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refactor graph contraction: flush moved into dedicated function

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Moritz Kobitzsch 2017-01-05 10:21:01 +01:00 committed by Patrick Niklaus
parent 559c88b36d
commit f6fef5c166
1 changed files with 81 additions and 93 deletions
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174
include/contractor/graph_contractor.hpp
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@ -254,6 +254,85 @@ class GraphContractor
util::Log() << "contractor finished initalization";
}
/* Flush all data from the contraction to disc and reorder stuff for better locality */
void FlushDataAndRebuildContractorGraph(ThreadDataContainer &thread_data_list,
std::vector<RemainingNodeData> &remaining_nodes,
std::vector<float> &node_priorities)
{
util::DeallocatingVector<ContractorEdge> new_edge_set; // this one is not explicitely
// cleared since it goes out of
// scope anywa
// Delete old heap data to free memory that we need for the coming operations
thread_data_list.data.clear();
// Create new priority array
std::vector<float> new_node_priority(remaining_nodes.size());
std::vector<EdgeWeight> new_node_weights(remaining_nodes.size());
// this map gives the old IDs from the new ones, necessary to get a consistent graph
// at the end of contraction
orig_node_id_from_new_node_id_map.resize(remaining_nodes.size());
// this map gives the new IDs from the old ones, necessary to remap targets from the
// remaining graph
const auto number_of_nodes = contractor_graph->GetNumberOfNodes();
std::vector<NodeID> new_node_id_from_orig_id_map(number_of_nodes, SPECIAL_NODEID);
for (const auto new_node_id : util::irange<std::size_t>(0UL, remaining_nodes.size()))
{
auto &node = remaining_nodes[new_node_id];
BOOST_ASSERT(node_priorities.size() > node.id);
new_node_priority[new_node_id] = node_priorities[node.id];
BOOST_ASSERT(node_weights.size() > node.id);
new_node_weights[new_node_id] = node_weights[node.id];
}
// build forward and backward renumbering map and remap ids in remaining_nodes
for (const auto new_node_id : util::irange<std::size_t>(0UL, remaining_nodes.size()))
{
auto &node = remaining_nodes[new_node_id];
// create renumbering maps in both directions
orig_node_id_from_new_node_id_map[new_node_id] = node.id;
new_node_id_from_orig_id_map[node.id] = new_node_id;
node.id = new_node_id;
}
// walk over all nodes
for (const auto source : util::irange<NodeID>(0UL, contractor_graph->GetNumberOfNodes()))
{
for (auto current_edge : contractor_graph->GetAdjacentEdgeRange(source))
{
ContractorGraph::EdgeData &data = contractor_graph->GetEdgeData(current_edge);
const NodeID target = contractor_graph->GetTarget(current_edge);
if (SPECIAL_NODEID == new_node_id_from_orig_id_map[source])
{
external_edge_list.push_back({source, target, data});
}
else
{
// node is not yet contracted.
// add (renumbered) outgoing edges to new util::DynamicGraph.
ContractorEdge new_edge = {new_node_id_from_orig_id_map[source],
new_node_id_from_orig_id_map[target],
data};
new_edge.data.is_original_via_node_ID = true;
BOOST_ASSERT_MSG(SPECIAL_NODEID != new_node_id_from_orig_id_map[source],
"new source id not resolveable");
BOOST_ASSERT_MSG(SPECIAL_NODEID != new_node_id_from_orig_id_map[target],
"new target id not resolveable");
new_edge_set.push_back(new_edge);
}
}
}
// Replace old priorities array by new one
node_priorities.swap(new_node_priority);
// Delete old node_priorities vector
node_weights.swap(new_node_weights);
// old Graph is removed
contractor_graph.reset();
// create new graph
tbb::parallel_sort(new_edge_set.begin(), new_edge_set.end());
contractor_graph = std::make_shared<ContractorGraph>(remaining_nodes.size(), new_edge_set);
new_edge_set.clear();
// INFO: MAKE SURE THIS IS THE LAST OPERATION OF THE FLUSH!
// reinitialize heaps and ThreadData objects with appropriate size
thread_data_list.number_of_nodes = contractor_graph->GetNumberOfNodes();
}
void Run(double core_factor = 1.0)
{
// for the preperation we can use a big grain size, which is much faster (probably cache)
@ -329,103 +408,12 @@ class GraphContractor
if (!flushed_contractor && (number_of_contracted_nodes >
static_cast<NodeID>(number_of_nodes * 0.65 * core_factor)))
{
util::DeallocatingVector<ContractorEdge>
new_edge_set; // this one is not explicitely
// cleared since it goes out of
// scope anywa
log << " [flush " << number_of_contracted_nodes << " nodes] ";
// Delete old heap data to free memory that we need for the coming operations
thread_data_list.data.clear();
FlushDataAndRebuildContractorGraph(
thread_data_list, remaining_nodes, node_priorities);
// Create new priority array
std::vector<float> new_node_priority(remaining_nodes.size());
std::vector<EdgeWeight> new_node_weights(remaining_nodes.size());
// this map gives the old IDs from the new ones, necessary to get a consistent graph
// at the end of contraction
orig_node_id_from_new_node_id_map.resize(remaining_nodes.size());
// this map gives the new IDs from the old ones, necessary to remap targets from the
// remaining graph
std::vector<NodeID> new_node_id_from_orig_id_map(number_of_nodes, SPECIAL_NODEID);
for (const auto new_node_id :
util::irange<std::size_t>(0UL, remaining_nodes.size()))
{
auto &node = remaining_nodes[new_node_id];
BOOST_ASSERT(node_priorities.size() > node.id);
new_node_priority[new_node_id] = node_priorities[node.id];
BOOST_ASSERT(node_weights.size() > node.id);
new_node_weights[new_node_id] = node_weights[node.id];
}
// build forward and backward renumbering map and remap ids in remaining_nodes
for (const auto new_node_id :
util::irange<std::size_t>(0UL, remaining_nodes.size()))
{
auto &node = remaining_nodes[new_node_id];
// create renumbering maps in both directions
orig_node_id_from_new_node_id_map[new_node_id] = node.id;
new_node_id_from_orig_id_map[node.id] = new_node_id;
node.id = new_node_id;
}
// walk over all nodes
for (const auto source :
util::irange<NodeID>(0UL, contractor_graph->GetNumberOfNodes()))
{
for (auto current_edge : contractor_graph->GetAdjacentEdgeRange(source))
{
ContractorGraph::EdgeData &data =
contractor_graph->GetEdgeData(current_edge);
const NodeID target = contractor_graph->GetTarget(current_edge);
if (SPECIAL_NODEID == new_node_id_from_orig_id_map[source])
{
external_edge_list.push_back({source, target, data});
}
else
{
// node is not yet contracted.
// add (renumbered) outgoing edges to new util::DynamicGraph.
ContractorEdge new_edge = {new_node_id_from_orig_id_map[source],
new_node_id_from_orig_id_map[target],
data};
new_edge.data.is_original_via_node_ID = true;
BOOST_ASSERT_MSG(SPECIAL_NODEID != new_node_id_from_orig_id_map[source],
"new source id not resolveable");
BOOST_ASSERT_MSG(SPECIAL_NODEID != new_node_id_from_orig_id_map[target],
"new target id not resolveable");
new_edge_set.push_back(new_edge);
}
}
}
// Delete map from old NodeIDs to new ones.
new_node_id_from_orig_id_map.clear();
new_node_id_from_orig_id_map.shrink_to_fit();
// Replace old priorities array by new one
node_priorities.swap(new_node_priority);
// Delete old node_priorities vector
// Due to the scope, these should get cleared automatically? @daniel-j-h do you
// agree?
new_node_priority.clear();
new_node_priority.shrink_to_fit();
node_weights.swap(new_node_weights);
// old Graph is removed
contractor_graph.reset();
// create new graph
tbb::parallel_sort(new_edge_set.begin(), new_edge_set.end());
contractor_graph =
std::make_shared<ContractorGraph>(remaining_nodes.size(), new_edge_set);
new_edge_set.clear();
flushed_contractor = true;
// INFO: MAKE SURE THIS IS THE LAST OPERATION OF THE FLUSH!
// reinitialize heaps and ThreadData objects with appropriate size
thread_data_list.number_of_nodes = contractor_graph->GetNumberOfNodes();
}
tbb::parallel_for(