path: root/src/H5Oattr.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 H5A_PACKAGE             /*prevent warning from including H5Apkg   */
#define H5O_PACKAGE		/*suppress error about including H5Opkg	  */
#define H5S_PACKAGE	        /*suppress error about including H5Spkg	  */


#include "H5private.h"		/* Generic Functions			*/
#include "H5Apkg.h"		/* Attributes				*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5MMprivate.h"	/* Memory management			*/
#include "H5Opkg.h"             /* Object headers			*/
#include "H5Spkg.h"		/* Dataspaces				*/

/* PRIVATE PROTOTYPES */
static herr_t H5O_attr_encode(H5F_t *f, uint8_t *p, const void *mesg);
static void *H5O_attr_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
    unsigned mesg_flags, unsigned *ioflags, const uint8_t *p);
static void *H5O_attr_copy(const void *_mesg, void *_dest);
static size_t H5O_attr_size(const H5F_t *f, const void *_mesg);
static herr_t H5O_attr_free(void *mesg);
static herr_t H5O_attr_pre_copy_file(H5F_t *file_src, const void *mesg_src,
    hbool_t *deleted, const H5O_copy_t *cpy_info, void *udata);
static void *H5O_attr_copy_file(H5F_t *file_src, const H5O_msg_class_t *mesg_type,
    void *native_src, H5F_t *file_dst, hbool_t *recompute_size,
    H5O_copy_t *cpy_info, void *udata, hid_t dxpl_id);
static herr_t H5O_attr_post_copy_file(const H5O_loc_t *src_oloc,
    const void *mesg_src, H5O_loc_t *dst_oloc, void *mesg_dst, hid_t dxpl_id,
    H5O_copy_t *cpy_info);
static herr_t H5O_attr_get_crt_index(const void *_mesg, H5O_msg_crt_idx_t *crt_idx);
static herr_t H5O_attr_set_crt_index(void *_mesg, H5O_msg_crt_idx_t crt_idx);
static herr_t H5O_attr_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg,
			      FILE * stream, int indent, int fwidth);

/* Set up & include shared message "interface" info */
#define H5O_SHARED_TYPE			H5O_MSG_ATTR
#define H5O_SHARED_DECODE		H5O_attr_shared_decode
#define H5O_SHARED_DECODE_REAL		H5O_attr_decode
#define H5O_SHARED_ENCODE		H5O_attr_shared_encode
#define H5O_SHARED_ENCODE_REAL		H5O_attr_encode
#define H5O_SHARED_SIZE			H5O_attr_shared_size
#define H5O_SHARED_SIZE_REAL		H5O_attr_size
#define H5O_SHARED_DELETE		H5O_attr_shared_delete
#define H5O_SHARED_DELETE_REAL		H5O_attr_delete
#define H5O_SHARED_LINK			H5O_attr_shared_link
#define H5O_SHARED_LINK_REAL		H5O_attr_link
#define H5O_SHARED_COPY_FILE		H5O_attr_shared_copy_file
#define H5O_SHARED_COPY_FILE_REAL	H5O_attr_copy_file
#define H5O_SHARED_POST_COPY_FILE	H5O_attr_shared_post_copy_file
#define H5O_SHARED_POST_COPY_FILE_REAL	H5O_attr_post_copy_file
#define H5O_SHARED_DEBUG		H5O_attr_shared_debug
#define H5O_SHARED_DEBUG_REAL		H5O_attr_debug
#include "H5Oshared.h"			/* Shared Object Header Message Callbacks */

/* This message derives from H5O message class */
const H5O_msg_class_t H5O_MSG_ATTR[1] = {{
    H5O_ATTR_ID,		/* message id number            */
    "attribute",		/* message name for debugging   */
    sizeof(H5A_t),		/* native message size          */
    H5O_SHARE_IS_SHARABLE,	/* messages are sharable?       */
    H5O_attr_shared_decode,	/* decode message               */
    H5O_attr_shared_encode,	/* encode message               */
    H5O_attr_copy,		/* copy the native value        */
    H5O_attr_shared_size,	/* size of raw message          */
    H5O_attr_reset,	        /* reset method                 */
    H5O_attr_free,	        /* free method			*/
    H5O_attr_shared_delete,	/* file delete method		*/
    H5O_attr_shared_link,	/* link method			*/
    NULL,			/*set share method		*/
    NULL,		    	/*can share method		*/
    H5O_attr_pre_copy_file,	/* pre copy native value to file */
    H5O_attr_shared_copy_file,	/* copy native value to file    */
    H5O_attr_shared_post_copy_file,	/* post copy native value to file    */
    H5O_attr_get_crt_index,	/* get creation index		*/
    H5O_attr_set_crt_index,	/* set creation index		*/
    H5O_attr_shared_debug	/* debug the message            */
}};

/* Flags for attribute flag encoding */
#define H5O_ATTR_FLAG_TYPE_SHARED       0x01
#define H5O_ATTR_FLAG_SPACE_SHARED      0x02
#define H5O_ATTR_FLAG_ALL               0x03

/* Declare external the free list for H5S_t's */
H5FL_EXTERN(H5S_t);

/* Declare external the free list for H5S_extent_t's */
H5FL_EXTERN(H5S_extent_t);


/*--------------------------------------------------------------------------
 NAME
    H5O_attr_decode
 PURPOSE
    Decode a attribute message and return a pointer to a memory struct
        with the decoded information
 USAGE
    void *H5O_attr_decode(f, dxpl_id, mesg_flags, p)
        H5F_t *f;               IN: pointer to the HDF5 file struct
        hid_t dxpl_id;          IN: DXPL for any I/O
        unsigned mesg_flags;    IN: Message flags to influence decoding
        const uint8_t *p;       IN: the raw information buffer
 RETURNS
    Pointer to the new message in native order on success, NULL on failure
 DESCRIPTION
        This function decodes the "raw" disk form of a attribute message
    into a struct in memory native format.  The struct is allocated within this
    function using malloc() and is returned to the caller.
--------------------------------------------------------------------------*/
static void *
H5O_attr_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, unsigned UNUSED mesg_flags,
    unsigned *ioflags, const uint8_t *p)
{
    H5A_t		*attr = NULL;
    H5S_extent_t	*extent;	/*extent dimensionality information  */
    size_t		name_len;   	/*attribute name length */
    unsigned            flags = 0;      /* Attribute flags */
    H5A_t		*ret_value;     /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_decode)

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

    if(NULL == (attr = H5FL_CALLOC(H5A_t)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    if(NULL == (attr->shared = H5FL_CALLOC(H5A_shared_t)))
        HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, NULL, "can't allocate shared attr structure")

    /* Version number */
    attr->shared->version = *p++;
    if(attr->shared->version < H5O_ATTR_VERSION_1 || attr->shared->version > H5O_ATTR_VERSION_LATEST)
	HGOTO_ERROR(H5E_ATTR, H5E_CANTLOAD, NULL, "bad version number for attribute message")

    /* Get the flags byte if we have a later version of the attribute */
    if(attr->shared->version >= H5O_ATTR_VERSION_2) {
        flags = *p++;

        /* Check for unknown flag */
        if(flags & (unsigned)~H5O_ATTR_FLAG_ALL)
            HGOTO_ERROR(H5E_ATTR, H5E_CANTLOAD, NULL, "unknown flag for attribute message")
    } /* end if */
    else
        p++;    /* Byte is unused when version<2 */

    /*
     * Decode the sizes of the parts of the attribute.  The sizes stored in
     * the file are exact but the parts are aligned on 8-byte boundaries.
     */
    UINT16DECODE(p, name_len); /*including null*/
    UINT16DECODE(p, attr->shared->dt_size);
    UINT16DECODE(p, attr->shared->ds_size);

    /*
     * Decode the character encoding for the name for versions 3 or later,
     * as well as some reserved bytes.
     */
    if(attr->shared->version >= H5O_ATTR_VERSION_3)
        attr->shared->encoding = *p++;

    /* Decode and store the name */
    if(NULL == (attr->shared->name = H5MM_strdup((const char *)p)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
    if(attr->shared->version < H5O_ATTR_VERSION_2)
        p += H5O_ALIGN_OLD(name_len);    /* advance the memory pointer */
    else
        p += name_len;    /* advance the memory pointer */

    /* Decode the attribute's datatype */
    if(NULL == (attr->shared->dt = (H5T_t *)(H5O_MSG_DTYPE->decode)(f, dxpl_id, open_oh,
        ((flags & H5O_ATTR_FLAG_TYPE_SHARED) ? H5O_MSG_FLAG_SHARED : 0), ioflags, p)))
        HGOTO_ERROR(H5E_ATTR, H5E_CANTDECODE, NULL, "can't decode attribute datatype")
    if(attr->shared->version < H5O_ATTR_VERSION_2)
        p += H5O_ALIGN_OLD(attr->shared->dt_size);
    else
        p += attr->shared->dt_size;

    /* decode the attribute dataspace.  It can be shared in versions >= 3
     * What's actually shared, though, is only the extent.
     */
    if(NULL == (attr->shared->ds = H5FL_CALLOC(H5S_t)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    /* Decode attribute's dataspace extent */
    if((extent = (H5S_extent_t *)(H5O_MSG_SDSPACE->decode)(f, dxpl_id, open_oh,
        ((flags & H5O_ATTR_FLAG_SPACE_SHARED) ? H5O_MSG_FLAG_SHARED : 0), ioflags, p)) == NULL)
        HGOTO_ERROR(H5E_ATTR, H5E_CANTDECODE, NULL, "can't decode attribute dataspace")

    /* Copy the extent information to the dataspace */
    HDmemcpy(&(attr->shared->ds->extent), extent, sizeof(H5S_extent_t));

    /* Release temporary extent information */
    (void)H5FL_FREE(H5S_extent_t, extent);

    /* Default to entire dataspace being selected */
    if(H5S_select_all(attr->shared->ds, FALSE) < 0)
        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSET, NULL, "unable to set all selection")

    if(attr->shared->version < H5O_ATTR_VERSION_2)
        p += H5O_ALIGN_OLD(attr->shared->ds_size);
    else
        p += attr->shared->ds_size;

    /* Compute the size of the data */
    H5_ASSIGN_OVERFLOW(attr->shared->data_size, H5S_GET_EXTENT_NPOINTS(attr->shared->ds) * H5T_get_size(attr->shared->dt), hsize_t, size_t);

    /* Go get the data */
    if(attr->shared->data_size) {
        if(NULL == (attr->shared->data = H5FL_BLK_MALLOC(attr_buf, attr->shared->data_size)))
            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
        HDmemcpy(attr->shared->data, p, attr->shared->data_size);
    } /* end if */

    /* Increment the reference count for this object header message in cache(compact
       storage) or for the object from dense storage. */
    attr->shared->nrefs++;

    /* Set return value */
    ret_value = attr;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_decode() */


/*--------------------------------------------------------------------------
 NAME
    H5O_attr_encode
 PURPOSE
    Encode a simple attribute message
 USAGE
    herr_t H5O_attr_encode(f, p, mesg)
        H5F_t *f;         IN: pointer to the HDF5 file struct
        const uint8 *p;         IN: the raw information buffer
        const void *mesg;       IN: Pointer to the simple datatype struct
 RETURNS
    Non-negative on success/Negative on failure
 DESCRIPTION
        This function encodes the native memory form of the attribute
    message in the "raw" disk form.
--------------------------------------------------------------------------*/
static herr_t
H5O_attr_encode(H5F_t *f, uint8_t *p, const void *mesg)
{
    const H5A_t *attr = (const H5A_t *) mesg;
    size_t      name_len;   /* Attribute name length */
    htri_t      is_type_shared;    /* Flag to indicate that a shared datatype is used for this attribute */
    htri_t      is_space_shared;   /* Flag to indicate that a shared dataspace is used for this attribute */
    unsigned    flags = 0;      /* Attribute flags */
    herr_t      ret_value = SUCCEED;      /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_encode)

    /* check args */
    HDassert(f);
    HDassert(p);
    HDassert(attr);

    /* Check whether datatype and dataspace are shared */
    if((is_type_shared = H5O_msg_is_shared(H5O_DTYPE_ID, attr->shared->dt)) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_BADMESG, FAIL, "can't determine if datatype is shared")

    if((is_space_shared = H5O_msg_is_shared(H5O_SDSPACE_ID, attr->shared->ds)) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_BADMESG, FAIL, "can't determine if dataspace is shared")

    /* Encode Version */
    *p++ = attr->shared->version;

    /* Set attribute flags if version >1 */
    if(attr->shared->version >= H5O_ATTR_VERSION_2) {
        flags = (is_type_shared ? H5O_ATTR_FLAG_TYPE_SHARED : 0 );
        flags |= (is_space_shared ? H5O_ATTR_FLAG_SPACE_SHARED : 0);
        *p++ = flags;    /* Set flags for attribute */
    } /* end if */
    else
        *p++ = 0; /* Reserved, for version <2 */

    /*
     * Encode the lengths of the various parts of the attribute message. The
     * encoded lengths are exact but we pad each part except the data to be a
     * multiple of eight bytes (in the first version).
     */
    name_len = HDstrlen(attr->shared->name) + 1;
    UINT16ENCODE(p, name_len);
    UINT16ENCODE(p, attr->shared->dt_size);
    UINT16ENCODE(p, attr->shared->ds_size);

    /* The character encoding for the attribute's name, in later versions */
    if(attr->shared->version >= H5O_ATTR_VERSION_3)
        *p++ = attr->shared->encoding;

    /* Write the name including null terminator */
    HDmemcpy(p, attr->shared->name, name_len);
    if(attr->shared->version < H5O_ATTR_VERSION_2) {
        /* Pad to the correct number of bytes */
        HDmemset(p + name_len, 0, H5O_ALIGN_OLD(name_len) - name_len);
        p += H5O_ALIGN_OLD(name_len);
    } /* end if */
    else
        p += name_len;

    /* encode the attribute datatype */
    if((H5O_MSG_DTYPE->encode)(f, FALSE, p, attr->shared->dt) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL, "can't encode attribute datatype")

    if(attr->shared->version < H5O_ATTR_VERSION_2) {
        HDmemset(p + attr->shared->dt_size, 0, H5O_ALIGN_OLD(attr->shared->dt_size) - attr->shared->dt_size);
        p += H5O_ALIGN_OLD(attr->shared->dt_size);
    } /* end if */
    else
        p += attr->shared->dt_size;

    /* encode the attribute dataspace */
    if((H5O_MSG_SDSPACE->encode)(f, FALSE, p, &(attr->shared->ds->extent)) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL, "can't encode attribute dataspace")

    if(attr->shared->version < H5O_ATTR_VERSION_2) {
        HDmemset(p + attr->shared->ds_size, 0, H5O_ALIGN_OLD(attr->shared->ds_size) - attr->shared->ds_size);
        p += H5O_ALIGN_OLD(attr->shared->ds_size);
    } /* end if */
    else
        p += attr->shared->ds_size;

    /* Store attribute data.  If there's no data, store 0 as fill value. */
    if(attr->shared->data)
        HDmemcpy(p, attr->shared->data, attr->shared->data_size);
    else
        HDmemset(p, 0, attr->shared->data_size);

done:
    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5O_attr_encode() */


/*--------------------------------------------------------------------------
 NAME
    H5O_attr_copy
 PURPOSE
    Copies a message from MESG to DEST, allocating DEST if necessary.
 USAGE
    void *H5O_attr_copy(mesg, dest)
        const void *mesg;       IN: Pointer to the source attribute struct
        const void *dest;       IN: Pointer to the destination attribute struct
 RETURNS
    Pointer to DEST on success, NULL on failure
 DESCRIPTION
        This function copies a native (memory) attribute message,
    allocating the destination structure if necessary.
--------------------------------------------------------------------------*/
static void *
H5O_attr_copy(const void *_src, void *_dst)
{
    void *ret_value;            /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_copy)

    /* check args */
    HDassert(_src);

    /* copy */
    if(NULL == (ret_value = (H5A_t *)H5A_copy((H5A_t *)_dst, (const H5A_t *)_src)))
        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "can't copy attribute")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_copy() */


/*--------------------------------------------------------------------------
 NAME
    H5O_attr_size
 PURPOSE
    Return the raw message size in bytes
 USAGE
    size_t H5O_attr_size(f, mesg)
        H5F_t *f;         IN: pointer to the HDF5 file struct
        const void *mesg;     IN: Pointer to the source attribute struct
 RETURNS
    Size of message on success, 0 on failure
 DESCRIPTION
        This function returns the size of the raw attribute message on
    success.  (Not counting the message type or size fields, only the data
    portion of the message).  It doesn't take into account alignment.
--------------------------------------------------------------------------*/
static size_t
H5O_attr_size(const H5F_t UNUSED *f, const void *_mesg)
{
    const H5A_t         *attr = (const H5A_t *)_mesg;
    size_t		name_len;
    size_t		ret_value = 0;

    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_attr_size)

    HDassert(attr);

    /* Common size information */
    ret_value = 1 +				/*version               */
                1 +				/*reserved/flags	*/
                2 +				/*name size inc. null	*/
                2 +				/*type size		*/
                2; 				/*space size		*/

    /* Length of attribute name */
    name_len = HDstrlen(attr->shared->name) + 1;

    /* Version-specific size information */
    if(attr->shared->version == H5O_ATTR_VERSION_1)
        ret_value += H5O_ALIGN_OLD(name_len) +	/*attribute name	*/
                    H5O_ALIGN_OLD(attr->shared->dt_size) +	/*datatype		*/
                    H5O_ALIGN_OLD(attr->shared->ds_size) +	/*dataspace		*/
                    attr->shared->data_size;		/*the data itself	*/
    else if(attr->shared->version == H5O_ATTR_VERSION_2)
        ret_value += name_len	+		/*attribute name	*/
                    attr->shared->dt_size +		/*datatype		*/
                    attr->shared->ds_size +		/*dataspace		*/
                    attr->shared->data_size;		/*the data itself	*/
    else if(attr->shared->version == H5O_ATTR_VERSION_3)
        ret_value += 1 +                        /*character encoding    */
                    name_len	+		/*attribute name	*/
                    attr->shared->dt_size +		/*datatype		*/
                    attr->shared->ds_size +		/*dataspace		*/
                    attr->shared->data_size;		/*the data itself	*/
    else
        HDassert(0 && "Bad attribute version");

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_size() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_reset
 *
 * Purpose:     Frees resources within a attribute message, but doesn't free
 *              the message itself.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Robb Matzke
 *              Tuesday, December  9, 1997
 *
 * Modification:Raymond Lu
 *              25 June 2008
 *              Made this function empty.  The freeing action is actually
 *              done in H5O_attr_free (see H5O_msg_free_real).  But this
 *              empty reset function needs to be here.  Otherwise, the
 *              caller function H5O_msg_reset_real will zero-set the whole
 *              message.
 *-------------------------------------------------------------------------
 */
herr_t
H5O_attr_reset(void UNUSED *_mesg)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_attr_reset)

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O_attr_reset() */


/*-------------------------------------------------------------------------
 * Function:	H5O_attr_free
 *
 * Purpose:	Free's the message
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, November 18, 2004
 *
 * Modification:Raymond Lu
 *              4 June 2008
 *              Let this function call H5A_close in turn.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O_attr_free(void *mesg)
{
    H5A_t *attr = (H5A_t *)mesg;
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_free)

    HDassert(mesg);

    if(H5A_close(attr) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_CANTCLOSEOBJ, FAIL, "unable to close attribute object")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_free() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_delete
 *
 * Purpose:     Free file space referenced by message
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Friday, September 26, 2003
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5O_attr_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh, void *_mesg)
{
    H5A_t *attr = (H5A_t *) _mesg;
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_delete)

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

    /* Decrement reference count on datatype in file */
    if((H5O_MSG_DTYPE->del)(f, dxpl_id, oh, attr->shared->dt) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust datatype link count")

    /* Decrement reference count on dataspace in file */
    if((H5O_MSG_SDSPACE->del)(f, dxpl_id, oh, attr->shared->ds) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust dataspace link count")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_delete() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_link
 *
 * Purpose:     Increment reference count on any objects referenced by
 *              message
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Friday, September 26, 2003
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5O_attr_link(H5F_t *f, hid_t dxpl_id, H5O_t *oh, void *_mesg)
{
    H5A_t *attr = (H5A_t *) _mesg;
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_link)

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

    /* Re-share attribute's datatype and dataspace to increment their
     * reference count if they're shared.
     * Otherwise they may be deleted when the attribute
     * message is deleted.
     */
    /* Increment reference count on datatype & dataspace in file */
    if((H5O_MSG_DTYPE->link)(f, dxpl_id, oh, attr->shared->dt) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust datatype link count")
    if((H5O_MSG_SDSPACE->link)(f, dxpl_id, oh, attr->shared->ds) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust dataspace link count")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_link() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_pre_copy_file
 *
 * Purpose:     Perform any necessary actions before copying message between
 *              files for attribute messages.
 *
 * Return:      Success:        Non-negative
 *
 *              Failure:        Negative
 *
 * Programmer:  Quincey Koziol
 *              Monday, June 26, 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O_attr_pre_copy_file(H5F_t UNUSED *file_src, const void UNUSED *native_src,
    hbool_t *deleted, const H5O_copy_t *cpy_info, void UNUSED *udata)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_attr_pre_copy_file)

    /* check args */
    HDassert(deleted);
    HDassert(cpy_info);

    /* If we are not copying attributes into the destination file, indicate
     *  that this message should be deleted.
     */
    if(cpy_info->copy_without_attr)
        *deleted = TRUE;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O_attr_pre_copy_file() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_copy_file
 *
 * Purpose:     Copies a message from _MESG to _DEST in file
 *
 * Return:      Success:        Ptr to _DEST
 *
 *              Failure:        NULL
 *
 * Programmer:  Quincey Koziol
 *              November 1, 2005
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O_attr_copy_file(H5F_t UNUSED *file_src, const H5O_msg_class_t UNUSED *mesg_type,
    void *native_src, H5F_t *file_dst, hbool_t *recompute_size,
    H5O_copy_t *cpy_info, void UNUSED *udata, hid_t dxpl_id)
{
    void        *ret_value;             /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_copy_file)

    /* check args */
    HDassert(native_src);
    HDassert(file_dst);
    HDassert(cpy_info);
    HDassert(!cpy_info->copy_without_attr);

    if ( NULL == (ret_value=H5A_attr_copy_file((H5A_t *)native_src, file_dst, recompute_size, cpy_info,  dxpl_id)))
        HGOTO_ERROR(H5E_ATTR, H5E_CANTCOPY, NULL, "can't copy attribute")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5O_attr_copy_file() */


/*-------------------------------------------------------------------------
 * Function:    H5O_attr_post_copy_file
 *
 * Purpose:     Finish copying a message from between files.
 *              We have to copy the values of a reference attribute in the
 *              post copy because H5O_post_copy_file() fails at the case that
 *              an object may have a reference attribute that points to the
 *              object itself.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Peter Cao
 *              March 6, 2005
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O_attr_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src,
    H5O_loc_t *dst_oloc, void *mesg_dst, hid_t dxpl_id, H5O_copy_t *cpy_info)
{
    herr_t ret_value = SUCCEED;   /* Return value */


    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_post_copy_file)

    if ( H5A_attr_post_copy_file(src_oloc, (const H5A_t *)mesg_src,
         dst_oloc, (H5A_t *)mesg_dst, dxpl_id, cpy_info) < 0)
        HGOTO_ERROR(H5E_ATTR, H5E_CANTCOPY, FAIL, "can't copy attribute")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5O_attr_post_copy_file() */


/*-------------------------------------------------------------------------
 * Function:	H5O_attr_get_crt_index
 *
 * Purpose:	Get creation index from the message
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:	Quincey Koziol
 *              Thursday, January 18, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5O_attr_get_crt_index(const void *_mesg, H5O_msg_crt_idx_t *crt_idx /*out*/)
{
    const H5A_t  *attr = (const H5A_t *)_mesg;

    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_attr_get_crt_index)

    HDassert(attr);
    HDassert(crt_idx);

    /* Get the attribute's creation index */
    *crt_idx = attr->shared->crt_idx;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O_attr_get_crt_index() */


/*-------------------------------------------------------------------------
 * Function:	H5O_attr_set_crt_index
 *
 * Purpose:	Set creation index from the message
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:	Quincey Koziol
 *              Thursday, January 18, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5O_attr_set_crt_index(void *_mesg, H5O_msg_crt_idx_t crt_idx)
{
    H5A_t  *attr = (H5A_t *)_mesg;

    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_attr_set_crt_index)

    HDassert(attr);

    /* Set the creation index */
    attr->shared->crt_idx = crt_idx;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O_attr_set_crt_index() */


/*--------------------------------------------------------------------------
 NAME
    H5O_attr_debug
 PURPOSE
    Prints debugging information for an attribute message
 USAGE
    void *H5O_attr_debug(f, mesg, stream, indent, fwidth)
        H5F_t *f;               IN: pointer to the HDF5 file struct
        const void *mesg;       IN: Pointer to the source attribute struct
        FILE *stream;           IN: Pointer to the stream for output data
        int indent;            IN: Amount to indent information by
        int fwidth;            IN: Field width (?)
 RETURNS
    Non-negative on success/Negative on failure
 DESCRIPTION
        This function prints debugging output to the stream passed as a
    parameter.
--------------------------------------------------------------------------*/
static herr_t
H5O_attr_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE * stream, int indent,
	       int fwidth)
{
    const H5A_t *mesg = (const H5A_t *)_mesg;
    const char		*s;             /* Temporary string pointer */
    char		buf[256];       /* Temporary string buffer */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5O_attr_debug)

    /* check args */
    HDassert(f);
    HDassert(stream);
    HDassert(indent >= 0);
    HDassert(fwidth >= 0);

    fprintf(stream, "%*s%-*s \"%s\"\n", indent, "", fwidth,
	    "Name:",
	    mesg->shared->name);
    switch(mesg->shared->encoding) {
        case H5T_CSET_ASCII:
            s = "ASCII";
            break;
        case H5T_CSET_UTF8:
            s = "UTF-8";
            break;
        default:
            sprintf(buf, "H5T_CSET_RESERVED_%d", (int)(mesg->shared->encoding));
            s = buf;
            break;
    } /* end switch */
    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
            "Character Set of Name:",
            s);
    HDfprintf(stream, "%*s%-*s %t\n", indent, "", fwidth,
	    "Object opened:",
	    mesg->obj_opened);
    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
	    "Object:",
	    mesg->oloc.addr);

    /* Check for attribute creation order index on the attribute */
    if(mesg->shared->crt_idx != H5O_MAX_CRT_ORDER_IDX)
        HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
                "Creation Index:",
                (unsigned)mesg->shared->crt_idx);

    fprintf(stream, "%*sDatatype...\n", indent, "");
    fprintf(stream, "%*s%-*s %lu\n", indent+3, "", MAX(0,fwidth-3),
	    "Encoded Size:",
	    (unsigned long)(mesg->shared->dt_size));
    if((H5O_MSG_DTYPE->debug)(f, dxpl_id, mesg->shared->dt, stream, indent + 3, MAX(0, fwidth - 3)) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL, "unable to display datatype message info")

    fprintf(stream, "%*sDataspace...\n", indent, "");
    fprintf(stream, "%*s%-*s %lu\n", indent+3, "", MAX(0, fwidth - 3),
	    "Encoded Size:",
	    (unsigned long)(mesg->shared->ds_size));
    if(H5S_debug(f, dxpl_id, mesg->shared->ds, stream, indent+3, MAX(0, fwidth - 3)) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL, "unable to display dataspace message info")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_attr_debug() */