Add zarr_class_info attribute to zarr files for unambiguous and extendible zarr read

src/spikeinterface/core/zarrextractors.py

@@ -5,10 +5,10 @@
 
 from probeinterface import ProbeGroup
 
-from .base import minimum_spike_dtype
+from .base import minimum_spike_dtype, _get_class_from_string
 from .baserecording import BaseRecording, BaseRecordingSegment
 from .basesorting import BaseSorting, SpikeVectorSortingSegment
-from .core_tools import define_function_from_class, check_json
+from .core_tools import define_function_from_class, check_json, retrieve_importing_provenance
 from .job_tools import split_job_kwargs
 from .core_tools import is_path_remote
 
@@ -212,6 +212,7 @@ def write_recording(
         recording: BaseRecording, folder_path: str | Path, storage_options: dict | None = None, **kwargs
     ):
         zarr_root = zarr.open(str(folder_path), mode="w", storage_options=storage_options)
+        zarr_root.attrs["zarr_class_info"] = retrieve_importing_provenance(ZarrRecordingExtractor)
         add_recording_to_zarr_group(recording, zarr_root, **kwargs)
 
 
@@ -320,6 +321,7 @@ def write_sorting(sorting: BaseSorting, folder_path: str | Path, storage_options
         Write a sorting extractor to zarr format.
         """
         zarr_root = zarr.open(str(folder_path), mode="w", storage_options=storage_options)
+        zarr_root.attrs["zarr_class_info"] = retrieve_importing_provenance(ZarrSortingExtractor)
         add_sorting_to_zarr_group(sorting, zarr_root, **kwargs)
 
 
@@ -345,15 +347,22 @@ def read_zarr(
     extractor : ZarrExtractor
         The loaded extractor
     """
-    # TODO @alessio : we should have something more explicit in our zarr format to tell which object it is.
-    # for the futur SortingAnalyzer we will have this 2 fields!!!
     root = super_zarr_open(folder_path, mode="r", storage_options=storage_options)
-    if "channel_ids" in root.keys():
-        return read_zarr_recording(folder_path, storage_options=storage_options)
-    elif "unit_ids" in root.keys():
-        return read_zarr_sorting(folder_path, storage_options=storage_options)
+    zarr_class_info = root.attrs.get("zarr_class_info", None)
+    if zarr_class_info is not None:
+        class_name = zarr_class_info["class"]
+        extractor_class = _get_class_from_string(class_name)
+        return extractor_class(folder_path, storage_options=storage_options)
     else:
-        raise ValueError("Cannot find 'channel_ids' or 'unit_ids' in zarr root. Not a valid SpikeInterface zarr format")
+        # For version<0.105.0 zarr files, revert to old way of loading based on the presence of "channel_ids"/"unit_ids"
+        if "channel_ids" in root.keys():
+            return read_zarr_recording(folder_path, storage_options=storage_options)
+        elif "unit_ids" in root.keys():
+            return read_zarr_sorting(folder_path, storage_options=storage_options)
+        else:
+            raise ValueError(
+                "Cannot find 'channel_ids' or 'unit_ids' in zarr root. Not a valid SpikeInterface zarr format"
+            )
 
 
 ### UTILITY FUNCTIONS ###