text: /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
   * 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.                                                        *
   * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
  
  /*
   * Purpose:	Test dataset filter plugin for the filter_pluging.c test.
   */
  
  
  #include <stdlib.h>
  #include <stdio.h>
  
  #include "H5PLextern.h"
  
  #define FILTER1_ID              257
  
  static size_t add_sub_value(unsigned int flags, size_t cd_nelmts,
          const unsigned int *cd_values, size_t nbytes, size_t *buf_size, void **buf);
  
  /* Filter class struct */
  const H5Z_class2_t FILTER_INFO[1] = {{
      H5Z_CLASS_T_VERS,                   /* H5Z_class_t version              */
      FILTER1_ID,                         /* Filter ID number                 */
      1,                                  /* Encoding enabled                 */
      1,                                  /* Decoding enabled                 */
      "test filter plugin 1",             /* Filter name for debugging        */
      NULL,                               /* The "can apply" callback         */
      NULL,                               /* The "set local" callback         */
      (H5Z_func_t)add_sub_value,          /* The actual filter function       */
  }};
  
  H5PL_type_t   H5PLget_plugin_type(void) {return H5PL_TYPE_FILTER;}
  const void    *H5PLget_plugin_info(void) {return FILTER_INFO;}
  
  
  /*-------------------------------------------------------------------------
   * Function:	add_sub_value
   *
   * Purpose:     On write:
   *                  Adds a caller-supplied value to the element
   *              On read:
   *                  Subtracts a caller-supplied value from the element
   *
   * Return:      Success:    Data chunk size in bytes
   *              Failure:    0
   *
   *-------------------------------------------------------------------------
   */
  static size_t
  add_sub_value(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 value = 0;                      /* Data value to add/subtract               */
  
      /* Check for the correct number of parameters */
      if (0 == cd_nelmts)
          return 0;
  
      /* Check that permanent parameters are set correctly */
      if (cd_values[0] > 9)
          return 0;
    
      value = (int)cd_values[0];
  
      if (flags & H5Z_FLAG_REVERSE) {
          /* READ - Substract the given value from all the data values */
          while (buf_left > 0) {
              *int_ptr++ -= value;
              buf_left -= sizeof(int);
          }
      }
      else {
          /* WRITE - Add the given value to all the data values */
          while (buf_left > 0) {
              *int_ptr++ += value;
              buf_left -= sizeof(int);
          }
      }
  
      return nbytes;
  
  } /* end add_sub_value() */
  
  