Hash.h File Reference

Utilities for calculating hash values. More...

#include <Objectively/Object.h>

Go to the source code of this file.

Macros
#define	HASH_SEED   13
	The hash seed value. More...

Functions
OBJECTIVELY_EXPORT int	HashForBytes (int hash, const uint8_t *bytes, const Range range)
	Accumulates the hash value of bytes into hash. More...
OBJECTIVELY_EXPORT int	HashForCharacters (int hash, const char *chars, const Range range)
	Accumulates the hash value of chars into hash. More...
OBJECTIVELY_EXPORT int	HashForCString (int hash, const char *chars)
	Accumulates the hash value of the null-terminated string into hash. More...
OBJECTIVELY_EXPORT int	HashForDecimal (int hash, const double decimal)
	Accumulates the hash value of decimal into hash. More...
OBJECTIVELY_EXPORT int	HashForInteger (int hash, const long integer)
	Accumulates the hash value of integer into hash. More...
OBJECTIVELY_EXPORT int	HashForObject (int hash, const ident obj)
	Accumulates the hash value of object into hash. More...

Detailed Description

Utilities for calculating hash values.

Definition in file Hash.h.

Macro Definition Documentation

HASH_SEED

#define HASH_SEED   13

The hash seed value.

Definition at line 37 of file Hash.h.

Function Documentation

HashForBytes()

OBJECTIVELY_EXPORT int HashForBytes	(	int	hash,
		const uint8_t *	bytes,
		const Range	range
	)

Accumulates the hash value of bytes into hash.

Parameters

hash	The hash accumulator.
bytes	The bytes to hash.
range	The Range to hash.

Returns

The accumulated hash value.

Definition at line 28 of file Hash.c.

                                                                    {
 
    for (size_t i = range.location; i < range.length; i++) {
 
        int shift;
        if (i & 1) {
            shift = 16 + (i % 16);
        } else {
            shift = (i % 16);
        }
 
        hash += 31 * ((int) bytes[i]) << shift;
    }
 
    return hash;
}

HashForCharacters()

OBJECTIVELY_EXPORT int HashForCharacters	(	int	hash,
		const char *	chars,
		const Range	range
	)

Accumulates the hash value of chars into hash.

Parameters

hash	The hash accumulator.
chars	The characters to hash.
range	The Range to hash.

Returns

The accumulated hash value.

Definition at line 45 of file Hash.c.

                                                                      {
    return HashForBytes(hash, (const uint8_t *) chars, range);
}

HashForCString()

OBJECTIVELY_EXPORT int HashForCString	(	int	hash,
		const char *	chars
	)

Accumulates the hash value of the null-terminated string into hash.

Parameters

hash	The hash accumulator.
chars	The null-terminated C string.

Returns

The accumulated hash value.

Definition at line 49 of file Hash.c.

                                                 {
 
    if (string) {
        return HashForCharacters(hash, string, (Range) { 0, strlen(string) });
    }
 
    return 0;
}

HashForDecimal()

OBJECTIVELY_EXPORT int HashForDecimal	(	int	hash,
		const double	decimal
	)

Accumulates the hash value of decimal into hash.

Parameters

hash	The hash accumulator.
decimal	The decimal to hash.

Returns

The accumulated hash value.

Definition at line 58 of file Hash.c.

                                                   {
    return hash + 31 * (int) decimal;
}

HashForInteger()

OBJECTIVELY_EXPORT int HashForInteger	(	int	hash,
		const long	integer
	)

Accumulates the hash value of integer into hash.

Parameters

hash	The hash accumulator.
integer	The integer to hash.

Returns

The accumulated hash value.

Definition at line 62 of file Hash.c.

                                                 {
    return hash + 31 * (int) integer;
}

HashForObject()

OBJECTIVELY_EXPORT int HashForObject	(	int	hash,
		const ident	obj
	)

Accumulates the hash value of object into hash.

Parameters

hash	The hash accumulator.
obj	The Object to hash.

Returns

The accumulated hash value.

Definition at line 66 of file Hash.c.

                                             {
 
    if (obj) {
        return hash + 31 * $(cast(Object, obj), hash);
    }
 
    return 0;
}