/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * 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 HDF5 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.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "hdf5.h"
#include "h5tools.h"

/*-------------------------------------------------------------------------
 * print a warning message
 *-------------------------------------------------------------------------
 */
static void print_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
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: March 1, 2004
 *
 *-------------------------------------------------------------------------
 */
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 */

	/* get information about filters */
	if ((nfilters = H5Pget_nfilters(dcpl_id)) < 0)
		return -1;

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

		switch (filtn) {
		/*-------------------------------------------------------------------------
		 * user defined filter
		 *-------------------------------------------------------------------------
		 */
		default:
			if ((udfilter_avail = H5Zfilter_avail(filtn)) < 0)
				return -1;
			else if (udfilter_avail == 0) {
				if (name)
					print_warning(name, "user defined");
				return 0;
			}
			break;

			/*-------------------------------------------------------------------------
			 * H5Z_FILTER_DEFLATE      1 , deflation like gzip
			 *-------------------------------------------------------------------------
			 */
		case H5Z_FILTER_DEFLATE:
#ifndef H5_HAVE_FILTER_DEFLATE
			if (name)
				print_warning(name,"deflate");
			return 0;
#endif
			break;
			/*-------------------------------------------------------------------------
			 * H5Z_FILTER_SZIP       4 , szip compression
			 *-------------------------------------------------------------------------
			 */
		case H5Z_FILTER_SZIP:
#ifndef H5_HAVE_FILTER_SZIP
			if (name)
				print_warning(name,"SZIP");
			return 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*/

	return 1;
}

/*-------------------------------------------------------------------------
 * Function: h5tools_canwritef
 *
 * Purpose: check if the filter is available and can write data.
 * At this time, all filters that are available can write data,
 * except SZIP, which may be configured decoder-only.
 *
 * Return: 1, can write, 0, cannot, -1 error
 *
 * Programmer:
 *
 * Date: October 5, 2004
 *
 *-------------------------------------------------------------------------
 */
int h5tools_can_encode(H5Z_filter_t filtn) {
	switch (filtn) {
	/* user defined filter     */
	default:
		return 0;

	case H5Z_FILTER_DEFLATE:
#ifndef H5_HAVE_FILTER_DEFLATE
		return 0;
#endif
		break;
	case H5Z_FILTER_SZIP:
#ifndef H5_HAVE_FILTER_SZIP
		return 0;
#else
	{
		unsigned int filter_config_flags;

		if (H5Zget_filter_info(filtn, &filter_config_flags) < 0)
			return -1;
		if ((filter_config_flags
				& (H5Z_FILTER_CONFIG_ENCODE_ENABLED | H5Z_FILTER_CONFIG_DECODE_ENABLED)) == 0) {
			/* filter present but neither encode nor decode is supported (???) */
			return -1;
		} 
		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 */
			return 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 (???) */
			return -1;
		} 
		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)) {
			return 1;
		}
	}
#endif
		break;
	case H5Z_FILTER_SHUFFLE:
		break;
	case H5Z_FILTER_FLETCHER32:
		break;
	case H5Z_FILTER_NBIT:
		break;
	case H5Z_FILTER_SCALEOFFSET:
		break;
	}/*switch*/

	return 1;
}
