1 files changed, 68 insertions, 0 deletions
diff --git a/toolsrc/src/vcpkg_Dependencies.cpp b/toolsrc/src/vcpkg_Dependencies.cpp
new file mode 100644
index 000000000..751b503c0
--- /dev/null
+++ b/toolsrc/src/vcpkg_Dependencies.cpp
@@ -0,0 +1,68 @@
+#include "vcpkg_Dependencies.h"
+#include <vector>
+#include "vcpkg_Graphs.h"
+#include "vcpkg_paths.h"
+#include "package_spec.h"
+#include "StatusParagraphs.h"
+#include <unordered_set>
+#include "vcpkg.h"
+#include "vcpkg_Maps.h"
+#include "vcpkg_Sets.h"
+
+namespace vcpkg { namespace Dependencies
+{
+    static Graphs::Graph<package_spec> build_dependency_graph(const vcpkg_paths& paths, const std::vector<package_spec>& specs, const StatusParagraphs& status_db)
+    {
+        std::vector<package_spec> examine_stack(specs);
+        std::unordered_set<package_spec> was_examined; // Examine = we have checked its immediate (non-recursive) dependencies
+        Graphs::Graph<package_spec> graph;
+        graph.add_vertices(examine_stack);
+
+        while (!examine_stack.empty())
+        {
+            package_spec spec = examine_stack.back();
+            examine_stack.pop_back();
+
+            if (was_examined.find(spec) != was_examined.end())
+            {
+                continue;
+            }
+
+            std::vector<std::string> dependencies_as_string = get_unmet_package_dependencies(paths, spec, status_db);
+
+            for (const std::string& dep_as_string : dependencies_as_string)
+            {
+                package_spec current_dep = {dep_as_string, spec.target_triplet};
+                auto it = status_db.find(current_dep.name, current_dep.target_triplet);
+                if (it != status_db.end() && (*it)->want == want_t::install)
+                {
+                    continue;
+                }
+
+                graph.add_edge(spec, current_dep);
+                if (was_examined.find(current_dep) == was_examined.end())
+                {
+                    examine_stack.push_back(std::move(current_dep));
+                }
+            }
+
+            was_examined.insert(spec);
+        }
+
+        return graph;
+    }
+
+    std::vector<package_spec> create_dependency_ordered_install_plan(const vcpkg_paths& paths, const std::vector<package_spec>& specs, const StatusParagraphs& status_db)
+    {
+        return build_dependency_graph(paths, specs, status_db).find_topological_sort();
+    }
+
+    std::unordered_set<package_spec> find_unmet_dependencies(const vcpkg_paths& paths, const std::vector<package_spec>& specs, const StatusParagraphs& status_db)
+    {
+        const Graphs::Graph<package_spec> dependency_graph = build_dependency_graph(paths, specs, status_db);
+        std::unordered_set<package_spec> key_set = Maps::extract_key_set(dependency_graph.adjacency_list());
+        Sets::remove_all(&key_set, specs);
+
+        return key_set;
+    }
+}}