Fix #1148 : Add passthrough on non-DCI H5DataIO to support its use in…

… pynwb TimeSeries. (#1149)

* Add passthrough on non-DCI H5DataIO to support its use in pynwb TimeSeries. Fixes #1148.

* CHANGELOG update for #1149

* Add another maxshape fallback (self.shape)

* Incorporated @stephprince suggestions on #1149.

---------

Co-authored-by: Steph Prince <[email protected]>

CHANGELOG.md

@@ -11,6 +11,7 @@
 
 ### Bug fixes
 - Fixed issue where scalar datasets with a compound data type were being written as non-scalar datasets @stephprince [#1176](https://github.com/hdmf-dev/hdmf/pull/1176)
+- Fixed H5DataIO not exposing `maxshape` on non-dci dsets. @cboulay [#1149](https://github.com/hdmf-dev/hdmf/pull/1149)
 
 ## HDMF 3.14.3 (July 29, 2024)
 

src/hdmf/backends/hdf5/h5_utils.py

@@ -21,7 +21,7 @@
 from ...query import HDMFDataset, ReferenceResolver, ContainerResolver, BuilderResolver
 from ...region import RegionSlicer
 from ...spec import SpecWriter, SpecReader
-from ...utils import docval, getargs, popargs, get_docval
+from ...utils import docval, getargs, popargs, get_docval, get_data_shape
 
 
 class HDF5IODataChunkIteratorQueue(deque):
@@ -672,3 +672,14 @@ def valid(self):
         if isinstance(self.data, Dataset) and not self.data.id.valid:
             return False
         return super().valid
+
+    @property
+    def maxshape(self):
+        if 'maxshape' in self.io_settings:
+            return self.io_settings['maxshape']
+        elif hasattr(self.data, 'maxshape'):
+            return self.data.maxshape
+        elif hasattr(self, "shape"):
+            return self.shape
+        else:
+            return get_data_shape(self.data)

tests/unit/test_io_hdf5_h5tools.py

@@ -607,6 +607,12 @@ def test_pass_through_of_chunk_shape_generic_data_chunk_iterator(self):
     #############################################
     #  H5DataIO general
     #############################################
+    def test_pass_through_of_maxshape_on_h5dataset(self):
+        k = 10
+        self.io.write_dataset(self.f, DatasetBuilder('test_dataset', np.arange(k), attributes={}))
+        dset = H5DataIO(self.f['test_dataset'])
+        self.assertEqual(dset.maxshape, (k,))
+
     def test_warning_on_non_gzip_compression(self):
         # Make sure no warning is issued when using gzip
         with warnings.catch_warnings(record=True) as w:
@@ -3763,6 +3769,14 @@ def test_dataio_shape_then_data(self):
         with self.assertRaisesRegex(ValueError, "Setting data when dtype and shape are not None is not supported"):
             dataio.data = list()
 
+    def test_dataio_maxshape(self):
+        dataio = H5DataIO(data=np.arange(10), maxshape=(None,))
+        self.assertEqual(dataio.maxshape, (None,))
+
+    def test_dataio_maxshape_from_data(self):
+        dataio = H5DataIO(data=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+        self.assertEqual(dataio.maxshape, (10,))
+
 
 def test_hdf5io_can_read():
     assert not HDF5IO.can_read("not_a_file")