rf: Cache layout for precomputed derivatives

Author: effigies

fmriprep/utils/bids.py

@@ -28,6 +28,7 @@
 import os
 import sys
 from collections import defaultdict
+from functools import cache
 from pathlib import Path
 
 from bids.layout import BIDSLayout
@@ -38,6 +39,15 @@
 from ..data import load as load_data
 
 
+@cache
+def _get_layout(derivatives_dir: Path) -> BIDSLayout:
+    import niworkflows.data
+
+    return BIDSLayout(
+        derivatives_dir, config=[niworkflows.data.load('nipreps.json')], validate=False
+    )
+
+
 def collect_derivatives(
     derivatives_dir: Path,
     entities: dict,
@@ -57,8 +67,7 @@ def collect_derivatives(
             patterns = _patterns
 
     derivs_cache = defaultdict(list, {})
-    layout = BIDSLayout(derivatives_dir, config=['bids', 'derivatives'], validate=False)
-    derivatives_dir = Path(derivatives_dir)
+    layout = _get_layout(derivatives_dir)
 
     # search for both boldrefs
     for k, q in spec['baseline'].items():