Implement afferent coupling at module level.

Author: Barnabás Domozi

plugins/cpp_metrics/model/include/model/cppfilemetrics.h

@@ -13,7 +13,8 @@ struct CppFileMetrics
 {
   enum Type
   {
-    EFFERENT_MODULE
+    EFFERENT_MODULE,
+    AFFERENT_MODULE
   };
 
   #pragma db id auto

plugins/cpp_metrics/model/include/model/cpptypedependencymetrics.h

@@ -57,12 +57,26 @@ struct CppTypeDependencyMetricsPathView
   object(CppAstNode = DependencyAstNode : CppTypeDependencyMetrics::dependencyHash == DependencyAstNode::entityHash \
     && DependencyAstNode::astType == cc::model::CppAstNode::AstType::Definition) \
   object(File = DependencyFile : DependencyAstNode::location.file == DependencyFile::id)
-struct CppTypeDependencyMetricsPathViewDistinctCount
+struct CppTypeDependencyMetrics_Distinct_D_Count
 {
   #pragma db column("count(distinct" + CppTypeDependencyMetrics::dependencyHash + ")")
   std::size_t count;
 };
 
+#pragma db view \
+  object(CppTypeDependencyMetrics) \
+  object(CppAstNode = EntityAstNode : CppTypeDependencyMetrics::entityHash == EntityAstNode::entityHash \
+    && EntityAstNode::astType == cc::model::CppAstNode::AstType::Definition) \
+  object(File = EntityFile : EntityAstNode::location.file == EntityFile::id) \
+  object(CppAstNode = DependencyAstNode : CppTypeDependencyMetrics::dependencyHash == DependencyAstNode::entityHash \
+    && DependencyAstNode::astType == cc::model::CppAstNode::AstType::Definition) \
+  object(File = DependencyFile : DependencyAstNode::location.file == DependencyFile::id)
+struct CppTypeDependencyMetrics_Distinct_E_Count
+{
+  #pragma db column("count(distinct" + CppTypeDependencyMetrics::entityHash + ")")
+  std::size_t count;
+};
+
 } // model
 } // cc
 

plugins/cpp_metrics/parser/include/cppmetricsparser/cppmetricsparser.h

@@ -82,6 +82,8 @@ class CppMetricsParser : public AbstractParser
   void afferentTypeLevel();
   // Calculate the efferent coupling at module level.
   void efferentModuleLevel();
+  // Calculate the afferent coupling at module level.
+  void afferentModuleLevel();
   // Returns module path query based on parser configuration.
   odb::query<model::File> getModulePathsQuery();
 
@@ -207,6 +209,7 @@ class CppMetricsParser : public AbstractParser
   static const int efferentCouplingTypesPartitionMultiplier = 5;
   static const int afferentCouplingTypesPartitionMultiplier = 5;
   static const int efferentCouplingModulesPartitionMultiplier = 5;
+  static const int afferentCouplingModulesPartitionMultiplier = 5;
 };
 
 } // parser

plugins/cpp_metrics/parser/src/cppmetricsparser.cpp

@@ -557,12 +557,12 @@ void CppMetricsParser::efferentModuleLevel()
     {
       util::OdbTransaction{_ctx.db}([&, this]
       {
-        typedef odb::query<model::CppTypeDependencyMetricsPathViewDistinctCount> TypeDependencyQuery;
-        typedef model::CppTypeDependencyMetricsPathViewDistinctCount TypeDependencyResult;
+        typedef odb::query<model::CppTypeDependencyMetrics_Distinct_D_Count> TypeDependencyQuery;
+        typedef model::CppTypeDependencyMetrics_Distinct_D_Count TypeDependencyResult;
 
         for (const model::File& file : tasks)
         {
-          TypeDependencyResult types = _ctx.db->query_value<model::CppTypeDependencyMetricsPathViewDistinctCount>(
+          TypeDependencyResult types = _ctx.db->query_value<model::CppTypeDependencyMetrics_Distinct_D_Count>(
             TypeDependencyQuery::EntityFile::path.like(file.path + '%') &&
             !TypeDependencyQuery::DependencyFile::path.like(file.path + '%'));
 
@@ -576,6 +576,35 @@ void CppMetricsParser::efferentModuleLevel()
   });
 }
 
+void CppMetricsParser::afferentModuleLevel()
+{
+  parallelCalcMetric<model::File>(
+    "Afferent coupling at module level",
+    _threadCount * afferentCouplingModulesPartitionMultiplier,// number of jobs; adjust for granularity
+    getModulePathsQuery(),
+    [&, this](const MetricsTasks<model::File>& tasks)
+    {
+      util::OdbTransaction{_ctx.db}([&, this]
+      {
+        typedef odb::query<model::CppTypeDependencyMetrics_Distinct_E_Count> TypeDependencyQuery;
+        typedef model::CppTypeDependencyMetrics_Distinct_E_Count TypeDependencyResult;
+
+        for (const model::File& file : tasks)
+        {
+          TypeDependencyResult types = _ctx.db->query_value<model::CppTypeDependencyMetrics_Distinct_E_Count>(
+            !TypeDependencyQuery::EntityFile::path.like(file.path + '%') &&
+            TypeDependencyQuery::DependencyFile::path.like(file.path + '%'));
+
+          model::CppFileMetrics metric;
+          metric.file = file.id;
+          metric.type = model::CppFileMetrics::Type::AFFERENT_MODULE;
+          metric.value = types.count;
+          _ctx.db->persist(metric);
+        }
+      });
+  });
+}
+
 bool CppMetricsParser::parse()
 {
   LOG(info) << "[cppmetricsparser] Computing function parameter count metric.";
@@ -594,6 +623,8 @@ bool CppMetricsParser::parse()
   afferentTypeLevel();
   LOG(info) << "[cppmetricsparser] Computing efferent coupling metric at module level.";
   efferentModuleLevel(); // This metric needs to be calculated after efferentTypeLevel
+  LOG(info) << "[cppmetricsparser] Computing afferent coupling metric at module level.";
+  afferentModuleLevel(); // This metric needs to be calculated after efferentTypeLevel
   return true;
 }
 

plugins/cpp_metrics/test/sources/parser/module_d/d1.h

@@ -0,0 +1,15 @@
+#ifndef CC_CPP_MODULE_METRICS_TEST_D1
+#define CC_CPP_MODULE_METRICS_TEST_D1
+
+#include "../module_c/c1.h"
+#include "../module_c/c2.h"
+
+namespace CC_CPP_MODULE_METRICS_TEST
+{
+class D1 {
+  C1 c1;
+  C2 c2;
+};
+}
+
+#endif

plugins/cpp_metrics/test/sources/parser/modulemetrics.cpp

@@ -4,3 +4,4 @@
 #include "./module_b/b2.h"
 #include "./module_c/c1.h"
 #include "./module_c/c2.h"
+#include "./module_d/d1.h"

plugins/cpp_metrics/test/src/cppmetricsparsertest.cpp

@@ -330,9 +330,10 @@ class ParameterizedEfferentModuleCouplingTest
 {};
 
 std::vector<StringUintParam> paramEfferentModule = {
-  {"%/test/sources/parser/module_a", 1},
+  {"%/test/sources/parser/module_a", 1}, // B1
   {"%/test/sources/parser/module_b", 0},
-  {"%/test/sources/parser/module_c", 2},
+  {"%/test/sources/parser/module_c", 2}, // A2, B1
+  {"%/test/sources/parser/module_d", 2}, // D1, D2
 };
 
 TEST_P(ParameterizedEfferentModuleCouplingTest, ModuleEfferentTest) {
@@ -353,3 +354,36 @@ INSTANTIATE_TEST_SUITE_P(
   ParameterizedEfferentModuleCouplingTest,
   ::testing::ValuesIn(paramEfferentModule)
 );
+
+// Afferent coupling at module level
+
+class ParameterizedAfferentModuleCouplingTest
+  : public CppMetricsParserTest,
+    public ::testing::WithParamInterface<StringUintParam>
+{};
+
+std::vector<StringUintParam> paramAfferentModule = {
+  {"%/test/sources/parser/module_a", 1}, // C2
+  {"%/test/sources/parser/module_b", 3}, // A2, C1, C2
+  {"%/test/sources/parser/module_c", 1}, // D1
+  {"%/test/sources/parser/module_d", 0},
+};
+
+TEST_P(ParameterizedAfferentModuleCouplingTest, ModuleAfferentTest) {
+  _transaction([&, this]() {
+
+    typedef odb::query<model::CppModuleMetricsForPathView> CppModuleMetricsQuery;
+
+    const auto metric = _db->query_value<model::CppModuleMetricsForPathView>(
+      CppModuleMetricsQuery::CppFileMetrics::type == model::CppFileMetrics::Type::AFFERENT_MODULE &&
+      CppModuleMetricsQuery::File::path.like(GetParam().first));
+
+    EXPECT_EQ(GetParam().second, metric.value);
+  });
+}
+
+INSTANTIATE_TEST_SUITE_P(
+  ParameterizedAfferentModuleCouplingTestSuite,
+  ParameterizedAfferentModuleCouplingTest,
+  ::testing::ValuesIn(paramAfferentModule)
+);