Reads a raw data chunk directly from a dataset in a file into a buffer
H5D_READ_CHUNK replaces the now deprecated H5DO_READ_CHUNK function, which was located in the high level optimization library. The parameters and behavior are identical to the original.
H5D_READ_CHUNK (dset_id, dxpl_id, offset, filters, buf)
herr_t H5Dread_chunk( hid_t dset_id, hid_t dxpl_id, const hsize_t *offset, uint32_t *filters, void *buf )
|hid_t||IN: Identifier for the dataset to be read|
|hid_t||IN: Transfer property list identifier for this I/O operation|
|const hsize_t *||IN: Logical position of the chunk’s first element in the dataspace|
|uint32_t *||IN/OUT: Mask for identifying the filters used with the chunk|
|void *||IN: Buffer containing the chunk read from the dataset|
H5D_READ_CHUNK reads a raw data chunk as specified by its logical
offset in a chunked dataset
dset_id from the dataset in the file into the application memory buffer
buf. The data in
buf is read directly from the file bypassing the library’s internal data transfer pipeline, including filters.
dxpl_id is a data transfer property list identifier.
offset is an array specifying the logical position of the first element of the chunk in the dataset’s dataspace. The length of the offset array must equal the number of dimensions, or rank, of the dataspace. The values in
offset must not exceed the dimension limits and must specify a point that falls on a dataset chunk boundary.
filters indicates which filters are used with the chunk when written. A zero value indicates that all enabled filters are applied on the chunk. A filter is skipped if the bit corresponding to the filter’s position in the pipeline (
0 ≤ position < 32) is turned on.
buf is the memory buffer containing the chunk read from the dataset in the file.
Exercise caution when using H5D_READ_CHUNK and H5D_WRITE_CHUNK, as they read and write data chunks directly in a file. H5D_WRITE_CHUNK bypasses hyperslab selection, the conversion of data from one datatype to another, and the filter pipeline to write the chunk. Developers should have experience with these processes before using this function. Please see Using the Direct Chunk Write Function for more information.
Also note that H5D_READ_CHUNK and H5D_WRITE_CHUNK are not supported under parallel and do not support variable length types.
Returns a non-negative value if successful; otherwise returns a negative value.
|1.10.3||Moved from HDF5 High Level Optimizations library to core library|
|1.10.2, 1.8.19||C function introduced as |