perf(langserver): speedup Visitor and AsyncVisitor a little bit

Author: d-biehl

.vscode/launch.json

@@ -44,7 +44,8 @@
 				// "--no-pager",
 				//"config", "info", "list",
 				// "analyze",
-				"profiles", "list"
+				// "profiles", "list"
+				"discover", "tests", "--tags"
 				// "."
 			]
 		},

packages/language_server/src/robotcode/language_server/robotframework/diagnostics/analyzer.py

@@ -75,6 +75,8 @@ def __init__(
     ) -> None:
         from robot.parsing.model.statements import Template, TestTemplate
 
+        super().__init__()
+
         self.model = model
         self.namespace = namespace
         self.finder = finder

packages/language_server/src/robotcode/language_server/robotframework/parts/code_action_helper_mixin.py

@@ -29,6 +29,7 @@ class CodeActionDataBase:
 
 class FindSectionsVisitor(Visitor):
     def __init__(self) -> None:
+        super().__init__()
         self.keyword_sections: List[ast.AST] = []
         self.variable_sections: List[ast.AST] = []
         self.setting_sections: List[ast.AST] = []

packages/language_server/src/robotcode/language_server/robotframework/utils/ast_utils.py

@@ -120,6 +120,7 @@ def range_from_token(token: Token) -> Range:
 
 class FirstAndLastRealStatementFinder(async_ast.Visitor):
     def __init__(self) -> None:
+        super().__init__()
         self.first_statement: Optional[ast.AST] = None
         self.last_statement: Optional[ast.AST] = None
 

packages/language_server/src/robotcode/language_server/robotframework/utils/async_ast.py

@@ -1,5 +1,5 @@
 import ast
-from typing import Any, AsyncIterator, Callable, Iterator, Optional, Type, cast
+from typing import Any, AsyncIterator, Callable, Dict, Iterator, Optional, Type
 
 __all__ = ["iter_fields", "iter_child_nodes", "AsyncVisitor"]
 
@@ -47,20 +47,31 @@ async def iter_nodes(node: ast.AST) -> AsyncIterator[ast.AST]:
 
 
 class VisitorFinder:
-    def _find_visitor(self, cls: Type[Any]) -> Optional[Callable[..., Any]]:
+    __NOT_SET = object()
+
+    def __init__(self) -> None:
+        self.__cache: Dict[Type[Any], Optional[Callable[..., Any]]] = {}
+
+    def __find_visitor(self, cls: Type[Any]) -> Optional[Callable[..., Any]]:
         if cls is ast.AST:
             return None
         method_name = "visit_" + cls.__name__
         if hasattr(self, method_name):
             method = getattr(self, method_name)
             if callable(method):
-                return cast("Callable[..., Any]", method)
+                return method  # type: ignore
         for base in cls.__bases__:
             method = self._find_visitor(base)
             if method:
-                return cast("Callable[..., Any]", method)
+                return method  # type: ignore
         return None
 
+    def _find_visitor(self, cls: Type[Any]) -> Optional[Callable[..., Any]]:
+        r = self.__cache.get(cls, self.__NOT_SET)
+        if r is self.__NOT_SET:
+            self.__cache[cls] = r = self.__find_visitor(cls)
+        return r  # type: ignore
+
 
 class AsyncVisitor(VisitorFinder):
     async def visit(self, node: ast.AST) -> None: