Virtual File Driver Features

Detailed Description

Functions
herr_t	H5FDonion_get_revision_count (const char *filename, hid_t fapl_id, uint64_t *revision_count)
	get the number of revisions
herr_t	H5FDdriver_query (hid_t driver_id, unsigned long *flags)
	Allows querying a VFD ID for features before the file is opened.

Function Documentation

H5FDdriver_query()

herr_t H5FDdriver_query	(	hid_t	driver_id,
		unsigned long *	flags
	)

Allows querying a VFD ID for features before the file is opened.

Parameters

[in]	driver_id	Virtual File Driver (VFD) ID
[out]	flags	VFD flags supported

Returns

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

Queries a virtual file driver (VFD) for feature flags. Takes a VFD hid_t so it can be used before the file is opened. For example, this could be used to check if a VFD supports SWMR.

Note

The flags obtained here are just those of the base driver and do not take any configuration options (e.g., set via a fapl call) into consideration.

Since

1.10.2

H5FDonion_get_revision_count()

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