Retrieve maxshape for Dataset

pyfive/dataobjects.py

@@ -19,6 +19,9 @@
 from .btree import GZIP_DEFLATE_FILTER, SHUFFLE_FILTER, FLETCH32_FILTER
 from .misc_low_level import Heap, SymbolTable, GlobalHeap, FractalHeap
 
+# these constants happen to have the same value...
+UNLIMITED_SIZE = UNDEFINED_ADDRESS
+
 
 class DataObjects(object):
  """
@@ -180,7 +183,7 @@ def unpack_attribute(self, offset):
  offset += _padded_size(attr_dict['datatype_size'], padding_multiple)
 
  # read in the dataspace information
- shape = determine_data_shape(self.msg_data, offset)
+ shape, maxshape = determine_data_shape(self.msg_data, offset)
  items = int(np.product(shape))
  offset += _padded_size(attr_dict['dataspace_size'], padding_multiple)
 
@@ -246,7 +249,16 @@ def shape(self):
  """ Shape of the dataset. """
  msg = self.find_msg_type(DATASPACE_MSG_TYPE)[0]
  msg_offset = msg['offset_to_message']
- return determine_data_shape(self.msg_data, msg_offset)
+ shape, maxshape = determine_data_shape(self.msg_data, msg_offset)
+ return shape
+
+ @property
+ def maxshape(self):
+ """ Maximum Shape of the dataset. (None for unlimited dimension) """
+ msg = self.find_msg_type(DATASPACE_MSG_TYPE)[0]
+ msg_offset = msg['offset_to_message']
+ shape, maxshape = determine_data_shape(self.msg_data, msg_offset)
+ return maxshape
 
  @property
  def fillvalue(self):
@@ -665,9 +677,15 @@ def determine_data_shape(buf, offset):
 
  ndims = header['dimensionality']
  dim_sizes = struct.unpack_from('<' + 'Q' * ndims, buf, offset)
+ offset += 8 * ndims
  # Dimension maximum size follows if header['flags'] bit 0 set
+ if header['flags'] & 2**0:
+ maxshape = struct.unpack_from('<' + 'Q' * ndims, buf, offset)
+ maxshape = tuple((None if d == UNLIMITED_SIZE else d) for d in maxshape)
+ else:
+ maxshape = dim_sizes
  # Permutation index follows if header['flags'] bit 1 set
- return dim_sizes
+ return dim_sizes, maxshape
 
 
 # HDF5 Structures

pyfive/high_level.py

@@ -310,6 +310,11 @@ def shape(self):
  """ shape attribute. """
  return self._dataobjects.shape
 
+ @property
+ def maxshape(self):
+ """ maxshape attribute. (None for unlimited dimensions) """
+ return self._dataobjects.maxshape
+
  @property
  def ndim(self):
  """ number of dimensions. """