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HDF5  1.15.0.f39b228
API Reference
H5FDonion.h File Reference

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

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

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]filenameThe name of the onion file
[in]fapl_idThe ID of the file access property list
[out]revision_countThe 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