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glm/test/external/boost/graph/distributed/betweenness_centrality.hpp

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// Copyright 2004 The Trustees of Indiana University.
// Distributed under 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
// Andrew Lumsdaine
#ifndef BOOST_GRAPH_PARALLEL_BRANDES_BETWEENNESS_CENTRALITY_HPP
#define BOOST_GRAPH_PARALLEL_BRANDES_BETWEENNESS_CENTRALITY_HPP
#ifndef BOOST_GRAPH_USE_MPI
#error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
#endif
// #define COMPUTE_PATH_COUNTS_INLINE
#include <boost/graph/betweenness_centrality.hpp>
#include <boost/graph/overloading.hpp>
#include <boost/graph/distributed/concepts.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/config.hpp>
#include <boost/assert.hpp>
// For additive_reducer
#include <boost/graph/distributed/distributed_graph_utility.hpp>
#include <boost/type_traits/is_convertible.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/property_map/property_map.hpp>
#include <boost/graph/named_function_params.hpp>
#include <boost/property_map/parallel/distributed_property_map.hpp>
#include <boost/graph/distributed/detail/dijkstra_shortest_paths.hpp>
#include <boost/tuple/tuple.hpp>
// NGE - Needed for minstd_rand at L807, should pass vertex list
// or generator instead
#include <boost/random/linear_congruential.hpp>
#include <algorithm>
#include <stack>
#include <vector>
// Appending reducer
template <typename T>
struct append_reducer {
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true);
template<typename K>
T operator()(const K&) const { return T(); }
template<typename K>
T operator()(const K&, const T& x, const T& y) const
{
T z(x.begin(), x.end());
for (typename T::const_iterator iter = y.begin(); iter != y.end(); ++iter)
if (std::find(z.begin(), z.end(), *iter) == z.end())
z.push_back(*iter);
return z;
}
};
namespace boost {
namespace serialization {
// TODO(nge): Write generalized serialization for tuples
template<typename Archive, typename T1, typename T2, typename T3,
typename T4>
void serialize(Archive & ar,
boost::tuple<T1,T2,T3, T4>& t,
const unsigned int)
{
ar & boost::tuples::get<0>(t);
ar & boost::tuples::get<1>(t);
ar & boost::tuples::get<2>(t);
ar & boost::tuples::get<3>(t);
}
} // serialization
template <typename OwnerMap, typename Tuple>
class get_owner_of_first_tuple_element {
public:
typedef typename property_traits<OwnerMap>::value_type owner_type;
get_owner_of_first_tuple_element(OwnerMap owner) : owner(owner) { }
owner_type get_owner(Tuple t) { return get(owner, boost::tuples::get<0>(t)); }
private:
OwnerMap owner;
};
template <typename OwnerMap, typename Tuple>
typename get_owner_of_first_tuple_element<OwnerMap, Tuple>::owner_type
get(get_owner_of_first_tuple_element<OwnerMap, Tuple> o, Tuple t)
{ return o.get_owner(t); }
template <typename OwnerMap>
class get_owner_of_first_pair_element {
public:
typedef typename property_traits<OwnerMap>::value_type owner_type;
get_owner_of_first_pair_element(OwnerMap owner) : owner(owner) { }
template <typename Vertex, typename T>
owner_type get_owner(std::pair<Vertex, T> p) { return get(owner, p.first); }
private:
OwnerMap owner;
};
template <typename OwnerMap, typename Vertex, typename T>
typename get_owner_of_first_pair_element<OwnerMap>::owner_type
get(get_owner_of_first_pair_element<OwnerMap> o, std::pair<Vertex, T> p)
{ return o.get_owner(p); }
namespace graph { namespace parallel { namespace detail {
template<typename DistanceMap, typename IncomingMap>
class betweenness_centrality_msg_value
{
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef typename property_traits<IncomingMap>::value_type incoming_type;
typedef typename incoming_type::value_type incoming_value_type;
public:
typedef std::pair<distance_type, incoming_value_type> type;
static type create(distance_type dist, incoming_value_type source)
{ return std::make_pair(dist, source); }
};
/************************************************************************/
/* Delta-stepping Betweenness Centrality */
/************************************************************************/
template<typename Graph, typename DistanceMap, typename IncomingMap,
typename EdgeWeightMap, typename PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, typename IsSettledMap, typename VertexIndexMap
#endif
>
class betweenness_centrality_delta_stepping_impl {
// Could inherit from delta_stepping_impl to get run() method
// but for the time being it's just reproduced here
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef typename graph_traits<Graph>::degree_size_type Degree;
typedef typename property_traits<EdgeWeightMap>::value_type Dist;
typedef typename property_traits<IncomingMap>::value_type IncomingType;
typedef typename boost::graph::parallel::process_group_type<Graph>::type
ProcessGroup;
typedef std::list<Vertex> Bucket;
typedef typename Bucket::iterator BucketIterator;
typedef typename std::vector<Bucket*>::size_type BucketIndex;
typedef betweenness_centrality_msg_value<DistanceMap, IncomingMap>
MessageValue;
enum {
// Relax a remote vertex. The message contains a pair<Vertex,
// MessageValue>, the first part of which is the vertex whose
// tentative distance is being relaxed and the second part
// contains either the new distance (if there is no predecessor
// map) or a pair with the distance and predecessor.
msg_relax
};
public:
// Must supply delta, ctor that guesses delta removed
betweenness_centrality_delta_stepping_impl(const Graph& g,
DistanceMap distance,
IncomingMap incoming,
EdgeWeightMap weight,
PathCountMap path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
IsSettledMap is_settled,
VertexIndexMap vertex_index,
#endif
Dist delta);
void run(Vertex s);
private:
// Relax the edge (u, v), creating a new best path of distance x.
void relax(Vertex u, Vertex v, Dist x);
// Synchronize all of the processes, by receiving all messages that
// have not yet been received.
void synchronize()
{
using boost::graph::parallel::synchronize;
synchronize(pg);
}
// Setup triggers for msg_relax messages
void setup_triggers()
{
using boost::graph::parallel::simple_trigger;
simple_trigger(pg, msg_relax, this,
&betweenness_centrality_delta_stepping_impl::handle_msg_relax);
}
void handle_msg_relax(int /*source*/, int /*tag*/,
const std::pair<Vertex, typename MessageValue::type>& data,
trigger_receive_context)
{ relax(data.second.second, data.first, data.second.first); }
const Graph& g;
IncomingMap incoming;
DistanceMap distance;
EdgeWeightMap weight;
PathCountMap path_count;
#ifdef COMPUTE_PATH_COUNTS_INLINE
IsSettledMap is_settled;
VertexIndexMap vertex_index;
#endif
Dist delta;
ProcessGroup pg;
typename property_map<Graph, vertex_owner_t>::const_type owner;
typename property_map<Graph, vertex_local_t>::const_type local;
// A "property map" that contains the position of each vertex in
// whatever bucket it resides in.
std::vector<BucketIterator> position_in_bucket;
// Bucket data structure. The ith bucket contains all local vertices
// with (tentative) distance in the range [i*delta,
// (i+1)*delta).
std::vector<Bucket*> buckets;
// This "dummy" list is used only so that we can initialize the
// position_in_bucket property map with non-singular iterators. This
// won't matter for most implementations of the C++ Standard
// Library, but it avoids undefined behavior and allows us to run
// with library "debug modes".
std::list<Vertex> dummy_list;
// A "property map" that states which vertices have been deleted
// from the bucket in this iteration.
std::vector<bool> vertex_was_deleted;
};
template<typename Graph, typename DistanceMap, typename IncomingMap,
typename EdgeWeightMap, typename PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, typename IsSettledMap, typename VertexIndexMap
#endif
>
betweenness_centrality_delta_stepping_impl<
Graph, DistanceMap, IncomingMap, EdgeWeightMap, PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, IsSettledMap, VertexIndexMap
#endif
>::
betweenness_centrality_delta_stepping_impl(const Graph& g,
DistanceMap distance,
IncomingMap incoming,
EdgeWeightMap weight,
PathCountMap path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
IsSettledMap is_settled,
VertexIndexMap vertex_index,
#endif
Dist delta)
: g(g),
incoming(incoming),
distance(distance),
weight(weight),
path_count(path_count),
#ifdef COMPUTE_PATH_COUNTS_INLINE
is_settled(is_settled),
vertex_index(vertex_index),
#endif
delta(delta),
pg(boost::graph::parallel::process_group_adl(g), attach_distributed_object()),
owner(get(vertex_owner, g)),
local(get(vertex_local, g))
{ setup_triggers(); }
template<typename Graph, typename DistanceMap, typename IncomingMap,
typename EdgeWeightMap, typename PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, typename IsSettledMap, typename VertexIndexMap
#endif
>
void
betweenness_centrality_delta_stepping_impl<
Graph, DistanceMap, IncomingMap, EdgeWeightMap, PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, IsSettledMap, VertexIndexMap
#endif
>::
run(Vertex s)
{
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
typename process_group_type::process_id_type id = process_id(pg);
Dist inf = (std::numeric_limits<Dist>::max)();
// None of the vertices are stored in the bucket.
position_in_bucket.clear();
position_in_bucket.resize(num_vertices(g), dummy_list.end());
// None of the vertices have been deleted
vertex_was_deleted.clear();
vertex_was_deleted.resize(num_vertices(g), false);
// No path from s to any other vertex, yet
BGL_FORALL_VERTICES_T(v, g, Graph)
put(distance, v, inf);
// The distance to the starting node is zero
if (get(owner, s) == id)
// Put "s" into its bucket (bucket 0)
relax(s, s, 0);
else
// Note that we know the distance to s is zero
cache(distance, s, 0);
#ifdef COMPUTE_PATH_COUNTS_INLINE
// Synchronize here to deliver initial relaxation since we don't
// synchronize at the beginning of the inner loop any more
synchronize();
// Incoming edge count map is an implementation detail and should
// be freed as soon as possible so build it here
typedef typename graph_traits<Graph>::edges_size_type edges_size_type;
std::vector<edges_size_type> incoming_edge_countS(num_vertices(g));
iterator_property_map<typename std::vector<edges_size_type>::iterator, VertexIndexMap>
incoming_edge_count(incoming_edge_countS.begin(), vertex_index);
#endif
BucketIndex max_bucket = (std::numeric_limits<BucketIndex>::max)();
BucketIndex current_bucket = 0;
do {
#ifdef COMPUTE_PATH_COUNTS_INLINE
// We need to clear the outgoing map after every bucket so just build it here
std::vector<IncomingType> outgoingS(num_vertices(g));
IncomingMap outgoing(outgoingS.begin(), vertex_index);
outgoing.set_reduce(append_reducer<IncomingType>());
#else
// Synchronize with all of the other processes.
synchronize();
#endif
// Find the next bucket that has something in it.
while (current_bucket < buckets.size()
&& (!buckets[current_bucket] || buckets[current_bucket]->empty()))
++current_bucket;
if (current_bucket >= buckets.size())
current_bucket = max_bucket;
// Find the smallest bucket (over all processes) that has vertices
// that need to be processed.
using boost::parallel::all_reduce;
using boost::parallel::minimum;
current_bucket = all_reduce(pg, current_bucket, minimum<BucketIndex>());
if (current_bucket == max_bucket)
// There are no non-empty buckets in any process; exit.
break;
// Contains the set of vertices that have been deleted in the
// relaxation of "light" edges. Note that we keep track of which
// vertices were deleted with the property map
// "vertex_was_deleted".
std::vector<Vertex> deleted_vertices;
// Repeatedly relax light edges
bool nonempty_bucket;
do {
// Someone has work to do in this bucket.
if (current_bucket < buckets.size() && buckets[current_bucket]) {
Bucket& bucket = *buckets[current_bucket];
// For each element in the bucket
while (!bucket.empty()) {
Vertex u = bucket.front();
// Remove u from the front of the bucket
bucket.pop_front();
// Insert u into the set of deleted vertices, if it hasn't
// been done already.
if (!vertex_was_deleted[get(local, u)]) {
vertex_was_deleted[get(local, u)] = true;
deleted_vertices.push_back(u);
}
// Relax each light edge.
Dist u_dist = get(distance, u);
BGL_FORALL_OUTEDGES_T(u, e, g, Graph)
if (get(weight, e) <= delta) // light edge
relax(u, target(e, g), u_dist + get(weight, e));
}
}
// Synchronize with all of the other processes.
synchronize();
// Is the bucket empty now?
nonempty_bucket = (current_bucket < buckets.size()
&& buckets[current_bucket]
&& !buckets[current_bucket]->empty());
} while (all_reduce(pg, nonempty_bucket, std::logical_or<bool>()));
// Relax heavy edges for each of the vertices that we previously
// deleted.
for (typename std::vector<Vertex>::iterator iter = deleted_vertices.begin();
iter != deleted_vertices.end(); ++iter) {
// Relax each heavy edge.
Vertex u = *iter;
Dist u_dist = get(distance, u);
BGL_FORALL_OUTEDGES_T(u, e, g, Graph)
if (get(weight, e) > delta) // heavy edge
relax(u, target(e, g), u_dist + get(weight, e));
#ifdef COMPUTE_PATH_COUNTS_INLINE
// Set outgoing paths
IncomingType in = get(incoming, u);
for (typename IncomingType::iterator pred = in.begin(); pred != in.end(); ++pred)
if (get(owner, *pred) == id) {
IncomingType x = get(outgoing, *pred);
if (std::find(x.begin(), x.end(), u) == x.end())
x.push_back(u);
put(outgoing, *pred, x);
} else {
IncomingType in;
in.push_back(u);
put(outgoing, *pred, in);
}
// Set incoming edge counts
put(incoming_edge_count, u, in.size());
#endif
}
#ifdef COMPUTE_PATH_COUNTS_INLINE
synchronize(); // Deliver heavy edge relaxations and outgoing paths
// Build Queue
typedef typename property_traits<PathCountMap>::value_type PathCountType;
typedef std::pair<Vertex, PathCountType> queue_value_type;
typedef typename property_map<Graph, vertex_owner_t>::const_type OwnerMap;
typedef typename get_owner_of_first_pair_element<OwnerMap> IndirectOwnerMap;
typedef boost::queue<queue_value_type> local_queue_type;
typedef boost::graph::distributed::distributed_queue<process_group_type,
IndirectOwnerMap,
local_queue_type> dist_queue_type;
IndirectOwnerMap indirect_owner(owner);
dist_queue_type Q(pg, indirect_owner);
// Find sources to initialize queue
BGL_FORALL_VERTICES_T(v, g, Graph) {
if (get(is_settled, v) && !(get(outgoing, v).empty())) {
put(incoming_edge_count, v, 1);
Q.push(std::make_pair(v, 0)); // Push this vertex with no additional path count
}
}
// Set path counts for vertices in this bucket
while (!Q.empty()) {
queue_value_type t = Q.top(); Q.pop();
Vertex v = t.first;
PathCountType p = t.second;
put(path_count, v, get(path_count, v) + p);
put(incoming_edge_count, v, get(incoming_edge_count, v) - 1);
if (get(incoming_edge_count, v) == 0) {
IncomingType out = get(outgoing, v);
for (typename IncomingType::iterator iter = out.begin(); iter != out.end(); ++iter)
Q.push(std::make_pair(*iter, get(path_count, v)));
}
}
// Mark the vertices in this bucket settled
for (typename std::vector<Vertex>::iterator iter = deleted_vertices.begin();
iter != deleted_vertices.end(); ++iter)
put(is_settled, *iter, true);
// No need to clear path count map as it is never read/written remotely
// No need to clear outgoing map as it is re-alloced every bucket
#endif
// Go to the next bucket: the current bucket must already be empty.
++current_bucket;
} while (true);
// Delete all of the buckets.
for (typename std::vector<Bucket*>::iterator iter = buckets.begin();
iter != buckets.end(); ++iter) {
if (*iter) {
delete *iter;
*iter = 0;
}
}
}
template<typename Graph, typename DistanceMap, typename IncomingMap,
typename EdgeWeightMap, typename PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, typename IsSettledMap, typename VertexIndexMap
#endif
>
void
betweenness_centrality_delta_stepping_impl<
Graph, DistanceMap, IncomingMap, EdgeWeightMap, PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, IsSettledMap, VertexIndexMap
#endif
>::
relax(Vertex u, Vertex v, Dist x)
{
if (x <= get(distance, v)) {
// We're relaxing the edge to vertex v.
if (get(owner, v) == process_id(pg)) {
if (x < get(distance, v)) {
// Compute the new bucket index for v
BucketIndex new_index = static_cast<BucketIndex>(x / delta);
// Make sure there is enough room in the buckets data structure.
if (new_index >= buckets.size()) buckets.resize(new_index + 1, 0);
// Make sure that we have allocated the bucket itself.
if (!buckets[new_index]) buckets[new_index] = new Bucket;
if (get(distance, v) != (std::numeric_limits<Dist>::max)()
&& !vertex_was_deleted[get(local, v)]) {
// We're moving v from an old bucket into a new one. Compute
// the old index, then splice it in.
BucketIndex old_index
= static_cast<BucketIndex>(get(distance, v) / delta);
buckets[new_index]->splice(buckets[new_index]->end(),
*buckets[old_index],
position_in_bucket[get(local, v)]);
} else {
// We're inserting v into a bucket for the first time. Put it
// at the end.
buckets[new_index]->push_back(v);
}
// v is now at the last position in the new bucket
position_in_bucket[get(local, v)] = buckets[new_index]->end();
--position_in_bucket[get(local, v)];
// Update tentative distance information and incoming, path_count
if (u != v) put(incoming, v, IncomingType(1, u));
put(distance, v, x);
} // u != v covers initial source relaxation and self-loops
else if (x == get(distance, v) && u != v) {
// Add incoming edge if it's not already in the list
IncomingType in = get(incoming, v);
if (std::find(in.begin(), in.end(), u) == in.end()) {
in.push_back(u);
put(incoming, v, in);
}
}
} else {
// The vertex is remote: send a request to the vertex's owner
send(pg, get(owner, v), msg_relax,
std::make_pair(v, MessageValue::create(x, u)));
// Cache tentative distance information
cache(distance, v, x);
}
}
}
/************************************************************************/
/* Shortest Paths function object for betweenness centrality */
/************************************************************************/
template<typename WeightMap>
struct brandes_shortest_paths {
typedef typename property_traits<WeightMap>::value_type weight_type;
brandes_shortest_paths()
: weight(1), delta(0) { }
brandes_shortest_paths(weight_type delta)
: weight(1), delta(delta) { }
brandes_shortest_paths(WeightMap w)
: weight(w), delta(0) { }
brandes_shortest_paths(WeightMap w, weight_type delta)
: weight(w), delta(delta) { }
template<typename Graph, typename IncomingMap, typename DistanceMap,
typename PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, typename IsSettledMap, typename VertexIndexMap
#endif
>
void
operator()(Graph& g,
typename graph_traits<Graph>::vertex_descriptor s,
IncomingMap incoming,
DistanceMap distance,
PathCountMap path_count
#ifdef COMPUTE_PATH_COUNTS_INLINE
, IsSettledMap is_settled,
VertexIndexMap vertex_index
#endif
)
{
typedef typename property_traits<DistanceMap>::value_type
distance_type;
typedef std::plus<distance_type> Combine;
typedef std::less<distance_type> Compare;
// The "distance" map needs to act like one, retrieving the default
// value of infinity.
set_property_map_role(vertex_distance, distance);
// Only calculate delta the first time operator() is called
// This presumes g is the same every time, but so does the fact
// that we're reusing the weight map
if (delta == 0)
set_delta(g);
// TODO (NGE): Restructure the code so we don't have to construct
// impl every time?
betweenness_centrality_delta_stepping_impl<
Graph, DistanceMap, IncomingMap, WeightMap, PathCountMap
#ifdef COMPUTE_PATH_COUNTS_INLINE
, IsSettledMap, VertexIndexMap
#endif
>
impl(g, distance, incoming, weight, path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
is_settled, vertex_index,
#endif
delta);
impl.run(s);
}
private:
template <typename Graph>
void
set_delta(const Graph& g)
{
using boost::parallel::all_reduce;
using boost::parallel::maximum;
using std::max;
typedef typename graph_traits<Graph>::degree_size_type Degree;
typedef weight_type Dist;
// Compute the maximum edge weight and degree
Dist max_edge_weight = 0;
Degree max_degree = 0;
BGL_FORALL_VERTICES_T(u, g, Graph) {
max_degree = max BOOST_PREVENT_MACRO_SUBSTITUTION (max_degree, out_degree(u, g));
BGL_FORALL_OUTEDGES_T(u, e, g, Graph)
max_edge_weight = max BOOST_PREVENT_MACRO_SUBSTITUTION (max_edge_weight, get(weight, e));
}
max_edge_weight = all_reduce(process_group(g), max_edge_weight, maximum<Dist>());
max_degree = all_reduce(process_group(g), max_degree, maximum<Degree>());
// Take a guess at delta, based on what works well for random
// graphs.
delta = max_edge_weight / max_degree;
if (delta == 0)
delta = 1;
}
WeightMap weight;
weight_type delta;
};
// Perform a single SSSP from the specified vertex and update the centrality map(s)
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap, typename DependencyMap,
typename PathCountMap,
#ifdef COMPUTE_PATH_COUNTS_INLINE
typename IsSettledMap,
#endif
typename VertexIndexMap, typename ShortestPaths>
void
do_brandes_sssp(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
IsSettledMap is_settled,
#endif
VertexIndexMap vertex_index,
ShortestPaths shortest_paths,
typename graph_traits<Graph>::vertex_descriptor s)
{
using boost::detail::graph::update_centrality;
using boost::graph::parallel::process_group;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator;
typedef typename graph_traits<Graph>::edges_size_type edges_size_type;
typedef typename property_traits<IncomingMap>::value_type incoming_type;
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef typename property_traits<DependencyMap>::value_type dependency_type;
typedef typename property_traits<PathCountMap>::value_type path_count_type;
typedef typename incoming_type::iterator incoming_iterator;
typedef typename property_map<Graph, vertex_owner_t>::const_type OwnerMap;
OwnerMap owner = get(vertex_owner, g);
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
process_group_type pg = process_group(g);
typename process_group_type::process_id_type id = process_id(pg);
// TODO: Is it faster not to clear some of these maps?
// Initialize for this iteration
distance.clear();
incoming.clear();
path_count.clear();
dependency.clear();
BGL_FORALL_VERTICES_T(v, g, Graph) {
put(path_count, v, 0);
put(dependency, v, 0);
}
if (get(owner, s) == id) {
put(incoming, s, incoming_type());
#ifdef COMPUTE_PATH_COUNTS_INLINE
put(path_count, s, 1);
put(is_settled, s, true);
#endif
}
// Execute the shortest paths algorithm. This will be either
// a weighted or unweighted customized breadth-first search,
shortest_paths(g, s, incoming, distance, path_count
#ifdef COMPUTE_PATH_COUNTS_INLINE
, is_settled, vertex_index
#endif
);
#ifndef COMPUTE_PATH_COUNTS_INLINE
//
// TODO: Optimize case where source has no out-edges
//
// Count of incoming edges to tell when all incoming edges have been relaxed in
// the induced shortest paths DAG
std::vector<edges_size_type> incoming_edge_countS(num_vertices(g));
iterator_property_map<typename std::vector<edges_size_type>::iterator, VertexIndexMap>
incoming_edge_count(incoming_edge_countS.begin(), vertex_index);
BGL_FORALL_VERTICES_T(v, g, Graph) {
put(incoming_edge_count, v, get(incoming, v).size());
}
if (get(owner, s) == id) {
put(incoming_edge_count, s, 1);
put(incoming, s, incoming_type());
}
std::vector<incoming_type> outgoingS(num_vertices(g));
iterator_property_map<typename std::vector<incoming_type>::iterator, VertexIndexMap>
outgoing(outgoingS.begin(), vertex_index);
outgoing.set_reduce(append_reducer<incoming_type>());
// Mark forward adjacencies in DAG of shortest paths
// TODO: It's possible to do this using edge flags but it's not currently done this way
// because during traversal of the DAG we would have to examine all out edges
// which would lead to more memory accesses and a larger cache footprint.
//
// In the bidirectional graph case edge flags would be an excellent way of marking
// edges in the DAG of shortest paths
BGL_FORALL_VERTICES_T(v, g, Graph) {
incoming_type i = get(incoming, v);
for (typename incoming_type::iterator iter = i.begin(); iter != i.end(); ++iter) {
if (get(owner, *iter) == id) {
incoming_type x = get(outgoing, *iter);
if (std::find(x.begin(), x.end(), v) == x.end())
x.push_back(v);
put(outgoing, *iter, x);
} else {
incoming_type in;
in.push_back(v);
put(outgoing, *iter, in);
}
}
}
synchronize(pg);
// Traverse DAG induced by forward edges in dependency order and compute path counts
{
typedef std::pair<vertex_descriptor, path_count_type> queue_value_type;
typedef get_owner_of_first_pair_element<OwnerMap> IndirectOwnerMap;
typedef boost::queue<queue_value_type> local_queue_type;
typedef boost::graph::distributed::distributed_queue<process_group_type,
IndirectOwnerMap,
local_queue_type> dist_queue_type;
IndirectOwnerMap indirect_owner(owner);
dist_queue_type Q(pg, indirect_owner);
if (get(owner, s) == id)
Q.push(std::make_pair(s, 1));
while (!Q.empty()) {
queue_value_type t = Q.top(); Q.pop();
vertex_descriptor v = t.first;
path_count_type p = t.second;
put(path_count, v, get(path_count, v) + p);
put(incoming_edge_count, v, get(incoming_edge_count, v) - 1);
if (get(incoming_edge_count, v) == 0) {
incoming_type out = get(outgoing, v);
for (typename incoming_type::iterator iter = out.begin(); iter != out.end(); ++iter)
Q.push(std::make_pair(*iter, get(path_count, v)));
}
}
}
#endif // COMPUTE_PATH_COUNTS_INLINE
//
// Compute dependencies
//
// Build the distributed_queue
// Value type consists of 1) target of update 2) source of update
// 3) dependency of source 4) path count of source
typedef boost::tuple<vertex_descriptor, vertex_descriptor, dependency_type, path_count_type>
queue_value_type;
typedef get_owner_of_first_tuple_element<OwnerMap, queue_value_type> IndirectOwnerMap;
typedef boost::queue<queue_value_type> local_queue_type;
typedef boost::graph::distributed::distributed_queue<process_group_type,
IndirectOwnerMap,
local_queue_type> dist_queue_type;
IndirectOwnerMap indirect_owner(owner);
dist_queue_type Q(pg, indirect_owner);
// Calculate number of vertices each vertex depends on, when a vertex has been pushed
// that number of times then we will update it
// AND Request path counts of sources of incoming edges
std::vector<dependency_type> dependency_countS(num_vertices(g), 0);
iterator_property_map<typename std::vector<dependency_type>::iterator, VertexIndexMap>
dependency_count(dependency_countS.begin(), vertex_index);
dependency_count.set_reduce(boost::graph::distributed::additive_reducer<dependency_type>());
path_count.set_max_ghost_cells(0);
BGL_FORALL_VERTICES_T(v, g, Graph) {
if (get(distance, v) < (std::numeric_limits<distance_type>::max)()) {
incoming_type el = get(incoming, v);
for (incoming_iterator vw = el.begin(); vw != el.end(); ++vw) {
if (get(owner, *vw) == id)
put(dependency_count, *vw, get(dependency_count, *vw) + 1);
else {
put(dependency_count, *vw, 1);
// Request path counts
get(path_count, *vw);
}
// request() doesn't work here, perhaps because we don't have a copy of this
// ghost cell already?
}
}
}
synchronize(pg);
// Push vertices with non-zero distance/path count and zero dependency count
BGL_FORALL_VERTICES_T(v, g, Graph) {
if (get(distance, v) < (std::numeric_limits<distance_type>::max)()
&& get(dependency_count, v) == 0)
Q.push(boost::make_tuple(v, v, get(dependency, v), get(path_count, v)));
}
dependency.set_max_ghost_cells(0);
while(!Q.empty()) {
queue_value_type x = Q.top(); Q.pop();
vertex_descriptor w = boost::tuples::get<0>(x);
vertex_descriptor source = boost::tuples::get<1>(x);
dependency_type dep = boost::tuples::get<2>(x);
path_count_type pc = boost::tuples::get<3>(x);
cache(dependency, source, dep);
cache(path_count, source, pc);
if (get(dependency_count, w) != 0)
put(dependency_count, w, get(dependency_count, w) - 1);
if (get(dependency_count, w) == 0) {
// Update dependency and centrality of sources of incoming edges
incoming_type el = get(incoming, w);
for (incoming_iterator vw = el.begin(); vw != el.end(); ++vw) {
vertex_descriptor v = *vw;
BOOST_ASSERT(get(path_count, w) != 0);
dependency_type factor = dependency_type(get(path_count, v))
/ dependency_type(get(path_count, w));
factor *= (dependency_type(1) + get(dependency, w));
if (get(owner, v) == id)
put(dependency, v, get(dependency, v) + factor);
else
put(dependency, v, factor);
update_centrality(edge_centrality_map, v, factor);
}
if (w != s)
update_centrality(centrality, w, get(dependency, w));
// Push sources of edges in incoming edge list
for (incoming_iterator vw = el.begin(); vw != el.end(); ++vw)
Q.push(boost::make_tuple(*vw, w, get(dependency, w), get(path_count, w)));
}
}
}
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap, typename DependencyMap,
typename PathCountMap, typename VertexIndexMap, typename ShortestPaths,
typename Buffer>
void
brandes_betweenness_centrality_impl(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
ShortestPaths shortest_paths,
Buffer sources)
{
using boost::detail::graph::init_centrality_map;
using boost::detail::graph::divide_centrality_by_two;
using boost::graph::parallel::process_group;
typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator;
typedef typename graph_traits<Graph>::edge_iterator edge_iterator;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename graph_traits<Graph>::vertices_size_type vertices_size_type;
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef typename property_traits<DependencyMap>::value_type dependency_type;
// Initialize centrality
init_centrality_map(vertices(g), centrality);
init_centrality_map(edges(g), edge_centrality_map);
// Set the reduction operation on the dependency map to be addition
dependency.set_reduce(boost::graph::distributed::additive_reducer<dependency_type>());
distance.set_reduce(boost::graph::distributed::choose_min_reducer<distance_type>());
// Don't allow remote procs to write incoming or path_count maps
// updating them is handled inside the betweenness_centrality_queue
incoming.set_consistency_model(0);
path_count.set_consistency_model(0);
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
process_group_type pg = process_group(g);
#ifdef COMPUTE_PATH_COUNTS_INLINE
// Build is_settled maps
std::vector<bool> is_settledS(num_vertices(g));
typedef iterator_property_map<std::vector<bool>::iterator, VertexIndexMap>
IsSettledMap;
IsSettledMap is_settled(is_settledS.begin(), vertex_index);
#endif
if (!sources.empty()) {
// DO SSSPs
while (!sources.empty()) {
do_brandes_sssp(g, centrality, edge_centrality_map, incoming, distance,
dependency, path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
is_settled,
#endif
vertex_index, shortest_paths, sources.top());
sources.pop();
}
} else { // Exact Betweenness Centrality
typedef typename graph_traits<Graph>::vertices_size_type vertices_size_type;
vertices_size_type n = num_vertices(g);
n = boost::parallel::all_reduce(pg, n, std::plus<vertices_size_type>());
for (vertices_size_type i = 0; i < n; ++i) {
vertex_descriptor v = vertex(i, g);
do_brandes_sssp(g, centrality, edge_centrality_map, incoming, distance,
dependency, path_count,
#ifdef COMPUTE_PATH_COUNTS_INLINE
is_settled,
#endif
vertex_index, shortest_paths, v);
}
}
typedef typename graph_traits<Graph>::directed_category directed_category;
const bool is_undirected =
is_convertible<directed_category*, undirected_tag*>::value;
if (is_undirected) {
divide_centrality_by_two(vertices(g), centrality);
divide_centrality_by_two(edges(g), edge_centrality_map);
}
}
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap, typename DependencyMap,
typename PathCountMap, typename VertexIndexMap, typename ShortestPaths,
typename Stack>
void
do_sequential_brandes_sssp(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
ShortestPaths shortest_paths,
Stack& ordered_vertices,
typename graph_traits<Graph>::vertex_descriptor v)
{
using boost::detail::graph::update_centrality;
typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename property_traits<IncomingMap>::value_type incoming_type;
// Initialize for this iteration
BGL_FORALL_VERTICES_T(w, g, Graph) {
// put(path_count, w, 0);
incoming[w].clear();
put(dependency, w, 0);
}
put(path_count, v, 1);
incoming[v].clear();
// Execute the shortest paths algorithm. This will be either
// Dijkstra's algorithm or a customized breadth-first search,
// depending on whether the graph is weighted or unweighted.
shortest_paths(g, v, ordered_vertices, incoming, distance,
path_count, vertex_index);
while (!ordered_vertices.empty()) {
vertex_descriptor w = ordered_vertices.top();
ordered_vertices.pop();
typedef typename property_traits<IncomingMap>::value_type
incoming_type;
typedef typename incoming_type::iterator incoming_iterator;
typedef typename property_traits<DependencyMap>::value_type
dependency_type;
for (incoming_iterator vw = incoming[w].begin();
vw != incoming[w].end(); ++vw) {
vertex_descriptor v = source(*vw, g);
dependency_type factor = dependency_type(get(path_count, v))
/ dependency_type(get(path_count, w));
factor *= (dependency_type(1) + get(dependency, w));
put(dependency, v, get(dependency, v) + factor);
update_centrality(edge_centrality_map, *vw, factor);
}
if (w != v) {
update_centrality(centrality, w, get(dependency, w));
}
}
}
// Betweenness Centrality variant that duplicates graph across processors
// and parallizes SSSPs
// This function expects a non-distributed graph and property-maps
template<typename ProcessGroup, typename Graph,
typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap,
typename DependencyMap, typename PathCountMap,
typename VertexIndexMap, typename ShortestPaths,
typename Buffer>
void
non_distributed_brandes_betweenness_centrality_impl(const ProcessGroup& pg,
const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming, // P
DistanceMap distance, // d
DependencyMap dependency, // delta
PathCountMap path_count, // sigma
VertexIndexMap vertex_index,
ShortestPaths shortest_paths,
Buffer sources)
{
using boost::detail::graph::init_centrality_map;
using boost::detail::graph::divide_centrality_by_two;
using boost::graph::parallel::process_group;
typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator;
typedef typename graph_traits<Graph>::edge_iterator edge_iterator;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename graph_traits<Graph>::vertices_size_type vertices_size_type;
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef ProcessGroup process_group_type;
typename process_group_type::process_id_type id = process_id(pg);
typename process_group_type::process_size_type p = num_processes(pg);
// Initialize centrality
init_centrality_map(vertices(g), centrality);
init_centrality_map(edges(g), edge_centrality_map);
std::stack<vertex_descriptor> ordered_vertices;
if (!sources.empty()) {
std::vector<vertex_descriptor> local_sources;
for (int i = 0; i < id; ++i) if (!sources.empty()) sources.pop();
while (!sources.empty()) {
local_sources.push_back(sources.top());
for (int i = 0; i < p; ++i) if (!sources.empty()) sources.pop();
}
// DO SSSPs
for(size_t i = 0; i < local_sources.size(); ++i)
do_sequential_brandes_sssp(g, centrality, edge_centrality_map, incoming,
distance, dependency, path_count, vertex_index,
shortest_paths, ordered_vertices, local_sources[i]);
} else { // Exact Betweenness Centrality
typedef typename graph_traits<Graph>::vertices_size_type vertices_size_type;
vertices_size_type n = num_vertices(g);
for (vertices_size_type i = id; i < n; i += p) {
vertex_descriptor v = vertex(i, g);
do_sequential_brandes_sssp(g, centrality, edge_centrality_map, incoming,
distance, dependency, path_count, vertex_index,
shortest_paths, ordered_vertices, v);
}
}
typedef typename graph_traits<Graph>::directed_category directed_category;
const bool is_undirected =
is_convertible<directed_category*, undirected_tag*>::value;
if (is_undirected) {
divide_centrality_by_two(vertices(g), centrality);
divide_centrality_by_two(edges(g), edge_centrality_map);
}
// Merge the centrality maps by summing the values at each vertex)
// TODO(nge): this copy-out, reduce, copy-in is lame
typedef typename property_traits<CentralityMap>::value_type centrality_type;
typedef typename property_traits<EdgeCentralityMap>::value_type edge_centrality_type;
std::vector<centrality_type> centrality_v(num_vertices(g));
std::vector<edge_centrality_type> edge_centrality_v;
edge_centrality_v.reserve(num_edges(g));
BGL_FORALL_VERTICES_T(v, g, Graph) {
centrality_v[get(vertex_index, v)] = get(centrality, v);
}
// Skip when EdgeCentralityMap is a dummy_property_map
if (!is_same<EdgeCentralityMap, dummy_property_map>::value) {
BGL_FORALL_EDGES_T(e, g, Graph) {
edge_centrality_v.push_back(get(edge_centrality_map, e));
}
// NGE: If we trust that the order of elements in the vector isn't changed in the
// all_reduce below then this method avoids the need for an edge index map
}
using boost::parallel::all_reduce;
all_reduce(pg, &centrality_v[0], &centrality_v[centrality_v.size()],
&centrality_v[0], std::plus<centrality_type>());
if (edge_centrality_v.size())
all_reduce(pg, &edge_centrality_v[0], &edge_centrality_v[edge_centrality_v.size()],
&edge_centrality_v[0], std::plus<edge_centrality_type>());
BGL_FORALL_VERTICES_T(v, g, Graph) {
put(centrality, v, centrality_v[get(vertex_index, v)]);
}
// Skip when EdgeCentralityMap is a dummy_property_map
if (!is_same<EdgeCentralityMap, dummy_property_map>::value) {
int i = 0;
BGL_FORALL_EDGES_T(e, g, Graph) {
put(edge_centrality_map, e, edge_centrality_v[i]);
++i;
}
}
}
} } } // end namespace graph::parallel::detail
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap, typename DependencyMap,
typename PathCountMap, typename VertexIndexMap, typename Buffer>
void
brandes_betweenness_centrality(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
Buffer sources,
typename property_traits<DistanceMap>::value_type delta
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef static_property_map<distance_type> WeightMap;
graph::parallel::detail::brandes_shortest_paths<WeightMap>
shortest_paths(delta);
graph::parallel::detail::brandes_betweenness_centrality_impl(g, centrality,
edge_centrality_map,
incoming, distance,
dependency, path_count,
vertex_index,
shortest_paths,
sources);
}
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename IncomingMap, typename DistanceMap, typename DependencyMap,
typename PathCountMap, typename VertexIndexMap, typename WeightMap,
typename Buffer>
void
brandes_betweenness_centrality(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
Buffer sources,
typename property_traits<WeightMap>::value_type delta,
WeightMap weight_map
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
graph::parallel::detail::brandes_shortest_paths<WeightMap> shortest_paths(weight_map, delta);
graph::parallel::detail::brandes_betweenness_centrality_impl(g, centrality,
edge_centrality_map,
incoming, distance,
dependency, path_count,
vertex_index,
shortest_paths,
sources);
}
namespace graph { namespace parallel { namespace detail {
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename WeightMap, typename VertexIndexMap, typename Buffer>
void
brandes_betweenness_centrality_dispatch2(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
WeightMap weight_map,
VertexIndexMap vertex_index,
Buffer sources,
typename property_traits<WeightMap>::value_type delta)
{
typedef typename graph_traits<Graph>::degree_size_type degree_size_type;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename mpl::if_c<(is_same<CentralityMap,
dummy_property_map>::value),
EdgeCentralityMap,
CentralityMap>::type a_centrality_map;
typedef typename property_traits<a_centrality_map>::value_type
centrality_type;
typename graph_traits<Graph>::vertices_size_type V = num_vertices(g);
std::vector<std::vector<vertex_descriptor> > incoming(V);
std::vector<centrality_type> distance(V);
std::vector<centrality_type> dependency(V);
std::vector<degree_size_type> path_count(V);
brandes_betweenness_centrality(
g, centrality, edge_centrality_map,
make_iterator_property_map(incoming.begin(), vertex_index),
make_iterator_property_map(distance.begin(), vertex_index),
make_iterator_property_map(dependency.begin(), vertex_index),
make_iterator_property_map(path_count.begin(), vertex_index),
vertex_index, unwrap_ref(sources), delta,
weight_map);
}
// TODO: Should the type of the distance and dependency map depend on the
// value type of the centrality map?
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename VertexIndexMap, typename Buffer>
void
brandes_betweenness_centrality_dispatch2(const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
VertexIndexMap vertex_index,
Buffer sources,
typename graph_traits<Graph>::edges_size_type delta)
{
typedef typename graph_traits<Graph>::degree_size_type degree_size_type;
typedef typename graph_traits<Graph>::edges_size_type edges_size_type;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename mpl::if_c<(is_same<CentralityMap,
dummy_property_map>::value),
EdgeCentralityMap,
CentralityMap>::type a_centrality_map;
typename graph_traits<Graph>::vertices_size_type V = num_vertices(g);
std::vector<std::vector<vertex_descriptor> > incoming(V);
std::vector<edges_size_type> distance(V);
std::vector<edges_size_type> dependency(V);
std::vector<degree_size_type> path_count(V);
brandes_betweenness_centrality(
g, centrality, edge_centrality_map,
make_iterator_property_map(incoming.begin(), vertex_index),
make_iterator_property_map(distance.begin(), vertex_index),
make_iterator_property_map(dependency.begin(), vertex_index),
make_iterator_property_map(path_count.begin(), vertex_index),
vertex_index, unwrap_ref(sources), delta);
}
template<typename WeightMap>
struct brandes_betweenness_centrality_dispatch1
{
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename VertexIndexMap, typename Buffer>
static void
run(const Graph& g, CentralityMap centrality, EdgeCentralityMap edge_centrality_map,
VertexIndexMap vertex_index, Buffer sources,
typename property_traits<WeightMap>::value_type delta, WeightMap weight_map)
{
boost::graph::parallel::detail::brandes_betweenness_centrality_dispatch2(
g, centrality, edge_centrality_map, weight_map, vertex_index, sources, delta);
}
};
template<>
struct brandes_betweenness_centrality_dispatch1<boost::detail::error_property_not_found>
{
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap,
typename VertexIndexMap, typename Buffer>
static void
run(const Graph& g, CentralityMap centrality, EdgeCentralityMap edge_centrality_map,
VertexIndexMap vertex_index, Buffer sources,
typename graph_traits<Graph>::edges_size_type delta,
boost::detail::error_property_not_found)
{
boost::graph::parallel::detail::brandes_betweenness_centrality_dispatch2(
g, centrality, edge_centrality_map, vertex_index, sources, delta);
}
};
} } } // end namespace graph::parallel::detail
template<typename Graph, typename Param, typename Tag, typename Rest>
void
brandes_betweenness_centrality(const Graph& g,
const bgl_named_params<Param,Tag,Rest>& params
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
typedef bgl_named_params<Param,Tag,Rest> named_params;
typedef queue<typename graph_traits<Graph>::vertex_descriptor> queue_t;
queue_t q;
typedef typename property_value<named_params, edge_weight_t>::type ew;
graph::parallel::detail::brandes_betweenness_centrality_dispatch1<ew>::run(
g,
choose_param(get_param(params, vertex_centrality),
dummy_property_map()),
choose_param(get_param(params, edge_centrality),
dummy_property_map()),
choose_const_pmap(get_param(params, vertex_index), g, vertex_index),
choose_param(get_param(params, buffer_param_t()), boost::ref(q)),
choose_param(get_param(params, lookahead_t()), 0),
get_param(params, edge_weight));
}
template<typename Graph, typename CentralityMap>
void
brandes_betweenness_centrality(const Graph& g, CentralityMap centrality
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
typedef queue<typename graph_traits<Graph>::vertex_descriptor> queue_t;
queue_t q;
boost::graph::parallel::detail::brandes_betweenness_centrality_dispatch2(
g, centrality, dummy_property_map(), get(vertex_index, g), boost::ref(q), 0);
}
template<typename Graph, typename CentralityMap, typename EdgeCentralityMap>
void
brandes_betweenness_centrality(const Graph& g, CentralityMap centrality,
EdgeCentralityMap edge_centrality_map
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
typedef queue<int> queue_t;
queue_t q;
boost::graph::parallel::detail::brandes_betweenness_centrality_dispatch2(
g, centrality, edge_centrality_map, get(vertex_index, g), boost::ref(q), 0);
}
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename IncomingMap, typename DistanceMap,
typename DependencyMap, typename PathCountMap, typename VertexIndexMap,
typename Buffer>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg,
const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
Buffer sources)
{
typedef typename property_traits<DistanceMap>::value_type distance_type;
typedef static_property_map<distance_type> WeightMap;
detail::graph::brandes_unweighted_shortest_paths shortest_paths;
graph::parallel::detail::non_distributed_brandes_betweenness_centrality_impl(pg, g, centrality,
edge_centrality_map,
incoming, distance,
dependency, path_count,
vertex_index,
shortest_paths,
sources);
}
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename IncomingMap, typename DistanceMap,
typename DependencyMap, typename PathCountMap, typename VertexIndexMap,
typename WeightMap, typename Buffer>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg,
const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
IncomingMap incoming,
DistanceMap distance,
DependencyMap dependency,
PathCountMap path_count,
VertexIndexMap vertex_index,
WeightMap weight_map,
Buffer sources)
{
detail::graph::brandes_dijkstra_shortest_paths<WeightMap> shortest_paths(weight_map);
graph::parallel::detail::non_distributed_brandes_betweenness_centrality_impl(pg, g, centrality,
edge_centrality_map,
incoming, distance,
dependency, path_count,
vertex_index,
shortest_paths,
sources);
}
namespace detail { namespace graph {
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename WeightMap, typename VertexIndexMap,
typename Buffer>
void
non_distributed_brandes_betweenness_centrality_dispatch2(const ProcessGroup& pg,
const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
WeightMap weight_map,
VertexIndexMap vertex_index,
Buffer sources)
{
typedef typename graph_traits<Graph>::degree_size_type degree_size_type;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename graph_traits<Graph>::edge_descriptor edge_descriptor;
typedef typename mpl::if_c<(is_same<CentralityMap,
dummy_property_map>::value),
EdgeCentralityMap,
CentralityMap>::type a_centrality_map;
typedef typename property_traits<a_centrality_map>::value_type
centrality_type;
typename graph_traits<Graph>::vertices_size_type V = num_vertices(g);
std::vector<std::vector<edge_descriptor> > incoming(V);
std::vector<centrality_type> distance(V);
std::vector<centrality_type> dependency(V);
std::vector<degree_size_type> path_count(V);
non_distributed_brandes_betweenness_centrality(
pg, g, centrality, edge_centrality_map,
make_iterator_property_map(incoming.begin(), vertex_index),
make_iterator_property_map(distance.begin(), vertex_index),
make_iterator_property_map(dependency.begin(), vertex_index),
make_iterator_property_map(path_count.begin(), vertex_index),
vertex_index, weight_map, unwrap_ref(sources));
}
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename VertexIndexMap, typename Buffer>
void
non_distributed_brandes_betweenness_centrality_dispatch2(const ProcessGroup& pg,
const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
VertexIndexMap vertex_index,
Buffer sources)
{
typedef typename graph_traits<Graph>::degree_size_type degree_size_type;
typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;
typedef typename graph_traits<Graph>::edge_descriptor edge_descriptor;
typedef typename mpl::if_c<(is_same<CentralityMap,
dummy_property_map>::value),
EdgeCentralityMap,
CentralityMap>::type a_centrality_map;
typedef typename property_traits<a_centrality_map>::value_type
centrality_type;
typename graph_traits<Graph>::vertices_size_type V = num_vertices(g);
std::vector<std::vector<edge_descriptor> > incoming(V);
std::vector<centrality_type> distance(V);
std::vector<centrality_type> dependency(V);
std::vector<degree_size_type> path_count(V);
non_distributed_brandes_betweenness_centrality(
pg, g, centrality, edge_centrality_map,
make_iterator_property_map(incoming.begin(), vertex_index),
make_iterator_property_map(distance.begin(), vertex_index),
make_iterator_property_map(dependency.begin(), vertex_index),
make_iterator_property_map(path_count.begin(), vertex_index),
vertex_index, unwrap_ref(sources));
}
template<typename WeightMap>
struct non_distributed_brandes_betweenness_centrality_dispatch1
{
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename VertexIndexMap, typename Buffer>
static void
run(const ProcessGroup& pg, const Graph& g, CentralityMap centrality,
EdgeCentralityMap edge_centrality_map, VertexIndexMap vertex_index,
Buffer sources, WeightMap weight_map)
{
non_distributed_brandes_betweenness_centrality_dispatch2(pg, g, centrality, edge_centrality_map,
weight_map, vertex_index, sources);
}
};
template<>
struct non_distributed_brandes_betweenness_centrality_dispatch1<detail::error_property_not_found>
{
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename VertexIndexMap, typename Buffer>
static void
run(const ProcessGroup& pg, const Graph& g, CentralityMap centrality,
EdgeCentralityMap edge_centrality_map, VertexIndexMap vertex_index,
Buffer sources, detail::error_property_not_found)
{
non_distributed_brandes_betweenness_centrality_dispatch2(pg, g, centrality, edge_centrality_map,
vertex_index, sources);
}
};
} } // end namespace detail::graph
template<typename ProcessGroup, typename Graph, typename Param, typename Tag, typename Rest>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg, const Graph& g,
const bgl_named_params<Param,Tag,Rest>& params)
{
typedef bgl_named_params<Param,Tag,Rest> named_params;
typedef queue<int> queue_t;
queue_t q;
typedef typename property_value<named_params, edge_weight_t>::type ew;
detail::graph::non_distributed_brandes_betweenness_centrality_dispatch1<ew>::run(
pg, g,
choose_param(get_param(params, vertex_centrality),
dummy_property_map()),
choose_param(get_param(params, edge_centrality),
dummy_property_map()),
choose_const_pmap(get_param(params, vertex_index), g, vertex_index),
choose_param(get_param(params, buffer_param_t()), boost::ref(q)),
get_param(params, edge_weight));
}
template<typename ProcessGroup, typename Graph, typename CentralityMap>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg, const Graph& g,
CentralityMap centrality)
{
typedef queue<int> queue_t;
queue_t q;
detail::graph::non_distributed_brandes_betweenness_centrality_dispatch2(
pg, g, centrality, dummy_property_map(), get(vertex_index, g), boost::ref(q));
}
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename Buffer>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg, const Graph& g,
CentralityMap centrality, Buffer sources)
{
detail::graph::non_distributed_brandes_betweenness_centrality_dispatch2(
pg, g, centrality, dummy_property_map(), get(vertex_index, g), sources);
}
template<typename ProcessGroup, typename Graph, typename CentralityMap,
typename EdgeCentralityMap, typename Buffer>
void
non_distributed_brandes_betweenness_centrality(const ProcessGroup& pg, const Graph& g,
CentralityMap centrality,
EdgeCentralityMap edge_centrality_map,
Buffer sources)
{
detail::graph::non_distributed_brandes_betweenness_centrality_dispatch2(
pg, g, centrality, edge_centrality_map, get(vertex_index, g), sources);
}
// Compute the central point dominance of a graph.
// TODO: Make sure central point dominance works in parallel case
template<typename Graph, typename CentralityMap>
typename property_traits<CentralityMap>::value_type
central_point_dominance(const Graph& g, CentralityMap centrality
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph,distributed_graph_tag))
{
using std::max;
typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator;
typedef typename property_traits<CentralityMap>::value_type centrality_type;
typedef typename graph_traits<Graph>::vertices_size_type vertices_size_type;
typedef typename boost::graph::parallel::process_group_type<Graph>::type
process_group_type;
process_group_type pg = boost::graph::parallel::process_group(g);
vertices_size_type n = num_vertices(g);
using boost::parallel::all_reduce;
n = all_reduce(pg, n, std::plus<vertices_size_type>());
// Find max centrality
centrality_type max_centrality(0);
vertex_iterator v, v_end;
for (boost::tie(v, v_end) = vertices(g); v != v_end; ++v) {
max_centrality = (max)(max_centrality, get(centrality, *v));
}
// All reduce to get global max centrality
max_centrality = all_reduce(pg, max_centrality, boost::parallel::maximum<centrality_type>());
// Compute central point dominance
centrality_type sum(0);
for (boost::tie(v, v_end) = vertices(g); v != v_end; ++v) {
sum += (max_centrality - get(centrality, *v));
}
sum = all_reduce(pg, sum, std::plus<centrality_type>());
return sum/(n-1);
}
} // end namespace boost
#endif // BOOST_GRAPH_PARALLEL_BRANDES_BETWEENNESS_CENTRALITY_HPP