hashfn.cpp File Reference

#include "mfcpch.h"
#include "hashfn.h"

Go to the source code of this file.

Functions
inT32	hash (inT32 bits, void *key, inT32 keysize)

Function Documentation

inT32 hash	(	inT32	bits,
		void *	key,
		inT32	keysize
	)

Definition at line 30 of file hashfn.cpp.

            {
  inT32 bitindex;                //current bit count
  uinT32 keybits;                //bit buffer
  uinT32 hcode;                  //current hash code
  uinT32 mask;                   //bit mask

  mask = (1 << bits) - 1;
  keysize *= 8;                  //in bits
  bitindex = 0;
  keybits = 0;
  hcode = 0;
  do {
    while (keysize > 0 && bitindex <= 24) {
      keybits |= *((uinT8 *) key) << bitindex;
      key = (uinT8 *) key + 1;
      bitindex += 8;
      keysize -= 8;
    }
    hcode ^= keybits & mask;     //key new key
    keybits >>= bits;
  }
  while (keysize > 0);
  return hcode;                  //initial hash
}