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Restructure the construction of the undirected graph

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This commit is contained in:
Patrick Niklaus 2015-06-29 00:42:22 +02:00
parent 4a7451682b
commit 021a1c7a39
7 changed files with 169 additions and 230 deletions
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5
algorithms/graph_compressor.cpp
View File

@ -6,6 +6,8 @@
#include "../data_structures/restriction_map.hpp"
#include "../data_structures/percent.hpp"
#include "../util/simple_logger.hpp"
GraphCompressor::GraphCompressor(const SpeedProfileProperties& speed_profile)
: speed_profile(speed_profile)
{
@ -59,8 +61,7 @@ void GraphCompressor::Compress(const std::unordered_set<NodeID>& barrier_nodes,
//
// If the edges are compatible.
const bool reverse_edge_order =
!(graph.GetEdgeData(graph.BeginEdges(node_v)).forward);
const bool reverse_edge_order = graph.GetEdgeData(graph.BeginEdges(node_v)).reversed;
const EdgeID forward_e2 = graph.BeginEdges(node_v) + reverse_edge_order;
BOOST_ASSERT(SPECIAL_EDGEID != forward_e2);
BOOST_ASSERT(forward_e2 >= graph.BeginEdges(node_v) &&

20
contractor/edge_based_graph_factory.cpp
View File

@ -180,20 +180,20 @@ void EdgeBasedGraphFactory::InsertEdgeBasedNode(const NodeID node_u,
if (forward_data.edge_id != SPECIAL_NODEID)
{
BOOST_ASSERT(forward_data.forward);
BOOST_ASSERT(!forward_data.reversed);
}
else
{
BOOST_ASSERT(!forward_data.forward);
BOOST_ASSERT(forward_data.reversed);
}
if (reverse_data.edge_id != SPECIAL_NODEID)
{
BOOST_ASSERT(reverse_data.forward);
BOOST_ASSERT(!reverse_data.reversed);
}
else
{
BOOST_ASSERT(!reverse_data.forward);
BOOST_ASSERT(reverse_data.reversed);
}
BOOST_ASSERT(forward_data.edge_id != SPECIAL_NODEID ||
@ -253,8 +253,8 @@ void EdgeBasedGraphFactory::RenumberEdges()
{
EdgeData &edge_data = m_node_based_graph->GetEdgeData(current_edge);
// this edge is an incoming edge
if (!edge_data.forward)
// only number incoming edges
if (edge_data.reversed)
{
continue;
}
@ -379,7 +379,7 @@ void EdgeBasedGraphFactory::GenerateEdgeExpandedEdges(
progress.printStatus(node_u);
for (const EdgeID e1 : m_node_based_graph->GetAdjacentEdgeRange(node_u))
{
if (!m_node_based_graph->GetEdgeData(e1).forward)
if (m_node_based_graph->GetEdgeData(e1).reversed)
{
continue;
}
@ -392,7 +392,7 @@ void EdgeBasedGraphFactory::GenerateEdgeExpandedEdges(
for (const EdgeID e2 : m_node_based_graph->GetAdjacentEdgeRange(node_v))
{
if (!m_node_based_graph->GetEdgeData(e2).forward)
if (m_node_based_graph->GetEdgeData(e2).reversed)
{
continue;
}
@ -439,8 +439,8 @@ void EdgeBasedGraphFactory::GenerateEdgeExpandedEdges(
const EdgeData &edge_data2 = m_node_based_graph->GetEdgeData(e2);
BOOST_ASSERT(edge_data1.edge_id != edge_data2.edge_id);
BOOST_ASSERT(edge_data1.forward);
BOOST_ASSERT(edge_data2.forward);
BOOST_ASSERT(!edge_data1.reversed);
BOOST_ASSERT(!edge_data2.reversed);
// the following is the core of the loop.
unsigned distance = edge_data1.distance;

2
contractor/processing_chain.cpp
View File

@ -355,7 +355,7 @@ Prepare::LoadNodeBasedGraph(std::unordered_set<NodeID> &barrier_nodes,
return std::shared_ptr<NodeBasedDynamicGraph>();
}
return NodeBasedDynamicGraphFromImportEdges(number_of_node_based_nodes, edge_list);
return NodeBasedDynamicGraphFromEdges(number_of_node_based_nodes, edge_list);
}

2
data_structures/dynamic_graph.hpp
View File

@ -138,7 +138,7 @@ template <typename EdgeDataT> class DynamicGraph
unsigned degree = 0;
for (const auto edge : osrm::irange(BeginEdges(n), EndEdges(n)))
{
if (GetEdgeData(edge).forward)
if (!GetEdgeData(edge).reversed)
{
++degree;
}

183
data_structures/node_based_graph.hpp
View File

@ -30,7 +30,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "dynamic_graph.hpp"
#include "import_edge.hpp"
#include "../util/simple_logger.hpp"
#include "../util/graph_utils.hpp"
#include <tbb/parallel_sort.h>
@ -41,16 +41,16 @@ struct NodeBasedEdgeData
NodeBasedEdgeData()
: distance(INVALID_EDGE_WEIGHT), edge_id(SPECIAL_NODEID),
name_id(std::numeric_limits<unsigned>::max()), access_restricted(false),
forward(false), backward(false), roundabout(false), travel_mode(TRAVEL_MODE_INACCESSIBLE)
reversed(false), roundabout(false), travel_mode(TRAVEL_MODE_INACCESSIBLE)
{
}
NodeBasedEdgeData(int distance, unsigned edge_id, unsigned name_id,
bool access_restricted, bool forward, bool backward,
bool access_restricted, bool reversed,
bool roundabout, TravelMode travel_mode)
: distance(distance), edge_id(edge_id),
name_id(name_id), access_restricted(access_restricted),
forward(forward), backward(backward), roundabout(roundabout), travel_mode(travel_mode)
: distance(distance), edge_id(edge_id), name_id(name_id),
access_restricted(access_restricted), reversed(reversed),
roundabout(roundabout), travel_mode(travel_mode)
{
}
@ -58,180 +58,43 @@ struct NodeBasedEdgeData
unsigned edge_id;
unsigned name_id;
bool access_restricted : 1;
bool forward : 1;
bool backward : 1;
bool reversed : 1;
bool roundabout : 1;
TravelMode travel_mode : 4;
void SwapDirectionFlags()
{
bool temp_flag = forward;
forward = backward;
backward = temp_flag;
}
bool IsCompatibleTo(const NodeBasedEdgeData &other) const
{
return (forward == other.forward) && (backward == other.backward) &&
(name_id == other.name_id) && (travel_mode == other.travel_mode);
return (reversed == other.reversed) && (name_id == other.name_id) &&
(travel_mode == other.travel_mode);
}
};
using NodeBasedDynamicGraph = DynamicGraph<NodeBasedEdgeData>;
inline bool validateNeighborHood(const NodeBasedDynamicGraph& graph, const NodeID source)
{
for (auto edge = graph.BeginEdges(source); edge < graph.EndEdges(source); ++edge)
{
const auto& data = graph.GetEdgeData(edge);
if (!data.forward && !data.backward)
{
SimpleLogger().Write(logWARNING) << "Invalid edge directions";
return false;
}
auto target = graph.GetTarget(edge);
if (target == SPECIAL_NODEID)
{
SimpleLogger().Write(logWARNING) << "Invalid edge target";
return false;
}
bool found_reverse = false;
for (auto rev_edge = graph.BeginEdges(target); rev_edge < graph.EndEdges(target); ++rev_edge)
{
auto rev_target = graph.GetTarget(rev_edge);
if (rev_target == SPECIAL_NODEID)
{
SimpleLogger().Write(logWARNING) << "Invalid reverse edge target";
return false;
}
if (rev_target != source)
{
continue;
}
if (found_reverse)
{
SimpleLogger().Write(logWARNING) << "Found more than one reverse edge";
return false;
}
const auto& rev_data = graph.GetEdgeData(rev_edge);
// edge is incoming, this must be an outgoing edge
if (data.backward && !rev_data.forward)
{
SimpleLogger().Write(logWARNING) << "Found no outgoing edge to an incoming edge!";
return false;
}
// edge is bi-directional, reverse must be as well
if (data.forward && data.backward && (!rev_data.forward || !rev_data.backward))
{
SimpleLogger().Write(logWARNING) << "Found bi-directional edge that is not bi-directional to both ends";
return false;
}
found_reverse = true;
}
if (!found_reverse)
{
SimpleLogger().Write(logWARNING) << "Could not find reverse edge";
return false;
}
}
return true;
}
// This function checks if the overal graph is undirected (has an edge in each direction).
inline bool validateNodeBasedGraph(const NodeBasedDynamicGraph& graph)
{
for (auto source = 0u; source < graph.GetNumberOfNodes(); ++source)
{
if (!validateNeighborHood(graph, source))
{
return false;
}
}
return true;
}
// Factory method to create NodeBasedDynamicGraph from NodeBasedEdges
// The since DynamicGraph expects directed edges, we need to insert
// two edges for undirected edges.
/// Factory method to create NodeBasedDynamicGraph from NodeBasedEdges
/// The since DynamicGraph expects directed edges, we need to insert
/// two edges for undirected edges.
inline std::shared_ptr<NodeBasedDynamicGraph>
NodeBasedDynamicGraphFromImportEdges(int number_of_nodes, std::vector<NodeBasedEdge> &input_edge_list)
NodeBasedDynamicGraphFromEdges(int number_of_nodes, const std::vector<NodeBasedEdge> &input_edge_list)
{
static_assert(sizeof(NodeBasedEdgeData) == 16,
"changing node based edge data size changes memory consumption");
DeallocatingVector<NodeBasedDynamicGraph::InputEdge> edges_list;
NodeBasedDynamicGraph::InputEdge edge;
// Since DynamicGraph assumes directed edges we have to make sure we transformed
// the compressed edge format into single directed edges. We do this to make sure
// every node also knows its incoming edges, not only its outgoing edges and use the backward=true
// flag to indicate which is which.
//
// We do the transformation in the following way:
//
// if the edge (a, b) is split:
// 1. this edge must be in only one direction, so its a --> b
// 2. there must be another directed edge b --> a somewhere in the data
// if the edge (a, b) is not split:
// 1. this edge be on of a --> b od a <-> b
// (a <-- b gets reducted to b --> a)
// 2. a --> b will be transformed to a --> b and b <-- a
// 3. a <-> b will be transformed to a <-> b and b <-> a (I think a --> b and b <-- a would work as well though)
for (const NodeBasedEdge &import_edge : input_edge_list)
{
// edges that are not forward get converted by flipping the end points
BOOST_ASSERT(import_edge.forward);
if (import_edge.forward)
auto edges_list = directedEdgesFromCompressed<NodeBasedDynamicGraph::InputEdge>(input_edge_list,
[](NodeBasedDynamicGraph::InputEdge& output_edge, const NodeBasedEdge& input_edge)
{
edge.source = import_edge.source;
edge.target = import_edge.target;
edge.data.forward = import_edge.forward;
edge.data.backward = import_edge.backward;
output_edge.data.distance = static_cast<int>(input_edge.weight);
BOOST_ASSERT(output_edge.data.distance > 0);
output_edge.data.roundabout = input_edge.roundabout;
output_edge.data.name_id = input_edge.name_id;
output_edge.data.access_restricted = input_edge.access_restricted;
output_edge.data.travel_mode = input_edge.travel_mode;
}
BOOST_ASSERT(edge.source != edge.target);
edge.data.distance = static_cast<int>(import_edge.weight);
BOOST_ASSERT(edge.data.distance > 0);
edge.data.roundabout = import_edge.roundabout;
edge.data.name_id = import_edge.name_id;
edge.data.access_restricted = import_edge.access_restricted;
edge.data.travel_mode = import_edge.travel_mode;
edges_list.push_back(edge);
if (!import_edge.is_split)
{
using std::swap; // enable ADL
swap(edge.source, edge.target);
edge.data.SwapDirectionFlags();
edges_list.push_back(edge);
}
}
);
tbb::parallel_sort(edges_list.begin(), edges_list.end());
auto graph = std::make_shared<NodeBasedDynamicGraph>(
static_cast<NodeBasedDynamicGraph::NodeIterator>(number_of_nodes), edges_list);
#ifndef NDEBUG
BOOST_ASSERT(validateNodeBasedGraph(*graph));
#endif
return graph;
}

93
unit_tests/algorithms/graph_compressor.cpp
View File

@ -12,25 +12,6 @@
BOOST_AUTO_TEST_SUITE(graph_compressor)
void dumpGraph(const NodeBasedDynamicGraph& graph)
{
for (auto i = 0u; i < graph.GetNumberOfNodes(); ++i)
{
std::cout << "## node " << i << " degree: " << graph.GetOutDegree(i) << std::endl;
for (auto e = graph.BeginEdges(i); e < graph.EndEdges(i); ++e)
{
const auto& data = graph.GetEdgeData(e);
auto target = graph.GetTarget(e);
if (data.forward && !data.backward)
std::cout << i << "->" << target << std::endl;
if (!data.forward && data.backward)
std::cout << i << "<-" << target << std::endl;
if (data.forward && data.backward)
std::cout << i << "--" << target << std::endl;
}
}
}
BOOST_AUTO_TEST_CASE(long_road_test)
{
//
@ -46,15 +27,15 @@ BOOST_AUTO_TEST_CASE(long_road_test)
using InputEdge = NodeBasedDynamicGraph::InputEdge;
std::vector<InputEdge> edges = {
// source, target, distance, edge_id, name_id, access_restricted, forward, backward, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 3, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{3, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{3, 4, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{4, 3, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT}
// source, target, distance, edge_id, name_id, access_restricted, reversed, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 3, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{3, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{3, 4, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{4, 3, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT}
};
BOOST_ASSERT(edges[0].data.IsCompatibleTo(edges[2].data));
@ -89,18 +70,18 @@ BOOST_AUTO_TEST_CASE(loop_test)
using InputEdge = NodeBasedDynamicGraph::InputEdge;
std::vector<InputEdge> edges = {
// source, target, distance, edge_id, name_id, access_restricted, forward, backward, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{0, 5, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 3, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{3, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{3, 4, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{4, 3, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{4, 5, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{5, 0, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{5, 4, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{0, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{0, 5, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 3, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{3, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{3, 4, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{4, 3, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{4, 5, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{5, 0, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{5, 4, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
};
BOOST_ASSERT(edges.size() == 12);
@ -145,13 +126,13 @@ BOOST_AUTO_TEST_CASE(t_intersection)
using InputEdge = NodeBasedDynamicGraph::InputEdge;
std::vector<InputEdge> edges = {
// source, target, distance, edge_id, name_id, access_restricted, forward, backward, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 3, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{3, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
// source, target, distance, edge_id, name_id, access_restricted, reversed, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 3, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{3, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
};
BOOST_ASSERT(edges[0].data.IsCompatibleTo(edges[1].data));
@ -184,10 +165,10 @@ BOOST_AUTO_TEST_CASE(street_name_changes)
using InputEdge = NodeBasedDynamicGraph::InputEdge;
std::vector<InputEdge> edges = {
// source, target, distance, edge_id, name_id, access_restricted, forward, backward, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 1, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 1, false, true, true, false, TRAVEL_MODE_DEFAULT},
{0, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 1, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 1, false, false, false, TRAVEL_MODE_DEFAULT},
};
BOOST_ASSERT(edges[0].data.IsCompatibleTo(edges[1].data));
@ -215,11 +196,11 @@ BOOST_AUTO_TEST_CASE(direction_changes)
using InputEdge = NodeBasedDynamicGraph::InputEdge;
std::vector<InputEdge> edges = {
// source, target, distance, edge_id, name_id, access_restricted, forward, backward, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, true, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, false, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, true, true, false, TRAVEL_MODE_DEFAULT},
// source, target, distance, edge_id, name_id, access_restricted, reverse, roundabout, travel_mode
{0, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{1, 0, 1, SPECIAL_EDGEID, 0, false, true, false, TRAVEL_MODE_DEFAULT},
{1, 2, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
{2, 1, 1, SPECIAL_EDGEID, 0, false, false, false, TRAVEL_MODE_DEFAULT},
};
NodeBasedDynamicGraph graph(5, edges);

94
util/graph_utils.hpp Normal file
View File

@ -0,0 +1,94 @@
#ifndef GRAPH_UTILS_HPP
#define GRAPH_UTILS_HPP
#include "../typedefs.h"
#include <boost/assert.hpp>
#include <vector>
/// This function checks if the graph (consisting of directed edges) is undirected
template<typename GraphT>
bool isUndirectedGraph(const GraphT& graph)
{
for (auto source = 0u; source < graph.GetNumberOfNodes(); ++source)
{
for (auto edge = graph.BeginEdges(source); edge < graph.EndEdges(source); ++edge)
{
const auto& data = graph.GetEdgeData(edge);
auto target = graph.GetTarget(edge);
BOOST_ASSERT(target != SPECIAL_NODEID);
bool found_reverse = false;
for (auto rev_edge = graph.BeginEdges(target); rev_edge < graph.EndEdges(target); ++rev_edge)
{
auto rev_target = graph.GetTarget(rev_edge);
BOOST_ASSERT(rev_target != SPECIAL_NODEID);
if (rev_target != source)
{
continue;
}
BOOST_ASSERT_MSG(!found_reverse, "Found more than one reverse edge");
found_reverse = true;
}
if (!found_reverse)
{
return false;
}
}
}
return true;
}
/// Since DynamicGraph assumes directed edges we have to make sure we transformed
/// the compressed edge format into single directed edges. We do this to make sure
/// every node also knows its incoming edges, not only its outgoing edges and use the reversed=true
/// flag to indicate which is which.
///
/// We do the transformation in the following way:
///
/// if the edge (a, b) is split:
/// 1. this edge must be in only one direction, so its a --> b
/// 2. there must be another directed edge b --> a somewhere in the data
/// if the edge (a, b) is not split:
/// 1. this edge be on of a --> b od a <-> b
/// (a <-- b gets reducted to b --> a)
/// 2. a --> b will be transformed to a --> b and b <-- a
/// 3. a <-> b will be transformed to a --> b and b --> a
template<typename OutputEdgeT, typename InputEdgeT, typename FunctorT>
std::vector<OutputEdgeT> directedEdgesFromCompressed(const std::vector<InputEdgeT>& input_edge_list, FunctorT copy_data)
{
std::vector<OutputEdgeT> output_edge_list;
OutputEdgeT edge;
for (const auto& input_edge : input_edge_list)
{
// edges that are not forward get converted by flipping the end points
BOOST_ASSERT(input_edge.forward);
edge.source = input_edge.source;
edge.target = input_edge.target;
edge.data.reversed = false;
BOOST_ASSERT(edge.source != edge.target);
copy_data(edge, input_edge);
output_edge_list.push_back(edge);
if (!input_edge.is_split)
{
std::swap(edge.source, edge.target);
edge.data.reversed = !input_edge.backward;
output_edge_list.push_back(edge);
}
}
return output_edge_list;
}
#endif