Add ObjSolver (#2504)

* Add ObjSolver

* Add ObjSolver problems

* Add ObjSolver rule getters

* Add ObjPool::add_conda_dependency

* Add ObjSolver::solve test

* Add extra header

libmamba/CMakeLists.txt

@@ -123,6 +123,7 @@ set(LIBMAMBA_SOURCES
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/pool.cpp
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/repo.cpp
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/solvable.cpp
+    ${LIBMAMBA_SOURCE_DIR}/solv-cpp/solver.cpp
     # C++ wrapping of libcurl
     ${LIBMAMBA_SOURCE_DIR}/core/curl.cpp
     # C++ wrapping of compression libs (zstd and bzlib)
@@ -275,6 +276,7 @@ set(LIBMAMBA_PRIVATE_HEADERS
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/ids.hpp
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/pool.hpp
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/solvable.hpp
+    ${LIBMAMBA_SOURCE_DIR}/solv-cpp/solver.hpp
     ${LIBMAMBA_SOURCE_DIR}/solv-cpp/repo.hpp
     # C++ wrapping of compression libs (zstd and bzlib)
     ${LIBMAMBA_SOURCE_DIR}/core/compression.hpp

libmamba/src/solv-cpp/ids.hpp

@@ -15,9 +15,12 @@ namespace mamba::solv
     using DependencyId = ::Id;
     using RepoId = ::Id;
     using SolvableId = ::Id;
+    using RuleId = ::Id;
+    using ProblemId = ::Id;
 
     using RelationFlag = int;
     using DistType = int;
+    using SolverFlag = int;
 }
 
 #endif

libmamba/src/solv-cpp/pool.cpp

@@ -12,6 +12,10 @@
 #include <solv/pooltypes.h>
 #include <solv/repo.h>
 #include <solv/selection.h>
+extern "C"  // Incomplete header
+{
+#include <solv/conda.h>
+}
 
 #include "solv-cpp/pool.hpp"
 
@@ -112,6 +116,16 @@ namespace mamba::solv
         return id;
     }
 
+    auto ObjPool::add_conda_dependency(raw_str_view dep) -> DependencyId
+    {
+        return ::pool_conda_matchspec(raw(), dep);
+    }
+
+    auto ObjPool::add_conda_dependency(const std::string& dep) -> DependencyId
+    {
+        return add_conda_dependency(dep.c_str());
+    }
+
     auto ObjPool::get_dependency_name(DependencyId id) const -> std::string_view
     {
         return ::pool_id2str(raw(), id);

libmamba/src/solv-cpp/pool.hpp

@@ -18,7 +18,10 @@
 #include "solv-cpp/repo.hpp"
 #include "solv-cpp/solvable.hpp"
 
-using Pool = struct s_Pool;
+extern "C"
+{
+    using Pool = struct s_Pool;
+}
 
 namespace mamba::solv
 {
@@ -33,6 +36,8 @@ namespace mamba::solv
     {
     public:
 
+        using raw_str_view = const char*;
+
         ObjPool();
         ~ObjPool();
 
@@ -95,6 +100,12 @@ namespace mamba::solv
          */
         auto add_dependency(StringId name_id, RelationFlag flag, StringId version_id) -> DependencyId;
 
+        /**
+         * Parse a dependency from string and add it to the pool.
+         */
+        auto add_conda_dependency(raw_str_view dep) -> DependencyId;
+        auto add_conda_dependency(const std::string& dep) -> DependencyId;
+
         /** Get the registered name of a dependency. */
         auto get_dependency_name(DependencyId id) const -> std::string_view;
 

libmamba/src/solv-cpp/repo.hpp

@@ -14,7 +14,10 @@
 #include "solv-cpp/ids.hpp"
 #include "solv-cpp/solvable.hpp"
 
-using Repo = struct s_Repo;
+extern "C"
+{
+    using Repo = struct s_Repo;
+}
 
 namespace fs
 {

libmamba/src/solv-cpp/solvable.hpp

@@ -16,7 +16,10 @@
 #include "solv-cpp/ids.hpp"
 #include "solv-cpp/queue.hpp"
 
-using Solvable = struct s_Solvable;
+extern "C"
+{
+    using Solvable = struct s_Solvable;
+}
 
 namespace mamba::solv
 {

libmamba/src/solv-cpp/solver.cpp

@@ -0,0 +1,115 @@
+// Copyright (c) 2023, QuantStack and Mamba Contributors
+//
+// Distributed under the terms of the BSD 3-Clause License.
+//
+// The full license is in the file LICENSE, distributed with this software.
+
+#include <cassert>
+
+#include <solv/poolid.h>
+#include <solv/solvable.h>
+#include <solv/solver.h>
+// broken headers go last
+#include <solv/problems.h>
+#include <solv/rules.h>
+
+#include "solv-cpp/pool.hpp"
+#include "solv-cpp/queue.hpp"
+#include "solv-cpp/solver.hpp"
+
+namespace mamba::solv
+{
+    void ObjSolver::SolverDeleter::operator()(::Solver* ptr)
+    {
+        ::solver_free(ptr);
+    }
+
+    ObjSolver::ObjSolver(const ObjPool& pool)
+        : m_solver(::solver_create(const_cast<::Pool*>(pool.raw())))
+    {
+    }
+
+    ObjSolver::~ObjSolver() = default;
+
+    auto ObjSolver::raw() -> ::Solver*
+    {
+        return m_solver.get();
+    }
+
+    void ObjSolver::set_flag(SolverFlag flag, bool value)
+    {
+        ::solver_set_flag(raw(), flag, value);
+    }
+
+    auto ObjSolver::get_flag(SolverFlag flag) const -> bool
+    {
+        const auto val = ::solver_get_flag(const_cast<::Solver*>(raw()), flag);
+        assert((val == 0) || (val == 1));
+        return val != 0;
+    }
+
+    auto ObjSolver::raw() const -> const ::Solver*
+    {
+        return m_solver.get();
+    }
+
+    auto ObjSolver::solve(const ObjPool& /* pool */, const ObjQueue& jobs) -> bool
+    {
+        // pool is captured inside solver so we take it as a parameter to be explicit.
+        const auto n_pbs = ::solver_solve(raw(), const_cast<::Queue*>(jobs.raw()));
+        return n_pbs == 0;
+    }
+
+    auto ObjSolver::problem_count() const -> std::size_t
+    {
+        return ::solver_problem_count(const_cast<::Solver*>(raw()));
+    }
+
+    auto ObjSolver::problem_to_string(const ObjPool& /* pool */, ProblemId id) const -> std::string
+    {
+        // pool is captured inside solver so we take it as a parameter to be explicit.
+        return ::solver_problem2str(const_cast<::Solver*>(raw()), id);
+    }
+
+    auto ObjSolver::next_problem(ProblemId id) const -> ProblemId
+    {
+        return ::solver_next_problem(const_cast<::Solver*>(raw()), id);
+    }
+
+    auto ObjSolver::problem_rules(ProblemId id) const -> ObjQueue
+    {
+        ObjQueue rules = {};
+        ::solver_findallproblemrules(const_cast<::Solver*>(raw()), id, rules.raw());
+        return rules;
+    }
+
+    auto ObjSolver::get_rule_info(const ObjPool& /* pool */, RuleId id) const -> ObjRuleInfo
+    {
+        // pool is captured inside solver so we take it as a parameter to be explicit.
+        SolvableId from_id = 0;
+        SolvableId to_id = 0;
+        DependencyId dep_id = 0;
+        const auto type = ::solver_ruleinfo(const_cast<::Solver*>(raw()), id, &from_id, &to_id, &dep_id);
+
+        return {
+            /* .from_id= */ (from_id != 0) ? std::optional{ from_id } : std::nullopt,
+            /* .to_id= */ (to_id != 0) ? std::optional{ to_id } : std::nullopt,
+            /* .dep_id= */ (dep_id != 0) ? std::optional{ dep_id } : std::nullopt,
+            /* .type= */ type,
+            /* .klass= */ ::solver_ruleclass(const_cast<::Solver*>(raw()), id),
+        };
+    }
+
+    auto ObjSolver::rule_info_to_string(const ObjPool& /* pool */, ObjRuleInfo ri) const -> std::string
+    {
+        // pool is captured inside solver so we take it as a parameter to be explicit.
+        return ::solver_ruleinfo2str(
+            const_cast<::Solver*>(raw()),
+            ri.type,
+            ri.from_id.value_or(0),
+            ri.to_id.value_or(0),
+            ri.dep_id.value_or(0)
+        );
+    }
+
+}

libmamba/src/solv-cpp/solver.hpp

@@ -0,0 +1,101 @@
+// Copyright (c) 2023, QuantStack and Mamba Contributors
+//
+// Distributed under the terms of the BSD 3-Clause License.
+//
+// The full license is in the file LICENSE, distributed with this software.
+
+#ifndef MAMBA_SOLV_SOLVER_HPP
+#define MAMBA_SOLV_SOLVER_HPP
+
+#include <memory>
+#include <optional>
+#include <string>
+
+// START Only required for broken header <solv/rule.h>
+#include <solv/poolid.h>
+extern "C"
+{
+    typedef struct s_Solvable Solvable;
+    typedef struct s_Map Map;
+    typedef struct s_Queue Queue;
+}
+// END
+#include <solv/rules.h>
+
+#include "solv-cpp/ids.hpp"
+#include "solv-cpp/queue.hpp"
+
+extern "C"
+{
+    using Solver = struct s_Solver;
+}
+
+namespace mamba::solv
+{
+    class ObjPool;
+    class ObjQueue;
+
+    struct ObjRuleInfo
+    {
+        std::optional<SolvableId> from_id;
+        std::optional<SolvableId> to_id;
+        std::optional<DependencyId> dep_id;
+        ::SolverRuleinfo type;
+        ::SolverRuleinfo klass;
+    };
+
+    class ObjSolver
+    {
+    public:
+
+        ObjSolver(const ObjPool& pool);
+        ~ObjSolver();
+
+        auto raw() -> ::Solver*;
+        auto raw() const -> const ::Solver*;
+
+        void set_flag(SolverFlag flag, bool value);
+        [[nodiscard]] auto get_flag(SolverFlag flag) const -> bool;
+
+        [[nodiscard]] auto solve(const ObjPool& pool, const ObjQueue& jobs) -> bool;
+
+        [[nodiscard]] auto problem_count() const -> std::size_t;
+        [[nodiscard]] auto problem_to_string(const ObjPool& pool, ProblemId id) const -> std::string;
+        template <typename UnaryFunc>
+        void for_each_problem_id(UnaryFunc&& func) const;
+
+        /**
+         * Return an @ref ObjQueue of @ref RuleId with all rules involved in a current problem.
+         */
+        [[nodiscard]] auto problem_rules(ProblemId id) const -> ObjQueue;
+        [[nodiscard]] auto get_rule_info(const ObjPool& pool, RuleId id) const -> ObjRuleInfo;
+        [[nodiscard]] auto rule_info_to_string(const ObjPool& pool, ObjRuleInfo id) const
+            -> std::string;
+
+    private:
+
+        struct SolverDeleter
+        {
+            void operator()(::Solver* ptr);
+        };
+
+        std::unique_ptr<::Solver, ObjSolver::SolverDeleter> m_solver = nullptr;
+
+        auto next_problem(ProblemId id = 0) const -> ProblemId;
+    };
+
+    /*********************************
+     *  Implementation of ObjSolver  *
+     *********************************/
+
+    template <typename UnaryFunc>
+    void ObjSolver::for_each_problem_id(UnaryFunc&& func) const
+    {
+        for (ProblemId id = next_problem(); id != 0; id = next_problem(id))
+        {
+            func(id);
+        }
+    }
+
+}
+#endif

libmamba/tests/CMakeLists.txt

@@ -17,6 +17,7 @@ set(LIBMAMBA_TEST_SRCS
     src/solv-cpp/test_pool.cpp
     src/solv-cpp/test_repo.cpp
     src/solv-cpp/test_solvable.cpp
+    src/solv-cpp/test_solver.cpp
     # Utility library
     src/util/test_flat_set.cpp
     src/util/test_graph.cpp

libmamba/tests/src/solv-cpp/test_pool.cpp

@@ -72,6 +72,13 @@ TEST_SUITE("ObjPool")
             CHECK_EQ(pool.get_dependency_relation(id_rel), " > ");
             CHECK_EQ(pool.get_dependency_version(id_rel), "1.0.0");
             CHECK_EQ(pool.dependency_to_string(id_rel), "mamba > 1.0.0");
+
+            SUBCASE("Parse a conda dependency")
+            {
+                const auto id_conda = pool.add_conda_dependency("rattler < 0.1");
+                CHECK_EQ(pool.get_dependency_name(id_conda), "rattler");
+                CHECK_EQ(pool.get_dependency_version(id_conda), "<0.1");
+            }
         }
 
         SUBCASE("Add repo")