init

build_graph.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <cstddef>
+#include <vector>
+
+#include "task.hpp"
+
+namespace build_system {
+
+struct IncorrectBuildGraph {};
+
+struct Rule {
+  size_t target;
+  size_t dependency;
+};
+
+struct Target {
+  size_t id;
+  Task task;
+  std::vector<size_t> dependences;
+};
+
+class BuildGraph {
+private:
+  // manage DFS, topsort, etc. safe
+  class TraversalManager {
+  private:
+    class View;
+
+  public:
+    TraversalManager(const BuildGraph& build_graph)
+        : build_graph_(build_graph), epoch_(kNeverVisited + 1) {}
+
+    void initArray() {
+      visited_ = std::vector<size_t>(build_graph_.graph_.size(), kNeverVisited);
+    }
+
+    View getView();
+
+  private:
+    void nextEpoch() { ++epoch_; }
+
+    void DFS(size_t vertex, std::vector<size_t>& current_visited);
+
+  private:
+    static const size_t kCurrentWayEpoch;
+    static const size_t kNeverVisited;
+
+    const BuildGraph &build_graph_;
+    std::vector<size_t> visited_;
+    size_t epoch_;
+  };
+
+public:
+  BuildGraph(const std::vector<Rule>& rules, std::vector<Task>&& tasks);
+
+  void isCorrectOrThrow(size_t target) const;
+
+  bool isCorrect(size_t target) const;
+
+  std::vector<Target> getRequiredTargetsOrder(size_t target) const;
+
+private:
+  std::vector<Target> graph_;
+  mutable TraversalManager traversal_manager_;
+};
+
+} // namespace build_system