Zoltan2_IdentifierTraits.cpp

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//   Zoltan2: A package of combinatorial algorithms for scientific computing
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#include <Zoltan2_Standards.hpp>
#include <Zoltan2_AlltoAll.hpp>
#include <Zoltan2_IdentifierTraits.hpp>

#include <Teuchos_SerializationTraits.hpp>
#include <Teuchos_HashUtils.hpp>
#include <Teuchos_ReductionOp.hpp>

#include <utility>
#include <iostream>
#include <sstream>
#include <string>
#include <limits>
#include <cstdlib>


namespace Zoltan2
{

int getHashCode(const unsigned char *a, size_t len)
{
  int total=0;
  unsigned char *to = reinterpret_cast<unsigned char *>(&total);
  int c=0;
  for (size_t i=0; i < len; i++){
    to[c++] += a[i];
    if (c == sizeof(int))
      c = 0;
  }
  if (total < 0)
  {
      /* Convert the largest -ve int to zero and -1 to
       * std::numeric_limits<int>::max()
       * */
      size_t maxIntBeforeWrap = std::numeric_limits<int>::max();
      maxIntBeforeWrap ++;
      total += maxIntBeforeWrap;
  }
  return total;
}

} // namespace Z2