Create a reference — H5Rcreate • rhdf5

Creates a reference to an object or dataset selection inside an HDF5 file.

Usage

H5Rcreate(h5loc, name, ref_type = "H5R_OBJECT", h5space = NULL)

Arguments

h5loc: An H5IdComponent object representing the location to be pointed to by the created reference.
name: Character string giving the name of the object to be referenced, relative to the location given by h5loc.
ref_type: The type of reference to create. Accepts either H5R_OBJECT or H5R_DATASET_REGION.
h5space: An object of class H5IdComponent representing a dataspace with a selection set. This argument is only used if creating a reference to a dataset region, and will be ignored otherwise.

Value

An H5Ref object storing the reference.

Examples

## first we'll create a file with a group named "foo" and a
## 1-dimensional dataset named "baa" inside that group.
file_name <- tempfile(fileext = ".h5")
h5createFile(file_name)
h5createGroup(file = file_name, group = "/foo")
h5write(1:100, file = file_name, name = "/foo/baa")


fid <- H5Fopen(file_name)
ref_to_group <- H5Rcreate(fid, name = "/foo")
ref_to_dataset <- H5Rcreate(fid, name = "/foo/baa")
two_refs <- c(ref_to_group, ref_to_dataset)
two_refs
#> HDF5 REFERENCE
#> Type: H5R_OBJECT 
#> Length: 2 

## the size of this dataspace is the number of object references
## we want to store
sid <- H5Screate_simple(2)
tid <- H5Tcopy(dtype_id = "H5T_STD_REF_OBJ")
did <- H5Dcreate(fid, name = "object_refs", dtype_id = tid, h5space = sid)
H5Dwrite(did, two_refs)
H5Dclose(did)
H5Sclose(sid)
H5Fclose(fid)