max_flow_driver.cpp File Reference

#include "drivers/max_flow/max_flow_driver.h"
#include <sstream>
#include <vector>
#include <set>
#include "max_flow/pgr_maxflow.hpp"
#include "cpp_common/pgr_assert.h"
#include "cpp_common/pgr_alloc.hpp"

Include dependency graph for max_flow_driver.cpp:

Go to the source code of this file.

Functions
void	do_pgr_max_flow (pgr_edge_t *data_edges, size_t total_edges, pgr_combination_t *combinations, size_t total_combinations, int64_t *source_vertices, size_t size_source_verticesArr, int64_t *sink_vertices, size_t size_sink_verticesArr, int algorithm, bool only_flow, pgr_flow_t **return_tuples, size_t *return_count, char **log_msg, char **notice_msg, char **err_msg)

Function Documentation

do_pgr_max_flow()

void do_pgr_max_flow	(	pgr_edge_t *	data_edges,
		size_t	total_edges,
		pgr_combination_t *	combinations,
		size_t	total_combinations,
		int64_t *	source_vertices,
		size_t	size_source_verticesArr,
		int64_t *	sink_vertices,
		size_t	size_sink_verticesArr,
		int	algorithm,
		bool	only_flow,
		pgr_flow_t **	return_tuples,
		size_t *	return_count,
		char **	log_msg,
		char **	notice_msg,
		char **	err_msg
	)

Definition at line 43 of file max_flow_driver.cpp.

                        {
    std::ostringstream log;
    std::ostringstream notice;
    std::ostringstream err;
 
    try {
        pgassert(!(*log_msg));
        pgassert(!(*notice_msg));
        pgassert(!(*err_msg));
        pgassert(!(*return_tuples));
        pgassert(*return_count == 0);
        pgassert(data_edges);
        pgassert(total_edges != 0);
        pgassert((source_vertices && sink_vertices) || combinations);
        pgassert((size_source_verticesArr && size_sink_verticesArr) || total_combinations);
 
        std::vector<pgr_edge_t> edges(data_edges, data_edges + total_edges);
        std::set<int64_t> sources(
                source_vertices, source_vertices + size_source_verticesArr);
        std::set<int64_t> targets(
                sink_vertices, sink_vertices + size_sink_verticesArr);
        std::vector< pgr_combination_t > combinations_vector(
                combinations, combinations + total_combinations);
 
        if (!combinations_vector.empty()) {
            pgassert(sources.empty());
            pgassert(targets.empty());
 
            for (const pgr_combination_t &comb : combinations_vector) {
                sources.insert(comb.source);
                targets.insert(comb.target);
            }
        }
 
        std::set<int64_t> vertices(sources);
        vertices.insert(targets.begin(), targets.end());
 
        if (vertices.size()
                != (sources.size() + targets.size())) {
            *err_msg = pgr_msg("A source found as sink");
            // TODO(vicky) return as hint the sources that are also sinks
            return;
        }
 
 
 
        pgrouting::graph::PgrFlowGraph digraph(
                edges, sources, targets, algorithm);
        // digraph.create_flow_graph(edges, sources, targets, algorithm);
 
        int64_t max_flow;
        if (algorithm == 1) {
            max_flow = digraph.push_relabel();
        } else if (algorithm == 3) {
            max_flow = digraph.edmonds_karp();
        } else if (algorithm == 2) {
            max_flow = digraph.boykov_kolmogorov();
        } else {
            log << "Unspecified algorithm!\n";
            *err_msg = pgr_msg(log.str().c_str());
            (*return_tuples) = NULL;
            (*return_count) = 0;
            return;
        }
 
 
        std::vector<pgr_flow_t> flow_edges;
 
        if (only_flow) {
            pgr_flow_t edge;
            edge.edge = -1;
            edge.source = -1;
            edge.target = -1;
            edge.flow = max_flow;
            edge.residual_capacity = -1;
            flow_edges.push_back(edge);
        } else {
            flow_edges = digraph.get_flow_edges();
        }
        (*return_tuples) = pgr_alloc(flow_edges.size(), (*return_tuples));
        for (size_t i = 0; i < flow_edges.size(); ++i) {
            (*return_tuples)[i] = flow_edges[i];
        }
        *return_count = flow_edges.size();
 
 
        *log_msg = log.str().empty()?
            *log_msg :
            pgr_msg(log.str().c_str());
        *notice_msg = notice.str().empty()?
            *notice_msg :
            pgr_msg(notice.str().c_str());
    } catch (AssertFailedException &except) {
        (*return_tuples) = pgr_free(*return_tuples);
        (*return_count) = 0;
        err << except.what();
        *err_msg = pgr_msg(err.str().c_str());
        *log_msg = pgr_msg(log.str().c_str());
    } catch (std::exception &except) {
        (*return_tuples) = pgr_free(*return_tuples);
        (*return_count) = 0;
        err << except.what();
        *err_msg = pgr_msg(err.str().c_str());
        *log_msg = pgr_msg(log.str().c_str());
    } catch(...) {
        (*return_tuples) = pgr_free(*return_tuples);
        (*return_count) = 0;
        err << "Caught unknown exception!";
        *err_msg = pgr_msg(err.str().c_str());
        *log_msg = pgr_msg(log.str().c_str());
    }
}

References pgrouting::graph::PgrFlowGraph::boykov_kolmogorov(), pgrouting::graph::PgrFlowGraph::edmonds_karp(), pgrouting::graph::PgrFlowGraph::get_flow_edges(), pgassert, pgr_alloc(), pgr_free(), pgr_msg(), pgrouting::graph::PgrFlowGraph::push_relabel(), edge::source, edge::target, and AssertFailedException::what().

Referenced by process().