hdf5/test/dynlib4.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 files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic document set and is     *
 * linked from the top-level documents page.  It can also be found at        *
 * http://hdfgroup.org/HDF5/doc/Copyright.html.  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_DYNLIB4      260

#define PUSH_ERR(func, minor, str) H5Epush2(H5E_DEFAULT, __FILE__, func, __LINE__, H5E_ERR_CLS, H5E_PLUGIN, minor, str)

static size_t H5Z_filter_dynlib4(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 */
const H5Z_class2_t H5Z_DYNLIB4[1] = {{
    H5Z_CLASS_T_VERS,                /* H5Z_class_t version             */
    H5Z_FILTER_DYNLIB4,             /* Filter id number        */
    1, 1,                            /* Encoding and decoding enabled   */
    "dynlib4",                 /* Filter name for debugging    */
    NULL,                            /* The "can apply" callback        */
    NULL,                            /* The "set local" callback        */
    (H5Z_func_t)H5Z_filter_dynlib4,    /* The actual filter function    */
}};

H5PL_type_t   H5PLget_plugin_type(void) {return H5PL_TYPE_FILTER;}
const void    *H5PLget_plugin_info(void) {return H5Z_DYNLIB4;}

/*-------------------------------------------------------------------------
 * Function:    H5Z_filter_dynlib4
 *
 * Purpose:    A dynlib4 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. Designed to call a HDF function.
 *
 * Return:    Success:    Data chunk size
 *
 *        Failure:    0
 *
 *-------------------------------------------------------------------------
 */
static size_t
H5Z_filter_dynlib4(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;
    unsigned ver_info[3];

    /* Check for the library version */
    if(H5get_libversion(&ver_info[0], &ver_info[1], &ver_info[2]) < 0) {
        PUSH_ERR("dynlib4", H5E_CALLBACK, "H5get_libversion");
        return(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);

    if(ver_info[0] != cd_values[1] || ver_info[1] != cd_values[2]) {
        PUSH_ERR("dynlib4", H5E_CALLBACK, "H5get_libversion does not match");
        return(0);
    }

    add_on = (int)cd_values[0];

    if(flags & H5Z_FLAG_REVERSE) { /*read*/
        /* Substract 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_dynlib4() */