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H5P_SET_META_BLOCK_SIZE

Sets the minimum metadata block size

Procedure:

H5P_SET_META_BLOCK_SIZE ( fapl_id, size )

Signature:

herr_t H5Pset_meta_block_size(
                     hid_t fapl_id,
                     hsize_t size
    )
  

Fortran90 Interface: h5pset_meta_block_size_f
    
SUBROUTINE h5pset_meta_block_size_f(plist_id, size, hdferr) 
  IMPLICIT NONE
  INTEGER(HID_T), INTENT(IN) :: plist_id ! File access property list 
                                         ! identifier
  INTEGER(HSIZE_T), INTENT(IN) :: size   ! Metadata block size
  INTEGER, INTENT(OUT)       :: hdferr   ! Error code
                                         ! 0 on success and -1 on failure
END SUBROUTINE h5pset_meta_block_size_f
	

Parameters:
hid_t fapl_id    IN: File access property list identifier
hsize_t sizeIN: Minimum size, in bytes, of metadata block allocations

Description:

H5P_SET_META_BLOCK_SIZE sets the minimum size, in bytes, of metadata block allocations when H5FD_FEAT_AGGREGATE_METADATA is set by a VFL driver.

Each raw metadata block is initially allocated to be of the given size. Specific metadata objects (e.g., object headers, local heaps, B-trees) are then sub-allocated from this block.

The default setting is 2048 bytes, meaning that the library will attempt to aggregate metadata in at least 2K blocks in the file. Setting the value to 0 (zero) with this function will turn off metadata aggregation, even if the VFL driver attempts to use the metadata aggregation strategy.

Metadata aggregation reduces the number of small data objects in the file that would otherwise be required for metadata. The aggregated block of metadata is usually written in a single write action and always in a contiguous block, potentially significantly improving library and application performance.

Returns:

Returns a non-negative value if successful. Otherwise returns a negative value.

Example:

Coming Soon!

History:
Release    C
1.4.0Function introduced in this release.

--- Last Modified: December 04, 2017 | 08:52 AM