/***********************************************************************
* Software License Agreement (BSD License)
*
* Copyright 2008-2010 Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
* Copyright 2008-2010 David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*************************************************************************/
#ifndef FLANN_MPI_HPP_
#define FLANN_MPI_HPP_
#include <boost/mpi.hpp>
#include <boost/serialization/array.hpp>
#include <FLANN/flann.hpp>
#include <FLANN/io/hdf5.h>
namespace flann
{
namespace mpi
{
template<typename DistanceType>
struct SearchResults
{
flann::Matrix<int> indices;
flann::Matrix<DistanceType> dists;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar& indices.rows;
ar& indices.cols;
if (Archive::is_loading::value) {
indices = Matrix<int>(new int[indices.rows*indices.cols], indices.rows, indices.cols);
}
ar& boost::serialization::make_array(indices.ptr(), indices.rows*indices.cols);
if (Archive::is_saving::value) {
delete[] indices.ptr();
}
ar& dists.rows;
ar& dists.cols;
if (Archive::is_loading::value) {
dists = Matrix<DistanceType>(new DistanceType[dists.rows*dists.cols], dists.rows, dists.cols);
}
ar& boost::serialization::make_array(dists.ptr(), dists.rows*dists.cols);
if (Archive::is_saving::value) {
delete[] dists.ptr();
}
}
};
template<typename DistanceType>
struct ResultsMerger
{
SearchResults<DistanceType> operator()(SearchResults<DistanceType> a, SearchResults<DistanceType> b)
{
SearchResults<DistanceType> results;
results.indices = flann::Matrix<int>(new int[a.indices.rows*a.indices.cols],a.indices.rows,a.indices.cols);
results.dists = flann::Matrix<DistanceType>(new DistanceType[a.dists.rows*a.dists.cols],a.dists.rows,a.dists.cols);
for (size_t i = 0; i < results.dists.rows; ++i) {
size_t idx = 0;
size_t a_idx = 0;
size_t b_idx = 0;
while (idx < results.dists.cols) {
if (a.dists[i][a_idx] <= b.dists[i][b_idx]) {
results.dists[i][idx] = a.dists[i][a_idx];
results.indices[i][idx] = a.indices[i][a_idx];
idx++;
a_idx++;
}
else {
results.dists[i][idx] = b.dists[i][b_idx];
results.indices[i][idx] = b.indices[i][b_idx];
idx++;
b_idx++;
}
}
}
delete[] a.indices.ptr();
delete[] a.dists.ptr();
delete[] b.indices.ptr();
delete[] b.dists.ptr();
return results;
}
};
template<typename Distance>
class Index
{
typedef typename Distance::ElementType ElementType;
typedef typename Distance::ResultType DistanceType;
flann::Index<Distance>* flann_index;
flann::Matrix<ElementType> dataset;
int size_;
int offset_;
public:
Index(const std::string& file_name,
const std::string& dataset_name,
const IndexParams& params);
~Index();
void buildIndex()
{
flann_index->buildIndex();
}
void knnSearch(const flann::Matrix<ElementType>& queries,
flann::Matrix<int>& indices,
flann::Matrix<DistanceType>& dists,
int knn, const
SearchParams& params);
int radiusSearch(const flann::Matrix<ElementType>& query,
flann::Matrix<int>& indices,
flann::Matrix<DistanceType>& dists,
float radius,
const SearchParams& params);
// void save(std::string filename);
int veclen() const
{
return flann_index->veclen();
}
int size() const
{
return size_;
}
IndexParams getIndexParameters()
{
return flann_index->getParameters();
}
};
template<typename Distance>
Index<Distance>::Index(const std::string& file_name, const std::string& dataset_name, const IndexParams& params)
{
boost::mpi::communicator world;
flann_algorithm_t index_type = get_param<flann_algorithm_t>(params,"algorithm");
if (index_type == FLANN_INDEX_SAVED) {
throw FLANNException("Saving/loading of MPI indexes is not currently supported.");
}
flann::mpi::load_from_file(dataset, file_name, dataset_name);
flann_index = new flann::Index<Distance>(dataset, params);
std::vector<int> sizes;
// get the sizes of all MPI indices
all_gather(world, (int)flann_index->size(), sizes);
size_ = 0;
offset_ = 0;
for (size_t i = 0; i < sizes.size(); ++i) {
if ((int)i < world.rank()) offset_ += sizes[i];
size_ += sizes[i];
}
}
template<typename Distance>
Index<Distance>::~Index()
{
delete flann_index;
delete[] dataset.ptr();
}
template<typename Distance>
void Index<Distance>::knnSearch(const flann::Matrix<ElementType>& queries, flann::Matrix<int>& indices, flann::Matrix<DistanceType>& dists, int knn, const SearchParams& params)
{
boost::mpi::communicator world;
flann::Matrix<int> local_indices(new int[queries.rows*knn], queries.rows, knn);
flann::Matrix<DistanceType> local_dists(new DistanceType[queries.rows*knn], queries.rows, knn);
flann_index->knnSearch(queries, local_indices, local_dists, knn, params);
for (size_t i = 0; i < local_indices.rows; ++i) {
for (size_t j = 0; j < local_indices.cols; ++j) {
local_indices[i][j] += offset_;
}
}
SearchResults<DistanceType> local_results;
local_results.indices = local_indices;
local_results.dists = local_dists;
SearchResults<DistanceType> results;
// perform MPI reduce
reduce(world, local_results, results, ResultsMerger<DistanceType>(), 0);
if (world.rank() == 0) {
for (size_t i = 0; i < results.indices.rows; ++i) {
for (size_t j = 0; j < results.indices.cols; ++j) {
indices[i][j] = results.indices[i][j];
dists[i][j] = results.dists[i][j];
}
}
delete[] results.indices.ptr();
delete[] results.dists.ptr();
}
}
template<typename Distance>
int Index<Distance>::radiusSearch(const flann::Matrix<ElementType>& query, flann::Matrix<int>& indices, flann::Matrix<DistanceType>& dists, float radius, const SearchParams& params)
{
boost::mpi::communicator world;
flann::Matrix<int> local_indices(new int[indices.rows*indices.cols], indices.rows, indices.cols);
flann::Matrix<DistanceType> local_dists(new DistanceType[dists.rows*dists.cols], dists.rows, dists.cols);
flann_index->radiusSearch(query, local_indices, local_dists, radius, params);
for (size_t i = 0; i < local_indices.rows; ++i) {
for (size_t j = 0; j < local_indices.cols; ++j) {
local_indices[i][j] += offset_;
}
}
SearchResults<DistanceType> local_results;
local_results.indices = local_indices;
local_results.dists = local_dists;
SearchResults<DistanceType> results;
// perform MPI reduce
reduce(world, local_results, results, ResultsMerger<DistanceType>(), 0);
if (world.rank() == 0) {
for (int i = 0; i < std::min(results.indices.rows, indices.rows); ++i) {
for (int j = 0; j < std::min(results.indices.cols, indices.cols); ++j) {
indices[i][j] = results.indices[i][j];
dists[i][j] = results.dists[i][j];
}
}
delete[] results.indices.ptr();
delete[] results.dists.ptr();
}
return 0;
}
}
} //namespace flann::mpi
namespace boost { namespace mpi {
template<typename DistanceType>
struct is_commutative<flann::mpi::ResultsMerger<DistanceType>, flann::mpi::SearchResults<DistanceType> > : mpl::true_ { };
} } // end namespace boost::mpi
#endif /* FLANN_MPI_HPP_ */