hdf5/test/dynlib1.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://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
 * Programmer:	Raymond Lu
 *		13 February 2013
 *
 * 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 */
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_func_t)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
 *
 * Programmer:	Raymond Lu
 *              29 March 2013
 *
 *-------------------------------------------------------------------------
 */
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*/
        /* 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_dynlib1() */