H5Oopen_by_addr
(
hid_t loc_id
,
haddr_t addr
)
H5Oopen_by_addr
opens a group, dataset, or named datatype
using its address within an HDF5 file, addr
.
The resulting opened object is identical to an object opened with
H5Oopen
and should be closed with H5Oclose
or an object-type-specific closing function
(such as H5Gclose
) when no longer needed.
loc_id
can be either the file identifier or a
group identifier in the file. In either case, the HDF5 Library
uses the identifier only to identify the file.
The object’s address within the file, addr
, is the
byte offset of the first byte of the object header from the beginning
of the HDF5 file space, i.e., from the beginning of the super block
(see the “HDF5 Storage Model” section of the
“The
HDF5 Data Model and File Structure” chapter
of the HDF5 User’ Guide).
addr
can be obtained via either of two function calls.
H5Gget_objinfo
returns the object’s address in the
objno
field of the H5G_stat_t
struct;
H5Lget_info
returns the address in the address
field of the
H5L_linkinfo_t
struct.
Warning: This function must be used with care!
Improper use can lead to inaccessible data, wasted space in the file, or file corruption.
This function is dangerous if called on an invalid address.
The risk can be safely overcome by retrieving the object address
with |
The address of the HDF5 file on a physical device has no effect on
H5Oopen_by_addr
, nor does the use of any file driver.
As stated above, the object address is its offset within the HDF5 file;
HDF5’s file drivers will transparently map this to an address
on a storage device.
hid_t loc_id
|
IN: File or group identifier |
haddr_t addr
|
IN: Object’s address in the file |
Release | Change |
1.8.0 | Function introduced in this release. |
1.8.4 | Fortran subroutine added in this release. |