Zoltan2_GidLookupHelper.hpp

Go to the documentation of this file.

// @HEADER
//
// ***********************************************************************
//
//   Zoltan2: A package of combinatorial algorithms for scientific computing
//                  Copyright 2012 Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact Karen Devine      (kddevin@sandia.gov)
//                    Erik Boman        (egboman@sandia.gov)
//                    Siva Rajamanickam (srajama@sandia.gov)
//
// ***********************************************************************
//
// @HEADER
// @HEADER
// ***********************************************************************
//            copyright
// ***********************************************************************
// @HEADER

#ifndef _ZOLTAN2_GIDLOOKUPHELPER
#define _ZOLTAN2_GIDLOOKUPHELPER

#include <Zoltan2_Standards.hpp>
#include <Zoltan2_Environment.hpp>
#include <Zoltan2_IdentifierTraits.hpp>
#include <Teuchos_Hashtable.hpp>
#include <map>

namespace Zoltan2
{
template <typename T, typename lno_t>
  class GidLookupHelper{

private:

  RCP<const Environment> env_;
  ArrayRCP<const T> gidList_;
  bool useHashTable_;

  std::map<T, lno_t> indexMap_;

  RCP<Teuchos::Hashtable<double, lno_t> > indexHash_;

public:
  GidLookupHelper(const RCP<const Environment> &env, 
    const ArrayRCP<const T> &gidList);

  GidLookupHelper();

  lno_t lookup(const T gid) const;

  lno_t size() const {
    if (useHashTable_)
      return indexHash_->size();
    else
      return indexMap_.size();
  }

  void getIndices(ArrayRCP<lno_t> &indices) const;
};

template<typename T, typename lno_t>
  GidLookupHelper<T, lno_t>::GidLookupHelper():
    env_(rcp(new Environment)), gidList_(), useHashTable_(false), 
    indexMap_(), indexHash_()
 {}

template<typename T, typename lno_t>
  GidLookupHelper<T, lno_t>::GidLookupHelper(
    const RCP<const Environment> &env, 
    const ArrayRCP<const T> &gidList):
    env_(env),
    gidList_(gidList), useHashTable_(false), indexMap_(), indexHash_()
{
  lno_t len = gidList_.size();

  if (len < 1)
    return;

  if (IdentifierTraits<T>::hasUniqueKey())
    useHashTable_ = true;

  const T *ids = gidList_.getRawPtr();

  if (!useHashTable_){
    try{
      for (lno_t i=0; i < gidList.size(); i++){
        typename std::map<T, lno_t>::iterator rec = indexMap_.find(*ids);
        if (rec == indexMap_.end())
          indexMap_[*ids] = i;
        ids++;
      }
    }
    catch (const std::exception &e){
      env_->localMemoryAssertion(__FILE__, __LINE__, len, false);
    }
  }
  else{
    typedef typename Teuchos::Hashtable<double, lno_t> id2index_hash_t;
    id2index_hash_t *p = NULL;
  
    try{
      p = new id2index_hash_t(len);
    }
    catch (const std::exception &e){
      env_->localMemoryAssertion(__FILE__, __LINE__, len, false);
    }
  
    for (lno_t i=0; i < len; i++){
      double key = IdentifierTraits<T>::key(*ids++);
      try{
        if (!p->containsKey(key))
          p->put(key, i);
      }
      Z2_THROW_OUTSIDE_ERROR(*env_);
    }

    indexHash_ = rcp<id2index_hash_t>(p);
  }
}

template<typename T, typename lno_t>
  lno_t GidLookupHelper<T, lno_t>::lookup(const T gid) const
{
  lno_t idx=0;
  bool badId=false;
  if (useHashTable_){
    try{
      double key = IdentifierTraits<T>::key(gid);
      idx = indexHash_->get(key);
    }
    catch (const std::exception &e) {
      badId = true;
    }
  }
  else{
    typename std::map<T, lno_t>::const_iterator next = indexMap_.find(gid);
    if (next == indexMap_.end())
      badId = true;
    else
      idx = (*next).second;
  }

  env_->localInputAssertion(__FILE__, __LINE__, "invalid global id",
    badId==false, BASIC_ASSERTION);

  return idx;
}

template<typename T, typename lno_t>
  void GidLookupHelper<T, lno_t>::getIndices(
    ArrayRCP<lno_t> &indices) const
{
  lno_t numIds = size();
  lno_t *idx = new lno_t [numIds];
  ArrayRCP<lno_t> indexList = arcp(idx, 0, numIds, true);

  if (numIds == gidList_.size()){
    for (lno_t i=0; i < gidList_.size(); i++){
       *idx++ = i;
    }
  }
  else{
    const T *ids = gidList_.getRawPtr();
    std::set<T> allGids;

    for (lno_t i=0; i < gidList_.size(); i++){
      typename std::set<T>::iterator rec = allGids.find(ids[i]);
      if (rec == allGids.end()){
        allGids.insert(ids[i]);
        *idx++ = i;
      }
    }
  }

  indices = indexList;
}

} // namespace Z2

#endif // _ZOLTAN2_GIDLOOKUPHELPER