fix for scalar datasets

Author: jreadey

src/h5json/hdf5db.py

@@ -603,7 +603,11 @@ def getDatasetValues(self, dset_id, sel):
                     stop = start + sel_inter.count[dim]
                     slices.append(slice(start, stop, 1))
                 slices = tuple(slices)
-                arr[slices] = update_val
+                # TBD: needs updating to work in the general case!
+                if slices == ():
+                    arr[slices] = update_val[slices]
+                else:
+                    arr[slices] = update_val
 
         return arr
 
@@ -620,6 +624,11 @@ def setDatasetValues(self, dset_id, sel, arr):
             raise ValueError("Only hyperslab selections are currently supported")
         if not isinstance(arr, np.ndarray):
             raise TypeError("Expected ndarray for data value")
+        tgt_dt = self.getDtype(dset_json)
+        src_dt = arr.dtype
+        if src_dt != tgt_dt:
+            raise TypeError("arr.dtype doesn't match dataset dtype")
+
         if shape_json["class"] == "H5S_NULL":
             raise ValueError("writing to null space dataset not supported")
         if shape_json["class"] == "H5S_SCALAR":

test/unit/hsds_writer_test.py

@@ -244,23 +244,42 @@ def testReaderWriter(self):
         self.assertTrue(db.writer.lastModified is None)  # no flush yet
 
         # create a scalar dataset
-        dset_id = db.createDataset(shape=(), dtype=np.int32)
-        dset_json = db.getObjectById(dset_id)
+        dsetA_id = db.createDataset(shape=(), dtype=np.int32)
+        dset_json = db.getObjectById(dsetA_id)
         self.assertTrue("created" in dset_json)
         dset_create_time = dset_json["created"]
         self.assertTrue(dset_create_time > 0)
 
+        db.createHardLink(root_id, "dset_a", dsetA_id)
+
         arr = np.zeros((), dtype=np.int32)
         arr[()] = 42
         sel_all = selections.select((), ...)
-        db.setDatasetValues(dset_id, sel_all, arr)
-        dset_json = db.getObjectById(dset_id)
+        db.setDatasetValues(dsetA_id, sel_all, arr)
+
+        dset_json = db.getObjectById(dsetA_id)
         self.assertTrue("lastModified" in dset_json)
         self.assertTrue(dset_json["lastModified"] > dset_create_time)
 
-        arr = db.getDatasetValues(dset_id, sel_all)
+        arr = db.getDatasetValues(dsetA_id, sel_all)
         self.assertEqual(arr[()], 42)
 
+        # create a scalar dataset with string
+        dt_str = special_dtype(vlen=str)
+        dsetB_id = db.createDataset(shape=(), dtype=dt_str)
+        dset_json = db.getObjectById(dsetB_id)
+        db.createHardLink(root_id, "dset_b", dsetB_id)
+
+        arr = np.zeros((), dtype=dt_str)
+        arr[()] = "hello world"
+        db.setDatasetValues(dsetB_id, sel_all, arr)
+
+        arr = db.getDatasetValues(dsetB_id, sel_all)
+
+        e = arr[()]
+        self.assertEqual(e, "hello world")
+        self.assertTrue(isinstance(e, str))
+
         db.close()
 
     def testH5PyToHS(self):