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VILLASnode/common/include/villas/graph/directed.hpp
Niklas Eiling f25e1dd689 log: fix undefined intitialization order of static objects. fixes #799.
Signed-off-by: Niklas Eiling <niklas.eiling@eonerc.rwth-aachen.de>
2024-08-05 14:57:13 +02:00

255 lines
6.8 KiB
C++

/* A directed graph.
*
* Author: Daniel Krebs <github@daniel-krebs.net>
* SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include <algorithm>
#include <fstream>
#include <list>
#include <map>
#include <memory>
#include <sstream>
#include <stdexcept>
#include <string>
#include <villas/graph/edge.hpp>
#include <villas/graph/vertex.hpp>
#include <villas/log.hpp>
namespace villas {
namespace graph {
template <typename VertexType = Vertex, typename EdgeType = Edge>
class DirectedGraph {
public:
using VertexIdentifier = Vertex::Identifier;
using EdgeIdentifier = Edge::Identifier;
using Path = std::list<EdgeIdentifier>;
DirectedGraph(const std::string &name = "DirectedGraph")
: lastVertexId(0), lastEdgeId(0), logger(Log::get(name)) {}
std::shared_ptr<VertexType> getVertex(VertexIdentifier vertexId) const {
// Cannot use [] operator, because creates non-existing elements
// at() will throw std::out_of_range if element does not exist
return vertices.at(vertexId);
}
template <class UnaryPredicate>
VertexIdentifier findVertex(UnaryPredicate p) {
for (auto &v : vertices) {
auto &vertexId = v.first;
auto &vertex = v.second;
if (p(vertex)) {
return vertexId;
}
}
throw std::out_of_range("vertex not found");
}
std::shared_ptr<EdgeType> getEdge(EdgeIdentifier edgeId) const {
if (edgeId >= lastEdgeId)
throw std::invalid_argument("edge doesn't exist");
// Cannot use [] operator, because creates non-existing elements
// at() will throw std::out_of_range if element does not exist
return edges.at(edgeId);
}
std::size_t getEdgeCount() const { return edges.size(); }
std::size_t getVertexCount() const { return vertices.size(); }
VertexIdentifier addVertex(std::shared_ptr<VertexType> vertex) {
vertex->id = lastVertexId++;
logger->debug("New vertex: {}", vertex->toString());
vertices[vertex->id] = vertex;
return vertex->id;
}
EdgeIdentifier addEdge(std::shared_ptr<EdgeType> edge,
VertexIdentifier fromVertexId,
VertexIdentifier toVertexId) {
// Allocate edge id
edge->id = lastEdgeId++;
// Connect it
edge->from = fromVertexId;
edge->to = toVertexId;
logger->debug("New edge {}: {} -> {}", edge->toString(), edge->from,
edge->to);
// This is a directed graph, so only push edge to starting vertex
getVertex(edge->from)->edges.push_back(edge->id);
// Add new edge to graph
edges[edge->id] = edge;
return edge->id;
}
EdgeIdentifier addDefaultEdge(VertexIdentifier fromVertexId,
VertexIdentifier toVertexId) {
// Create a new edge
std::shared_ptr<EdgeType> edge(new EdgeType);
return addEdge(edge, fromVertexId, toVertexId);
}
void removeEdge(EdgeIdentifier edgeId) {
auto edge = getEdge(edgeId);
auto startVertex = getVertex(edge->from);
// Remove edge only from starting vertex (this is a directed graph)
logger->debug("Remove edge {} from vertex {}", edgeId, edge->from);
startVertex->edges.remove(edgeId);
logger->debug("Remove edge {}", edgeId);
edges.erase(edgeId);
}
void removeVertex(VertexIdentifier vertexId) {
// Delete every edge that start or ends at this vertex
auto it = edges.begin();
while (it != edges.end()) {
auto &edgeId = it->first;
auto &edge = it->second;
bool removeEdge = false;
if (edge->to == vertexId) {
logger->debug("Remove edge {} from vertex {}'s edge list", edgeId,
edge->from);
removeEdge = true;
auto startVertex = getVertex(edge->from);
startVertex->edges.remove(edge->id);
}
if ((edge->from == vertexId) or removeEdge) {
logger->debug("Remove edge {}", edgeId);
// Remove edge from global edge list
it = edges.erase(it);
} else
++it;
}
logger->debug("Remove vertex {}", vertexId);
vertices.erase(vertexId);
lastVertexId--;
}
const std::list<EdgeIdentifier> &
vertexGetEdges(VertexIdentifier vertexId) const {
return getVertex(vertexId)->edges;
}
using check_path_fn = std::function<bool(const Path &)>;
static bool checkPath(const Path &) { return true; }
bool getPath(VertexIdentifier fromVertexId, VertexIdentifier toVertexId,
Path &path, check_path_fn pathCheckFunc = checkPath) {
if (fromVertexId == toVertexId)
// Arrived at the destination
return true;
else {
auto fromVertex = getVertex(fromVertexId);
for (auto &edgeId : fromVertex->edges) {
auto edgeOfFromVertex = getEdge(edgeId);
// Loop detection
bool loop = false;
for (auto &edgeIdInPath : path) {
auto edgeInPath = getEdge(edgeIdInPath);
if (edgeInPath->from == edgeOfFromVertex->to) {
loop = true;
break;
}
}
if (loop) {
logger->debug("Loop detected via edge {}", edgeId);
continue;
}
// Remember the path we're investigating to detect loops
path.push_back(edgeId);
// Recursive, depth-first search
if (getPath(edgeOfFromVertex->to, toVertexId, path, pathCheckFunc) and
pathCheckFunc(path))
// Path found, we're done
return true;
else
// Tear down path that didn't lead to the destination
path.pop_back();
}
}
return false;
}
void dump(const std::string &fileName = "") const {
logger->info("Vertices:");
for (auto &v : vertices) {
auto &vertex = v.second;
// Format connected vertices into a list
std::stringstream ssEdges;
for (auto &edge : vertex->edges) {
ssEdges << getEdge(edge)->to << " ";
}
logger->info(" {} connected to: {}", vertex->toString(), ssEdges.str());
}
std::fstream s(fileName, s.out | s.trunc);
if (s.is_open()) {
s << "digraph memgraph {" << std::endl;
}
logger->info("Edges:");
for (auto &e : edges) {
auto &edge = e.second;
logger->info(" {}: {} -> {}", edge->toString(), edge->from, edge->to);
if (s.is_open()) {
auto from = getVertex(edge->from);
auto to = getVertex(edge->to);
s << std::dec;
s << " \"" << *from << "\" -> \"" << *to << "\""
<< " [label=\"" << *edge << "\"];" << std::endl;
}
}
if (s.is_open()) {
s << "}" << std::endl;
s.close();
}
}
protected:
VertexIdentifier lastVertexId;
EdgeIdentifier lastEdgeId;
std::map<VertexIdentifier, std::shared_ptr<VertexType>> vertices;
std::map<EdgeIdentifier, std::shared_ptr<EdgeType>> edges;
Logger logger;
};
} // namespace graph
} // namespace villas