SONARPY-2467 Fix performance bottleneck of GlobalSymbolComputation due to DjangoViewsVisitor (#2246)

Author: guillaume-dequenne

python-frontend/src/main/java/org/sonar/python/semantic/ProjectLevelSymbolTable.java

@@ -46,6 +46,7 @@
 import org.sonar.python.types.v2.FunctionType;
 import org.sonar.python.types.v2.PythonType;
 import org.sonar.python.types.v2.TriBool;
+import org.sonar.python.types.v2.TypeCheckBuilder;
 import org.sonar.python.types.v2.TypeChecker;
 import org.sonar.python.types.v2.UnknownType;
 
@@ -223,11 +224,21 @@ public Collection<Symbol> stubFilesSymbols() {
   private class DjangoViewsVisitor extends BaseTreeVisitor {
 
     String fullyQualifiedModuleName;
+    private TypeCheckBuilder confPathCall = null;
+    private TypeCheckBuilder pathCall = null;
 
     public DjangoViewsVisitor(String fullyQualifiedModuleName) {
       this.fullyQualifiedModuleName = fullyQualifiedModuleName;
     }
 
+    @Override
+    public void visitFileInput(FileInput fileInput) {
+      TypeChecker typeChecker = new TypeChecker(new BasicTypeTable(new ProjectLevelTypeTable(ProjectLevelSymbolTable.this)));
+      confPathCall = typeChecker.typeCheckBuilder().isTypeWithName("django.urls.conf.path");
+      pathCall = typeChecker.typeCheckBuilder().isTypeWithName("django.urls.path");
+      super.visitFileInput(fileInput);
+    }
+
     @Override
     public void visitCallExpression(CallExpression callExpression) {
       super.visitCallExpression(callExpression);
@@ -246,9 +257,8 @@ public void visitCallExpression(CallExpression callExpression) {
     }
 
     private boolean isCallRegisteringDjangoView(CallExpression callExpression) {
-      TypeChecker typeChecker = new TypeChecker(new BasicTypeTable(new ProjectLevelTypeTable(ProjectLevelSymbolTable.this)));
-      TriBool isConfPathCall = typeChecker.typeCheckBuilder().isTypeWithName("django.urls.conf.path").check(callExpression.callee().typeV2());
-      TriBool isPathCall = typeChecker.typeCheckBuilder().isTypeWithName("django.urls.path").check(callExpression.callee().typeV2());
+      TriBool isConfPathCall = confPathCall.check(callExpression.callee().typeV2());
+      TriBool isPathCall = pathCall.check(callExpression.callee().typeV2());
       return isConfPathCall.equals(TriBool.TRUE) || isPathCall.equals(TriBool.TRUE);
     }
   }

python-frontend/src/test/java/org/sonar/python/semantic/ProjectLevelSymbolTableTest.java

@@ -521,7 +521,7 @@ void importedStubModules() {
       """);
     ProjectLevelSymbolTable projectLevelSymbolTable = ProjectLevelSymbolTable.empty();
     projectLevelSymbolTable.addModule(tree, "my_package", pythonFile("mod.py"));
-    assertThat(projectLevelSymbolTable.typeShedDescriptorsProvider().stubModules()).containsExactlyInAnyOrder("math", "os");
+    assertThat(projectLevelSymbolTable.typeShedDescriptorsProvider().stubModules()).containsExactlyInAnyOrder("math", "os", "django", "django.urls.conf", "django.urls");
   }
 
   @Test

sonar-python-plugin/src/test/java/org/sonar/plugins/python/PythonSensorTest.java

@@ -1113,7 +1113,7 @@ void write_cpd_tokens_to_cache() throws IOException {
 
     assertThat(writeCache.getData().keySet()).containsExactlyInAnyOrder(
       "python:cache_version", "python:files", "python:descriptors:moduleKey:pass.py", "python:imports:moduleKey:pass.py",
-      "python:cpd:data:moduleKey:pass.py", "python:cpd:stringTable:moduleKey:pass.py", "python:content_hashes:moduleKey:pass.py");
+      "python:cpd:data:moduleKey:pass.py", "python:cpd:stringTable:moduleKey:pass.py", "python:content_hashes:moduleKey:pass.py", "python:typeshed_modules");
 
     byte[] tokenData = writeCache.getData().get("python:cpd:data:moduleKey:pass.py");
     byte[] stringTable = writeCache.getData().get("python:cpd:stringTable:moduleKey:pass.py");