[svn-r26420] Added new example for simple I/O. Modified other examples according to the suggestion in H5VDS-7 (see VDS-178)

1 files changed, 186 insertions, 0 deletions

diff --git a/examples/h5_vds-simpleIO.c b/examples/h5_vds-simpleIO.c
new file mode 100644
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--- /dev/null
+++ b/examples/h5_vds-simpleIO.c
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+/************************************************************
+
+  This example illustrates the concept of virtual dataset I/O
+  The program  creates 2-dim source dataset and writes
+  data to it. Then it creates 2-dim virtual dataset that has
+  the same dimesnion sizes and maps the all elements of the 
+  virtual dataset to all elements of the source dataset.
+  Then VDS is read back.
+
+  This file is intended for use with HDF5 Library version 1.10
+
+ ************************************************************/
+/* EIP Add link to the picture */
+
+#include "hdf5.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+#define FILE         "vds-simpleIO.h5"
+#define DATASET      "VDS"
+#define DIM1            6
+#define DIM0            4 
+#define RANK            2
+
+#define SRC_FILE      "a.h5"
+#define SRC_DATASET    "/A"
+
+
+int
+main (void)
+{
+    hid_t        file, space, src_space, vspace, dset; /* Handles */ 
+    hid_t        dcpl;
+    herr_t       status;
+    hsize_t      vdsdims[2] = {DIM0, DIM1},     /* Virtual dataset dimension */
+                 dims[2] = {DIM0, DIM1};        /* Source dataset dimensions */
+    int          wdata[DIM0][DIM1],             /* Write buffer for source dataset */
+                 rdata[DIM0][DIM1],             /* Read buffer for virtual dataset */
+                 i, j;  
+    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;                  
+    char         *dsetname;
+    /*
+     * Initialize data.
+     */
+        for (i = 0; i < DIM0; i++) 
+            for (j = 0; j < DIM1; j++) wdata[i][j] = i+1;
+         
+     /*
+      * Create the source file and the dataset. Write data to the source dataset 
+      * and close all resources.
+      */
+
+     file = H5Fcreate (SRC_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+     space = H5Screate_simple (RANK, dims, NULL);
+     dset = H5Dcreate (file, SRC_DATASET, H5T_NATIVE_INT, space, H5P_DEFAULT,
+                 H5P_DEFAULT, H5P_DEFAULT);
+     status = H5Dwrite (dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+                 wdata[0]);
+     status = H5Sclose (space);
+     status = H5Dclose (dset);
+     status = H5Fclose (file);
+
+    /* Create file in which virtual dataset will be stored. */
+    file = H5Fcreate (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+    /* Create VDS dataspace.  */
+    vspace = H5Screate_simple (RANK, vdsdims, NULL);
+
+    /* Set VDS creation property. */
+    dcpl = H5Pcreate (H5P_DATASET_CREATE);
+     
+    /* 
+     * Build the mappings.
+     * Selections in the source datasets are H5S_ALL.
+     * In the virtual dataset we select the first, the second and the third rows 
+     * and map each row to the data in the corresponding source dataset. 
+     */
+    src_space = H5Screate_simple (RANK, dims, NULL);
+    status = H5Pset_virtual (dcpl, vspace, SRC_FILE, SRC_DATASET, src_space);
+
+    /* Create a virtual dataset. */
+    dset = H5Dcreate (file, DATASET, H5T_NATIVE_INT, vspace, H5P_DEFAULT,
+                dcpl, H5P_DEFAULT);
+    status = H5Sclose (vspace);
+    status = H5Sclose (src_space);
+    status = H5Dclose (dset);
+#ifdef EIP /*Currently the file with VDS should stay open. Neil will fix the issue */
+    status = H5Fclose (file);    
+     
+    /*
+     * Now we begin the read section of this example.
+     */
+
+    /*
+     * Open the file and virtual dataset.
+     */
+    file = H5Fopen (FILE, H5F_ACC_RDONLY, H5P_DEFAULT);
+#endif
+    dset = H5Dopen (file, DATASET, H5P_DEFAULT);
+    /*
+     * Get creation property list and mapping properties.
+     */
+    dcpl = H5Dget_create_plist (dset);
+
+    /*
+     * 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 %d\n", 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 ");
+        /* Get selection in the virttual  dataset */
+        vspace = H5Pget_virtual_vspace (dcpl, (size_t)i);
+
+        /* Make sure it is ALL selection and then print selection. */
+        if(H5Sget_select_type(vspace) == H5S_SEL_ALL) {
+                printf("Selection is H5S_ALL \n");
+        }
+        /* 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 ");
+        src_space = H5Pget_virtual_srcspace (dcpl, (size_t)i);
+
+        /* Make sure it is ALL selection and then print selection. */
+        if(H5Sget_select_type(src_space) == H5S_SEL_ALL) {
+                printf("Selection is H5S_ALL \n");
+        }
+        H5Sclose(vspace);
+        H5Sclose(src_space);
+        free(filename);
+        free(dsetname);
+    }
+    /*
+     * Read the data using the default properties.
+     */
+    status = H5Dread (dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+                rdata[0]);
+
+    /*
+     * Output the data to the screen.
+     */
+    printf (" VDS Data:\n");
+    for (i=0; i<DIM0; i++) {
+        printf (" [");
+        for (j=0; j<DIM1; j++)
+            printf (" %3d", rdata[i][j]);
+        printf ("]\n");
+    }
+    /*
+     * Close and release resources.
+     */
+    status = H5Pclose (dcpl);
+    status = H5Dclose (dset);
+    status = H5Fclose (file);
+
+    return 0;
+}
+