Extend a blob

ss_blob_extend is a function defined in ssblob.c.

Synopsis:

herr_t ss_blob_extend(ss_blob_t *blob, const hsize_t *size, unsigned flags, ss_prop_t UNUSED *props)

Formal Arguments:

  • blob: Blob which is possibly to be extended.
  • size: New size of the blob on each calling task per dataset dimension
  • flags: Bit flags such as SS_ALLSAME.
  • props: Optional property list (none defined yet).

Description: Certain blobs are considered to be extendible (see ss_blob_bind_f) and this function can be used to make such a blob larger. The new size of the blob is the maximum size from across all collectively calling tasks but a blob is never made smaller than its current size. Each dimension of the blob is resized independently of the others. If the SS_ALLSAME bit is set in the flags argument then the MPI reduction to find the maximum is skipped and we assume that all tasks passed the same value for size.

Return Value: Returns non-negative on success; negative on failure.

Parallel Notes: Collective across the file communicator to which the blob belongs. Tasks that are not part of the blob’s scope should pass the top-scope of the blob’s file in place of the blob argument. This restriction is due to HDF5’s requirement that an H5Dextend call is file collective.

See Also:

  • ss_blob_bind_f: 15.4: Bind a blob to a dataset
  • I/O: Introduction for current chapter