h5tools_filters.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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 LICENSE 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.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "H5private.h"
#include "h5tools.h"

/*-------------------------------------------------------------------------
 * print a warning message
 *-------------------------------------------------------------------------
 */
static void
print_filter_warning(const char *dname, const char *fname)
{
    fprintf(stderr, "Warning: dataset <%s> cannot be read, %s filter is not available\n", dname, fname);
}

/*-------------------------------------------------------------------------
 * Function: h5tools_canreadf
 *
 * Purpose:  check if the dataset creation property list has filters that
 *           are not registered in the current configuration
 *               1) the external filters GZIP and SZIP might not be available
 *               2) the internal filters might be turned off
 *
 * Return:
 *           1 can read,
 *           0 cannot,
 *           -1 error
 *-------------------------------------------------------------------------
 */
int
h5tools_canreadf(const char *name, /* object name, serves also as boolean print */
                 hid_t       dcpl_id)    /* dataset creation property list */
{
    int          nfilters;       /* number of filters */
    H5Z_filter_t filtn;          /* filter identification number */
    int          i;              /* index */
    int          udfilter_avail; /* index */
    int          ret_value = 1;

    /* get information about filters */
    if ((nfilters = H5Pget_nfilters(dcpl_id)) < 0)
        H5TOOLS_GOTO_ERROR(FAIL, "H5Pget_nfilters failed");

    /* if we do not have filters, we can read the dataset safely */
    if (!nfilters)
        H5TOOLS_GOTO_DONE(1);

    /* check availability of filters */
    for (i = 0; i < nfilters; i++) {
        if ((filtn = H5Pget_filter2(dcpl_id, (unsigned)i, 0, 0, 0, (size_t)0, 0, NULL)) < 0)
            H5TOOLS_GOTO_ERROR(FAIL, "H5Pget_filter2 failed");

        switch (filtn) {
            /*-------------------------------------------------------------------------
             * user defined filter
             *-------------------------------------------------------------------------
             */
            default:
                if ((udfilter_avail = H5Zfilter_avail(filtn)) < 0) {
                    H5TOOLS_GOTO_ERROR(FAIL, "H5Zfilter_avail failed");
                }
                else if (!udfilter_avail) {
                    if (name)
                        print_filter_warning(name, "user defined");
                    ret_value = 0;
                }
                break;

                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_DEFLATE      1 , deflation like gzip
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_DEFLATE:
#ifndef H5_HAVE_FILTER_DEFLATE
                if (name)
                    print_filter_warning(name, "deflate");
                ret_value = 0;
#endif
                break;
                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_SZIP       4 , szip compression
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_SZIP:
#ifndef H5_HAVE_FILTER_SZIP
                if (name)
                    print_filter_warning(name, "SZIP");
                ret_value = 0;
#endif
                break;
                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_SHUFFLE    2 , shuffle the data
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_SHUFFLE:
                break;
                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_FLETCHER32 3 , fletcher32 checksum of EDC
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_FLETCHER32:
                break;
                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_NBIT
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_NBIT:
                break;
                /*-------------------------------------------------------------------------
                 * H5Z_FILTER_SCALEOFFSET
                 *-------------------------------------------------------------------------
                 */
            case H5Z_FILTER_SCALEOFFSET:
                break;
        } /*switch*/
    }     /*for*/

done:
    return ret_value;
}

/*-------------------------------------------------------------------------
 * Function: h5tools_canwritef
 *
 * Purpose:  check if the filter is available and can write data.
 *
 * Return:   1 can write,
 *           0 cannot,
 *           -1 error
 *-------------------------------------------------------------------------
 */
H5_ATTR_CONST int
h5tools_can_encode(H5Z_filter_t filtn)
{
    int ret_value = 1;

    switch (filtn) {
        /* user defined filter     */
        default:
            H5TOOLS_GOTO_DONE(0);
            break;
        case H5Z_FILTER_DEFLATE:
#ifndef H5_HAVE_FILTER_DEFLATE
            H5TOOLS_GOTO_DONE(0);
#endif
            break;

        case H5Z_FILTER_SZIP:
#ifndef H5_HAVE_FILTER_SZIP
            H5TOOLS_GOTO_DONE(0);
#else
        {
            unsigned int filter_config_flags;

            if (H5Zget_filter_info(filtn, &filter_config_flags) < 0)
                H5TOOLS_GOTO_ERROR(FAIL, "H5Zget_filter_info failed");
            if ((filter_config_flags &
                 (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) == 0) {
                /* filter present but neither encode nor decode is supported (???) */
                H5TOOLS_GOTO_ERROR(FAIL, "neither encode nor decode is supported");
            }
            else if ((filter_config_flags &
                      (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) ==
                     H5Z_FILTER_CONFIG_DECODE_ENABLED) {
                /* decoder only: read but not write */
                H5TOOLS_GOTO_DONE(0);
            }
            else if ((filter_config_flags &
                      (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) ==
                     H5Z_FILTER_CONFIG_ENCODE_ENABLED) {
                /* encoder only: write but not read (???) */
                H5TOOLS_GOTO_ERROR(FAIL, "encoder only: write but not read");
            }
            else if ((filter_config_flags &
                      (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) ==
                     (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) {
                H5TOOLS_GOTO_DONE(1);
            }
        }
#endif
            break;

        case H5Z_FILTER_SHUFFLE:
            break;

        case H5Z_FILTER_FLETCHER32:
            break;

        case H5Z_FILTER_NBIT:
            break;

        case H5Z_FILTER_SCALEOFFSET:
            break;
    } /*switch*/

done:
    return ret_value;
}