Cache track_length_grace and track_length_max access

beets/autotag/match.py

@@ -22,6 +22,7 @@ import datetime
 import re
 from collections.abc import Iterable, Sequence
 from enum import IntEnum
+from functools import cache
 from typing import TYPE_CHECKING, Any, NamedTuple, TypeVar, cast
 
 import lap
@@ -149,8 +150,16 @@ def track_index_changed(item: Item, track_info: TrackInfo) -> bool:
     return item.track not in (track_info.medium_index, track_info.index)
 
 
-track_length_grace = config["match"]["track_length_grace"].as_number()
-track_length_max = config["match"]["track_length_max"].as_number()
+@cache
+def get_track_length_grace() -> float:
+    """Get cached grace period for track length matching."""
+    return config["match"]["track_length_grace"].as_number()
+
+
+@cache
+def get_track_length_max() -> float:
+    """Get cached maximum track length for track length matching."""
+    return config["match"]["track_length_max"].as_number()
 
 
 def track_distance(
@@ -161,13 +170,17 @@ def track_distance(
     """Determines the significance of a track metadata change. Returns a
     Distance object. `incl_artist` indicates that a distance component should
     be included for the track artist (i.e., for various-artist releases).
+
+    ``track_length_grace`` and ``track_length_max`` configuration options are
+    cached because this function is called many times during the matching
+    process and their access comes with a performance overhead.
     """
     dist = hooks.Distance()
 
     # Length.
     if info_length := track_info.length:
-        diff = abs(item.length - info_length) - track_length_grace
-        dist.add_ratio("track_length", diff, track_length_max)
+        diff = abs(item.length - info_length) - get_track_length_grace()
+        dist.add_ratio("track_length", diff, get_track_length_max())
 
     # Title.
     dist.add_string("track_title", item.title, track_info.title)