revert h5py_util.py

Author: jreadey

src/h5json/h5py_util.py

@@ -0,0 +1,109 @@
+##############################################################################
+# Copyright by The HDF Group.                                                #
+# All rights reserved.                                                       #
+#                                                                            #
+# This file is part of H5Serv (HDF5 REST Server) Service, Libraries and      #
+# Utilities.  The full HDF5 REST Server copyright notice, including          #
+# terms governing use, modification, and redistribution, is contained in     #
+# the file COPYING, which can be found at the root of the source code        #
+# distribution tree.  If you do not have access to this file, you may        #
+# request a copy from help@hdfgroup.org.                                     #
+##############################################################################
+
+import h5py
+import numpy as np
+
+from . import hdf5dtype
+
+
+def is_reference(val):
+    """ Return True if the type or value is a Reference """
+
+    if isinstance(val, object) and val.__class__.__name__ == "Reference":
+        return True
+    elif isinstance(val, type) and val.__name__ == "Reference":
+        return True
+    else:
+        return False
+
+
+def is_regionreference(val):
+    """ Return True if the type or value is a RegionReference """
+
+    if isinstance(val, object) and val.__class__.__name__ == "RegionReference":
+        return True
+    elif isinstance(val, type) and val.__name__ == "RegionReference":
+        return True
+
+    return False
+
+
+def has_reference(dtype):
+    """ return True if the dtype (or a sub-type) is a Reference type """
+    has_ref = False
+    if not isinstance(dtype, np.dtype):
+        return False
+    if len(dtype) > 0:
+        for name in dtype.fields:
+            item = dtype.fields[name]
+            if has_reference(item[0]):
+                has_ref = True
+                break
+    elif dtype.metadata and "ref" in dtype.metadata:
+        basedt = dtype.metadata["ref"]
+        has_ref = is_reference(basedt)
+    elif dtype.metadata and "vlen" in dtype.metadata:
+        basedt = dtype.metadata["vlen"]
+        has_ref = has_reference(basedt)
+    return has_ref
+
+
+def convert_dtype(srcdt, to_h5py=True):
+    """Return a dtype based on input dtype, converting any Reference types from
+    h5py style to h5json and vice-versa.
+    """
+
+    if len(srcdt) > 0:
+        fields = []
+        for name in srcdt.fields:
+            item = srcdt.fields[name]
+            # item is a tuple of dtype and integer offset
+            field_dt = convert_dtype(item[0], to_h5py=to_h5py)
+            fields.append((name, field_dt))
+        tgt_dt = np.dtype(fields)
+    else:
+        # check if this a "special dtype"
+        if srcdt.metadata and "ref" in srcdt.metadata:
+            ref = srcdt.metadata["ref"]
+            if is_reference(ref):
+                if to_h5py:
+                    tgt_dt = h5py.special_dtype(ref=h5py.Reference)
+                else:
+                    tgt_dt = hdf5dtype.special_dtype(ref=hdf5dtype.Reference)
+            elif is_regionreference(ref):
+                if to_h5py:
+                    tgt_dt = h5py.special_dtype(ref=h5py.RegionReference)
+                else:
+                    tgt_dt = hdf5dtype.special_dtype(ref=hdf5dtype.RegionReference)
+            else:
+                msg = f"Unexpected ref type: {srcdt}"
+                raise TypeError(msg)
+        elif srcdt.metadata and "vlen" in srcdt.metadata:
+            src_vlen = srcdt.metadata["vlen"]
+            if isinstance(src_vlen, np.dtype):
+                tgt_base = convert_dtype(src_vlen, to_h5py=to_h5py)
+            else:
+                tgt_base = src_vlen
+            if to_h5py:
+                tgt_dt = h5py.special_dtype(vlen=tgt_base)
+            else:
+                tgt_dt = hdf5dtype.special_dtype(vlen=tgt_base)
+        elif srcdt.kind == "U":
+            # use vlen for unicode strings
+            if to_h5py:
+                tgt_dt = h5py.special_dtype(vlen=str)
+            else:
+                tgt_dt = hdf5dtype.special_dtype(vlen=str)
+        else:
+            tgt_dt = srcdt
+    return tgt_dt