Macros
#define	CDC_DIGITS_CHAR   (CHAR_BIT - (CHAR_MIN < 0))
#define	CDC_DIGITS_SCHAR   (CHAR_BIT - 1)
#define	CDC_DIGITS_UCHAR   (CHAR_BIT)
#define	CDC_DIGITS_SHORT   (CHAR_BIT * sizeof(short) - 1)
#define	CDC_DIGITS_USHORT   (CHAR_BIT * sizeof(short))
#define	CDC_DIGITS_INT   (CHAR_BIT * sizeof(int) - 1)
#define	CDC_DIGITS_UINT   (CHAR_BIT * sizeof(int))
#define	CDC_DIGITS_LONG   (CHAR_BIT * sizeof(long) - 1)
#define	CDC_DIGITS_ULONG   (CHAR_BIT * sizeof(long))
#define	CDC_DIGITS_SIZE   (CHAR_BIT * sizeof(size_t))
#define	MAKE_SIGNED_HASH(T, DIGITS, NAME)
#define	MAKE_UNSIGNED_HASH(T, DIGITS, NAME)
#define	MAKE_FLOAT_HASH(T, NAME)
#define	MAKE_POINTER_DATA_HASH(T, NAME, CAST_FUNC)

Typedefs
typedef size_t(*	cdc_hash_fn_t) (void const *)

Functions
static size_t	cdc_hash_float_combine (size_t seed, size_t value)
static size_t	cdc_hash_binary (char *ptr, size_t length)

Detailed Description

This file contains different utilities for hashing. The ideas of algorithms were borrowed from the boost library. http://www.boost.org/doc/libs/1_64_0/boost/functional/hash/hash.hpp http://www.boost.org/doc/libs/1_64_0/boost/functional/hash/detail/hash_float.hpp.

Author

Maksim Andrianov maksi.nosp@m.mand.nosp@m.riano.nosp@m.v1@y.nosp@m.andex.nosp@m..ru

Macro Definition Documentation

CDC_DIGITS_CHAR

#define CDC_DIGITS_CHAR   (CHAR_BIT - (CHAR_MIN < 0))

CDC_DIGITS_SCHAR

#define CDC_DIGITS_SCHAR   (CHAR_BIT - 1)

CDC_DIGITS_UCHAR

#define CDC_DIGITS_UCHAR   (CHAR_BIT)

CDC_DIGITS_SHORT

#define CDC_DIGITS_SHORT   (CHAR_BIT * sizeof(short) - 1)

CDC_DIGITS_USHORT

#define CDC_DIGITS_USHORT   (CHAR_BIT * sizeof(short))

CDC_DIGITS_INT

#define CDC_DIGITS_INT   (CHAR_BIT * sizeof(int) - 1)

CDC_DIGITS_UINT

#define CDC_DIGITS_UINT   (CHAR_BIT * sizeof(int))

CDC_DIGITS_LONG

#define CDC_DIGITS_LONG   (CHAR_BIT * sizeof(long) - 1)

CDC_DIGITS_ULONG

#define CDC_DIGITS_ULONG   (CHAR_BIT * sizeof(long))

CDC_DIGITS_SIZE

#define CDC_DIGITS_SIZE   (CHAR_BIT * sizeof(size_t))

MAKE_SIGNED_HASH

#define MAKE_SIGNED_HASH	(		T,
			DIGITS,
			NAME
	)

Value:

static inline size_t cdc_hash_##NAME(T val)                      \
  {                                                                \
    const unsigned int size_t_bits = CDC_DIGITS_SIZE;              \
    const int length = (DIGITS - 1) / (int)(size_t_bits);          \
    unsigned int i;                                                \
    size_t seed = 0;                                               \
    T positive = val < 0 ? -1 - val : val;                         \
    for (i = length * size_t_bits; i > 0; i -= size_t_bits)        \
      seed ^= (size_t)(positive >> i) + (seed << 6) + (seed >> 2); \
    seed ^= (size_t)val + (seed << 6) + (seed >> 2);               \
    return seed;                                                   \
  }

MAKE_UNSIGNED_HASH

#define MAKE_UNSIGNED_HASH	(		T,
			DIGITS,
			NAME
	)

Value:

static inline size_t cdc_hash_##NAME(T val)                  \
  {                                                            \
    const unsigned int size_t_bits = CDC_DIGITS_SIZE;          \
    const int length = (DIGITS - 1) / (int)(size_t_bits);      \
    unsigned int i;                                            \
    size_t seed = 0;                                           \
    for (i = length * size_t_bits; i > 0; i -= size_t_bits)    \
      seed ^= (size_t)(seed >> i) + (seed << 6) + (seed >> 2); \
    seed ^= (size_t)val + (seed << 6) + (seed >> 2);           \
    return seed;                                               \
  }

MAKE_FLOAT_HASH

#define MAKE_FLOAT_HASH	(		T,
			NAME
	)

Value:

static inline size_t cdc_hash_##NAME(T val)        \
  {                                                  \
    return cdc_hash_binary((char *)&val, sizeof(T)); \
  }

MAKE_POINTER_DATA_HASH

#define MAKE_POINTER_DATA_HASH	(		T,
			NAME,
			CAST_FUNC
	)

Value:

static inline size_t cdc_pdhash_##NAME(void *val) \
  {                                                 \
    T t = CAST_FUNC(val);                           \
    return cdc_hash_##NAME(t);                      \
  }

Typedef Documentation

cdc_hash_fn_t

typedef size_t(* cdc_hash_fn_t) (void const *)

Function Documentation

cdc_hash_float_combine()

static size_t cdc_hash_float_combine ( size_t  seed, size_t  value  )

inlinestatic

cdc_hash_binary()

static size_t cdc_hash_binary ( char *  ptr, size_t  length  )

inlinestatic