From 35c1cedd9ad1c35225cd8626a457031b08348d57 Mon Sep 17 00:00:00 2001
From: J007X <92790555+J007X@users.noreply.github.com>
Date: Wed, 5 Apr 2023 08:35:04 +0400
Subject: [PATCH] Improving class loading efficiency and considering dynamic
 type list (#919)

* Initial commit for the performance change relating to class loadind in new code after underline changes related to data pack. After discussed with Hector using standard LRU_Cache instead of custom cache.

* Option 2 for considering dynamic type list as mentioned in #765: created an non-cached version of get_class (get_class_nc) and used in get_class to avoid dynamic list issue as mentioned in comments of #765 as pointed out my Hector.

* Fixed related method sequence issue and added doc

* made lru_cache compatible with Python 3.7

* using full_class_name instead of class_name in get_class_nc

* fixed black format issue

* fixed lint format issue (import sequence)

* fixed for lint issue (import grouping)

* Fix CI warning (in ontology)

* Fix "unhashable key type issue" when using LRU cache for get_class that have optional list as parameter -- change to cache lower level result from "locate" method called in this method, and also provide a non-cached version (same as before) for resolving #765.

* Fix comments on duplicate code of "get_class" and "get_class_nc" by re-factoring into one method with "cached_lookup" optional flag -- by default this is true but in _get_sub_class this flag needs to set to "false" based on comments in #765 (for dynamic class loading scenario).

* Need to remove the old "get_class_nc" signature removed in refactoring

---------

Co-authored-by: Hector <hunterhector@gmail.com>
---
 forte/data/data_store.py |  2 +-
 forte/utils/utils.py     | 38 ++++++++++++++++++++++++++++++--------
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/forte/data/data_store.py b/forte/data/data_store.py
index 016ed2991..aab05364b 100644
--- a/forte/data/data_store.py
+++ b/forte/data/data_store.py
@@ -895,7 +895,7 @@ def _is_subclass(
             if cls_qualified_name in type_name_parent_class:
                 return True
             else:
-                entry_class = get_class(type_name)
+                entry_class = get_class(type_name, cached_lookup=False)
                 if issubclass(entry_class, cls):
                     type_name_parent_class.add(cls_qualified_name)
                     return True
diff --git a/forte/utils/utils.py b/forte/utils/utils.py
index 4035509e9..b17f9a4d3 100644
--- a/forte/utils/utils.py
+++ b/forte/utils/utils.py
@@ -16,7 +16,7 @@
 """
 import sys
 import difflib
-from functools import wraps
+from functools import wraps, lru_cache
 from inspect import getfullargspec
 from pydoc import locate
 from typing import Dict, List, Optional, get_type_hints, Tuple
@@ -78,8 +78,26 @@ def get_class_name(o, lower: bool = False) -> str:
         return o.__name__
 
 
-def get_class(full_class_name: str, module_paths: Optional[List[str]] = None):
-    r"""Returns the class based on class name.
+@lru_cache()
+def cached_locate(name_to_locate_class):
+    r"""Wrapped version of locate for loading class based on
+        ``name_to_locate_class``, cached by lru_cache.
+    Args:
+        name_to_locate_class (str): Name or full path to the class.
+
+    Returns:
+        The target class.
+
+    """
+    return locate(name_to_locate_class)
+
+
+def get_class(
+    full_class_name: str,
+    module_paths: Optional[List[str]] = None,
+    cached_lookup: Optional[bool] = True,
+):
+    r"""Returns the class based on class name, with cached lookup option.
 
     Args:
         full_class_name (str): Name or full path to the class.
@@ -87,18 +105,22 @@ def get_class(full_class_name: str, module_paths: Optional[List[str]] = None):
             class. This is used if the class cannot be located solely based on
             ``class_name``. The first module in the list that contains the class
             is used.
+        cached_lookup (bool): Flag to use "cached_locate" for class loading
 
     Returns:
         The target class.
 
-    Raises:
-        ValueError: If class is not found based on :attr:`class_name` and
-            :attr:`module_paths`.
     """
-    class_ = locate(full_class_name)
+    if cached_lookup:
+        class_ = cached_locate(full_class_name)
+    else:
+        class_ = locate(full_class_name)
     if (class_ is None) and (module_paths is not None):
         for module_path in module_paths:
-            class_ = locate(".".join([module_path, full_class_name]))
+            if cached_lookup:
+                class_ = cached_locate(".".join([module_path, full_class_name]))
+            else:
+                class_ = locate(".".join([module_path, full_class_name]))
             if class_ is not None:
                 break