FIX: Hash multi session runs, filter by session when collecting

Author: mgxd

src/smriprep/utils/misc.py

@@ -95,3 +95,20 @@ def fs_isRunning(subjects_dir, subject_id, mtime_tol=86400, logger=None):
     if logger:
         logger.warn(f'Removed "IsRunning*" files found under {subj_dir}')
     return subjects_dir
+
+
+def hash_list(lst: list[str], digest_size: int = 2) -> str:
+    """
+    Hash a list of strings into a string.
+
+    Example
+    -------
+    >>> hash_list(['a', 'b', 'c'])
+    '1279'
+    >>> hash_list(['a', 'b', 'c'], digest_size=3)
+    'fb7bf6'
+
+    """
+    from hashlib import blake2b
+
+    return blake2b(','.join(lst).encode('utf-8'), digest_size=digest_size).hexdigest()

src/smriprep/workflows/base.py

@@ -182,8 +182,14 @@ def init_smriprep_wf(
 
         name = f'sub-{subject_id}_wf'
         if session_ids:
-            if isinstance(session_ids, str):
-                ses_str = session_ids
+            ses_str = session_ids
+            if isinstance(session_ids, list):
+                if len(session_ids) == 1:
+                    ses_str = session_ids[0]
+                else:
+                    from smriprep.utils.misc import hash_list
+
+                    ses_str = hash_list(session_ids, digest_size=2)
 
             name = f'sub-{subject_id}_ses-{ses_str}_wf'
 
@@ -358,7 +364,9 @@ def init_single_subject_wf(
             'flair': [],
         }
     else:
-        subject_data = collect_data(layout, subject_id, bids_filters=bids_filters)[0]
+        subject_data = collect_data(
+            layout, subject_id, session_id=session_id, bids_filters=bids_filters
+        )[0]
 
     if not subject_data['t1w']:
         raise Exception(
@@ -492,9 +500,17 @@ def _prefix(subject_id, session_id=None):
     """Create FreeSurfer subject ID."""
     if not subject_id.startswith('sub-'):
         subject_id = f'sub-{subject_id}'
-    if session_id and not isinstance(session_id, list):
-        # For now, drop ses label if multiple sessions
-        if not session_id.startswith('ses-'):
-            session_id = f'ses-{session_id}'
-        subject_id = f'{subject_id}_{session_id}'
+
+    if session_id:
+        ses_str = session_id
+        if isinstance(session_id, list):
+            if len(session_id) == 1:
+                ses_str = session_id[0]
+            else:
+                from smriprep.utils.misc import hash_list
+
+                ses_str = f'multi{hash_list(session_id, digest_size=2)}'
+        if not ses_str.startswith('ses-'):
+            ses_str = f'ses-{ses_str}'
+        subject_id += f'_{ses_str}'
     return subject_id