pmem2_source_size()

#include <libpmem2.h>
struct pmem2_source;
int pmem2_source_size(const struct pmem2_source *source, size_t *size);
    

The pmem2_source_size() function retrieves the size of the file in bytes pointed by file descriptor or handle stored in the source and puts it in *size.

This function is a portable replacement for OS-specific APIs. On Linux, it hides the quirkiness of Device DAX size detection.

The pmem2_source_size() function returns 0 on success. If the function fails, the *size variable is left unmodified and a negative error code is returned.

The pmem2_source_size() can fail with the following errors:

On all systems:

• PMEM2_E_INVALID_FILE_HANDLE - source contains an invalid file handle.

On Windows:

• PMEM2_E_INVALID_FILE_TYPE - handle points to a resource that is not a regular file.

On Linux:

• PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a directory, block device, pipe, or socket.
• PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a character device other than Device DAX.
• PMEM2_E_INVALID_SIZE_FORMAT - kernel query for Device DAX size returned data in invalid format.
• -errno set by failing fstat(2), while trying to validate the file descriptor.
• -errno set by failing realpath(3), while trying to determine whether fd points to a Device DAX.
• -errno set by failing open(2), while trying to determine Device DAX’s size.
• -errno set by failing read(2), while trying to determine Device DAX’s size.
• -errno set by failing strtoull(3), while trying to determine Device DAX’s size.

On FreeBSD:

• PMEM2_E_INVALID_FILE_TYPE - file descriptor points to a directory, block device, pipe, socket, or character device.
• -errno set by failing fstat(2), while trying to validate the file descriptor.

errno(3), fstat(2), realpath(3), open(2), read(2), strtoull(3), pmem2_config_new(3), libpmem2(7) and <https://pmem.io>