ecency-mobile/ios/Pods/boost-for-react-native/boost/graph/parallel/distribution.hpp

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// Copyright 2004 The Trustees of Indiana University.
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Authors: Douglas Gregor
// Peter Gottschling
// Andrew Lumsdaine
#ifndef BOOST_PARALLEL_DISTRIBUTION_HPP
#define BOOST_PARALLEL_DISTRIBUTION_HPP
#ifndef BOOST_GRAPH_USE_MPI
#error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
#endif
#include <cstddef>
#include <vector>
#include <algorithm>
#include <numeric>
#include <boost/assert.hpp>
#include <boost/iterator/counting_iterator.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/shared_ptr.hpp>
#include <typeinfo>
namespace boost { namespace parallel {
template<typename ProcessGroup, typename SizeType = std::size_t>
class variant_distribution
{
public:
typedef typename ProcessGroup::process_id_type process_id_type;
typedef typename ProcessGroup::process_size_type process_size_type;
typedef SizeType size_type;
private:
struct basic_distribution
{
virtual ~basic_distribution() {}
virtual size_type block_size(process_id_type, size_type) const = 0;
virtual process_id_type in_process(size_type) const = 0;
virtual size_type local(size_type) const = 0;
virtual size_type global(size_type) const = 0;
virtual size_type global(process_id_type, size_type) const = 0;
virtual void* address() = 0;
virtual const void* address() const = 0;
virtual const std::type_info& type() const = 0;
};
template<typename Distribution>
struct poly_distribution : public basic_distribution
{
explicit poly_distribution(const Distribution& distribution)
: distribution_(distribution) { }
virtual size_type block_size(process_id_type id, size_type n) const
{ return distribution_.block_size(id, n); }
virtual process_id_type in_process(size_type i) const
{ return distribution_(i); }
virtual size_type local(size_type i) const
{ return distribution_.local(i); }
virtual size_type global(size_type n) const
{ return distribution_.global(n); }
virtual size_type global(process_id_type id, size_type n) const
{ return distribution_.global(id, n); }
virtual void* address() { return &distribution_; }
virtual const void* address() const { return &distribution_; }
virtual const std::type_info& type() const { return typeid(Distribution); }
private:
Distribution distribution_;
};
public:
variant_distribution() { }
template<typename Distribution>
variant_distribution(const Distribution& distribution)
: distribution_(new poly_distribution<Distribution>(distribution)) { }
size_type block_size(process_id_type id, size_type n) const
{ return distribution_->block_size(id, n); }
process_id_type operator()(size_type i) const
{ return distribution_->in_process(i); }
size_type local(size_type i) const
{ return distribution_->local(i); }
size_type global(size_type n) const
{ return distribution_->global(n); }
size_type global(process_id_type id, size_type n) const
{ return distribution_->global(id, n); }
operator bool() const { return distribution_; }
void clear() { distribution_.reset(); }
template<typename T>
T* as()
{
if (distribution_->type() == typeid(T))
return static_cast<T*>(distribution_->address());
else
return 0;
}
template<typename T>
const T* as() const
{
if (distribution_->type() == typeid(T))
return static_cast<T*>(distribution_->address());
else
return 0;
}
private:
shared_ptr<basic_distribution> distribution_;
};
struct block
{
template<typename LinearProcessGroup>
explicit block(const LinearProcessGroup& pg, std::size_t n)
: id(process_id(pg)), p(num_processes(pg)), n(n) { }
// If there are n elements in the distributed data structure, returns the number of elements stored locally.
template<typename SizeType>
SizeType block_size(SizeType n) const
{ return (n / p) + ((std::size_t)(n % p) > id? 1 : 0); }
// If there are n elements in the distributed data structure, returns the number of elements stored on processor ID
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType n) const
{ return (n / p) + ((ProcessID)(n % p) > id? 1 : 0); }
// Returns the processor on which element with global index i is stored
template<typename SizeType>
SizeType operator()(SizeType i) const
{
SizeType cutoff_processor = n % p;
SizeType cutoff = cutoff_processor * (n / p + 1);
if (i < cutoff) return i / (n / p + 1);
else return cutoff_processor + (i - cutoff) / (n / p);
}
// Find the starting index for processor with the given id
template<typename ID>
std::size_t start(ID id) const
{
std::size_t estimate = id * (n / p + 1);
ID cutoff_processor = n % p;
if (id < cutoff_processor) return estimate;
else return estimate - (id - cutoff_processor);
}
// Find the local index for the ith global element
template<typename SizeType>
SizeType local(SizeType i) const
{
SizeType owner = (*this)(i);
return i - start(owner);
}
// Returns the global index of local element i
template<typename SizeType>
SizeType global(SizeType i) const
{ return global(id, i); }
// Returns the global index of the ith local element on processor id
template<typename ProcessID, typename SizeType>
SizeType global(ProcessID id, SizeType i) const
{ return i + start(id); }
private:
std::size_t id; //< The ID number of this processor
std::size_t p; //< The number of processors
std::size_t n; //< The size of the problem space
};
// Block distribution with arbitrary block sizes
struct uneven_block
{
typedef std::vector<std::size_t> size_vector;
template<typename LinearProcessGroup>
explicit uneven_block(const LinearProcessGroup& pg, const std::vector<std::size_t>& local_sizes)
: id(process_id(pg)), p(num_processes(pg)), local_sizes(local_sizes)
{
BOOST_ASSERT(local_sizes.size() == p);
local_starts.resize(p + 1);
local_starts[0] = 0;
std::partial_sum(local_sizes.begin(), local_sizes.end(), &local_starts[1]);
n = local_starts[p];
}
// To do maybe: enter local size in each process and gather in constructor (much handier)
// template<typename LinearProcessGroup>
// explicit uneven_block(const LinearProcessGroup& pg, std::size_t my_local_size)
// If there are n elements in the distributed data structure, returns the number of elements stored locally.
template<typename SizeType>
SizeType block_size(SizeType) const
{ return local_sizes[id]; }
// If there are n elements in the distributed data structure, returns the number of elements stored on processor ID
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType) const
{ return local_sizes[id]; }
// Returns the processor on which element with global index i is stored
template<typename SizeType>
SizeType operator()(SizeType i) const
{
BOOST_ASSERT (i >= (SizeType) 0 && i < (SizeType) n); // check for valid range
size_vector::const_iterator lb = std::lower_bound(local_starts.begin(), local_starts.end(), (std::size_t) i);
return ((SizeType)(*lb) == i ? lb : --lb) - local_starts.begin();
}
// Find the starting index for processor with the given id
template<typename ID>
std::size_t start(ID id) const
{
return local_starts[id];
}
// Find the local index for the ith global element
template<typename SizeType>
SizeType local(SizeType i) const
{
SizeType owner = (*this)(i);
return i - start(owner);
}
// Returns the global index of local element i
template<typename SizeType>
SizeType global(SizeType i) const
{ return global(id, i); }
// Returns the global index of the ith local element on processor id
template<typename ProcessID, typename SizeType>
SizeType global(ProcessID id, SizeType i) const
{ return i + start(id); }
private:
std::size_t id; //< The ID number of this processor
std::size_t p; //< The number of processors
std::size_t n; //< The size of the problem space
std::vector<std::size_t> local_sizes; //< The sizes of all blocks
std::vector<std::size_t> local_starts; //< Lowest global index of each block
};
struct oned_block_cyclic
{
template<typename LinearProcessGroup>
explicit oned_block_cyclic(const LinearProcessGroup& pg, std::size_t size)
: id(process_id(pg)), p(num_processes(pg)), size(size) { }
template<typename SizeType>
SizeType block_size(SizeType n) const
{
return block_size(id, n);
}
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType n) const
{
SizeType all_blocks = n / size;
SizeType extra_elements = n % size;
SizeType everyone_gets = all_blocks / p;
SizeType extra_blocks = all_blocks % p;
SizeType my_blocks = everyone_gets + (p < extra_blocks? 1 : 0);
SizeType my_elements = my_blocks * size
+ (p == extra_blocks? extra_elements : 0);
return my_elements;
}
template<typename SizeType>
SizeType operator()(SizeType i) const
{
return (i / size) % p;
}
template<typename SizeType>
SizeType local(SizeType i) const
{
return ((i / size) / p) * size + i % size;
}
template<typename SizeType>
SizeType global(SizeType i) const
{ return global(id, i); }
template<typename ProcessID, typename SizeType>
SizeType global(ProcessID id, SizeType i) const
{
return ((i / size) * p + id) * size + i % size;
}
private:
std::size_t id; //< The ID number of this processor
std::size_t p; //< The number of processors
std::size_t size; //< Block size
};
struct twod_block_cyclic
{
template<typename LinearProcessGroup>
explicit twod_block_cyclic(const LinearProcessGroup& pg,
std::size_t block_rows, std::size_t block_columns,
std::size_t data_columns_per_row)
: id(process_id(pg)), p(num_processes(pg)),
block_rows(block_rows), block_columns(block_columns),
data_columns_per_row(data_columns_per_row)
{ }
template<typename SizeType>
SizeType block_size(SizeType n) const
{
return block_size(id, n);
}
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType n) const
{
// TBD: This is really lame :)
int result = -1;
while (n > 0) {
--n;
if ((*this)(n) == id && (int)local(n) > result) result = local(n);
}
++result;
// std::cerr << "Block size of id " << id << " is " << result << std::endl;
return result;
}
template<typename SizeType>
SizeType operator()(SizeType i) const
{
SizeType result = get_block_num(i) % p;
// std::cerr << "Item " << i << " goes on processor " << result << std::endl;
return result;
}
template<typename SizeType>
SizeType local(SizeType i) const
{
// Compute the start of the block
std::size_t block_num = get_block_num(i);
// std::cerr << "Item " << i << " is in block #" << block_num << std::endl;
std::size_t local_block_num = block_num / p;
std::size_t block_start = local_block_num * block_rows * block_columns;
// Compute the offset into the block
std::size_t data_row = i / data_columns_per_row;
std::size_t data_col = i % data_columns_per_row;
std::size_t block_offset = (data_row % block_rows) * block_columns
+ (data_col % block_columns);
// std::cerr << "Item " << i << " maps to local index " << block_start+block_offset << std::endl;
return block_start + block_offset;
}
template<typename SizeType>
SizeType global(SizeType i) const
{
// Compute the (global) block in which this element resides
SizeType local_block_num = i / (block_rows * block_columns);
SizeType block_offset = i % (block_rows * block_columns);
SizeType block_num = local_block_num * p + id;
// Compute the position of the start of the block (globally)
SizeType block_start = block_num * block_rows * block_columns;
std::cerr << "Block " << block_num << " starts at index " << block_start
<< std::endl;
// Compute the row and column of this block
SizeType block_row = block_num / (data_columns_per_row / block_columns);
SizeType block_col = block_num % (data_columns_per_row / block_columns);
SizeType row_in_block = block_offset / block_columns;
SizeType col_in_block = block_offset % block_columns;
std::cerr << "Local index " << i << " is in block at row " << block_row
<< ", column " << block_col << ", in-block row " << row_in_block
<< ", in-block col " << col_in_block << std::endl;
SizeType result = block_row * block_rows + block_col * block_columns
+ row_in_block * block_rows + col_in_block;
std::cerr << "global(" << i << "@" << id << ") = " << result
<< " =? " << local(result) << std::endl;
BOOST_ASSERT(i == local(result));
return result;
}
private:
template<typename SizeType>
std::size_t get_block_num(SizeType i) const
{
std::size_t data_row = i / data_columns_per_row;
std::size_t data_col = i % data_columns_per_row;
std::size_t block_row = data_row / block_rows;
std::size_t block_col = data_col / block_columns;
std::size_t blocks_in_row = data_columns_per_row / block_columns;
std::size_t block_num = block_col * blocks_in_row + block_row;
return block_num;
}
std::size_t id; //< The ID number of this processor
std::size_t p; //< The number of processors
std::size_t block_rows; //< The # of rows in each block
std::size_t block_columns; //< The # of columns in each block
std::size_t data_columns_per_row; //< The # of columns per row of data
};
class twod_random
{
template<typename RandomNumberGen>
struct random_int
{
explicit random_int(RandomNumberGen& gen) : gen(gen) { }
template<typename T>
T operator()(T n) const
{
uniform_int<T> distrib(0, n-1);
return distrib(gen);
}
private:
RandomNumberGen& gen;
};
public:
template<typename LinearProcessGroup, typename RandomNumberGen>
explicit twod_random(const LinearProcessGroup& pg,
std::size_t block_rows, std::size_t block_columns,
std::size_t data_columns_per_row,
std::size_t n,
RandomNumberGen& gen)
: id(process_id(pg)), p(num_processes(pg)),
block_rows(block_rows), block_columns(block_columns),
data_columns_per_row(data_columns_per_row),
global_to_local(n / (block_rows * block_columns))
{
std::copy(make_counting_iterator(std::size_t(0)),
make_counting_iterator(global_to_local.size()),
global_to_local.begin());
random_int<RandomNumberGen> rand(gen);
std::random_shuffle(global_to_local.begin(), global_to_local.end(), rand);
}
template<typename SizeType>
SizeType block_size(SizeType n) const
{
return block_size(id, n);
}
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType n) const
{
// TBD: This is really lame :)
int result = -1;
while (n > 0) {
--n;
if ((*this)(n) == id && (int)local(n) > result) result = local(n);
}
++result;
// std::cerr << "Block size of id " << id << " is " << result << std::endl;
return result;
}
template<typename SizeType>
SizeType operator()(SizeType i) const
{
SizeType result = get_block_num(i) % p;
// std::cerr << "Item " << i << " goes on processor " << result << std::endl;
return result;
}
template<typename SizeType>
SizeType local(SizeType i) const
{
// Compute the start of the block
std::size_t block_num = get_block_num(i);
// std::cerr << "Item " << i << " is in block #" << block_num << std::endl;
std::size_t local_block_num = block_num / p;
std::size_t block_start = local_block_num * block_rows * block_columns;
// Compute the offset into the block
std::size_t data_row = i / data_columns_per_row;
std::size_t data_col = i % data_columns_per_row;
std::size_t block_offset = (data_row % block_rows) * block_columns
+ (data_col % block_columns);
// std::cerr << "Item " << i << " maps to local index " << block_start+block_offset << std::endl;
return block_start + block_offset;
}
private:
template<typename SizeType>
std::size_t get_block_num(SizeType i) const
{
std::size_t data_row = i / data_columns_per_row;
std::size_t data_col = i % data_columns_per_row;
std::size_t block_row = data_row / block_rows;
std::size_t block_col = data_col / block_columns;
std::size_t blocks_in_row = data_columns_per_row / block_columns;
std::size_t block_num = block_col * blocks_in_row + block_row;
return global_to_local[block_num];
}
std::size_t id; //< The ID number of this processor
std::size_t p; //< The number of processors
std::size_t block_rows; //< The # of rows in each block
std::size_t block_columns; //< The # of columns in each block
std::size_t data_columns_per_row; //< The # of columns per row of data
std::vector<std::size_t> global_to_local;
};
class random_distribution
{
template<typename RandomNumberGen>
struct random_int
{
explicit random_int(RandomNumberGen& gen) : gen(gen) { }
template<typename T>
T operator()(T n) const
{
uniform_int<T> distrib(0, n-1);
return distrib(gen);
}
private:
RandomNumberGen& gen;
};
public:
template<typename LinearProcessGroup, typename RandomNumberGen>
random_distribution(const LinearProcessGroup& pg, RandomNumberGen& gen,
std::size_t n)
: base(pg, n), local_to_global(n), global_to_local(n)
{
std::copy(make_counting_iterator(std::size_t(0)),
make_counting_iterator(n),
local_to_global.begin());
random_int<RandomNumberGen> rand(gen);
std::random_shuffle(local_to_global.begin(), local_to_global.end(), rand);
for (std::vector<std::size_t>::size_type i = 0; i < n; ++i)
global_to_local[local_to_global[i]] = i;
}
template<typename SizeType>
SizeType block_size(SizeType n) const
{ return base.block_size(n); }
template<typename SizeType, typename ProcessID>
SizeType block_size(ProcessID id, SizeType n) const
{ return base.block_size(id, n); }
template<typename SizeType>
SizeType operator()(SizeType i) const
{
return base(global_to_local[i]);
}
template<typename SizeType>
SizeType local(SizeType i) const
{
return base.local(global_to_local[i]);
}
template<typename ProcessID, typename SizeType>
SizeType global(ProcessID p, SizeType i) const
{
return local_to_global[base.global(p, i)];
}
template<typename SizeType>
SizeType global(SizeType i) const
{
return local_to_global[base.global(i)];
}
private:
block base;
std::vector<std::size_t> local_to_global;
std::vector<std::size_t> global_to_local;
};
} } // end namespace boost::parallel
#endif // BOOST_PARALLEL_DISTRIBUTION_HPP