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Diffstat (limited to 'HDF5Examples/C/H5D/h5ex_d_alloc.c')
| -rw-r--r-- | HDF5Examples/C/H5D/h5ex_d_alloc.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5D/h5ex_d_alloc.c b/HDF5Examples/C/H5D/h5ex_d_alloc.c new file mode 100644 index 0000000..37d2b8c --- /dev/null +++ b/HDF5Examples/C/H5D/h5ex_d_alloc.c @@ -0,0 +1,135 @@ +/************************************************************ + + This example shows how to set the space allocation time + for a dataset. The program first creates two datasets, + one with the default allocation time (late) and one with + early allocation time, and displays whether each has been + allocated and their allocation size. Next, it writes data + to the datasets, and again displays whether each has been + allocated and their allocation size. + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_d_alloc.h5" +#define DATASET1 "DS1" +#define DATASET2 "DS2" +#define DIM0 4 +#define DIM1 7 +#define FILLVAL 99 + +int +main(void) +{ + hid_t file = H5I_INVALID_HID; + hid_t space = H5I_INVALID_HID; + hid_t dset1 = H5I_INVALID_HID; + hid_t dset2 = H5I_INVALID_HID; + hid_t dcpl = H5I_INVALID_HID; + /* Handles */ + herr_t status; + H5D_space_status_t space_status; + hsize_t dims[2] = {DIM0, DIM1}; + hsize_t storage_size; + int wdata[DIM0][DIM1]; /* Write buffer */ + hsize_t i, j; + + /* + * Initialize data. + */ + for (i = 0; i < DIM0; i++) + for (j = 0; j < DIM1; j++) + wdata[i][j] = i * j - j; + + /* + * Create a new file using the default properties. + */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* + * Create dataspace. Setting maximum size to NULL sets the maximum + * size to be the current size. + */ + space = H5Screate_simple(2, dims, NULL); + + /* + * Create the dataset creation property list, and set the chunk + * size. + */ + dcpl = H5Pcreate(H5P_DATASET_CREATE); + + /* + * Set the allocation time to "early". This way we can be sure + * that reading from the dataset immediately after creation will + * return the fill value. + */ + status = H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY); + + printf("Creating datasets...\n"); + printf("%s has allocation time H5D_ALLOC_TIME_LATE\n", DATASET1); + printf("%s has allocation time H5D_ALLOC_TIME_EARLY\n\n", DATASET2); + + /* + * Create the dataset using the dataset creation property list. + */ + dset1 = H5Dcreate(file, DATASET1, H5T_STD_I32LE, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + dset2 = H5Dcreate(file, DATASET2, H5T_STD_I32LE, space, H5P_DEFAULT, dcpl, H5P_DEFAULT); + + /* + * Retrieve and print space status and storage size for dset1. + */ + status = H5Dget_space_status(dset1, &space_status); + storage_size = H5Dget_storage_size(dset1); + printf("Space for %s has%sbeen allocated.\n", DATASET1, + space_status == H5D_SPACE_STATUS_ALLOCATED ? " " : " not "); + printf("Storage size for %s is: %ld bytes.\n", DATASET1, (long)storage_size); + + /* + * Retrieve and print space status and storage size for dset2. + */ + status = H5Dget_space_status(dset2, &space_status); + storage_size = H5Dget_storage_size(dset2); + printf("Space for %s has%sbeen allocated.\n", DATASET2, + space_status == H5D_SPACE_STATUS_ALLOCATED ? " " : " not "); + printf("Storage size for %s is: %ld bytes.\n", DATASET2, (long)storage_size); + + printf("\nWriting data...\n\n"); + + /* + * Write the data to the datasets. + */ + status = H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata[0]); + status = H5Dwrite(dset2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata[0]); + + /* + * Retrieve and print space status and storage size for dset1. + */ + status = H5Dget_space_status(dset1, &space_status); + storage_size = H5Dget_storage_size(dset1); + printf("Space for %s has%sbeen allocated.\n", DATASET1, + space_status == H5D_SPACE_STATUS_ALLOCATED ? " " : " not "); + printf("Storage size for %s is: %ld bytes.\n", DATASET1, (long)storage_size); + + /* + * Retrieve and print space status and storage size for dset2. + */ + status = H5Dget_space_status(dset2, &space_status); + storage_size = H5Dget_storage_size(dset2); + printf("Space for %s has%sbeen allocated.\n", DATASET2, + space_status == H5D_SPACE_STATUS_ALLOCATED ? " " : " not "); + printf("Storage size for %s is: %ld bytes.\n", DATASET2, (long)storage_size); + + /* + * Close and release resources. + */ + status = H5Pclose(dcpl); + status = H5Dclose(dset1); + status = H5Dclose(dset2); + status = H5Sclose(space); + status = H5Fclose(file); + + return 0; +} |