path: root/src/H5Z.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#define H5Z_PACKAGE		/*suppress error about including H5Zpkg	  */

/* Interface initialization */
#define H5_INTERFACE_INIT_FUNC	H5Z_init_interface


#include "H5private.h"		/* Generic Functions			*/
#include "H5Dprivate.h"		/* Dataset functions			*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5Iprivate.h"		/* IDs			  		*/
#include "H5MMprivate.h"	/* Memory management			*/
#include "H5Oprivate.h"		/* Object headers		  	*/
#include "H5Pprivate.h"         /* Property lists                       */
#include "H5Sprivate.h"		/* Dataspace functions			*/
#include "H5Zpkg.h"		/* Data filters				*/

#ifdef H5_HAVE_SZLIB_H
#   include "szlib.h"
#endif

/* Local typedefs */
#ifdef H5Z_DEBUG
typedef struct H5Z_stats_t {
    struct {
	hsize_t	total;		/*total number of bytes processed	*/
	hsize_t	errors;		/*bytes of total attributable to errors	*/
	H5_timer_t timer;	/*execution time including errors	*/
    } stats[2];			/*0=output, 1=input			*/
} H5Z_stats_t;
#endif /* H5Z_DEBUG */

/* Enumerated type for dataset creation prelude callbacks */
typedef enum {
    H5Z_PRELUDE_CAN_APPLY,      /* Call "can apply" callback */
    H5Z_PRELUDE_SET_LOCAL       /* Call "set local" callback */
} H5Z_prelude_type_t;

/* Local variables */
static size_t		H5Z_table_alloc_g = 0;
static size_t		H5Z_table_used_g = 0;
static H5Z_class2_t	*H5Z_table_g = NULL;
#ifdef H5Z_DEBUG
static H5Z_stats_t	*H5Z_stat_table_g = NULL;
#endif /* H5Z_DEBUG */

/* Local functions */
static int H5Z_find_idx(H5Z_filter_t id);


/*-------------------------------------------------------------------------
 * Function:	H5Z_init_interface
 *
 * Purpose:	Initializes the data filter layer.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Thursday, April 16, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5Z_init_interface (void)
{
    herr_t	ret_value=SUCCEED;      /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5Z_init_interface)

#ifdef H5_HAVE_FILTER_DEFLATE
    if (H5Z_register (H5Z_DEFLATE)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register deflate filter")
#endif /* H5_HAVE_FILTER_DEFLATE */
#ifdef H5_HAVE_FILTER_SHUFFLE
    if (H5Z_register (H5Z_SHUFFLE)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register shuffle filter")
#endif /* H5_HAVE_FILTER_SHUFFLE */
#ifdef H5_HAVE_FILTER_FLETCHER32
    if (H5Z_register (H5Z_FLETCHER32)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register fletcher32 filter")
#endif /* H5_HAVE_FILTER_FLETCHER32 */
#ifdef H5_HAVE_FILTER_SZIP
    H5Z_SZIP->encoder_present = SZ_encoder_enabled();
    if (H5Z_SZIP->encoder_present < 0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "szip filter reports bad status")
    if (H5Z_register (H5Z_SZIP)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register szip filter")
#endif /* H5_HAVE_FILTER_SZIP */
#ifdef H5_HAVE_FILTER_NBIT
    if (H5Z_register (H5Z_NBIT)<0)
        HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register nbit filter")
#endif /* H5_HAVE_FILTER_NBIT */
#ifdef H5_HAVE_FILTER_SCALEOFFSET
    if (H5Z_register (H5Z_SCALEOFFSET)<0)
        HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register scaleoffset filter")
#endif /* H5_HAVE_FILTER_SCALEOFFSET */

#if (defined H5_HAVE_FILTER_DEFLATE | defined H5_HAVE_FILTER_FLETCHER32 | defined H5_HAVE_FILTER_SHUFFLE | defined H5_HAVE_FILTER_SZIP | defined H5_HAVE_FILTER_NBIT | defined H5_HAVE_FILTER_SCALEOFFSET)
done:
#endif /* (defined H5_HAVE_FILTER_DEFLATE | defined H5_HAVE_FILTER_FLETCHER32 | defined H5_HAVE_FILTER_SHUFFLE | defined H5_HAVE_FILTER_SZIP | defined H5_HAVE_FILTER_NBIT | defined H5_HAVE_FILTER_SCALEOFFSET) */
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:	H5Z_term_interface
 *
 * Purpose:	Terminate the H5Z layer.
 *
 * Return:	void
 *
 * Programmer:	Robb Matzke
 *              Thursday, April 16, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
int
H5Z_term_interface(void)
{
#ifdef H5Z_DEBUG
    size_t	i;
    int		dir, nprint=0;
    char	comment[16], bandwidth[32];
#endif

    if(H5_interface_initialize_g) {
#ifdef H5Z_DEBUG
	if (H5DEBUG(Z)) {
	    for (i=0; i<H5Z_table_used_g; i++) {
		for (dir=0; dir<2; dir++) {
		    if (0==H5Z_stat_table_g[i].stats[dir].total) continue;

		    if (0==nprint++) {
			/* Print column headers */
			HDfprintf (H5DEBUG(Z), "H5Z: filter statistics "
				   "accumulated over life of library:\n");
			HDfprintf (H5DEBUG(Z),
				   "   %-16s %10s %10s %8s %8s %8s %10s\n",
				   "Filter", "Total", "Errors", "User",
				   "System", "Elapsed", "Bandwidth");
			HDfprintf (H5DEBUG(Z),
				   "   %-16s %10s %10s %8s %8s %8s %10s\n",
				   "------", "-----", "------", "----",
				   "------", "-------", "---------");
		    }

		    /* Truncate the comment to fit in the field */
		    HDstrncpy(comment, H5Z_table_g[i].name,
			      sizeof comment);
		    comment[sizeof(comment)-1] = '\0';

		    /*
		     * Format bandwidth to have four significant digits and
		     * units of `B/s', `kB/s', `MB/s', `GB/s', or `TB/s' or
		     * the word `Inf' if the elapsed time is zero.
		     */
		    H5_bandwidth(bandwidth,
				 (double)(H5Z_stat_table_g[i].stats[dir].total),
				 H5Z_stat_table_g[i].stats[dir].timer.etime);

		    /* Print the statistics */
		    HDfprintf (H5DEBUG(Z),
			       "   %s%-15s %10Hd %10Hd %8.2f %8.2f %8.2f "
			       "%10s\n", dir?"<":">", comment,
			       H5Z_stat_table_g[i].stats[dir].total,
			       H5Z_stat_table_g[i].stats[dir].errors,
			       H5Z_stat_table_g[i].stats[dir].timer.utime,
			       H5Z_stat_table_g[i].stats[dir].timer.stime,
			       H5Z_stat_table_g[i].stats[dir].timer.etime,
			       bandwidth);
		}
	    }
	}
#endif /* H5Z_DEBUG */
	/* Free the table of filters */
	H5Z_table_g = (H5Z_class2_t *)H5MM_xfree(H5Z_table_g);
#ifdef H5Z_DEBUG
	H5Z_stat_table_g = (H5Z_stats_t *)H5MM_xfree(H5Z_stat_table_g);
#endif /* H5Z_DEBUG */
	H5Z_table_used_g = H5Z_table_alloc_g = 0;
	H5_interface_initialize_g = 0;
    } /* end if */

    return(0);
} /* end H5Z_term_interface() */


/*-------------------------------------------------------------------------
 * Function:	H5Zregister
 *
 * Purpose:	This function registers new filter.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Thursday, April 16, 1998
 *
 * Modifications:
 *              Changed to pass in H5Z_class_t struct
 *              Quincey Koziol, April  5, 2003
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Zregister(const void *cls)
{
    const H5Z_class2_t  *cls_real = (const H5Z_class2_t *) cls; /* "Real" class pointer */
    H5Z_class2_t        cls_new;                /* Translated class struct */
    herr_t              ret_value=SUCCEED;      /* Return value */

    FUNC_ENTER_API(H5Zregister, FAIL)
    H5TRACE1("e", "*Zc", cls);

    /* Check args */
    if (cls_real==NULL)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid filter class")

    /* Check H5Z_class_t version number; this is where a function to convert
     * from an outdated version should be called.
     *
     * If the version number is invalid, we assume that the target of cls is the
     * old style "H5Z_class1_t" structure, which did not contain a version
     * field.  In this structure, the first field is the id.  Since both version
     * and id are integers they will have the same value, and since id must be
     * at least 256, there should be no overlap and the version of the struct
     * can be determined by the value of the first field.
     */
    if(cls_real->version != H5Z_CLASS_T_VERS) {
        /* Assume it is an old "H5Z_class1_t" instead */
        const H5Z_class1_t *cls_old = (const H5Z_class1_t *) cls;

        /* Translate to new H5Z_class2_t */
        cls_new.version = H5Z_CLASS_T_VERS;
        cls_new.id = cls_old->id;
        cls_new.encoder_present = 1;
        cls_new.decoder_present = 1;
        cls_new.name = cls_old->name;
        cls_new.can_apply = cls_old->can_apply;
        cls_new.set_local = cls_old->set_local;
        cls_new.filter = cls_old->filter;

        /* Set cls_real to point to the translated structure */
        cls_real = &cls_new;
    } /* end if */

    if (cls_real->id<0 || cls_real->id>H5Z_FILTER_MAX)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid filter identification number")
    if (cls_real->id<H5Z_FILTER_RESERVED)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "unable to modify predefined filters")
    if (cls_real->filter==NULL)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no filter function specified")

    /* Do it */
    if (H5Z_register (cls_real)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to register filter")

done:
    FUNC_LEAVE_API(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:	H5Z_register
 *
 * Purpose:	Same as the public version except this one allows filters
 *		to be set for predefined method numbers <H5Z_FILTER_RESERVED
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Thursday, April 16, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_register (const H5Z_class2_t *cls)
{
    size_t	i;
    herr_t      ret_value = SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5Z_register, FAIL)

    HDassert(cls);
    HDassert(cls->id >= 0 && cls->id <= H5Z_FILTER_MAX);

    /* Is the filter already registered? */
    for(i = 0; i < H5Z_table_used_g; i++)
	if(H5Z_table_g[i].id == cls->id)
            break;

    /* Filter not already registered */
    if(i >= H5Z_table_used_g) {
	if(H5Z_table_used_g >= H5Z_table_alloc_g) {
	    size_t n = MAX(H5Z_MAX_NFILTERS, 2*H5Z_table_alloc_g);
	    H5Z_class2_t *table = (H5Z_class2_t *)H5MM_realloc(H5Z_table_g, n * sizeof(H5Z_class2_t));
#ifdef H5Z_DEBUG
	    H5Z_stats_t *stat_table = (H5Z_stats_t *)H5MM_realloc(H5Z_stat_table_g, n * sizeof(H5Z_stats_t));
#endif /* H5Z_DEBUG */
	    if(!table)
		HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to extend filter table")
	    H5Z_table_g = table;
#ifdef H5Z_DEBUG
	    if(!stat_table)
		HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to extend filter statistics table")
	    H5Z_stat_table_g = stat_table;
#endif /* H5Z_DEBUG */
	    H5Z_table_alloc_g = n;
	} /* end if */

	/* Initialize */
	i = H5Z_table_used_g++;
	HDmemcpy(H5Z_table_g+i, cls, sizeof(H5Z_class2_t));
#ifdef H5Z_DEBUG
	HDmemset(H5Z_stat_table_g+i, 0, sizeof(H5Z_stats_t));
#endif /* H5Z_DEBUG */
    } /* end if */
    /* Filter already registered */
    else {
	/* Replace old contents */
	HDmemcpy(H5Z_table_g+i, cls, sizeof(H5Z_class2_t));
    } /* end else */

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:	H5Zunregister
 *
 * Purpose:	This function unregisters a filter.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, November 14, 2002
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Zunregister(H5Z_filter_t id)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_API(H5Zunregister, FAIL)
    H5TRACE1("e", "Zf", id);

    /* Check args */
    if (id<0 || id>H5Z_FILTER_MAX)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid filter identification number")
    if (id<H5Z_FILTER_RESERVED)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "unable to modify predefined filters")

    /* Do it */
    if (H5Z_unregister (id)<0)
	HGOTO_ERROR (H5E_PLINE, H5E_CANTINIT, FAIL, "unable to unregister filter")

done:
    FUNC_LEAVE_API(ret_value)
} /* end H5Zunregister() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_unregister
 *
 * Purpose:	Same as the public version except this one allows filters
 *		to be unset for predefined method numbers <H5Z_FILTER_RESERVED
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, November 14, 2002
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_unregister (H5Z_filter_t id)
{
    size_t i;                   /* Local index variable */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5Z_unregister,FAIL)

    assert (id>=0 && id<=H5Z_FILTER_MAX);

    /* Is the filter already registered? */
    for (i=0; i<H5Z_table_used_g; i++)
	if (H5Z_table_g[i].id==id)
            break;

    /* Fail if filter not found */
    if (i>=H5Z_table_used_g)
        HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "filter is not registered")

    /* Remove filter from table */
    /* Don't worry about shrinking table size (for now) */
    HDmemmove(&H5Z_table_g[i],&H5Z_table_g[i+1],sizeof(H5Z_class2_t)*((H5Z_table_used_g-1)-i));
#ifdef H5Z_DEBUG
    HDmemmove(&H5Z_stat_table_g[i],&H5Z_stat_table_g[i+1],sizeof(H5Z_stats_t)*((H5Z_table_used_g-1)-i));
#endif /* H5Z_DEBUG */
    H5Z_table_used_g--;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_unregister() */


/*-------------------------------------------------------------------------
 * Function:	H5Zfilter_avail
 *
 * Purpose:	Check if a filter is available
 *
 * Return:	Non-negative (TRUE/FALSE) on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, November 14, 2002
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5Zfilter_avail(H5Z_filter_t id)
{
    size_t i;                   /* Local index variable */
    htri_t ret_value=FALSE;     /* Return value */

    FUNC_ENTER_API(H5Zfilter_avail, FAIL)
    H5TRACE1("t", "Zf", id);

    /* Check args */
    if(id<0 || id>H5Z_FILTER_MAX)
        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid filter identification number")

    /* Is the filter already registered? */
    for(i=0; i<H5Z_table_used_g; i++)
	if(H5Z_table_g[i].id==id) {
            ret_value=TRUE;
            break;
        } /* end if */

done:
    FUNC_LEAVE_API(ret_value)
} /* end H5Zfilter_avail() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_prelude_callback
 *
 * Purpose:	Makes a dataset creation "prelude" callback for the "can_apply"
 *              or "set_local" routines.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Friday, April 4, 2003
 *
 * Notes:
 *              The chunk dimensions are used to create a dataspace, instead
 *              of passing in the dataset's dataspace, since the chunk
 *              dimensions are what the I/O filter will actually see
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5Z_prelude_callback(hid_t dcpl_id, hid_t type_id, H5Z_prelude_type_t prelude_type)
{
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5Z_prelude_callback)

    HDassert(H5I_GENPROP_LST == H5I_get_type(dcpl_id));
    HDassert(H5I_DATATYPE == H5I_get_type(type_id));

    /* Check if the property list is non-default */
    if(dcpl_id != H5P_DATASET_CREATE_DEFAULT) {
        H5P_genplist_t 	*dc_plist;      /* Dataset creation property list object */
        H5O_layout_t    dcpl_layout;    /* Dataset's layout information */

        /* Get dataset creation property list object */
        if(NULL == (dc_plist = (H5P_genplist_t *)H5I_object(dcpl_id)))
            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get dataset creation property list")

        /* Get layout information */
        if(H5P_get(dc_plist, H5D_CRT_LAYOUT_NAME, &dcpl_layout) < 0)
            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't retrieve layout")

        /* Check if the dataset is chunked */
        if(H5D_CHUNKED == dcpl_layout.type) {
            H5O_pline_t     dcpl_pline;     /* Dataset's I/O pipeline information */

            /* Get I/O pipeline information */
            if(H5P_get(dc_plist, H5D_CRT_DATA_PIPELINE_NAME, &dcpl_pline) < 0)
                HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't retrieve pipeline filter")

            /* Check if the chunks have filters */
            if(dcpl_pline.nused > 0) {
                hsize_t chunk_dims[H5O_LAYOUT_NDIMS];      /* Size of chunk dimensions */
                H5S_t *space;           /* Dataspace describing chunk */
                hid_t space_id;         /* ID for dataspace describing chunk */
                size_t u;               /* Local index variable */

                /* Create a data space for a chunk & set the extent */
                for(u = 0; u < dcpl_layout.u.chunk.ndims; u++)
                    chunk_dims[u] = dcpl_layout.u.chunk.dim[u];
                if(NULL == (space = H5S_create_simple(dcpl_layout.u.chunk.ndims, chunk_dims, NULL)))
                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCREATE, FAIL, "can't create simple dataspace")

                /* Get ID for dataspace to pass to filter routines */
                if((space_id = H5I_register(H5I_DATASPACE, space, FALSE)) < 0) {
                    (void)H5S_close(space);
                    HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace ID")
                } /* end if */

                /* Iterate over filters */
                for(u = 0; u < dcpl_pline.nused; u++) {
                    H5Z_class2_t	*fclass;        /* Individual filter information */

                    /* Get filter information */
                    if(NULL == (fclass = H5Z_find(dcpl_pline.filter[u].id))) {
                        /* Ignore errors from optional filters */
                        if(dcpl_pline.filter[u].flags & H5Z_FLAG_OPTIONAL)
                            H5E_clear_stack(NULL);
                        else
                            HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "required filter was not located")
                    } /* end if */
                    else {
                        /* Make correct callback */
                        switch(prelude_type) {
                            case H5Z_PRELUDE_CAN_APPLY:
                                /* Check if filter is configured to be able to encode */
                                if(!fclass->encoder_present)
                                    HGOTO_ERROR(H5E_PLINE, H5E_NOENCODER, FAIL, "Filter present but encoding is disabled.");


                                /* Check if there is a "can apply" callback */
                                if(fclass->can_apply) {
                                    /* Make callback to filter's "can apply" function */
                                    herr_t status = (fclass->can_apply)(dcpl_id, type_id, space_id);

                                    /* Check return value */
                                    if(status <= 0) {
                                        /* We're leaving, so close dataspace */
                                        if(H5I_dec_ref(space_id, FALSE) < 0)
                                            HGOTO_ERROR(H5E_PLINE, H5E_CANTRELEASE, FAIL, "unable to close dataspace")

                                        /* Indicate filter can't apply to this combination of parameters */
                                        if(status == 0)
                                            HGOTO_ERROR(H5E_PLINE, H5E_CANAPPLY, FAIL, "filter parameters not appropriate")
                                        /* Indicate error during filter callback */
                                        else
                                            HGOTO_ERROR(H5E_PLINE, H5E_CANAPPLY, FAIL, "error during user callback")
                                    } /* end if */
                                } /* end if */
                                break;

                            case H5Z_PRELUDE_SET_LOCAL:
                                /* Check if there is a "set local" callback */
                                if(fclass->set_local) {
                                    /* Make callback to filter's "set local" function */
                                    if((fclass->set_local)(dcpl_id, type_id, space_id)<0) {
                                        /* We're leaving, so close dataspace */
                                        if(H5I_dec_ref(space_id, FALSE)<0)
                                            HGOTO_ERROR (H5E_PLINE, H5E_CANTRELEASE, FAIL, "unable to close dataspace")

                                        /* Indicate error during filter callback */
                                        HGOTO_ERROR(H5E_PLINE, H5E_SETLOCAL, FAIL, "error during user callback")
                                    } /* end if */
                                } /* end if */
                                break;

                            default:
                                HDassert("invalid prelude type" && 0);
                        } /* end switch */
                    } /* end else */
                } /* end for */

                /* Close dataspace */
                if(H5I_dec_ref(space_id, FALSE) < 0)
                    HGOTO_ERROR (H5E_PLINE, H5E_CANTRELEASE, FAIL, "unable to close dataspace")
            } /* end if */
        } /* end if */
    } /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_prelude_callback() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_can_apply
 *
 * Purpose:	Checks if all the filters defined in the dataset creation
 *              property list can be applied to a particular combination of
 *              datatype and dataspace for a dataset.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, April 3, 2003
 *
 * Notes:
 *              The chunk dimensions are used to create a dataspace, instead
 *              of passing in the dataset's dataspace, since the chunk
 *              dimensions are what the I/O filter will actually see
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_can_apply(hid_t dcpl_id, hid_t type_id)
{
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5Z_can_apply, FAIL)

    HDassert(H5I_GENPROP_LST == H5I_get_type(dcpl_id));
    HDassert(H5I_DATATYPE == H5I_get_type(type_id));

    /* Make "can apply" callbacks for filters in pipeline */
    if(H5Z_prelude_callback(dcpl_id, type_id, H5Z_PRELUDE_CAN_APPLY) < 0)
        HGOTO_ERROR(H5E_PLINE, H5E_CANAPPLY, FAIL, "unable to apply filter")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_can_apply() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_set_local
 *
 * Purpose:	Makes callbacks to modify dataset creation list property
 *              settings for filters on a new dataset, based on the datatype
 *              and dataspace of that dataset (chunk).
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Friday, April 4, 2003
 *
 * Notes:
 *              The chunk dimensions are used to create a dataspace, instead
 *              of passing in the dataset's dataspace, since the chunk
 *              dimensions are what the I/O filter will actually see
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_set_local(hid_t dcpl_id, hid_t type_id)
{
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5Z_set_local, FAIL)

    HDassert(H5I_GENPROP_LST == H5I_get_type(dcpl_id));
    HDassert(H5I_DATATYPE == H5I_get_type(type_id));

    /* Make "set local" callbacks for filters in pipeline */
    if(H5Z_prelude_callback(dcpl_id, type_id, H5Z_PRELUDE_SET_LOCAL) < 0)
        HGOTO_ERROR(H5E_PLINE, H5E_SETLOCAL, FAIL, "local filter parameters not set")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_set_local() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_modify
 *
 * Purpose:	Modify filter parameters for specified pipeline.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Friday, April  5, 2003
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_modify(const H5O_pline_t *pline, H5Z_filter_t filter, unsigned flags,
	   size_t cd_nelmts, const unsigned int cd_values[/*cd_nelmts*/])
{
    size_t	idx;                    /* Index of filter in pipeline */
    herr_t      ret_value = SUCCEED;      /* Return value */

    FUNC_ENTER_NOAPI(H5Z_modify, FAIL)

    HDassert(pline);
    HDassert(filter >= 0 && filter <= H5Z_FILTER_MAX);
    HDassert(0 == (flags & ~((unsigned)H5Z_FLAG_DEFMASK)));
    HDassert(0 == cd_nelmts || cd_values);

    /* Locate the filter in the pipeline */
    for(idx = 0; idx < pline->nused; idx++)
        if(pline->filter[idx].id == filter)
            break;

    /* Check if the filter was not already in the pipeline */
    if(idx > pline->nused)
	HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "filter not in pipeline")

    /* Change parameters for filter */
    pline->filter[idx].flags = flags;
    pline->filter[idx].cd_nelmts = cd_nelmts;

    /* Free any existing parameters */
    if(pline->filter[idx].cd_values != NULL && pline->filter[idx].cd_values != pline->filter[idx]._cd_values)
	H5MM_xfree(pline->filter[idx].cd_values);

    /* Set parameters */
    if(cd_nelmts > 0) {
        size_t	i;                      /* Local index variable */

        /* Allocate memory or point at internal buffer */
        if(cd_nelmts > H5Z_COMMON_CD_VALUES) {
            pline->filter[idx].cd_values = (unsigned *)H5MM_malloc(cd_nelmts * sizeof(unsigned));
            if(NULL == pline->filter[idx].cd_values)
                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for filter parameters")
        } /* end if */
        else
            pline->filter[idx].cd_values = pline->filter[idx]._cd_values;

        /* Copy client data values */
	for(i = 0; i < cd_nelmts; i++)
	    pline->filter[idx].cd_values[i] = cd_values[i];
    } /* end if */
    else
       pline->filter[idx].cd_values = NULL;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_modify() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_append
 *
 * Purpose:	Append another filter to the specified pipeline.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Tuesday, August  4, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_append(H5O_pline_t *pline, H5Z_filter_t filter, unsigned flags,
	   size_t cd_nelmts, const unsigned int cd_values[/*cd_nelmts*/])
{
    size_t	idx;
    herr_t      ret_value = SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5Z_append, FAIL)

    HDassert(pline);
    HDassert(filter >= 0 && filter <= H5Z_FILTER_MAX);
    HDassert(0 == (flags & ~((unsigned)H5Z_FLAG_DEFMASK)));
    HDassert(0 == cd_nelmts || cd_values);

    /*
     * Check filter limit.  We do it here for early warnings although we may
     * decide to relax this restriction in the future.
     */
    if(pline->nused >= H5Z_MAX_NFILTERS)
	HGOTO_ERROR(H5E_PLINE, H5E_CANTINIT, FAIL, "too many filters in pipeline")

    /* Check for freshly allocated filter pipeline */
    if(pline->version == 0)
        pline->version = H5O_PLINE_VERSION_1;

    /* Allocate additional space in the pipeline if it's full */
    if(pline->nused >= pline->nalloc) {
	H5O_pline_t x;
        size_t n;

        /* Each filter's data may be stored internally or may be
         * a separate block of memory.
         * For each filter, if cd_values points to the internal array
         * _cd_values, the pointer will need to be updated when the
         * filter struct is reallocated.  Set these pointers to ~NULL
         * so that we can reset them after reallocating the filters array.
         */
        for(n = 0; n < pline->nalloc; ++n)
            if(pline->filter[n].cd_values == pline->filter[n]._cd_values)
                pline->filter[n].cd_values = (unsigned *)((void *) ~((size_t)NULL));

	x.nalloc = MAX(H5Z_MAX_NFILTERS, 2 * pline->nalloc);
	x.filter = (H5Z_filter_info_t *)H5MM_realloc(pline->filter, x.nalloc * sizeof(x.filter[0]));
	if(NULL == x.filter)
	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for filter pipeline")

        /* Fix pointers in previous filters that need to point to their own
         *      internal data.
         */
        for(n = 0; n < pline->nalloc; ++n)
            if(x.filter[n].cd_values == (void *) ~((size_t) NULL))
                x.filter[n].cd_values = x.filter[n]._cd_values;

        /* Point to newly allocated buffer */
	pline->nalloc = x.nalloc;
	pline->filter = x.filter;
    } /* end if */

    /* Add the new filter to the pipeline */
    idx = pline->nused;
    pline->filter[idx].id = filter;
    pline->filter[idx].flags = flags;
    pline->filter[idx].name = NULL; /*we'll pick it up later*/
    pline->filter[idx].cd_nelmts = cd_nelmts;
    if(cd_nelmts > 0) {
        size_t	i;                      /* Local index variable */

        /* Allocate memory or point at internal buffer */
        if(cd_nelmts > H5Z_COMMON_CD_VALUES) {
            pline->filter[idx].cd_values = (unsigned *)H5MM_malloc(cd_nelmts * sizeof(unsigned));
            if(NULL == pline->filter[idx].cd_values)
                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for filter")
        } /* end if */
        else
            pline->filter[idx].cd_values = pline->filter[idx]._cd_values;

        /* Copy client data values */
	for(i = 0; i < cd_nelmts; i++)
	    pline->filter[idx].cd_values[i] = cd_values[i];
    } /* end if */
    else
       pline->filter[idx].cd_values = NULL;

    pline->nused++;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_append() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_find_idx
 *
 * Purpose:	Given a filter ID return the offset in the global array
 *              that holds all the registered filters.
 *
 * Return:	Success:	Non-negative index of entry in global filter table.
 *		Failure:	Negative
 *
 * Programmer:	Quincey Koziol
 *              Friday, April  5, 2003
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static int
H5Z_find_idx(H5Z_filter_t id)
{
    size_t i;                   /* Local index variable */
    int ret_value=FAIL;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5Z_find_idx)

    for (i=0; i<H5Z_table_used_g; i++)
	if (H5Z_table_g[i].id == id)
	    HGOTO_DONE((int)i)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_find_idx() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_find
 *
 * Purpose:	Given a filter ID return a pointer to a global struct that
 *		defines the filter.
 *
 * Return:	Success:	Ptr to entry in global filter table.
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  5, 1998
 *
 * Modifications:
 *              Use H5Z_find_idx now
 *              Quincey Koziol, April  5, 2003
 *
 *-------------------------------------------------------------------------
 */
H5Z_class2_t *
H5Z_find(H5Z_filter_t id)
{
    int	idx;                            /* Filter index in global table */
    H5Z_class2_t *ret_value=NULL;        /* Return value */

    FUNC_ENTER_NOAPI(H5Z_find, NULL)

    /* Get the index in the global table */
    if((idx=H5Z_find_idx(id))<0)
        HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, NULL, "required filter is not registered")

    /* Set return value */
    ret_value=H5Z_table_g+idx;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5Z_find() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_pipeline
 *
 * Purpose:	Process data through the filter pipeline.  The FLAGS argument
 *		is the filter invocation flags (definition flags come from
 *		the PLINE->filter[].flags).  The filters are processed in
 *		definition order unless the H5Z_FLAG_REVERSE is set.  The
 *		FILTER_MASK is a bit-mask to indicate which filters to skip
 *		and on exit will indicate which filters failed.  Each
 *		filter has an index number in the pipeline and that index
 *		number is the filter's bit in the FILTER_MASK.  NBYTES is the
 *		number of bytes of data to filter and on exit should be the
 *		number of resulting bytes while BUF_SIZE holds the total
 *		allocated size of the buffer, which is pointed to BUF.
 *
 *		If the buffer must grow during processing of the pipeline
 *		then the pipeline function should free the original buffer
 *		and return a fresh buffer, adjusting BUF_SIZE accordingly.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Tuesday, August  4, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_pipeline(const H5O_pline_t *pline, unsigned flags,
 	     unsigned *filter_mask/*in,out*/, H5Z_EDC_t edc_read,
             H5Z_cb_t cb_struct, size_t *nbytes/*in,out*/,
             size_t *buf_size/*in,out*/, void **buf/*in,out*/)
{
    size_t	i, idx, new_nbytes;
    int fclass_idx;             /* Index of filter class in global table */
    H5Z_class2_t	*fclass=NULL;   /* Filter class pointer */
#ifdef H5Z_DEBUG
    H5Z_stats_t	*fstats=NULL;   /* Filter stats pointer */
    H5_timer_t	timer;
#endif
    unsigned	failed = 0;
    unsigned	tmp_flags;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5Z_pipeline, FAIL)

    assert(0==(flags & ~((unsigned)H5Z_FLAG_INVMASK)));
    assert(filter_mask);
    assert(nbytes && *nbytes>0);
    assert(buf_size && *buf_size>0);
    assert(buf && *buf);
    assert(!pline || pline->nused<H5Z_MAX_NFILTERS);

    if (pline && (flags & H5Z_FLAG_REVERSE)) { /* Read */
	for (i=pline->nused; i>0; --i) {
	    idx = i-1;

	    if (*filter_mask & ((unsigned)1<<idx)) {
		failed |= (unsigned)1 << idx;
		continue;/*filter excluded*/
	    }
	    if ((fclass_idx=H5Z_find_idx(pline->filter[idx].id))<0) {
		HGOTO_ERROR(H5E_PLINE, H5E_READERROR, FAIL, "required filter is not registered")
	    }
            fclass=&H5Z_table_g[fclass_idx];
#ifdef H5Z_DEBUG
            fstats=&H5Z_stat_table_g[fclass_idx];
	    H5_timer_begin(&timer);
#endif
            tmp_flags=flags|(pline->filter[idx].flags);
            tmp_flags|=(edc_read== H5Z_DISABLE_EDC) ? H5Z_FLAG_SKIP_EDC : 0;
	    new_nbytes = (fclass->filter)(tmp_flags, pline->filter[idx].cd_nelmts,
                                        pline->filter[idx].cd_values, *nbytes, buf_size, buf);

#ifdef H5Z_DEBUG
	    H5_timer_end(&(fstats->stats[1].timer), &timer);
	    fstats->stats[1].total += MAX(*nbytes, new_nbytes);
	    if (0==new_nbytes) fstats->stats[1].errors += *nbytes;
#endif

            if(0==new_nbytes) {
                if((cb_struct.func && (H5Z_CB_FAIL==cb_struct.func(pline->filter[idx].id, *buf, *buf_size, cb_struct.op_data)))
                    || !cb_struct.func)
		      HGOTO_ERROR(H5E_PLINE, H5E_READERROR, FAIL, "filter returned failure during read")

                *nbytes = *buf_size;
                failed |= (unsigned)1 << idx;
                H5E_clear_stack(NULL);
            } else {
                *nbytes = new_nbytes;
            }
	}
    } else if (pline) { /* Write */
	for (idx=0; idx<pline->nused; idx++) {
	    if (*filter_mask & ((unsigned)1<<idx)) {
		failed |= (unsigned)1 << idx;
		continue; /*filter excluded*/
	    }
	    if ((fclass_idx=H5Z_find_idx(pline->filter[idx].id))<0) {
                /* Check if filter is optional -- If it isn't, then error */
		if ((pline->filter[idx].flags & H5Z_FLAG_OPTIONAL) == 0)
		    HGOTO_ERROR(H5E_PLINE, H5E_WRITEERROR, FAIL, "required filter is not registered")

		failed |= (unsigned)1 << idx;
                H5E_clear_stack(NULL);
		continue; /*filter excluded*/
	    }
            fclass=&H5Z_table_g[fclass_idx];
#ifdef H5Z_DEBUG
            fstats=&H5Z_stat_table_g[fclass_idx];
	    H5_timer_begin(&timer);
#endif
	    new_nbytes = (fclass->filter)(flags|(pline->filter[idx].flags), pline->filter[idx].cd_nelmts,
					pline->filter[idx].cd_values, *nbytes, buf_size, buf);
#ifdef H5Z_DEBUG
	    H5_timer_end(&(fstats->stats[0].timer), &timer);
	    fstats->stats[0].total += MAX(*nbytes, new_nbytes);
	    if (0==new_nbytes) fstats->stats[0].errors += *nbytes;
#endif
            if(0==new_nbytes) {
                if (0==(pline->filter[idx].flags & H5Z_FLAG_OPTIONAL)) {
                    if((cb_struct.func && (H5Z_CB_FAIL==cb_struct.func(pline->filter[idx].id, *buf, *nbytes, cb_struct.op_data)))
                            || !cb_struct.func)
                        HGOTO_ERROR(H5E_PLINE, H5E_WRITEERROR, FAIL, "filter returned failure")

                    *nbytes = *buf_size;
                }

                failed |= (unsigned)1 << idx;
                H5E_clear_stack(NULL);
            } else {
                *nbytes = new_nbytes;
            }
	}
    }

    *filter_mask = failed;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:	H5Z_filter_info
 *
 * Purpose:	Get pointer to filter info for pipeline
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Friday, April  5, 2003
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5Z_filter_info_t *
H5Z_filter_info(const H5O_pline_t *pline, H5Z_filter_t filter)
{
    size_t	idx;                    /* Index of filter in pipeline */
    H5Z_filter_info_t *ret_value;       /* Return value */

    FUNC_ENTER_NOAPI(H5Z_filter_info, NULL)

    assert(pline);
    assert(filter>=0 && filter<=H5Z_FILTER_MAX);

    /* Locate the filter in the pipeline */
    for(idx=0; idx<pline->nused; idx++)
        if(pline->filter[idx].id==filter)
            break;

    /* Check if the filter was not already in the pipeline */
    if(idx>pline->nused)
	HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, NULL, "filter not in pipeline")

    /* Set return value */
    ret_value=&pline->filter[idx];

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_filter_info() */


/*-------------------------------------------------------------------------
 * Function:	H5Z_all_filters_avail
 *
 * Purpose:	Verify that all the filters in a pipeline are currently
 *              available (i.e. registered)
 *
 * Return:	Non-negative (TRUE/FALSE) on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Tuesday, April  8, 2003
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5Z_all_filters_avail(const H5O_pline_t *pline)
{
    size_t i,j;                 /* Local index variable */
    htri_t ret_value=TRUE;      /* Return value */

    FUNC_ENTER_NOAPI(H5Z_all_filters_avail, FAIL)

    /* Check args */
    assert(pline);

    /* Iterate through all the filters in pipeline */
    for(i=0; i<pline->nused; i++) {

        /* Look for each filter in the list of registered filters */
        for(j=0; j<H5Z_table_used_g; j++)
            if(H5Z_table_g[j].id==pline->filter[i].id)
                break;

        /* Check if we didn't find the filter */
        if(j==H5Z_table_used_g)
            HGOTO_DONE(FALSE)
    } /* end for */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_all_filters_avail() */



/*-------------------------------------------------------------------------
 * Function: H5Z_delete
 *
 * Purpose: Delete filter FILTER from pipeline PLINE;
 *  deletes all filters if FILTER is H5Z_FILTER_NONE
 *
 * Return: Non-negative on success/Negative on failure
 *
 * Programmer: Pedro Vicente
 *              Monday, January 26, 2004
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_delete(H5O_pline_t *pline, H5Z_filter_t filter)
{
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI(H5Z_delete, FAIL)

    /* Check args */
    HDassert(pline);
    HDassert(filter >= 0 && filter <= H5Z_FILTER_MAX);

    /* if the pipeline has no filters, just return */
    if(pline->nused==0)
        HGOTO_DONE(SUCCEED)

    /* Delete all filters */
    if(H5Z_FILTER_ALL == filter) {
        if(H5O_msg_reset(H5O_PLINE_ID, pline) < 0)
            HGOTO_ERROR(H5E_PLINE, H5E_CANTFREE, FAIL, "can't release pipeline info")
    } /* end if */
    /* Delete filter */
    else {
        size_t idx;             /* Index of filter in pipeline */
        hbool_t found = FALSE;  /* Indicate filter was found in pipeline */

        /* Locate the filter in the pipeline */
        for(idx = 0; idx < pline->nused; idx++)
            if(pline->filter[idx].id == filter) {
                found = TRUE;
                break;
            } /* end if */

        /* filter was not found in the pipeline */
        if(!found)
            HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "filter not in pipeline")

        /* Free information for deleted filter */
        if(pline->filter[idx].name && pline->filter[idx].name != pline->filter[idx]._name)
            HDassert((HDstrlen(pline->filter[idx].name) + 1) > H5Z_COMMON_NAME_LEN);
        if(pline->filter[idx].name != pline->filter[idx]._name)
            pline->filter[idx].name = (char *)H5MM_xfree(pline->filter[idx].name);
        if(pline->filter[idx].cd_values && pline->filter[idx].cd_values != pline->filter[idx]._cd_values)
            HDassert(pline->filter[idx].cd_nelmts > H5Z_COMMON_CD_VALUES);
        if(pline->filter[idx].cd_values != pline->filter[idx]._cd_values)
            pline->filter[idx].cd_values = (unsigned *)H5MM_xfree(pline->filter[idx].cd_values);

        /* Remove filter from pipeline array */
        if((idx + 1) < pline->nused) {
            /* Copy filters down & fix up any client data value arrays using internal storage */
            for(; (idx + 1) < pline->nused; idx++) {
                pline->filter[idx] = pline->filter[idx + 1];
                if(pline->filter[idx].name && (HDstrlen(pline->filter[idx].name) + 1) <= H5Z_COMMON_NAME_LEN)
                    pline->filter[idx].name = pline->filter[idx]._name;
                if(pline->filter[idx].cd_nelmts <= H5Z_COMMON_CD_VALUES)
                    pline->filter[idx].cd_values = pline->filter[idx]._cd_values;
            } /* end for */
        } /* end if */

        /* Decrement number of used filters */
        pline->nused--;

        /* Reset information for previous last filter in pipeline */
        HDmemset(&pline->filter[pline->nused], 0, sizeof(H5Z_filter_info_t));
    } /* end else */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_delete() */


/*-------------------------------------------------------------------------
 * Function: H5Zget_filter_info
 *
 * Purpose: Gets information about a pipeline data filter and stores it
 *          in filter_config_flags.
 *
 * Return: zero on success / negative on failure
 *
 * Programmer: James Laird and Nat Furrer
 *              Monday, June 7, 2004
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Zget_filter_info(H5Z_filter_t filter, unsigned int *filter_config_flags)
{
    H5Z_class2_t *fclass;
    herr_t ret_value = SUCCEED;

    FUNC_ENTER_API(H5Zget_filter_info, FAIL)
    H5TRACE2("e", "Zf*Iu", filter, filter_config_flags);

    /* Look up the filter class info */
    if(NULL == (fclass = H5Z_find(filter)))
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Filter not defined")

    /* Set the filter config flags for the application */
    if(filter_config_flags != NULL) {
        *filter_config_flags = 0;

        if(fclass->encoder_present)
            *filter_config_flags |= H5Z_FILTER_CONFIG_ENCODE_ENABLED;
        if(fclass->decoder_present)
            *filter_config_flags |= H5Z_FILTER_CONFIG_DECODE_ENABLED;
    } /* end if */

done:
    FUNC_LEAVE_API(ret_value)
} /* end H5Zget_filter_info() */


/*-------------------------------------------------------------------------
 * Function:    H5Z_set_latest_version
 *
 * Purpose:     Set the encoding for a I/O filter pipeline to the latest version.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Tuesday, July 24, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Z_set_latest_version(H5O_pline_t *pline)
{
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(H5Z_set_latest_version, FAIL)

    /* Sanity check */
    HDassert(pline);

    /* Set encoding of I/O pipeline to latest version */
    pline->version = H5O_PLINE_VERSION_LATEST;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5Z_set_latest_version() */