Hash.c File Reference

#include <string.h>
#include "Hash.h"

Go to the source code of this file.

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

Function Documentation

HashForBytes()

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.

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

HashForCharacters()

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 47 of file Hash.c.

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

HashForCString()

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 51 of file Hash.c.

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

HashForDecimal()

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 60 of file Hash.c.

                                                   {
  unsigned int uhash = (unsigned int) hash;
  uhash += 31U * (unsigned int) decimal;
  return (int) uhash;
}

HashForInteger()

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 66 of file Hash.c.

                                                 {
  unsigned int uhash = (unsigned int) hash;
  uhash += 31U * (unsigned int) integer;
  return (int) uhash;
}

HashForObject()

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 72 of file Hash.c.

                                             {
 
  if (obj) {
    unsigned int uhash = (unsigned int) hash;
    uhash += 31U * (unsigned int) $(cast(Object, obj), hash);
    return (int) uhash;
  }
 
  return 0;
}