Data Structures
struct	H5FD_onion_fapl_info_t

Macros
#define	H5FD_ONION (H5FDperform_init(H5FD_onion_init))

#define	H5FD_ONION_VALUE H5_VFD_ONION

#define	H5FD_ONION_FAPL_INFO_VERSION_CURR 1

#define	H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT (0x0001u)

#define	H5FD_ONION_FAPL_INFO_COMMENT_MAX_LEN 255

#define	H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST UINT64_MAX

Enumerations
enum	H5FD_onion_target_file_constant_t { H5FD_ONION_STORE_TARGET_ONION }

Functions
H5_DLL herr_t	H5Pget_fapl_onion (hid_t fapl_id, H5FD_onion_fapl_info_t *fa_out)
	get the onion info from the file access property list

H5_DLL herr_t	H5Pset_fapl_onion (hid_t fapl_id, const H5FD_onion_fapl_info_t *fa)
	set the onion info for the file access property list

H5_DLL herr_t	H5FDonion_get_revision_count (const char filename, hid_t fapl_id, uint64_t revision_count)
	get the number of revisions

Macro Definition Documentation

◆ H5FD_ONION

#define H5FD_ONION (H5FDperform_init(H5FD_onion_init))

Initializer for the onion VFD

◆ H5FD_ONION_FAPL_INFO_COMMENT_MAX_LEN

#define H5FD_ONION_FAPL_INFO_COMMENT_MAX_LEN 255

Max length of a comment. The buffer is defined to be this size + 1 to handle the NUL.

◆ H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT

#define H5FD_ONION_FAPL_INFO_CREATE_FLAG_ENABLE_PAGE_ALIGNMENT (0x0001u)

\ Onion history metadata will align to page_size. \ Partial pages of unused space will occur in the file, \ but may improve read performance from the backing store \ on some systems. \ If disabled (0), padding will not be inserted to align \ to page boundaries. \

◆ H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST

#define H5FD_ONION_FAPL_INFO_REVISION_ID_LATEST UINT64_MAX

Indicates that you want the latest revision.

◆ H5FD_ONION_FAPL_INFO_VERSION_CURR

#define H5FD_ONION_FAPL_INFO_VERSION_CURR 1

Current version of the onion VFD fapl info struct

◆ H5FD_ONION_VALUE

#define H5FD_ONION_VALUE H5_VFD_ONION

Identifier for the onion VFD

Enumeration Type Documentation

◆ H5FD_onion_target_file_constant_t

enum H5FD_onion_target_file_constant_t

Indicates how the new onion data will be stored.

Enumerator
H5FD_ONION_STORE_TARGET_ONION	Onion history is stored in a single, separate "onion file". Shares filename and path as hdf5 file (if any), with only a different filename extension.

Function Documentation

◆ H5FDonion_get_revision_count()

H5_DLL herr_t H5FDonion_get_revision_count	(	const char *	filename,
		hid_t	fapl_id,
		uint64_t *	revision_count
	)

get the number of revisions

Parameters

[in]	filename	The name of the onion file
[in]	fapl_id	The ID of the file access property list
[out]	revision_count	The number of revisions

Returns: Returns a non-negative value if successful; otherwise, returns a negative value.

H5FDonion_get_revision_count() returns the number of revisions for an onion file. It takes the file name and file access property list that is set for the onion VFD driver.

Since: 1.14.0

Data Structures

Macros

Enumerations

Functions