Merge pull request #644 from elbeno/flow-logging

✨ Fine-grained logging control for flows

Author: lukevalenty

include/flow/graph_builder.hpp

@@ -26,7 +26,13 @@
 namespace flow {
 namespace detail {
 template <typename T> using is_duplicated = std::bool_constant<(T::size() > 1)>;
-}
+
+template <typename CTNode, typename Output>
+concept is_output_compatible = requires(CTNode n) {
+    { Output::create_node(n) } -> std::same_as<typename Output::node_t>;
+};
+} // namespace detail
+
 template <typename T> using name_for = typename T::name_t;
 
 [[nodiscard]] constexpr auto edge_size(auto const &nodes,
@@ -56,12 +62,14 @@ template <stdx::ct_string Name,
           template <stdx::ct_string, std::size_t> typename Impl>
 struct graph_builder {
     // NOLINTBEGIN(readability-function-cognitive-complexity)
-    template <typename Node, std::size_t N, std::size_t E>
+    template <typename Output, std::size_t N, std::size_t E>
     [[nodiscard]] constexpr static auto make_graph(auto const &nodes,
                                                    auto const &edges) {
-        using graph_t = stdx::cx_multimap<Node, Node, N, E>;
+        using output_node_t = typename Output::node_t;
+        using graph_t = stdx::cx_multimap<output_node_t, output_node_t, N, E>;
         graph_t g{};
-        for_each([&](auto const &node) { g.put(node); }, nodes);
+        for_each([&]<typename Node>(Node n) { g.put(Output::create_node(n)); },
+                 nodes);
 
         auto const named_nodes = stdx::apply_indices<name_for>(nodes);
         for_each(
@@ -95,7 +103,7 @@ struct graph_builder {
                     },
                     node_ps);
 
-                g.put(lhs, rhs);
+                g.put(Output::create_node(lhs), Output::create_node(rhs));
             },
             edges);
         return g;
@@ -212,18 +220,16 @@ struct graph_builder {
         constexpr auto edge_capacity = edge_size(node_set, edges);
 
         using output_t = Impl<Graph::name, node_capacity>;
-        using rt_node_t = typename output_t::node_t;
-
         static_assert(
             all_of(
                 []<typename N>(N const &) {
-                    return std::is_convertible_v<N, rt_node_t>;
+                    return detail::is_output_compatible<N, output_t>;
                 },
                 node_set),
             "Output node type is not compatible with given input nodes");
 
-        auto g = make_graph<rt_node_t, node_capacity, edge_capacity>(node_set,
-                                                                     edges);
+        auto g =
+            make_graph<output_t, node_capacity, edge_capacity>(node_set, edges);
         return topo_sort<output_t>(g);
     }
 

include/flow/impl.hpp

@@ -4,6 +4,7 @@
 #include <flow/step.hpp>
 #include <log/log.hpp>
 
+#include <stdx/ct_string.hpp>
 #include <stdx/cx_vector.hpp>
 #include <stdx/span.hpp>
 
@@ -13,6 +14,31 @@
 #include <type_traits>
 
 namespace flow {
+namespace detail {
+template <typename CTNode> constexpr auto run_func() -> void {
+    if (CTNode::condition) {
+        typename CTNode::func_t{}();
+    }
+}
+
+template <typename Flow, typename CTNode> constexpr auto log_func() -> void {
+    if (CTNode::condition) {
+        using log_spec_t = decltype(get_log_spec<CTNode, Flow>());
+        CIB_LOG(typename log_spec_t::flavor, log_spec_t::level, "flow.{}({})",
+                typename CTNode::type_t{}, typename CTNode::name_t{});
+    }
+}
+} // namespace detail
+
+struct rt_node {
+    FunctionPtr run{};
+    FunctionPtr log_name{};
+
+  private:
+    friend constexpr auto operator==(rt_node const &,
+                                     rt_node const &) -> bool = default;
+};
+
 /**
  * flow::impl is a constant representation of a series of Milestones and actions
  * to be executed in a specific order.
@@ -45,11 +71,18 @@ template <stdx::ct_string Name, std::size_t NumSteps> class impl {
   public:
     stdx::cx_vector<FunctionPtr, capacity> functionPtrs{};
 
-    using node_t = rt_node;
     constexpr static bool active = capacity > 0;
-
     constexpr static auto name = Name;
 
+    using node_t = rt_node;
+
+    template <typename CTNode>
+    constexpr static auto create_node(CTNode) -> node_t {
+        constexpr auto rf = detail::run_func<CTNode>;
+        constexpr auto lf = detail::log_func<log_spec_id_t<Name>, CTNode>;
+        return node_t{rf, lf};
+    }
+
     /**
      * Create a new flow::impl of Milestones.
      *
@@ -60,24 +93,24 @@ template <stdx::ct_string Name, std::size_t NumSteps> class impl {
      *
      * @see flow::builder
      */
-    constexpr explicit(true)
-        impl(stdx::span<node_t const, NumSteps> newMilestones) {
+    constexpr explicit(true) impl(stdx::span<node_t const, NumSteps> steps) {
         if constexpr (loggingEnabled) {
-            for (auto const &milestone : newMilestones) {
-                functionPtrs.push_back(milestone.log_name);
-                functionPtrs.push_back(milestone.run);
+            for (auto const &step : steps) {
+                functionPtrs.push_back(step.log_name);
+                functionPtrs.push_back(step.run);
             }
         } else {
-            std::transform(std::cbegin(newMilestones), std::cend(newMilestones),
+            std::transform(std::cbegin(steps), std::cend(steps),
                            std::back_inserter(functionPtrs),
-                           [](auto const &milestone) { return milestone.run; });
+                           [](auto const &step) { return step.run; });
         }
     }
 };
 
 namespace detail {
 template <stdx::ct_string Name, auto... FuncPtrs> struct inlined_func_list {
     constexpr static auto active = sizeof...(FuncPtrs) > 0;
+    constexpr static auto ct_name = Name;
 
     __attribute__((flatten, always_inline)) auto operator()() const -> void {
         constexpr static bool loggingEnabled = not Name.empty();
@@ -86,13 +119,17 @@ template <stdx::ct_string Name, auto... FuncPtrs> struct inlined_func_list {
             stdx::ct_string_to_type<Name, sc::string_constant>();
 
         if constexpr (loggingEnabled) {
-            CIB_TRACE("flow.start({})", name);
+            using log_spec_t = decltype(get_log_spec<inlined_func_list>());
+            CIB_LOG(typename log_spec_t::flavor, log_spec_t::level,
+                    "flow.start({})", name);
         }
 
         (FuncPtrs(), ...);
 
         if constexpr (loggingEnabled) {
-            CIB_TRACE("flow.end({})", name);
+            using log_spec_t = decltype(get_log_spec<inlined_func_list>());
+            CIB_LOG(typename log_spec_t::flavor, log_spec_t::level,
+                    "flow.end({})", name);
         }
     }
 };

include/flow/log.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <log/log.hpp>
+
+#include <stdx/ct_string.hpp>
+
+#include <type_traits>
+
+namespace flow {
+struct default_log_spec {
+    using flavor = logging::default_flavor_t;
+    constexpr static auto level = logging::level::TRACE;
+};
+template <stdx::ct_string, typename...>
+constexpr auto log_spec = default_log_spec{};
+
+template <stdx::ct_string Name> struct log_spec_id_t {
+    constexpr static auto ct_name = Name;
+};
+
+template <typename T, typename Fallback = log_spec_id_t<"default">,
+          typename... DummyArgs>
+    requires(sizeof...(DummyArgs) == 0)
+constexpr static auto get_log_spec() {
+    using log_spec_t = decltype(log_spec<T::ct_name, DummyArgs...>);
+    if constexpr (std::is_same_v<log_spec_t, default_log_spec const>) {
+        if constexpr (Fallback::ct_name == stdx::ct_string{"default"}) {
+            return log_spec<Fallback::ct_name, DummyArgs...>;
+        } else {
+            return get_log_spec<Fallback>();
+        }
+    } else {
+        return log_spec_t{};
+    }
+}
+} // namespace flow

include/flow/step.hpp

@@ -3,8 +3,8 @@
 #include <cib/detail/runtime_conditional.hpp>
 #include <cib/func_decl.hpp>
 #include <flow/common.hpp>
+#include <flow/log.hpp>
 #include <flow/subgraph_identity.hpp>
-#include <log/log.hpp>
 #include <sc/string_constant.hpp>
 
 #include <stdx/compiler.hpp>
@@ -14,45 +14,20 @@
 #include <type_traits>
 
 namespace flow {
-struct rt_node {
-    FunctionPtr run;
-    FunctionPtr log_name;
-
-  private:
-    friend constexpr auto operator==(rt_node const &,
-                                     rt_node const &) -> bool = default;
-};
-
 template <stdx::ct_string Type, stdx::ct_string Name,
           subgraph_identity Identity, typename Cond, typename F>
-struct ct_node : rt_node {
+struct ct_node {
     using is_subgraph = void;
     using type_t =
         decltype(stdx::ct_string_to_type<Type, sc::string_constant>());
-
     using name_t =
         decltype(stdx::ct_string_to_type<Name, sc::string_constant>());
+    using func_t = F;
 
     constexpr static auto ct_name = Name;
-
     constexpr static auto identity = Identity;
-
     constexpr static auto condition = Cond{};
 
-    constexpr static auto run_func = [] {
-        if (condition) {
-            F{}();
-        }
-    };
-
-    constexpr static auto log_func = [] {
-        if (condition) {
-            CIB_TRACE("flow.{}({})", type_t{}, name_t{});
-        }
-    };
-
-    constexpr ct_node() : rt_node{run_func, log_func} {}
-
     constexpr auto operator*() const {
         if constexpr (Identity == subgraph_identity::REFERENCE) {
             return ct_node<Type, Name, subgraph_identity::VALUE, Cond, F>{};

include/seq/impl.hpp

@@ -24,6 +24,11 @@ template <stdx::ct_string, std::size_t NumSteps> struct impl {
 
     using node_t = rt_step;
 
+    template <typename CTNode>
+    constexpr static auto create_node(CTNode n) -> node_t {
+        return n;
+    }
+
     constexpr explicit(true) impl(stdx::span<node_t const, NumSteps> steps) {
         for (auto const &step : steps) {
             _forward_steps.push_back(step.forward_ptr);

test/flow/CMakeLists.txt

@@ -1,13 +1,13 @@
 add_unit_test(
-    "flow_flow_test"
+    "flow_separate_actions_test"
     CATCH2
     FILES
-    "flow.cpp"
     "flow_cib_func.cpp"
+    "separate_actions.cpp"
     LIBRARIES
     warnings
     cib)
 
-add_tests(graph graph_builder)
+add_tests(flow graph graph_builder logging log_levels custom_log_levels)
 
 add_subdirectory(fail)

test/flow/custom_log_levels.cpp

@@ -0,0 +1,96 @@
+#include <cib/cib.hpp>
+#include <flow/flow.hpp>
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <string>
+#include <vector>
+
+namespace {
+using namespace flow::literals;
+
+template <auto... Cs> struct wrapper {
+    struct inner {
+        constexpr static auto config = cib::config(Cs...);
+    };
+    constexpr static auto n = cib::nexus<inner>{};
+
+    wrapper() { n.init(); }
+
+    template <typename S> static auto run() -> void { n.template service<S>(); }
+};
+
+std::vector<logging::level> log_calls{};
+
+template <typename S, auto... Cs>
+constexpr auto run_flow = []() -> void {
+    log_calls.clear();
+    wrapper<Cs...>::template run<S>();
+};
+
+struct TestFlowA : public flow::service<"A"> {};
+struct TestFlowB : public flow::service<"B"> {};
+struct TestFlowC : public flow::service<"C"> {};
+
+constexpr auto msA = flow::milestone<"msA">();
+constexpr auto msB = flow::milestone<"msB">();
+
+struct log_config {
+    struct log_handler {
+        template <logging::level Level, typename ModuleId,
+                  typename FilenameStringType, typename LineNumberType,
+                  typename MsgType>
+        auto log(FilenameStringType, LineNumberType, MsgType const &) -> void {
+            log_calls.push_back(Level);
+        }
+    };
+    log_handler logger;
+};
+} // namespace
+
+template <> inline auto logging::config<> = log_config{};
+
+struct user1_log_spec : flow::default_log_spec {
+    constexpr static auto level = logging::level::USER1;
+};
+struct user2_log_spec : flow::default_log_spec {
+    constexpr static auto level = logging::level::USER2;
+};
+struct info_log_spec : flow::default_log_spec {
+    constexpr static auto level = logging::level::INFO;
+};
+template <> constexpr auto flow::log_spec<"default"> = info_log_spec{};
+
+TEST_CASE("override default log level", "[flow_custom_log_levels]") {
+    run_flow<TestFlowA, cib::exports<TestFlowA>,
+             cib::extend<TestFlowA>(*msA)>();
+
+    REQUIRE(not log_calls.empty());
+    std::for_each(std::begin(log_calls), std::end(log_calls),
+                  [](auto level) { CHECK(level == logging::level::INFO); });
+}
+
+template <> constexpr auto flow::log_spec<"B"> = user1_log_spec{};
+template <> constexpr auto flow::log_spec<"msB"> = user2_log_spec{};
+
+TEST_CASE("override log level by name", "[flow_custom_log_levels]") {
+    run_flow<TestFlowB, cib::exports<TestFlowB>,
+             cib::extend<TestFlowB>(*msB)>();
+
+    REQUIRE(log_calls.size() == 3);
+    CHECK(log_calls[0] == logging::level::USER1);
+    CHECK(log_calls[1] == logging::level::USER2);
+    CHECK(log_calls[2] == logging::level::USER1);
+}
+
+template <> constexpr auto flow::log_spec<"C"> = user1_log_spec{};
+
+TEST_CASE("default log spec for step will use overridden log spec for flow",
+          "[flow_custom_log_levels]") {
+    run_flow<TestFlowC, cib::exports<TestFlowC>,
+             cib::extend<TestFlowC>(*msA)>();
+
+    REQUIRE(log_calls.size() == 3);
+    std::for_each(std::begin(log_calls), std::end(log_calls),
+                  [](auto level) { CHECK(level == logging::level::USER1); });
+}