🐛 cache load_dag in PathFinder only (#2518)

etl/helpers.py

@@ -8,6 +8,7 @@
 import tempfile
 from collections.abc import Generator
 from contextlib import contextmanager
+from functools import cache
 from pathlib import Path
 from typing import Any, Dict, Iterable, Iterator, List, Literal, Optional, Union, cast
 from urllib.parse import urljoin
@@ -377,6 +378,10 @@ class WrongStepName(ExceptionFromDocstring):
     """Wrong step name. If this step was in the dag, it should be corrected."""
 
 
+# loading DAG can take up to 1 second, so cache it
+load_dag_cached = cache(load_dag)
+
+
 class PathFinder:
     """Helper object with naming conventions. It uses your module path (__file__) and
     extracts from it commonly used attributes like channel / namespace / version / short_name or
@@ -414,9 +419,9 @@ def dag(self):
         """Lazy loading of DAG."""
         if self._dag is None:
             if "/archive/" in str(self.f):
-                self._dag = load_dag(paths.DAG_ARCHIVE_FILE)
+                self._dag = load_dag_cached(paths.DAG_ARCHIVE_FILE)
             else:
-                self._dag = load_dag()
+                self._dag = load_dag_cached()
         return self._dag
 
     @property

etl/steps/__init__.py

@@ -14,7 +14,6 @@
 from collections import defaultdict
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from dataclasses import dataclass, field
-from functools import cache
 from glob import glob
 from importlib import import_module
 from pathlib import Path
@@ -131,7 +130,6 @@ def traverse(graph: Graph, nodes: Set[str]) -> Graph:
     return dict(reachable)
 
 
-@cache
 def load_dag(filename: Union[str, Path] = paths.DEFAULT_DAG_FILE) -> Dict[str, Any]:
     return _load_dag(filename, {})