File size: 6,902 Bytes
d844fc8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | #include <networkit/graph/BFS.hpp>
#include <networkit/graph/Dijkstra.hpp>
#include <networkit/graph/Graph.hpp>
#include <networkit/graph/GraphBuilder.hpp>
#include <algorithm>
#include <chrono>
#include <cstdint>
#include <fstream>
#include <iostream>
#include <limits>
#include <numeric>
#include <sstream>
#include <stdexcept>
#include <string>
#include <utility>
#include <vector>
namespace {
using Edge = std::pair<NetworKit::node, NetworKit::node>;
using Clock = std::chrono::steady_clock;
std::vector<Edge> read_edges(const std::string &path, std::size_t &vertices) {
std::ifstream in(path);
if (!in) throw std::runtime_error("cannot open edge list: " + path);
std::vector<Edge> edges;
std::string line;
std::uint64_t max_vertex = 0;
bool saw = false;
while (std::getline(in, line)) {
if (line.empty() || line[0] == '#') continue;
std::istringstream row(line);
std::uint64_t u = 0, v = 0;
if (!(row >> u >> v)) continue;
edges.emplace_back(static_cast<NetworKit::node>(u), static_cast<NetworKit::node>(v));
max_vertex = std::max(max_vertex, std::max(u, v));
saw = true;
}
vertices = saw ? static_cast<std::size_t>(max_vertex + 1) : 0;
return edges;
}
NetworKit::Graph build_graph(const std::vector<Edge> &edges, std::size_t n) {
// GraphBuilder is NetworKit's bulk-construction path. autoCompleteEdges=true
// supplies both half-edge structures required by a directed Graph.
NetworKit::GraphBuilder builder(static_cast<NetworKit::count>(n), false, true, true);
for (const auto &[u, v] : edges) builder.addHalfEdge(u, v);
return builder.completeGraph();
}
struct TraversalResult {
std::uint64_t visited = 0;
std::uint64_t distance_sum = 0;
};
TraversalResult run_bfs(const NetworKit::Graph &graph, NetworKit::node root) {
TraversalResult out;
NetworKit::Traversal::BFSfrom(graph, root, [&](NetworKit::node, NetworKit::count distance) {
++out.visited;
out.distance_sum += static_cast<std::uint64_t>(distance);
});
return out;
}
TraversalResult run_dijkstra(const NetworKit::Graph &graph, NetworKit::node root) {
TraversalResult out;
NetworKit::Traversal::DijkstraFrom(graph, root, [&](NetworKit::node, NetworKit::edgeweight distance) {
++out.visited;
out.distance_sum += static_cast<std::uint64_t>(distance);
});
return out;
}
double median(std::vector<double> values) {
if (values.empty()) return 0.0;
std::sort(values.begin(), values.end());
const auto mid = values.size() / 2;
if (values.size() % 2) return values[mid];
return (values[mid - 1] + values[mid]) / 2.0;
}
void print_samples(const std::vector<double> &values) {
std::cout << '[';
for (std::size_t i = 0; i < values.size(); ++i) {
if (i) std::cout << ',';
std::cout << values[i];
}
std::cout << ']';
}
} // namespace
int main(int argc, char **argv) {
if (argc != 4) {
std::cerr << "usage: " << argv[0] << " edge_list root repetitions\n";
return 2;
}
const std::string path = argv[1];
const auto root = static_cast<NetworKit::node>(std::stoull(argv[2]));
const auto repetitions = static_cast<std::size_t>(std::stoull(argv[3]));
if (repetitions == 0) return 2;
std::size_t n = 0;
const auto parse_start = Clock::now();
const auto edges = read_edges(path, n);
const auto parse_end = Clock::now();
if (n == 0 || edges.empty() || root >= n) return 2;
const auto build_start = Clock::now();
auto graph = build_graph(edges, n);
const auto build_end = Clock::now();
if (graph.numberOfEdges() != edges.size()) {
throw std::runtime_error("GraphBuilder edge count differs from normalized input; duplicate edges are not valid for this contract");
}
// One identical, unmeasured warm-up for each traversal.
const auto warm_bfs = run_bfs(graph, root);
const auto warm_dijkstra = run_dijkstra(graph, root);
if (warm_bfs.visited != warm_dijkstra.visited || warm_bfs.distance_sum != warm_dijkstra.distance_sum) {
throw std::runtime_error("BFS and unit-weight Dijkstra disagree during warm-up");
}
std::vector<double> bfs_samples;
std::vector<double> dijkstra_samples;
bfs_samples.reserve(repetitions);
dijkstra_samples.reserve(repetitions);
TraversalResult bfs_reference = warm_bfs;
for (std::size_t rep = 0; rep < repetitions; ++rep) {
const auto t0 = Clock::now();
const auto bfs = run_bfs(graph, root);
const auto t1 = Clock::now();
const auto dijkstra = run_dijkstra(graph, root);
const auto t2 = Clock::now();
if (bfs.visited != bfs_reference.visited || bfs.distance_sum != bfs_reference.distance_sum ||
dijkstra.visited != bfs_reference.visited || dijkstra.distance_sum != bfs_reference.distance_sum) {
throw std::runtime_error("traversal result changed across repetitions");
}
bfs_samples.push_back(std::chrono::duration<double, std::micro>(t1 - t0).count());
dijkstra_samples.push_back(std::chrono::duration<double, std::micro>(t2 - t1).count());
}
const double parse_us = std::chrono::duration<double, std::micro>(parse_end - parse_start).count();
const double build_us = std::chrono::duration<double, std::micro>(build_end - build_start).count();
const double bfs_median_us = median(bfs_samples);
const double dijkstra_median_us = median(dijkstra_samples);
std::cout << "{\"schema_version\":1,"
<< "\"artifact_type\":\"velographx-networkit-fair-static-contract\","
<< "\"native_cpp\":true,\"directed\":true,\"weighted\":false,"
<< "\"graph_builder\":\"NetworKit::GraphBuilder\","
<< "\"bfs_api\":\"NetworKit::Traversal::BFSfrom(callback)\","
<< "\"dijkstra_api\":\"NetworKit::Traversal::DijkstraFrom(callback)\","
<< "\"path_storage\":false,\"warmup_runs_per_algorithm\":1,"
<< "\"vertices\":" << n << ",\"edges\":" << edges.size() << ','
<< "\"root\":" << root << ",\"repetitions\":" << repetitions << ','
<< "\"parse_us\":" << parse_us << ",\"graph_build_us\":" << build_us << ','
<< "\"bfs_algorithm_median_us\":" << bfs_median_us << ','
<< "\"dijkstra_algorithm_median_us\":" << dijkstra_median_us << ','
<< "\"bfs_build_plus_algorithm_median_us\":" << (build_us + bfs_median_us) << ','
<< "\"dijkstra_build_plus_algorithm_median_us\":" << (build_us + dijkstra_median_us) << ','
<< "\"visited_vertices\":" << bfs_reference.visited << ','
<< "\"distance_sum\":" << bfs_reference.distance_sum << ','
<< "\"bfs_samples_us\":";
print_samples(bfs_samples);
std::cout << ",\"dijkstra_samples_us\":";
print_samples(dijkstra_samples);
std::cout << ",\"bfs_equals_unit_weight_dijkstra\":true,"
<< "\"guidance_source\":\"personal technical advice from Mikhail Kirilin\","
<< "\"networkit_endorsement\":false,\"research_claim\":false}\n";
return 0;
}
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