path: root/src/H5Dlayout.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.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/****************/
/* Module Setup */
/****************/

#define H5D_PACKAGE		/*suppress error about including H5Dpkg	  */


/***********/
/* Headers */
/***********/
#include "H5private.h"		/* Generic Functions			*/
#include "H5Dpkg.h"		/* Datasets 				*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5HLprivate.h"	/* Local heaps				*/


/****************/
/* Local Macros */
/****************/


/******************/
/* Local Typedefs */
/******************/


/********************/
/* Local Prototypes */
/********************/


/*********************/
/* Package Variables */
/*********************/


/*****************************/
/* Library Private Variables */
/*****************************/


/*******************/
/* Local Variables */
/*******************/



/*-------------------------------------------------------------------------
 * Function:	H5D_layout_set_io_ops
 *
 * Purpose:	Set the I/O operation function pointers for a dataset,
 *              according to the dataset's layout
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Thursday, March 20, 2008
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5D_layout_set_io_ops(const H5D_t *dataset)
{
    herr_t ret_value = SUCCEED;		/* Return value */

    FUNC_ENTER_NOAPI(H5D_layout_set_io_ops, FAIL)

    /* check args */
    HDassert(dataset);

    /* Set the I/O functions for each layout type */
    switch(dataset->shared->layout.type) {
        case H5D_CONTIGUOUS:
            if(dataset->shared->dcpl_cache.efl.nused > 0)
                dataset->shared->layout.ops = H5D_LOPS_EFL;
            else
                dataset->shared->layout.ops = H5D_LOPS_CONTIG;
            break;

        case H5D_CHUNKED:
            dataset->shared->layout.ops = H5D_LOPS_CHUNK;

            /* Set the chunk operations */
            switch(dataset->shared->layout.u.chunk.idx_type) {
                case H5D_CHUNK_IDX_BTREE:
                    dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_BTREE;
                    break;

                case H5D_CHUNK_IDX_FARRAY:
                    dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_FARRAY;
                    break;

                case H5D_CHUNK_IDX_EARRAY:
                    dataset->shared->layout.storage.u.chunk.ops = H5D_COPS_EARRAY;
                    break;

                default:
                    HDassert(0 && "Unknown chunk index method!");
                    HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "unknown chunk index method")
            } /* end switch */
            break;

        case H5D_COMPACT:
            dataset->shared->layout.ops = H5D_LOPS_COMPACT;
            break;

        default:
            HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "unknown storage method")
    } /* end switch */ /*lint !e788 All appropriate cases are covered */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_set_io_ops() */


/*-------------------------------------------------------------------------
 * Function:    H5D_layout_meta_size
 *
 * Purpose:     Returns the size of the raw message in bytes except raw data
 *              part for compact dataset.  This function doesn't take into
 *              account message alignment.
 *
 * Return:      Success:        Message data size in bytes
 *              Failure:        0
 *
 * Programmer:  Raymond Lu
 *              August 14, 2002
 *
 *-------------------------------------------------------------------------
 */
size_t
H5D_layout_meta_size(const H5F_t *f, const H5O_layout_t *layout, hbool_t include_compact_data)
{
    size_t                  ret_value;

    FUNC_ENTER_NOAPI_NOINIT(H5D_layout_meta_size)

    /* check args */
    HDassert(f);
    HDassert(layout);

    ret_value = 1 +                     /* Version number                       */
                1;                      /* layout class type                    */

    switch(layout->type) {
        case H5D_COMPACT:
            /* This information only present in older versions of message */
            if(layout->version < H5O_LAYOUT_VERSION_4) {
                /* Size of raw data */
                ret_value += 2;
                if(include_compact_data)
                    ret_value += layout->storage.u.compact.size;/* data for compact dataset             */
            } /* end if */
            break;

        case H5D_CONTIGUOUS:
            /* This information only present in older versions of message */
            if(layout->version < H5O_LAYOUT_VERSION_4) {
                ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */
                ret_value += H5F_SIZEOF_SIZE(f);    /* Length of data */
            } /* end if */
            break;

        case H5D_CHUNKED:
            if(layout->version < H5O_LAYOUT_VERSION_4) {
                /* Number of dimensions (1 byte) */
                HDassert(layout->u.chunk.ndims > 0 && layout->u.chunk.ndims <= H5O_LAYOUT_NDIMS);
                ret_value++;

                /* B-tree address */
                ret_value += H5F_SIZEOF_ADDR(f);    /* Address of data */

                /* Dimension sizes */
                ret_value += layout->u.chunk.ndims * 4;
            } /* end if */
            else {
                /* Chunked layout feature flags */
                ret_value++;

                /* Number of dimensions (1 byte) */
                HDassert(layout->u.chunk.ndims > 0 && layout->u.chunk.ndims <= H5O_LAYOUT_NDIMS);
                ret_value++;

                /* Encoded # of bytes for each chunk dimension */
                HDassert(layout->u.chunk.enc_bytes_per_dim > 0 && layout->u.chunk.enc_bytes_per_dim <= 8);
                ret_value++;

                /* Dimension sizes */
                ret_value += layout->u.chunk.ndims * layout->u.chunk.enc_bytes_per_dim;

                /* Type of chunk index */
                ret_value++;

                switch(layout->u.chunk.idx_type) {
                    case H5D_CHUNK_IDX_BTREE:   /* Remove this when v2 B-tree indices added */
                        /* Nothing to do */
                        break;

                    case H5D_CHUNK_IDX_FARRAY:
                        /* Fixed array creation parameters */
                        ret_value += 1;
                        break;

                    case H5D_CHUNK_IDX_EARRAY:
                        /* Extensible array creation parameters */
                        ret_value += 5;
                        break;

                    default:
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, 0, "Invalid chunk index type")
                } /* end switch */
            } /* end else */
            break;

        default:
            HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, 0, "Invalid layout class")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_meta_size() */


/*-------------------------------------------------------------------------
 * Function:    H5D_layout_set_latest_version
 *
 * Purpose:     Set the encoding for a layout to the latest version.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Thursday, January 15, 2009
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5D_layout_set_latest_version(H5O_layout_t *layout, const H5S_t *space)
{
    int sndims;                         /* Rank of dataspace */
    unsigned ndims;                     /* Rank of dataspace */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(H5D_layout_set_latest_version, FAIL)

    /* Sanity check */
    HDassert(layout);

    /* Set encoding of layout to latest version */
    layout->version = H5O_LAYOUT_VERSION_LATEST;

    /* Query the dimensionality of the dataspace */
    if((sndims = H5S_GET_EXTENT_NDIMS(space)) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "invalid dataspace rank")
    ndims = (unsigned)sndims;

    /* Avoid scalar/null dataspace */
    if(ndims > 0) {
        hsize_t max_dims[H5O_LAYOUT_NDIMS];     /* Maximum dimension sizes */
        hsize_t curr_dims[H5O_LAYOUT_NDIMS];    /* Current dimension sizes */
        unsigned unlim_count;           /* Count of unlimited max. dimensions */
	hbool_t	fixed = FALSE;		/* Fixed dimension or not */
        unsigned u;                     /* Local index variable */

        /* Query the dataspace's dimensions */
        if(H5S_get_simple_extent_dims(space, curr_dims, max_dims) < 0)
            HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get dataspace max. dimensions")

        /* Spin through the max. dimensions, looking for unlimited dimensions */
        unlim_count = 0;
        for(u = 0; u < ndims; u++)
            if(max_dims[u] == H5S_UNLIMITED)
                unlim_count++;

        /* Check if it is fixed dimension */
	if(0 == unlim_count) {
	    fixed = TRUE;
	    for(u = 0; u < ndims; u++)
		if(curr_dims[u] != max_dims[u]) {
		    fixed = FALSE;
		    break;
		} /* end if */
	} /* end if */

        /* If we have only 1 unlimited dimension, we can use extensible array index */
        if(1 == unlim_count) {
            /* Set the chunk index type to an extensible array */
            layout->u.chunk.idx_type = H5D_CHUNK_IDX_EARRAY;
            layout->storage.u.chunk.idx_type = H5D_CHUNK_IDX_EARRAY;
            layout->storage.u.chunk.ops = H5D_COPS_EARRAY;;

            /* Set the extensible array creation parameters */
            /* (use hard-coded defaults for now, until we give applications
             *          control over this with a property list - QAK)
             */
            layout->u.chunk.u.earray.cparam.max_nelmts_bits = H5D_EARRAY_MAX_NELMTS_BITS;
            layout->u.chunk.u.earray.cparam.idx_blk_elmts = H5D_EARRAY_IDX_BLK_ELMTS;
            layout->u.chunk.u.earray.cparam.sup_blk_min_data_ptrs = H5D_EARRAY_SUP_BLK_MIN_DATA_PTRS;
            layout->u.chunk.u.earray.cparam.data_blk_min_elmts = H5D_EARRAY_DATA_BLK_MIN_ELMTS;
            layout->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits = H5D_EARRAY_MAX_DBLOCK_PAGE_NELMTS_BITS;
        } /* end if */
        /* Chunked datasets with fixed dimensions */
        else if(layout->type == H5D_CHUNKED && fixed) {
            /* Set the chunk index type to a fixed array */
	    layout->u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
            layout->storage.u.chunk.idx_type = H5D_CHUNK_IDX_FARRAY;
            layout->storage.u.chunk.ops = H5D_COPS_FARRAY;;

            /* Set the fixed array creation parameters */
            /* (use hard-coded defaults for now, until we give applications
             *          control over this with a property list - QAK)
             */
            layout->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = H5D_FARRAY_MAX_DBLK_PAGE_NELMTS_BITS;
	} /* end if */
        else {
            /* Add setup for v2 B-tree indices here */
        } /* end else */
    } /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_set_latest_version() */


/*-------------------------------------------------------------------------
 * Function:	H5D_layout_oh_create
 *
 * Purpose:	Create layout/pline/efl information for dataset
 *
 * Return:	Success:    SUCCEED
 *		Failure:    FAIL
 *
 * Programmer:	Quincey Koziol
 *		Monday, July 27, 2009
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5D_layout_oh_create(H5F_t *file, hid_t dxpl_id, H5O_t *oh, H5D_t *dset,
    hid_t dapl_id)
{
    H5O_layout_t        *layout;         /* Dataset's layout information */
    const H5O_fill_t	*fill_prop;     /* Pointer to dataset's fill value information */
    hbool_t             layout_init = FALSE;    /* Flag to indicate that chunk information was initialized */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5D_layout_oh_create)

    /* Sanity checking */
    HDassert(file);
    HDassert(oh);
    HDassert(dset);

    /* Set some local variables, for convenience */
    layout = &dset->shared->layout;
    fill_prop = &dset->shared->dcpl_cache.fill;

    /* Update the filters message, if this is a chunked dataset */
    if(layout->type == H5D_CHUNKED) {
        H5O_pline_t     *pline;         /* Dataset's I/O pipeline information */

        pline = &dset->shared->dcpl_cache.pline;
        if(pline->nused > 0 && H5O_msg_append_oh(file, dxpl_id, oh, H5O_PLINE_ID, H5O_MSG_FLAG_CONSTANT, 0, pline) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update filter header message")
    } /* end if */

    /* Initialize the layout information for the new dataset */
    if(dset->shared->layout.ops->init && (dset->shared->layout.ops->init)(file, dxpl_id, dset, dapl_id) < 0)
        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize layout information")

    /* Indicate that the layout information was initialized */
    layout_init = TRUE;

    /*
     * Allocate storage if space allocate time is early; otherwise delay
     * allocation until later.
     */
    if(fill_prop->alloc_time == H5D_ALLOC_TIME_EARLY)
        if(H5D_alloc_storage(dset, dxpl_id, H5D_ALLOC_CREATE, FALSE) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize storage")

    /* Update external storage message, if it's used */
    if(dset->shared->dcpl_cache.efl.nused > 0) {
        H5O_efl_t *efl = &dset->shared->dcpl_cache.efl; /* Dataset's external file list */
        H5HL_t *heap;                           /* Pointer to local heap for EFL file names */
        size_t heap_size = H5HL_ALIGN(1);
        size_t u;

        /* Determine size of heap needed to stored the file names */
        for(u = 0; u < efl->nused; ++u)
            heap_size += H5HL_ALIGN(HDstrlen(efl->slot[u].name) + 1);

        /* Create the heap for the EFL file names */
        if(H5HL_create(file, dxpl_id, heap_size, &efl->heap_addr/*out*/) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create EFL file name heap")

        /* Pin the heap down in memory */
        if(NULL == (heap = H5HL_protect(file, dxpl_id, efl->heap_addr, H5AC_WRITE)))
            HGOTO_ERROR(H5E_DATASET, H5E_CANTPROTECT, FAIL, "unable to protect EFL file name heap")

        /* Insert "empty" name first */
        if((size_t)(-1) == H5HL_insert(file, dxpl_id, heap, (size_t)1, "")) {
            H5HL_unprotect(file, dxpl_id, heap, efl->heap_addr);
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert file name into heap")
        } /* end if */

        for(u = 0; u < efl->nused; ++u) {
            size_t offset;      /* Offset of file name in heap */

            /* Insert file name into heap */
            if((size_t)(-1) == (offset = H5HL_insert(file, dxpl_id, heap,
                        HDstrlen(efl->slot[u].name) + 1, efl->slot[u].name))) {
                H5HL_unprotect(file, dxpl_id, heap, efl->heap_addr);
                HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert file name into heap")
            } /* end if */

            /* Store EFL file name offset */
            HDassert(0 == efl->slot[u].name_offset);
            efl->slot[u].name_offset = offset;
        } /* end for */

        /* Release the heap */
        if(H5HL_unprotect(file, dxpl_id, heap, efl->heap_addr) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTUNPROTECT, FAIL, "unable to unprotect EFL file name heap")
        heap = NULL;

        /* Insert EFL message into dataset object header */
        if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_EFL_ID, H5O_MSG_FLAG_CONSTANT, 0, efl) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update external file list message")
    } /* end if */

    /* Check what version of the layout message to write */
    if(layout->version < H5O_LAYOUT_VERSION_4) {
        /* Create layout message */
        /* (Don't make layout message constant unless allocation time is early, since space may not be allocated) */
        /* (Note: this is relying on H5D_alloc_storage not calling H5O_msg_write during dataset creation) */
        if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_LAYOUT_ID, ((fill_prop->alloc_time == H5D_ALLOC_TIME_EARLY && H5D_COMPACT != layout->type) ? H5O_MSG_FLAG_CONSTANT : 0), 0, layout) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")
    } /* end if */
    else {
        /* Create layout message */
        /* (Note: this is relying on H5D_alloc_storage not calling H5O_msg_write during dataset creation) */
        if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_LAYOUT_ID, H5O_MSG_FLAG_CONSTANT, 0, layout) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout")

        /* Create storage message */
        if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_STORAGE_ID, 0, 0, &layout->storage) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update storage")
    } /* end else */

done:
    /* Error cleanup */
    if(ret_value < 0) {
        if(dset->shared->layout.type == H5D_CHUNKED && layout_init) {
            if(H5D_chunk_dest(file, dxpl_id, dset) < 0)
                HDONE_ERROR(H5E_DATASET, H5E_CANTRELEASE, FAIL, "unable to destroy chunk cache")
        } /* end if */
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_oh_create() */


/*-------------------------------------------------------------------------
 * Function:	H5D_layout_oh_read
 *
 * Purpose:	Read layout/pline/efl information for dataset
 *
 * Return:	Success:    SUCCEED
 *		Failure:    FAIL
 *
 * Programmer:	Quincey Koziol
 *		Monday, July 27, 2009
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5D_layout_oh_read(H5D_t *dataset, hid_t dxpl_id, hid_t dapl_id, H5P_genplist_t *plist)
{
    htri_t msg_exists;                  /* Whether a particular type of message exists */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5D_layout_oh_read)

    /* Sanity checking */
    HDassert(dataset);
    HDassert(plist);

    /* Get the optional filters message */
    if((msg_exists = H5O_msg_exists(&(dataset->oloc), H5O_PLINE_ID, dxpl_id)) < 0)
        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't check if message exists")
    if(msg_exists) {
        /* Retrieve the I/O pipeline message */
        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_PLINE_ID, &dataset->shared->dcpl_cache.pline, dxpl_id))
            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve message")

        /* Set the I/O pipeline info in the property list */
        if(H5P_set(plist, H5O_CRT_PIPELINE_NAME, &dataset->shared->dcpl_cache.pline) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set pipeline")
    } /* end if */

    /*
     * Get the raw data layout info.  It's actually stored in two locations:
     * the storage message of the dataset (dataset->storage) and certain
     * values are copied to the dataset create plist so the user can query
     * them.
     */
    if(NULL == H5O_msg_read(&(dataset->oloc), H5O_LAYOUT_ID, &(dataset->shared->layout), dxpl_id))
        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data layout message")

    /* Check for newer version of the layout message, which indicates that some
     * information is stored in the 'storage' message.
     */
    if(dataset->shared->layout.version >= H5O_LAYOUT_VERSION_4) {
        /* Retrieve the storage information */
        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_STORAGE_ID, &(dataset->shared->layout.storage), dxpl_id))
            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data storage message")
    } /* end if */

    /* Check for external file list message (which might not exist) */
    if((msg_exists = H5O_msg_exists(&(dataset->oloc), H5O_EFL_ID, dxpl_id)) < 0)
        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't check if message exists")
    if(msg_exists) {
        /* Retrieve the EFL  message */
        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_EFL_ID, &dataset->shared->dcpl_cache.efl, dxpl_id))
            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve message")

        /* Set the EFL info in the property list */
        if(H5P_set(plist, H5D_CRT_EXT_FILE_LIST_NAME, &dataset->shared->dcpl_cache.efl) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set external file list")

        /* Set the dataset's I/O operations */
        dataset->shared->layout.ops = H5D_LOPS_EFL;
    } /* end if */

    /* Sanity check that the layout operations are set up */
    HDassert(dataset->shared->layout.ops);

    /* Adjust chunk dimensions to omit datatype size (in last dimension) for creation property */
    if(H5D_CHUNKED == dataset->shared->layout.type)
        dataset->shared->layout.u.chunk.ndims--;
    /* Copy layout to the DCPL */
    if(H5P_set(plist, H5D_CRT_LAYOUT_NAME, &dataset->shared->layout) < 0)
        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set layout")
    /* Adjust chunk dimensions back again (*sigh*) */
    if(H5D_CHUNKED == dataset->shared->layout.type)
        dataset->shared->layout.u.chunk.ndims++;

    switch(dataset->shared->layout.type) {
        case H5D_CONTIGUOUS:
            /* Compute the size of the contiguous storage for versions of the
             * layout message less than version 3 because versions 1 & 2 would
             * truncate the dimension sizes to 32-bits of information. - QAK 5/26/04
             */
            if(dataset->shared->layout.version < 3) {
                hssize_t snelmts;                   /* Temporary holder for number of elements in dataspace */
                hsize_t nelmts;                     /* Number of elements in dataspace */
                size_t dt_size;                     /* Size of datatype */
                hsize_t tmp_size;                   /* Temporary holder for raw data size */

                /* Retrieve the number of elements in the dataspace */
                if((snelmts = H5S_GET_EXTENT_NPOINTS(dataset->shared->space)) < 0)
                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to retrieve number of elements in dataspace")
                nelmts = (hsize_t)snelmts;

                /* Get the datatype's size */
                if(0 == (dt_size = H5T_GET_SIZE(dataset->shared->type)))
                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to retrieve size of datatype")

                /* Compute the size of the dataset's contiguous storage */
                tmp_size = nelmts * dt_size;

                /* Check for overflow during multiplication */
                if(nelmts != (tmp_size / dt_size))
                    HGOTO_ERROR(H5E_DATASET, H5E_OVERFLOW, FAIL, "size of dataset's storage overflowed")

                /* Assign the dataset's contiguous storage size */
                dataset->shared->layout.storage.u.contig.size = tmp_size;
            } /* end if */

            /* Get the sieve buffer size for this dataset */
            dataset->shared->cache.contig.sieve_buf_size = H5F_SIEVE_BUF_SIZE(dataset->oloc.file);
            break;

        case H5D_CHUNKED:
            /* Initialize the chunk cache for the dataset */
            if(H5D_chunk_init(dataset->oloc.file, dxpl_id, dataset, dapl_id) < 0)
                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't initialize chunk cache")
            break;

        case H5D_COMPACT:
            break;

        default:
            HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "unknown storage method")
    } /* end switch */ /*lint !e788 All appropriate cases are covered */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_oh_read() */


/*-------------------------------------------------------------------------
 * Function:	H5D_layout_oh_write
 *
 * Purpose:	Write layout/pline/efl information for dataset
 *
 * Return:	Success:    SUCCEED
 *		Failure:    FAIL
 *
 * Programmer:	Quincey Koziol
 *		Monday, July 27, 2009
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5D_layout_oh_write(H5D_t *dataset, hid_t dxpl_id, H5O_t *oh, unsigned update_flags)
{
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5D_layout_oh_write)

    /* Sanity checking */
    HDassert(dataset);
    HDassert(oh);

    /* Determine which message to write, based on the version of the layout info */
    if(dataset->shared->layout.version < H5O_LAYOUT_VERSION_4) {
        /* Write the layout message to the dataset's header */
        if(H5O_msg_write_oh(dataset->oloc.file, dxpl_id, oh, H5O_LAYOUT_ID, H5O_MSG_FLAG_CONSTANT, update_flags, &dataset->shared->layout) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update layout message")
    } /* end if */
    else {
        /* Write the storage message to the dataset's header */
        if(H5O_msg_write_oh(dataset->oloc.file, dxpl_id, oh, H5O_STORAGE_ID, 0, update_flags, &dataset->shared->layout.storage) < 0)
            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update storage message")
    } /* end else */


done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5D_layout_oh_write() */