src/hashpjw.c

/*
  This File is copied from
  
  http://www.oreilly.com/catalog/masteralgoc/index.html
  Mastering Algorithms with C
  By Kyle Loudon
  ISBN: 1-56592-453-3
  Publishd by O'Reilly

  We have added our own struct to these function.
 */

/*****************************************************************************
*                                                                            *
*  ------------------------------- hashpjw.c ------------------------------  *
*                                                                            *
*****************************************************************************/

#include <include/hashpjw.h>

/*****************************************************************************
*                                                                            *
*  -------------------------------- hashpjw -------------------------------  *
*                                                                            *
*****************************************************************************/

int hashpjw(const void *key) {

  const char         *ptr;
  unsigned int        val;
  appsess *appsession_temp;

  /*****************************************************************************
   *                                                                            *
   *  Hash the key by performing a number of bit operations on it.              *
   *                                                                            *
   *****************************************************************************/

  val = 0;
  appsession_temp = (appsess *)key;
  ptr = appsession_temp->sessid;

  while (*ptr != '\0') {

    int tmp;

    val = (val << 4) + (*ptr);

    if((tmp = (val & 0xf0000000))) {
      val = val ^ (tmp >> 24);
      val = val ^ tmp;
    }
    ptr++;
  }/* end while */

  /*****************************************************************************
   *                                                                            *
   *  In practice, replace PRIME_TBLSIZ with the actual table size.             *
   *                                                                            *
   *****************************************************************************/
  return val % PRIME_TBLSIZ;
}/* end hashpjw */