/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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 illustrates the concept of the virtual dataset.
  Percival use case. Every fifth 10x10 plane in VDS is stored in
  the corresponding 3D unlimited dataset.
  There are 4 source datasets total.
  Each of the source datasets is extended to different sizes.
  VDS access property can be used to get max and min extent.
  This file is intended for use with HDF5 Library version 1.10

 ************************************************************/

#include "hdf5.h"
#include <stdio.h>
#include <stdlib.h>

#define VFILE   "h5ex_vds-percival-unlim-maxmin.h5"
#define DATASET "VDS-Percival-unlim-maxmin"
#define VDSDIM0 H5S_UNLIMITED
#define VDSDIM1 10
#define VDSDIM2 10

#define DIM0         H5S_UNLIMITED
#define DIM0_1       4 /* Initial size of the source datasets */
#define DIM1         10
#define DIM2         10
#define RANK         3
#define PLANE_STRIDE 4

const char *SRC_FILE[] = {"apum.h5", "bpum.h5", "cpum.h5", "dpum.h5"};

const char *SRC_DATASET[] = {"A", "B", "C", "D"};

int
main(void)
{
    hid_t   file      = H5I_INVALID_HID;
    hid_t   vfile     = H5I_INVALID_HID;
    hid_t   space     = H5I_INVALID_HID;
    hid_t   dset      = H5I_INVALID_HID;
    hid_t   vdset     = H5I_INVALID_HID;
    hid_t   src_space = H5I_INVALID_HID;
    hid_t   mem_space = H5I_INVALID_HID;
    hid_t   vspace    = H5I_INVALID_HID;
    hid_t   dcpl      = H5I_INVALID_HID;
    hid_t   dapl      = H5I_INVALID_HID;
    herr_t  status;
    hsize_t vdsdims[3]     = {4 * DIM0_1, VDSDIM1, VDSDIM2};
    hsize_t vdsdims_max[3] = {VDSDIM0, VDSDIM1, VDSDIM2};
    hsize_t dims[3]        = {DIM0_1, DIM1, DIM2};
    hsize_t memdims[3]     = {DIM0_1, DIM1, DIM2};
    hsize_t extdims[3]     = {0, DIM1, DIM2}; /* Dimensions of the extended source datasets */
    hsize_t chunk_dims[3]  = {DIM0_1, DIM1, DIM2};
    hsize_t dims_max[3]    = {DIM0, DIM1, DIM2};
    hsize_t vdsdims_out[3];
    hsize_t vdsdims_max_out[3], start[3], stride[3], count[3], src_count[3],
        block[3];                                                         /* Hyperslab parameters */
    hsize_t      start_out[3], stride_out[3], count_out[3], block_out[3]; /* Hyperslab parameter out */
    int          wdata[DIM0_1 * DIM1 * DIM2];
    int          rdata[8 * DIM0_1][VDSDIM1][VDSDIM2]; /* Read buffer for virtual dataset */
    int          i, j, k;
    H5D_layout_t layout;  /* Storage layout */
    size_t       num_map; /* Number of mappings */
    ssize_t      len;     /* Length of the string; also a return value */
    char        *filename = NULL;
    char        *dsetname = NULL;

    /*
     * Create source files and datasets. This step is optional.
     */
    for (i = 0; i < PLANE_STRIDE; i++) {
        /*
         * Initialize data for i-th source dataset.
         */
        for (j = 0; j < DIM0_1 * DIM1 * DIM2; j++)
            wdata[j] = i + 1;

        /*
         * Create the source files and  datasets. Write data to each dataset and
         * close all resources.
         */

        file      = H5Fcreate(SRC_FILE[i], H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
        src_space = H5Screate_simple(RANK, dims, dims_max);
        dcpl      = H5Pcreate(H5P_DATASET_CREATE);
        status    = H5Pset_chunk(dcpl, RANK, chunk_dims);
        dset   = H5Dcreate2(file, SRC_DATASET[i], H5T_STD_I32LE, src_space, H5P_DEFAULT, dcpl, H5P_DEFAULT);
        status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata);
        status = H5Sclose(src_space);
        status = H5Pclose(dcpl);
        status = H5Dclose(dset);
        status = H5Fclose(file);
    }

    vfile = H5Fcreate(VFILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /* Create VDS dataspace.  */
    vspace = H5Screate_simple(RANK, vdsdims, vdsdims_max);

    /* Create dataspaces for the source dataset. */
    src_space = H5Screate_simple(RANK, dims, dims_max);

    /* Create VDS creation property */
    dcpl = H5Pcreate(H5P_DATASET_CREATE);

    /* Initialize hyperslab values */

    start[0]     = 0;
    start[1]     = 0;
    start[2]     = 0;
    stride[0]    = PLANE_STRIDE; /* we will select every fifth plane in VDS */
    stride[1]    = 1;
    stride[2]    = 1;
    count[0]     = H5S_UNLIMITED;
    count[1]     = 1;
    count[2]     = 1;
    src_count[0] = H5S_UNLIMITED;
    src_count[1] = 1;
    src_count[2] = 1;
    block[0]     = 1;
    block[1]     = DIM1;
    block[2]     = DIM2;

    /*
     * Build the mappings
     */
    status = H5Sselect_hyperslab(src_space, H5S_SELECT_SET, start, NULL, src_count, block);
    for (i = 0; i < PLANE_STRIDE; i++) {
        status = H5Sselect_hyperslab(vspace, H5S_SELECT_SET, start, stride, count, block);
        status = H5Pset_virtual(dcpl, vspace, SRC_FILE[i], SRC_DATASET[i], src_space);
        start[0]++;
    }

    H5Sselect_none(vspace);

    /* Create a virtual dataset */
    vdset  = H5Dcreate2(vfile, DATASET, H5T_STD_I32LE, vspace, H5P_DEFAULT, dcpl, H5P_DEFAULT);
    status = H5Sclose(vspace);
    status = H5Sclose(src_space);
    status = H5Pclose(dcpl);

    /* Let's add data to the source datasets and check new dimensions for VDS */
    /* We will add only one plane to the first source dataset, two planes to the
       second one, three to the third, and four to the forth.                 */

    /* Let's add data to the source datasets and check new dimensions for VDS */
    for (i = 0; i < PLANE_STRIDE; i++) {
        /*
         * Initialize data for i-th source dataset.
         */
        for (j = 0; j < (i + 1) * DIM1 * DIM2; j++)
            wdata[j] = 10 * (i + 1);

        /*
         * Open the source files and datasets. Append data to each dataset and
         * close all resources.
         */

        file       = H5Fopen(SRC_FILE[i], H5F_ACC_RDWR, H5P_DEFAULT);
        dset       = H5Dopen2(file, SRC_DATASET[i], H5P_DEFAULT);
        extdims[0] = DIM0_1 + i + 1;
        status     = H5Dset_extent(dset, extdims);
        src_space  = H5Dget_space(dset);
        start[0]   = DIM0_1;
        start[1]   = 0;
        start[2]   = 0;
        count[0]   = 1;
        count[1]   = 1;
        count[2]   = 1;
        block[0]   = i + 1;
        block[1]   = DIM1;
        block[2]   = DIM2;

        memdims[0] = i + 1;
        mem_space  = H5Screate_simple(RANK, memdims, NULL);
        status     = H5Sselect_hyperslab(src_space, H5S_SELECT_SET, start, NULL, count, block);
        status     = H5Dwrite(dset, H5T_NATIVE_INT, mem_space, src_space, H5P_DEFAULT, wdata);
        status     = H5Sclose(src_space);
        status     = H5Dclose(dset);
        status     = H5Fclose(file);
    }

    status = H5Dclose(vdset);
    status = H5Fclose(vfile);

    /*
     * Now we begin the read section of this example.
     */

    /*
     * Open file and dataset using the default properties.
     */
    vfile = H5Fopen(VFILE, H5F_ACC_RDONLY, H5P_DEFAULT);

    /*
     * Open VDS using different access properties to use max or
     * min extents depending on the sizes of the underlying datasets
     */
    dapl = H5Pcreate(H5P_DATASET_ACCESS);

    for (i = 0; i < 2; i++) {
        status = H5Pset_virtual_view(dapl, i ? H5D_VDS_LAST_AVAILABLE : H5D_VDS_FIRST_MISSING);
        vdset  = H5Dopen2(vfile, DATASET, dapl);

        /* Let's get space of the VDS and its dimension; we should get 32(or 20)x10x10 */
        vspace = H5Dget_space(vdset);
        H5Sget_simple_extent_dims(vspace, vdsdims_out, vdsdims_max_out);
        printf("VDS dimensions, bounds = H5D_VDS_%s: ", i ? "LAST_AVAILABLE" : "FIRST_MISSING");
        for (j = 0; j < RANK; j++)
            printf(" %d ", (int)vdsdims_out[j]);
        printf("\n");

        /* Close */
        status = H5Dclose(vdset);
        status = H5Sclose(vspace);
    }

    status = H5Pclose(dapl);

    vdset = H5Dopen2(vfile, DATASET, H5P_DEFAULT);

    /*
     * Get creation property list and mapping properties.
     */
    dcpl = H5Dget_create_plist(vdset);

    /*
     * Get storage layout.
     */
    layout = H5Pget_layout(dcpl);
    if (H5D_VIRTUAL == layout)
        printf(" Dataset has a virtual layout \n");
    else
        printf("Wrong layout found \n");

    /*
     * Find the number of mappings.
     */
    status = H5Pget_virtual_count(dcpl, &num_map);
    printf(" Number of mappings is %lu\n", (unsigned long)num_map);

    /*
     * Get mapping parameters for each mapping.
     */
    for (i = 0; i < (int)num_map; i++) {
        printf(" Mapping %d \n", i);
        printf("         Selection in the virtual dataset \n");
        /* Get selection in the virtual dataset */
        vspace = H5Pget_virtual_vspace(dcpl, (size_t)i);

        /* Make sure that this is a hyperslab selection and then print information. */
        if (H5Sget_select_type(vspace) == H5S_SEL_HYPERSLABS) {
            if (H5Sis_regular_hyperslab(vspace)) {
                status = H5Sget_regular_hyperslab(vspace, start_out, stride_out, count_out, block_out);
                printf("         start  = [%llu, %llu, %llu] \n", (unsigned long long)start_out[0],
                       (unsigned long long)start_out[1], (unsigned long long)start_out[2]);
                printf("         stride = [%llu, %llu, %llu] \n", (unsigned long long)stride_out[0],
                       (unsigned long long)stride_out[1], (unsigned long long)stride_out[2]);
                printf("         count  = [%llu, %llu, %llu] \n", (unsigned long long)count_out[0],
                       (unsigned long long)count_out[1], (unsigned long long)count_out[2]);
                printf("         block  = [%llu, %llu, %llu] \n", (unsigned long long)block_out[0],
                       (unsigned long long)block_out[1], (unsigned long long)block_out[2]);
            }
        }
        /* Get source file name */
        len      = H5Pget_virtual_filename(dcpl, (size_t)i, NULL, 0);
        filename = (char *)malloc((size_t)len * sizeof(char) + 1);
        H5Pget_virtual_filename(dcpl, (size_t)i, filename, len + 1);
        printf("         Source filename %s\n", filename);

        /* Get source dataset name */
        len      = H5Pget_virtual_dsetname(dcpl, (size_t)i, NULL, 0);
        dsetname = (char *)malloc((size_t)len * sizeof(char) + 1);
        H5Pget_virtual_dsetname(dcpl, (size_t)i, dsetname, len + 1);
        printf("         Source dataset name %s\n", dsetname);

        /* Get selection in the source dataset */
        printf("         Selection in the source dataset \n");
        src_space = H5Pget_virtual_srcspace(dcpl, (size_t)i);
        if (H5Sget_select_type(src_space) == H5S_SEL_HYPERSLABS) {
            if (H5Sis_regular_hyperslab(src_space)) {
                status = H5Sget_regular_hyperslab(src_space, start_out, stride_out, count_out, block_out);
                printf("         start  = [%llu, %llu, %llu] \n", (unsigned long long)start_out[0],
                       (unsigned long long)start_out[1], (unsigned long long)start_out[2]);
                printf("         stride = [%llu, %llu, %llu] \n", (unsigned long long)stride_out[0],
                       (unsigned long long)stride_out[1], (unsigned long long)stride_out[2]);
                printf("         count  = [%llu, %llu, %llu] \n", (unsigned long long)count_out[0],
                       (unsigned long long)count_out[1], (unsigned long long)count_out[2]);
                printf("         block  = [%llu, %llu, %llu] \n", (unsigned long long)block_out[0],
                       (unsigned long long)block_out[1], (unsigned long long)block_out[2]);
            }
        }
        H5Sclose(vspace);
        H5Sclose(src_space);
        free(filename);
        free(dsetname);
    }

    /*
     * Read data from VDS.
     */
    vspace = H5Dget_space(vdset);
    H5Sget_simple_extent_dims(vspace, vdsdims_out, vdsdims_max_out);
    printf("VDS dimensions second time \n");
    printf(" Current: ");
    for (i = 0; i < RANK; i++)
        printf(" %d ", (int)vdsdims_out[i]);
    printf("\n");

    /* Read all VDS data */

    /* We should be able to do it by using H5S_ALL instead of making selection
     * or using H5Sselect_all from vspace.
     */
    start[0] = 0;
    start[1] = 0;
    start[2] = 0;
    count[0] = 1;
    count[1] = 1;
    count[2] = 1;
    block[0] = vdsdims_out[0];
    block[1] = vdsdims_out[1];
    block[2] = vdsdims_out[2];

    status    = H5Sselect_hyperslab(vspace, H5S_SELECT_SET, start, NULL, count, block);
    mem_space = H5Screate_simple(RANK, vdsdims_out, NULL);
    status    = H5Dread(vdset, H5T_NATIVE_INT, mem_space, vspace, H5P_DEFAULT, rdata);
    printf(" All data: \n");
    for (i = 0; i < (int)vdsdims_out[0]; i++) {
        for (j = 0; j < (int)vdsdims_out[1]; j++) {
            printf("(%d, %d, 0)", i, j);
            for (k = 0; k < (int)vdsdims_out[2]; k++)
                printf(" %d ", rdata[i][j][k]);
            printf("\n");
        }
    }

    /*
     * Close and release resources.
     */
    status = H5Sclose(mem_space);
    status = H5Pclose(dcpl);
    status = H5Dclose(vdset);
    status = H5Fclose(vfile);

    return 0;
}
