path: root/src/H5C.c

/****************************************************************************
* NCSA HDF                                                                 *
* Software Development Group                                               *
* National Center for Supercomputing Applications                          *
* University of Illinois at Urbana-Champaign                               *
* 605 E. Springfield, Champaign IL 61820                                   *
*                                                                          *
* For conditions of distribution and use, see the accompanying             *
* hdf/COPYING file.                                                        *
*                                                                          *
****************************************************************************/

#ifdef RCSID
static char             RcsId[] = "@(#)$Revision$";
#endif

/* $Id$ */

#include <stdarg.h>

/* Private header files */
#include <H5private.h>          /* Generic Functions                      */
#include <H5Aprivate.h>         /* Atoms                          */
#include <H5Bprivate.h>         /* B-tree subclass names          */
#include <H5Cprivate.h>         /* Template information           */
#include <H5Dprivate.h>         /* Datasets                               */
#include <H5Eprivate.h>         /* Error handling                 */
#include <H5MMprivate.h>        /* Memory management                      */

#define PABLO_MASK      H5C_mask

/* Is the interface initialized? */
static hbool_t          interface_initialize_g = FALSE;
#define INTERFACE_INIT H5C_init_interface
static herr_t           H5C_init_interface(void);

/* PRIVATE PROTOTYPES */
static void             H5C_term_interface(void);

/*--------------------------------------------------------------------------
NAME
   H5C_init_interface -- Initialize interface-specific information
USAGE
    herr_t H5C_init_interface()
   
RETURNS
   SUCCEED/FAIL
DESCRIPTION
    Initializes any interface-specific data or routines.

--------------------------------------------------------------------------*/
static herr_t
H5C_init_interface(void)
{
    herr_t                  ret_value = SUCCEED;
    intn                    i;
    herr_t                  status;

    FUNC_ENTER(H5C_init_interface, FAIL);

    /*
     * Make sure the file creation and file access default templates are
     * initialized since this might be done at run-time instead of compile
     * time.
     */
    if (H5F_init_interface ()<0) {
	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
		       "unable to initialize H5F and H5C interfaces");
    }

    assert(H5C_NCLASSES <= H5_TEMPLATE_MAX - H5_TEMPLATE_0);

    /*
     * Initialize the mappings between template classes and atom groups. We
     * keep the two separate because template classes are publicly visible but
     * atom groups aren't.
     */
    for (i = 0; i < H5C_NCLASSES; i++) {
        status = H5A_init_group((group_t)(H5_TEMPLATE_0 +i),
				H5A_TEMPID_HASHSIZE, 0, NULL);
        if (status < 0) ret_value = FAIL;
    }
    if (ret_value < 0) {
        HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
                      "unable to initialize atom group");
    }
    
    /*
     * Register cleanup function.
     */
    if (H5_add_exit(H5C_term_interface) < 0) {
        HRETURN_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL,
                      "unable to install atexit function");
    }
    
    FUNC_LEAVE(ret_value);
}

/*--------------------------------------------------------------------------
 NAME
    H5C_term_interface
 PURPOSE
    Terminate various H5C objects
 USAGE
    void H5C_term_interface()
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
    Release the atom group and any other resources allocated.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
     Can't report errors...
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static void
H5C_term_interface(void)
{
    intn                    i;

    for (i = 0; i < H5C_NCLASSES; i++) {
        H5A_destroy_group((group_t)(H5_TEMPLATE_0 + i));
    }
}

/*--------------------------------------------------------------------------
 NAME
    H5Ccreate
 PURPOSE
    Returns a copy of the default template for some class of templates.
 USAGE
    herr_t H5Ccreate (type)
        H5C_class_t type;       IN: Template class whose default is desired.
 RETURNS
    Template ID or FAIL
 
 ERRORS
    ARGS      BADVALUE      Unknown template class. 
    ATOM      CANTINIT      Can't register template. 
    INTERNAL  UNSUPPORTED   Not implemented yet. 

 DESCRIPTION
    Returns a copy of the default template for some class of templates.
--------------------------------------------------------------------------*/
hid_t
H5Ccreate(H5C_class_t type)
{
    hid_t                   ret_value = FAIL;
    void                   *tmpl = NULL;

    FUNC_ENTER(H5Ccreate, FAIL);

    /* Allocate a new template and initialize it with default values */
    switch (type) {
    case H5C_FILE_CREATE:
	tmpl = H5MM_xmalloc(sizeof(H5F_create_t));
        memcpy(tmpl, &H5F_create_dflt, sizeof(H5F_create_t));
        break;

    case H5C_FILE_ACCESS:
        tmpl = H5MM_xmalloc(sizeof(H5F_access_t));
        memcpy(tmpl, &H5F_access_dflt, sizeof(H5F_access_t));
        break;

    case H5C_DATASET_CREATE:
        tmpl = H5MM_xmalloc(sizeof(H5D_create_t));
        memcpy(tmpl, &H5D_create_dflt, sizeof(H5D_create_t));
        break;

    case H5C_DATASET_XFER:
        tmpl = H5MM_xmalloc(sizeof(H5D_xfer_t));
        memcpy(tmpl, &H5D_xfer_dflt, sizeof(H5D_xfer_t));
        break;

    default:
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "unknown template class");
    }

    /* Atomize the new template */
    if ((ret_value = H5C_create(type, tmpl)) < 0) {
        HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
                      "can't register template");
    }
    FUNC_LEAVE(ret_value);
}

/*-------------------------------------------------------------------------
 * Function:    H5C_create
 *
 * Purpose:     Given a pointer to some template struct, atomize the template
 *              and return its ID. The template memory is not copied, so the
 *              caller should not free it; it will be freed by H5C_release().
 *
 * Return:      Success:        A new template ID.
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, December  3, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5C_create(H5C_class_t type, void *tmpl)
{
    hid_t	ret_value = FAIL;

    FUNC_ENTER(H5C_create, FAIL);

    /* check args */
    assert(type >= 0 && type < H5C_NCLASSES);
    assert(tmpl);

    /* Atomize the new template */
    if ((ret_value=H5A_register((group_t)(H5_TEMPLATE_0+type), tmpl)) < 0) {
        HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
                      "can't register template");
    }
    
    FUNC_LEAVE(ret_value);
}

/*--------------------------------------------------------------------------
 NAME
    H5Cclose
 PURPOSE
    Release access to a template object.
 USAGE
    herr_t H5Cclose(oid)
        hid_t oid;       IN: Template object to release access to
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
        This function releases access to a template object
--------------------------------------------------------------------------*/
herr_t
H5Cclose(hid_t tid)
{
    H5C_class_t		type;
    void                *tmpl = NULL;

    FUNC_ENTER(H5Cclose, FAIL);

    /* Check arguments */
    if ((type=H5Cget_class (tid))<0 ||
	NULL==(tmpl=H5A_object (tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list");
    }
	
    /*
     * Chuck the object! This will fail when the reference count reaches zero
     * since there is no free func registered for the property list groups.
     */
    if (H5A_dec_ref (tid)<0) {
	H5ECLEAR;
	H5C_close (type, tmpl);
    }

    FUNC_LEAVE (SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5C_close
 *
 * Purpose:	Closes a template and frees the memory associated with the
 *		template.
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Wednesday, February 18, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5C_close (H5C_class_t type, void *tmpl)
{
    FUNC_ENTER (H5C_close, FAIL);

    /* Check args */
    assert (tmpl);

    /* Some templates may need to do special things */
    switch (type) {
    case H5C_FILE_ACCESS:
#ifdef LATER
	/* Need to free the COMM and INFO objects too. */
#endif
	break;
	
    case H5C_FILE_CREATE:
    case H5C_DATASET_CREATE:
    case H5C_DATASET_XFER:
	/*nothing to do*/
	break;

    default:
	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
		       "unknown property list class");
    }

    /* Free the template struct and return */
    H5MM_xfree(tmpl);
    FUNC_LEAVE(SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:    H5Cget_class
 *
 * Purpose:     Returns the class identifier for a template.
 *
 * Return:      Success:        A template class
 *
 *              Failure:        H5C_NO_CLASS (-1)
 *
 * Programmer:  Robb Matzke
 *              Wednesday, December  3, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5C_class_t
H5Cget_class(hid_t tid)
{
    group_t                 group;
    H5C_class_t             ret_value = H5C_NO_CLASS;

    FUNC_ENTER(H5Cget_class, H5C_NO_CLASS);

    if ((group = H5A_group(tid)) < 0 ||
#ifndef NDEBUG
        group >= H5_TEMPLATE_MAX ||
#endif
        group < H5_TEMPLATE_0) {
        HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, H5C_NO_CLASS, "not a template");
    }
    ret_value = (H5C_class_t)(group - H5_TEMPLATE_0);
    FUNC_LEAVE(ret_value);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_version
 *
 * Purpose:     Retrieves version information for various parts of a file.
 *
 *              BOOT:           The file boot block.
 *              HEAP:           The global heap.
 *              FREELIST:       The global free list.
 *              STAB:           The root symbol table entry.
 *              SHHDR:          Shared object headers.
 *
 *              Any (or even all) of the output arguments can be null
 *              pointers.
 *
 * Return:      Success:        SUCCEED, version information is returned
 *                              through the arguments.
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cget_version(hid_t tid, int *boot /*out */ , int *heap /*out */ ,
         int *freelist /*out */ , int *stab /*out */ , int *shhdr /*out */ )
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_version, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Get values */
    if (boot)
        *boot = tmpl->bootblock_ver;
    if (heap)
        *heap = tmpl->smallobject_ver;
    if (freelist)
        *freelist = tmpl->freespace_ver;
    if (stab)
        *stab = tmpl->objectdir_ver;
    if (shhdr)
        *shhdr = tmpl->sharedheader_ver;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_userblock
 *
 * Purpose:     Sets the userblock size field of a file creation template.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_userblock(hid_t tid, size_t size)
{
    intn                    i;
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_userblock, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    for (i = 8; i < 8 * sizeof(int); i++) {
        uintn                   p2 = 8 == i ? 0 : 1 << i;
        if (size == p2)
            break;
    }
    if (i >= 8 * sizeof(int)) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "userblock size is not valid");
    }
    /* Set value */
    tmpl->userblock_size = size;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_userblock
 *
 * Purpose:     Queries the size of a user block in a file creation template.
 *
 * Return:      Success:        SUCCEED, size returned through SIZE argument.
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cget_userblock(hid_t tid, size_t *size)
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_userblock, FAIL);

    /* Check args */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Get value */
    if (size)
        *size = tmpl->userblock_size;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_sizes
 *
 * Purpose:     Sets file size-of addresses and sizes.  TEMPLATE
 *              should be a file creation template.  A value of zero causes
 *              the property to not change.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_sizes(hid_t tid, size_t sizeof_addr, size_t sizeof_size)
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_sizeof_addr, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    if (sizeof_addr) {
        if (sizeof_addr != 2 && sizeof_addr != 4 &&
            sizeof_addr != 8 && sizeof_addr != 16) {
            HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                          "file haddr_t size is not valid");
        }
    }
    if (sizeof_size) {
        if (sizeof_size != 2 && sizeof_size != 4 &&
            sizeof_size != 8 && sizeof_size != 16) {
            HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                          "file size_t size is not valid");
        }
    }
    /* Set value */
    if (sizeof_addr)
        tmpl->sizeof_addr = sizeof_addr;
    if (sizeof_size)
        tmpl->sizeof_size = sizeof_size;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_sizes
 *
 * Purpose:     Returns the size of address and size quantities stored in a
 *              file according to a file creation template.  Either (or even
 *              both) SIZEOF_ADDR and SIZEOF_SIZE may be null pointers.
 *
 * Return:      Success:        SUCCEED, sizes returned through arguments.
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cget_sizes(hid_t tid,
             size_t *sizeof_addr /*out */ , size_t *sizeof_size /*out */ )
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_sizes, FAIL);

    /* Check args */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Get values */
    if (sizeof_addr)
        *sizeof_addr = tmpl->sizeof_addr;
    if (sizeof_size)
        *sizeof_size = tmpl->sizeof_size;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_sym_k
 *
 * Purpose:     IK is one half the rank of a tree that stores a symbol
 *              table for a group.  Internal nodes of the symbol table are on
 *              average 75% full.  That is, the average rank of the tree is
 *              1.5 times the value of IK.
 *
 *              LK is one half of the number of symbols that can be stored in
 *              a symbol table node.  A symbol table node is the leaf of a
 *              symbol table tree which is used to store a group.  When
 *              symbols are inserted randomly into a group, the group's
 *              symbol table nodes are 75% full on average.  That is, they
 *              contain 1.5 times the number of symbols specified by LK.
 *
 *              Either (or even both) of IK and LK can be zero in which case
 *              that value is left unchanged.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_sym_k(hid_t tid, int ik, int lk)
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_sym_k, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Set values */
    if (ik > 0) {
        tmpl->btree_k[H5B_SNODE_ID] = ik;
    }
    if (lk > 0) {
        tmpl->sym_leaf_k = lk;
    }
    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_sym_k
 *
 * Purpose:     Retrieves the symbol table B-tree 1/2 rank (IK) and the
 *              symbol table leaf node 1/2 size (LK).  See H5Cset_sym_k() for
 *              details. Either (or even both) IK and LK may be null
 *              pointers.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cget_sym_k(hid_t tid, int *ik /*out */ , int *lk /*out */ )
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_sym_k, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Get values */
    if (ik)
        *ik = tmpl->btree_k[H5B_SNODE_ID];
    if (lk)
        *lk = tmpl->sym_leaf_k;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_istore_k
 *
 * Purpose:     IK is one half the rank of a tree that stores chunked raw
 *              data.  On average, such a tree will be 75% full, or have an
 *              average rank of 1.5 times the value of IK.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_istore_k(hid_t tid, int ik)
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_istore_k, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    if (ik <= 0) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "istore IK value must be positive");
    }
    /* Set value */
    tmpl->btree_k[H5B_ISTORE_ID] = ik;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_istore_k
 *
 * Purpose:     Queries the 1/2 rank of an indexed storage B-tree.  See
 *              H5Cset_istore_k() for details.  The argument IK may be the
 *              null pointer.
 *
 * Return:      Success:        SUCCEED, size returned through IK
 *
 *              Failure:        
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cget_istore_k(hid_t tid, int *ik /*out */ )
{
    H5F_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_istore_k, FAIL);

    /* Check arguments */
    if (H5C_FILE_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a file creation template");
    }
    /* Get value */
    if (ik)
        *ik = tmpl->btree_k[H5B_ISTORE_ID];

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_layout
 *
 * Purpose:     Sets the layout of raw data in the file.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_layout(hid_t tid, H5D_layout_t layout)
{
    H5D_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_layout, FAIL);

    /* Check arguments */
    if (H5C_DATASET_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a dataset creation template");
    }
    if (layout < 0 || layout >= H5D_NLAYOUTS) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
                      "raw data layout method is not valid");
    }
    /* Set value */
    tmpl->layout = layout;

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_layout
 *
 * Purpose:     Retrieves layout type of a dataset creation template.
 *
 * Return:      Success:        The layout type
 *
 *              Failure:        H5D_LAYOUT_ERROR (-1, same as FAIL)
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5D_layout_t
H5Cget_layout(hid_t tid)
{
    H5D_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_layout, H5D_LAYOUT_ERROR);

    /* Check arguments */
    if (H5C_DATASET_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, H5D_LAYOUT_ERROR,
                      "not a dataset creation template");
    }
    FUNC_LEAVE(tmpl->layout);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cset_chunk
 *
 * Purpose:     Sets the number of dimensions and the size of each chunk to
 *              the values specified.  The dimensionality of the chunk should
 *              match the dimensionality of the data space.
 *
 *              As a side effect, the layout method is changed to
 *              H5D_CHUNKED.
 *
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Tuesday, January  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_chunk(hid_t tid, int ndims, const size_t dim[])
{
    int                     i;
    H5D_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cset_chunk, FAIL);

    /* Check arguments */
    if (H5C_DATASET_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a dataset creation template");
    }
    if (ndims <= 0) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
                      "chunk dimensionality must be positive");
    }
    if (ndims > NELMTS(tmpl->chunk_size)) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
                      "chunk dimensionality is too large");
    }
    if (!dim) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "no chunk dimensions specified");
    }
    for (i = 0; i < ndims; i++) {
        if (dim[i] <= 0) {
            HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL,
                          "all chunk dimensions must be positive");
        }
    }

    /* Set value */
    tmpl->layout = H5D_CHUNKED;
    tmpl->chunk_ndims = ndims;
    for (i = 0; i < ndims; i++)
        tmpl->chunk_size[i] = dim[i];

    FUNC_LEAVE(SUCCEED);
}

/*-------------------------------------------------------------------------
 * Function:    H5Cget_chunk
 *
 * Purpose:     Retrieves the chunk size of chunked layout.  The chunk
 *              dimensionality is returned and the chunk size in each
 *              dimension is returned through the DIM argument.  At most
 *              MAX_NDIMS elements of DIM will be initialized.
 *
 * Return:      Success:        Positive Chunk dimensionality.
 *
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, January  7, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
int
H5Cget_chunk(hid_t tid, int max_ndims, size_t dim[] /*out */ )
{
    int                     i;
    H5D_create_t           *tmpl = NULL;

    FUNC_ENTER(H5Cget_chunk, FAIL);

    /* Check arguments */
    if (H5C_DATASET_CREATE != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
                      "not a dataset creation template");
    }
    if (H5D_CHUNKED != tmpl->layout) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "not a chunked storage layout");
    }
    for (i = 0; i < tmpl->chunk_ndims && i < max_ndims && dim; i++) {
        dim[i] = tmpl->chunk_size[i];
    }

    FUNC_LEAVE(tmpl->chunk_ndims);
}


/*-------------------------------------------------------------------------
 * Function:	H5Cset_stdio
 *
 * Purpose:	Set the low level file driver to use the functions declared
 *		in the stdio.h file: fopen(), fseek() or fseek64(), fread(),
 *		fwrite(), and fclose().
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Thursday, February 19, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_stdio (hid_t tid)
{
    H5F_access_t	*tmpl = NULL;
    
    FUNC_ENTER (H5Cset_stdio, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }

    /* Set driver */
    tmpl->driver = H5F_LOW_STDIO;

    FUNC_LEAVE (SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5Cset_sec2
 *
 * Purpose:	Set the low-level file driver to use the functions declared
 *		in the unistd.h file: open(), lseek() or lseek64(), read(),
 *		write(), and close().
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Thursday, February 19, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_sec2 (hid_t tid)
{
    H5F_access_t	*tmpl = NULL;
    
    FUNC_ENTER (H5Cset_sec2, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }

    /* Set driver */
    tmpl->driver = H5F_LOW_SEC2;

    FUNC_LEAVE (SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5Cset_core
 *
 * Purpose:	Set the low-level file driver to use malloc() and free().
 *		This driver is restricted to temporary files which are not
 *		larger than the amount of virtual memory available. The
 *		INCREMENT argument determines the file block size and memory
 *		will be allocated in multiples of INCREMENT bytes. A liberal
 *		INCREMENT results in fewer calls to realloc() and probably
 *		less memory fragmentation.
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Thursday, February 19, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_core (hid_t tid, size_t increment)
{
    H5F_access_t	*tmpl = NULL;
    
    FUNC_ENTER (H5Cset_core, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }
    if (increment<1) {
	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
		       "increment must be positive");
    }

    /* Set driver */
    tmpl->driver = H5F_LOW_CORE;
    tmpl->u.core.increment = increment;

    FUNC_LEAVE (SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5Cset_split
 *
 * Purpose:	Set the low-level driver to split meta data from raw data,
 *		storing meta data in one file and raw data in another file.
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Thursday, February 19, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_split (hid_t tid, hid_t meta_tid, hid_t raw_tid)
{
    H5F_access_t	*tmpl = NULL;
    H5F_access_t	*meta_tmpl = NULL;
    H5F_access_t	*raw_tmpl = NULL;
    
    FUNC_ENTER (H5Cset_split, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }
    if (H5C_DEFAULT!=meta_tid &&
	(H5C_FILE_ACCESS != H5Cget_class(meta_tid) ||
	 NULL == (tmpl = H5A_object(meta_tid)))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }
    if (H5C_DEFAULT!=raw_tid &&
	(H5C_FILE_ACCESS != H5Cget_class(raw_tid) ||
	 NULL == (tmpl = H5A_object(raw_tid)))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }

    /* Set driver */
    tmpl->driver = H5F_LOW_SPLIT;
    tmpl->u.split.meta_access = H5C_copy (H5C_FILE_ACCESS, meta_tmpl);
    tmpl->u.split.raw_access = H5C_copy (H5C_FILE_ACCESS, raw_tmpl);

    FUNC_LEAVE (SUCCEED);
}


/*-------------------------------------------------------------------------
 * Function:	H5Cset_family
 *
 * Purpose:	Sets the low-level driver to stripe the hdf5 address space
 *		across a family of files.
 *
 * Return:	Success:	SUCCEED
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *              Thursday, February 19, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_family (hid_t tid, hid_t memb_tid)
{
    
    H5F_access_t	*tmpl = NULL;
    H5F_access_t	*memb_tmpl = NULL;
    
    FUNC_ENTER (H5Cset_family, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }
    if (H5C_DEFAULT!=memb_tid &&
	(H5C_FILE_ACCESS != H5Cget_class(memb_tid) ||
	 NULL == (tmpl = H5A_object(memb_tid)))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }

    /* Set driver */
    tmpl->driver = H5F_LOW_FAMILY;
    tmpl->u.fam.memb_access = H5C_copy (H5C_FILE_ACCESS, memb_tmpl);

    FUNC_LEAVE (SUCCEED);
}
    
    

#ifdef HAVE_PARALLEL
/*-------------------------------------------------------------------------
 * Function:    H5Cset_mpi
 *
 * Signature:   herr_t H5Cset_mpi(hid_t tid, MPI_Comm comm, MPI_Info info,
 *                  uintn access_mode) 
 *
 * Purpose:     Store the access mode for MPIO call and the user supplied
 *              communicator and info in the access template which can then
 *              be used to open file.  This function is available only in the
 *              parallel HDF5 library and is not a collective function.
 *
 * Parameters:
 *              hid_t tid 
 *                  ID of template to modify 
 *              MPI_Comm comm 
 *      	    MPI communicator to be used for file open as defined in
 *                  MPI_FILE_OPEN of MPI-2.  This function  does not make a
 *                  duplicated communicator. Any modification to comm after
 *                  this function call returns may have undetermined effect
 *                  to the access template.  Users should call this function
 *                  again to setup the template.
 *              MPI_Info info 
 *      	    MPI info object to be used for file open as defined in
 *                  MPI_FILE_OPEN of MPI-2.  This function  does not make a
 *                  duplicated info. Any modification to info after
 *                  this function call returns may have undetermined effect
 *                  to the access template.  Users should call this function
 *                  again to setup the template.
 *              uintn access_mode 
 *      	    File data access modes: 
 *      		H5ACC_INDEPENDENT 
 *      	            Allow independent datasets access. 
 *      		H5ACC_COLLECTIVE 
 *      		    Allow only collective datasets access. 
 *           
 * Return:      Success:        SUCCEED
 *
 *              Failure:        FAIL
 *
 * Programmer:  Albert Cheng
 *              Feb 3, 1998
 *
 * Modifications:
 *
 * 	Robb Matzke, 18 Feb 1998
 *	Check all arguments before the template is updated so we don't leave
 *	the template in a bad state if something goes wrong.  Also, the
 *	template data type changed to allow more generality so all the
 *	mpi-related stuff is in the `u.mpi' member.  The `access_mode' will
 *	contain only mpi-related flags defined in H5Fpublic.h.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Cset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info, uintn access_mode)
{
    H5F_access_t           *tmpl = NULL;
    MPI_Comm		    lcomm;
    int			    mrc;		/* MPI return code */

    FUNC_ENTER(H5Cset_mpi, FAIL);

    /* Check arguments */
    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
        NULL == (tmpl = H5A_object(tid))) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
		      "not a file access template");
    }
    
    switch (access_mode){
    case H5ACC_INDEPENDENT:
    case H5ACC_COLLECTIVE:
	/* okay */
	break;

    default:
	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
		       "invalid mpio access mode");
    }

#ifdef LATER
    /*
     * Need to verify comm and info contain sensible information.
     */
#endif


    /*
     * Everything looks good.  Now go ahead and modify the access template.
     */
    tmpl->driver = H5F_LOW_MPIO;
    tmpl->u.mpio.access_mode = access_mode;

    /*
     * Store a duplicate copy of comm so that user may freely modify comm
     * after this call.
     */
    if ((mrc = MPI_Comm_dup(comm, &lcomm)) != MPI_SUCCESS) {
        HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                      "failure to duplicate communicator");
    }
    tmpl->u.mpio.comm = comm;
    
#ifdef LATER
    /* Need to duplicate info too but don't know a quick way to do it now */
#endif
    tmpl->u.mpio.info = info;

    FUNC_LEAVE(SUCCEED);
}

#endif /*HAVE_PARALLEL*/

/*--------------------------------------------------------------------------
 NAME
    H5Ccopy
 PURPOSE
    Copy a template
 USAGE
    hid_t H5C_copy(tid)
        hid_t tid;        IN: Template object to copy
 RETURNS
    Returns template ID (atom) on success, FAIL on failure

 ERRORS
    ARGS      BADRANGE      Unknown template class. 
    ATOM      BADATOM       Can't unatomize template. 
    ATOM      CANTREGISTER  Register the atom for the new template. 
    INTERNAL  UNSUPPORTED   Dataset transfer properties are not implemented
                            yet. 
    INTERNAL  UNSUPPORTED   File access properties are not implemented yet. 

 DESCRIPTION
    This function creates a new copy of a template with all the same parameter
    settings.
--------------------------------------------------------------------------*/
hid_t
H5Ccopy(hid_t tid)
{
    const void             *tmpl = NULL;
    void                   *new_tmpl = NULL;
    H5C_class_t             type;
    hid_t                   ret_value = FAIL;
    group_t                 group;

    FUNC_ENTER(H5Ccopy, FAIL);

    /* Check args */
    if (NULL == (tmpl = H5A_object(tid)) ||
        (type = H5Cget_class(tid)) < 0 ||
        (group = H5A_group(tid)) < 0) {
        HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL,
                      "can't unatomize template");
    }

    /* Copy it */
    if (NULL==(new_tmpl=H5C_copy (type, tmpl))) {
	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
		       "unable to copy template");
    }

    /* Register the atom for the new template */
    if ((ret_value = H5A_register(group, new_tmpl)) < 0) {
        HRETURN_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL,
                      "unable to atomize template pointer");
    }
    FUNC_LEAVE(ret_value);
}

/*-------------------------------------------------------------------------
 * Function:	H5C_copy
 *
 * Purpose:	Creates a new template and initializes it with some other
 *		template.
 *
 * Return:	Success:	Ptr to new template
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, February  3, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
void *
H5C_copy (H5C_class_t type, const void *src)
{
    size_t	size;
    void	*dst = NULL;
    
    FUNC_ENTER (H5C_copy, NULL);
    
    /* How big is the template */
    switch (type) {
    case H5C_FILE_CREATE:
        size = sizeof(H5F_create_t);
        break;

    case H5C_FILE_ACCESS:
	size = sizeof(H5F_access_t);
	break;

    case H5C_DATASET_CREATE:
        size = sizeof(H5D_create_t);
        break;

    case H5C_DATASET_XFER:
        size = sizeof(H5D_xfer_t);
        break;

    default:
        HRETURN_ERROR(H5E_ARGS, H5E_BADRANGE, NULL,
                      "unknown template class");
    }

    /* Create the new template */
    dst = H5MM_xmalloc(size);
    HDmemcpy(dst, src, size);

    FUNC_LEAVE (dst);
}