ht_hash_4.cc

这是处理语音信号的程序

// file: ht_hash_3.cc
//

// isip include files
//
#include "hash_table.h"
#include "hash_table_constants.h"
 
// method: hash_vector_cc
//
// arguments:
//  int_4* vec : (input) the vector to be hashed
//  int_4 size : (input) the length of the vector
//
// return: an int_4 with the hash index
//
// this method computes the hash index for the given vector
//
int_4 Hash_table::hash_vector_cc(int_4* vec_a, int_4 size_a) {

  // index variable
  //
  uint_4 index = (uint_4)0;
  uint_4 mask = size_d;
  
  // create the index for the given string using a concocted hash
  // function based loosely on the one obtained at
  // http://ourworld.compuserve.com/homepages/bob_jenkins/doobs.htm
  //
  for (int_4 i = 0; i < size_a; i++) {
    index += vec_a[i];
    index += (index << 10);
    index ^= (index >> 6);
  }
  index += (index << 3);
  index ^= (index >> 11);
  index += (index << 15);

  // mask the hash index
  //
  index %= mask;
      
  // exit gracefully
  //
  return (int_4)index;
}