H5D_EXTEND verifies that the dataset is at least of size
size, extending it if necessary. The dimensionality of
size is the same as that of the dataspace of the dataset being changed.
This function can be applied to the following datasets:
- Any dataset with unlimited dimensions
- A dataset with fixed dimensions if the current dimension sizes are less than the maximum sizes set with
maxdims (see H5S_CREATE_SIMPLE)
Space on disk is immediately allocated for the new dataset extent if the dataset’s space allocation time is set to
H5D_ALLOC_TIME_EARLY. Fill values will be written to the dataset if the dataset’s fill time is set to
H5D_FILL_TIME_ALLOC. (See H5P_SET_FILL_TIME and H5P_SET_ALLOC_TIME.)
This function ensures that the dataset dimensions are of at least the sizes specified in
size. The function H5D_SET_EXTENT must be used if the dataset dimension sizes are are to be reduced.