Re: questions about H5DSiterate_scales

Pedro,
    Can you look at Ed's program and see if you can help him?

        Quincey

[ Charset ISO-8859-15 unsupported, converting... ]
> Howdy all!
> 
> I've isolated the code into it's own program, and you can see the
> problem I'm having by compiling and running the program appended below
> (tst_h_dimscales2.c) including its header file, tests.h, also appended
> below.
> 
> This program creates a very simple HDF5 file (tst_h_dimscales2.h5),
> with two 1D datasets. One dataset is marked as a dimension scale, the
> other attaches it as it's dimscale. Then the file is closed. The
> h5dump of the file at this point is included below. Everything looks
> fine to me, including all the names.
> 
> The file is then reopened and I iterate through the objects. When I
> find the dimscale I check the name, and it's fine. When I encounter
> the other dataset, "var1", I check that it has one scale, and then
> call iterate_scales to execute the function alien_visitor on that
> dataset/dimscale combination.
> 
> The function, alien_visitor, gets the associated names of it's did and
> dsid parameters. The did parameter yields a name, as expected:
> "/var1". But the dsid parameter, which supposedly points to the
> dimscale dataset, returns a name of garbage characters.
> 
> How do I know that dsid is really pointing to the dimscale dataset,
> named "dimscale" in this example?
> 
> Is this a H5DS bug, or am I doing something horribly, tragically, but
> hopefully not inexplicably wrong?
> 
> Thanks,
> 
> Ed
> 
> Here's the output:
> 
> ./tst_h_dimscales2
> *** Creating a file with one var with one dimension scale...ok.
> *** Checking that one var, one dimscale file can be read...
> Encountered: HDF5 object obj_class 2 obj_name dimscale
> Encountered: HDF5 object obj_class 2 obj_name var1
> unexpected result, tst_h_dimscales2.c, line: 34
> visiting did 0x6000003 dim 0 dsid 0x6000004 name of did /var1 
> :???z????????
> 1 failures
> 
> h5dump of tst_h_dimscales2.h5:
> HDF5 "tst_h_dimscales2.h5" {
> GROUP "/" {
>    DATASET "dimscale" {
>       DATATYPE  H5T_STD_I32LE
>       DATASPACE  SIMPLE { ( 3 ) / ( H5S_UNLIMITED ) }
>       DATA {
>       (0): 0, 0, 0
>       }
>       ATTRIBUTE "CLASS" {
>          DATATYPE  H5T_STRING {
>                STRSIZE 16;
>                STRPAD H5T_STR_NULLTERM;
>                CSET H5T_CSET_ASCII;
>                CTYPE H5T_C_S1;
>             }
>          DATASPACE  SCALAR
>          DATA {
>          (0): "DIMENSION_SCALE"
>          }
>       }
>       ATTRIBUTE "NAME" {
>          DATATYPE  H5T_STRING {
>                STRSIZE 24;
>                STRPAD H5T_STR_NULLTERM;
>                CSET H5T_CSET_ASCII;
>                CTYPE H5T_C_S1;
>             }
>          DATASPACE  SCALAR
>          DATA {
>          (0): "dimscale_name_attribute"
>          }
>       }
>       ATTRIBUTE "REFERENCE_LIST" {
>          DATATYPE  H5T_COMPOUND {
>             H5T_REFERENCE "dataset";
>             H5T_STD_I32LE "dimension";
>          }
>          DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
>          DATA {
>          (0): {
>                DATASET 1576 /var1 ,
>                0
>             }
>          }
>       }
>    }
>    DATASET "var1" {
>       DATATYPE  H5T_STD_I32LE
>       DATASPACE  SIMPLE { ( 3 ) / ( H5S_UNLIMITED ) }
>       DATA {
>       (0): 0, 0, 0
>       }
>       ATTRIBUTE "DIMENSION_LIST" {
>          DATATYPE  H5T_VLEN { H5T_REFERENCE}
>          DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
>          DATA {
>          (0): (DATASET 976 /dimscale )
>          }
>       }
>       ATTRIBUTE "DIMENSION_LABELS" {
>          DATATYPE  H5T_STRING {
>                STRSIZE H5T_VARIABLE;
>                STRPAD H5T_STR_NULLTERM;
>                CSET H5T_CSET_ASCII;
>                CTYPE H5T_C_S1;
>             }
>          DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
>          DATA {
>          (0): "dimscale_label"
>          }
>       }
>    }
> }
> }
> 
> 
> tests.h:
> 
> /* This is part of the netCDF package.
>    Copyright 2005 University Corporation for Atmospheric Research/Unidata
>    See COPYRIGHT file for conditions of use.
> 
>    Common includes, defines, etc., for test code in the libsrc4
>    directory.
> 
>    $Id: tests.h,v 1.6 2005/06/06 20:36:22 ed Exp $
> */
> #ifndef _NC4_TESTS_
> #define _NC4_TESTS_
> 
> #include <config.h>
> #include <assert.h>
> #include <stdio.h>
> #include <string.h>
> #include "error.h"
> 
> int total_err = 0, err = 0;
> 
> /* This is handy for print statements. */
> char *format_name[] = {"", "classic", "64-bit offset", "netCDF-4", "netCDF-4 
> strict NC3"};
> 
> #define ERR do { \
> fflush(stdout); /* Make sure our stdout is synced with stderr. */ \
> err++; \
> fprintf(stderr, "unexpected result, %s, line: %d\n", __FILE__, __LINE__); \
> } while (0)
> 
> #define SUMMARIZE_ERR do { \
>    if (err) \
>    { \
>       printf("%d failures\n", err); \
>       total_err += err; \
>       err = 0; \
>    } \
>    else \
>       printf("ok.\n"); \
> } while (0)
> 
> 
> #endif /* _NC4_TESTS_ */
> 
> tst_h_dimscales2.c:
> 
> /* This is part of the netCDF package.
>    Copyright 2005 University Corporation for Atmospheric Research/Unidata
>    See COPYRIGHT file for conditions of use.
> 
>    Test HDF5 file code. These are not intended to be exhaustive tests,
>    but they use HDF5 the same way that netCDF-4 does, so if these
>    tests don't work, than netCDF-4 won't work either.
> 
>    $Id: tst_h_dimscales.c,v 1.5 2005/07/01 09:33:05 ed Exp $
> */
> #include "tests.h"
> #include "H5DS.h"
> 
> #define FILE_NAME "tst_h_dimscales2.h5"
> #define DIMSCALE_NAME "dimscale"
> #define VAR1_NAME "var1"
> #define NDIMS 1
> #define DIM1_LEN 3
> #define NAME_ATTRIBUTE "dimscale_name_attribute"
> #define DIMSCALE_LABEL "dimscale_label"
> 
> herr_t alien_visitor(hid_t did, unsigned dim, hid_t dsid, 
>                    void *visitor_data)
> {
>    char name1[NC_MAX_NAME], name2[NC_MAX_NAME];
> 
>    /* This should get "/var1", the name of the dataset that the scale
>     * is attached to. */
>    if (H5Iget_name(did, name1, NC_MAX_NAME) < 0) ERR;
>    if (strcmp(&name1[1], VAR1_NAME)) ERR;
>    
>    /* This should get "/dimscale" but it doesn't seem to be! */
>    if (H5Iget_name(dsid, name2, NC_MAX_NAME) < 0) ERR;
>    if (strcmp(&name2[1], DIMSCALE_NAME)) ERR;
> 
>    printf("visiting did 0x%x dim %d dsid 0x%x name of did %s \n", 
>         did, dim, dsid, name1);
>    printf("name of dsid: %s\n", name2);
>    return 0;
> }
> 
> int
> main()
> {
>    printf("*** Creating a file with one var with one dimension scale...");
>    
>    {
>       hid_t fileid, spaceid, datasetid, dimscaleid, cparmsid;
>       hsize_t dims[NDIMS] = {DIM1_LEN}, maxdims[NDIMS] = {H5S_UNLIMITED};
> 
>       /* Create file. */
>       if ((fileid = H5Fcreate(FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, 
>                             H5P_DEFAULT)) < 0) ERR;
> 
>       /* Create the space that will be used both for the dimscale and
>        * the 1D dataset that will attach it. */
>       if ((spaceid = H5Screate_simple(NDIMS, dims, maxdims)) < 0) ERR;
> 
>       /* Modify dataset creation properties, i.e. enable chunking. */
>       dims[0] = 1;
>       if ((cparmsid = H5Pcreate(H5P_DATASET_CREATE)) < 0) ERR;
>       if (H5Pset_chunk(cparmsid, NDIMS, dims) < 0) ERR;
> 
>       /* Create our dimension scale, as an unlimited dataset. */
>       if ((dimscaleid = H5Dcreate(fileid, DIMSCALE_NAME, H5T_NATIVE_INT, 
>                                 spaceid, cparmsid)) < 0) ERR;
>       if (H5DSset_scale(dimscaleid, NAME_ATTRIBUTE) < 0) ERR;
> 
>       /* Create a variable which uses it. */
>       if ((datasetid = H5Dcreate(fileid, VAR1_NAME, H5T_NATIVE_INT, 
>                                spaceid, cparmsid)) < 0) ERR;
>       if (H5DSattach_scale(datasetid, dimscaleid, 0) < 0) ERR;
>       if (H5DSset_label(datasetid, 0, DIMSCALE_LABEL) < 0) ERR;
> 
>       /* Fold up our tents. */
>       if (H5Dclose(dimscaleid) < 0 ||
>         H5Dclose(datasetid) < 0 ||
>         H5Sclose(spaceid) < 0 ||
>         H5Fclose(fileid) < 0) ERR;
>    }
> 
>    SUMMARIZE_ERR;
>    printf("*** Checking that one var, one dimscale file can be read...");
> 
>    {
>       hid_t fileid, spaceid = 0, datasetid = 0;
>       hsize_t num_obj, i;
>       int obj_class;
>       char obj_name[NC_MAX_NAME + 1];
>       char dimscale_name[NC_MAX_NAME+1];
>       htri_t is_scale;
>       char label[NC_MAX_NAME+1];
>       int visitor_data = 0;
>       int num_scales;
>       hsize_t dims[1], maxdims[1];
> 
>       /* Open the file. */
>       if ((fileid = H5Fopen(FILE_NAME, H5F_ACC_RDWR, H5P_DEFAULT)) < 0) ERR;
>       
>       /* Loop through objects in the root group. */
>       if (H5Gget_num_objs(fileid, &num_obj) < 0) ERR;
>       for (i=0; i<num_obj; i++)
>       {
>        /* Get the type (i.e. group, dataset, etc.), and the name of
>         * the object. */
>        if ((obj_class = H5Gget_objtype_by_idx(fileid, i)) < 0) ERR;
>        if (H5Gget_objname_by_idx(fileid, i, obj_name, NC_MAX_NAME) < 0) ERR;
> 
>        printf("\nEncountered: HDF5 object obj_class %d obj_name %s\n", 
>               obj_class, obj_name);
> 
>        /* Deal with object based on its obj_class. */
>        switch(obj_class)
>        {
>           case H5G_GROUP:
>              break;
>           case H5G_DATASET:
>              /* Open the dataset. */
>              if ((datasetid = H5Dopen(fileid, obj_name)) < 0) ERR;
> 
>              /* This should be an unlimited dataset. */
>              if ((spaceid = H5Dget_space(datasetid)) < 0) ERR;
>              if (H5Sget_simple_extent_dims(spaceid, dims, maxdims) < 0) ERR;
>              if (maxdims[0] != H5S_UNLIMITED) ERR;
> 
>              /* Is this a dimscale? */
>              if ((is_scale = H5DSis_scale(datasetid)) < 0) ERR;
>              if (is_scale && strcmp(obj_name, DIMSCALE_NAME)) ERR;
>              if (is_scale)
>              {
>                 /* A dimscale comes with a NAME attribute, in
>                  * addition to it's real name. */
>                 if (H5DSget_scale_name(datasetid, dimscale_name, NC_MAX_NAME) 
> < 0) ERR;
>                 if (strcmp(dimscale_name, NAME_ATTRIBUTE)) ERR;
>              }
>              else
>              {
>                 /* Here's how to get the number of scales attached
>                  * to the dataset's dimension 0. */
>                 if ((num_scales = H5DSget_num_scales(datasetid, 0)) < 0) ERR;
>                 if (num_scales != 1) ERR;
> 
>                 /* Go through all dimscales for this var and learn about 
> them. */
>                 if (H5DSiterate_scales(datasetid, 0, NULL, alien_visitor, 
>                                        &visitor_data) < 0) ERR;
>                 
>                 /* There's also a label for dimension 0. */
>                 if (H5DSget_label(datasetid, 0, label, NC_MAX_NAME) < 0) ERR;
> 
>                 /*printf("found non-scale dataset %s, label %s\n", obj_name, 
> label);*/
>              }
>              if (H5Dclose(datasetid) < 0) ERR;
>              break;
>           case H5G_TYPE:
>              break;
>           case H5G_LINK:
>              break;
>           default:
>              printf("Unknown object class %d in rec_read_metadata!", 
> obj_class);
>        }
>       }
> 
>       /* Close up the shop. */
>       if (H5Sclose(spaceid) < 0 ||
>         H5Fclose(fileid) < 0) ERR;
>    }
> 
>    SUMMARIZE_ERR;
> 
>    /* Print out our number of errors, if any, and exit badly. */
>    if (total_err)
>    {
>       printf("%d errors detected! Sorry!\n", total_err);
>       return 2;
>    }
>    
>    printf("*** Tests successful!\n");
>    return 0;
> }
> 
> 
> 
> -- 
> Ed Hartnett  -- ed@xxxxxxxxxxxxxxxx
> 
>