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Diffstat (limited to 'examples/h5_extend.c')
| -rw-r--r-- | examples/h5_extend.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/examples/h5_extend.c b/examples/h5_extend.c new file mode 100644 index 0000000..91d7db7 --- /dev/null +++ b/examples/h5_extend.c @@ -0,0 +1,130 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by The HDF Group. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the COPYING file, which can be found at the root of the source code * + * distribution tree, or in https://www.hdfgroup.org/licenses. * + * If you do not have access to either file, you may request a copy from * + * help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * This example how to work with extendible datasets. The dataset + * must be chunked in order to be extendible. + * + * It is used in the HDF5 Tutorial. + */ + +#include "hdf5.h" + +#define FILENAME "extend.h5" +#define DATASETNAME "ExtendibleArray" +#define RANK 2 + +int +main(void) +{ + hid_t file; /* handles */ + hid_t dataspace, dataset; + hid_t filespace, memspace; + hid_t prop; + + hsize_t dims[2] = {3, 3}; /* dataset dimensions at creation time */ + hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED}; + herr_t status; + hsize_t chunk_dims[2] = {2, 5}; + int data[3][3] = {{1, 1, 1}, /* data to write */ + {1, 1, 1}, + {1, 1, 1}}; + + /* Variables used in extending and writing to the extended portion of dataset */ + hsize_t size[2]; + hsize_t offset[2]; + hsize_t dimsext[2] = {7, 3}; /* extend dimensions */ + int dataext[7][3] = {{2, 3, 4}, {2, 3, 4}, {2, 3, 4}, {2, 3, 4}, {2, 3, 4}, {2, 3, 4}, {2, 3, 4}}; + + /* Variables used in reading data back */ + hsize_t chunk_dimsr[2]; + hsize_t dimsr[2]; + hsize_t i, j; + int rdata[10][3]; + herr_t status_n; + int rank, rank_chunk; + + /* Create the data space with unlimited dimensions. */ + dataspace = H5Screate_simple(RANK, dims, maxdims); + + /* Create a new file. If file exists its contents will be overwritten. */ + file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* Modify dataset creation properties, i.e. enable chunking */ + prop = H5Pcreate(H5P_DATASET_CREATE); + status = H5Pset_chunk(prop, RANK, chunk_dims); + + /* Create a new dataset within the file using chunk + creation properties. */ + dataset = H5Dcreate2(file, DATASETNAME, H5T_NATIVE_INT, dataspace, H5P_DEFAULT, prop, H5P_DEFAULT); + + /* Write data to dataset */ + status = H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data); + + /* Extend the dataset. Dataset becomes 10 x 3 */ + size[0] = dims[0] + dimsext[0]; + size[1] = dims[1]; + status = H5Dset_extent(dataset, size); + + /* Select a hyperslab in extended portion of dataset */ + filespace = H5Dget_space(dataset); + offset[0] = 3; + offset[1] = 0; + status = H5Sselect_hyperslab(filespace, H5S_SELECT_SET, offset, NULL, dimsext, NULL); + + /* Define memory space */ + memspace = H5Screate_simple(RANK, dimsext, NULL); + + /* Write the data to the extended portion of dataset */ + status = H5Dwrite(dataset, H5T_NATIVE_INT, memspace, filespace, H5P_DEFAULT, dataext); + + /* Close resources */ + status = H5Dclose(dataset); + status = H5Pclose(prop); + status = H5Sclose(dataspace); + status = H5Sclose(memspace); + status = H5Sclose(filespace); + status = H5Fclose(file); + + /******************************************** + * Re-open the file and read the data back. * + ********************************************/ + + file = H5Fopen(FILENAME, H5F_ACC_RDONLY, H5P_DEFAULT); + dataset = H5Dopen2(file, DATASETNAME, H5P_DEFAULT); + + filespace = H5Dget_space(dataset); + rank = H5Sget_simple_extent_ndims(filespace); + status_n = H5Sget_simple_extent_dims(filespace, dimsr, NULL); + + prop = H5Dget_create_plist(dataset); + + if (H5D_CHUNKED == H5Pget_layout(prop)) + rank_chunk = H5Pget_chunk(prop, rank, chunk_dimsr); + + memspace = H5Screate_simple(rank, dimsr, NULL); + status = H5Dread(dataset, H5T_NATIVE_INT, memspace, filespace, H5P_DEFAULT, rdata); + + printf("\n"); + printf("Dataset: \n"); + for (j = 0; j < dimsr[0]; j++) { + for (i = 0; i < dimsr[1]; i++) + printf("%d ", rdata[j][i]); + printf("\n"); + } + + status = H5Pclose(prop); + status = H5Dclose(dataset); + status = H5Sclose(filespace); + status = H5Sclose(memspace); + status = H5Fclose(file); +} |