hdf5/tools/test/h5repack/dynlib_rpk.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 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.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
 * Purpose:    Tests the plugin module (H5PL)
 */

#include <stdlib.h>
#include <stdio.h>
#include "H5PLextern.h"

#define H5Z_FILTER_DYNLIB1 257

static size_t H5Z_filter_dynlib1(unsigned int flags, size_t cd_nelmts, const unsigned int *cd_values,
                                 size_t nbytes, size_t *buf_size, void **buf);

/* This message derives from H5Z */
static const H5Z_class2_t H5Z_DYNLIB1[1] = {{
    H5Z_CLASS_T_VERS,   /* H5Z_class_t version             */
    H5Z_FILTER_DYNLIB1, /* Filter id number        */
    1, 1,               /* Encoding and decoding enabled   */
    "dynlib1",          /* Filter name for debugging    */
    NULL,               /* The "can apply" callback        */
    NULL,               /* The "set local" callback        */
    H5Z_filter_dynlib1, /* The actual filter function    */
}};

H5PL_type_t
H5PLget_plugin_type(void)
{
    return H5PL_TYPE_FILTER;
}
const void *
H5PLget_plugin_info(void)
{
    return H5Z_DYNLIB1;
}

/*-------------------------------------------------------------------------
 * Function:    H5Z_filter_dynlib1
 *
 * Purpose:    A dynlib1 filter method that adds on and subtract from
 *              the original value with another value.  It will be built
 *              as a shared library.  plugin.c test will load and use
 *              this filter library.
 *
 * Return:    Success:    Data chunk size
 *
 *        Failure:    0
 *
 *-------------------------------------------------------------------------
 */
static size_t
H5Z_filter_dynlib1(unsigned int flags, size_t cd_nelmts, const unsigned int *cd_values, size_t nbytes,
                   size_t *buf_size, void **buf)
{
    int   *int_ptr  = (int *)*buf; /* Pointer to the data values */
    size_t buf_left = *buf_size;   /* Amount of data buffer left to process */
    int    add_on   = 0;

    /* Check for the correct number of parameters */
    if (cd_nelmts == 0)
        return 0;

    /* Check that permanent parameters are set correctly */
    if (cd_values[0] > 9)
        return 0;

    add_on = (int)cd_values[0];

    if (flags & H5Z_FLAG_REVERSE) { /*read*/
        /* Subtract the "add on" value to all the data values */
        while (buf_left > 0) {
            *int_ptr++ -= add_on;
            buf_left -= sizeof(int);
        }  /* end while */
    }      /* end if */
    else { /*write*/
        /* Add the "add on" value to all the data values */
        while (buf_left > 0) {
            *int_ptr++ += add_on;
            buf_left -= sizeof(int);
        } /* end while */
    }     /* end else */

    return nbytes;
} /* end H5Z_filter_dynlib1() */