/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

 * Copyright by The HDF Group.                                               *

 * 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 LICENSE file, which can be found at the root of the source code       *

 * distribution tree, or in https://www.hdfgroup.org/licenses.               *

 * If you do not have access to either file, you may request a copy from     *

 * help@hdfgroup.org.                                                        *

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------

 *

 * Created:             H5Olink.c

 *

 * Purpose:             Link messages

 *

 *-------------------------------------------------------------------------

 */

#define H5L_FRIEND     /*suppress error about including H5Lpkg    */

#include "H5Omodule.h" /* This source code file is part of the H5O module */

#include "H5private.h"   /* Generic Functions     */

#include "H5Eprivate.h"  /* Error handling        */

#include "H5FLprivate.h" /* Free lists                           */

#include "H5Iprivate.h"  /* IDs                                  */

#include "H5Lpkg.h"      /* Links                                */

#include "H5MMprivate.h" /* Memory management     */

#include "H5Opkg.h"      /* Object headers      */

/* PRIVATE PROTOTYPES */

static void *H5O__link_decode(H5F_t *f, H5O_t *open_oh, unsigned mesg_flags, unsigned *ioflags, size_t p_size,

                              const uint8_t *p);

static herr_t H5O__link_encode(H5F_t *f, bool disable_shared, size_t H5_ATTR_UNUSED p_size, uint8_t *p,

                               const void *_mesg);

static void  *H5O__link_copy(const void *_mesg, void *_dest);

static size_t H5O__link_size(const H5F_t *f, bool disable_shared, const void *_mesg);

static herr_t H5O__link_reset(void *_mesg);

static herr_t H5O__link_free(void *_mesg);

static herr_t H5O__link_pre_copy_file(H5F_t *file_src, const void *mesg_src, bool *deleted,

                                      const H5O_copy_t *cpy_info, void *udata);

static void  *H5O__link_copy_file(H5F_t *file_src, void *native_src, H5F_t *file_dst, bool *recompute_size,

                                  unsigned *mesg_flags, H5O_copy_t *cpy_info, void *udata);

static herr_t H5O__link_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src, H5O_loc_t *dst_oloc,

                                       void *mesg_dst, unsigned *mesg_flags, H5O_copy_t *cpy_info);

static herr_t H5O__link_debug(H5F_t *f, const void *_mesg, FILE *stream, int indent, int fwidth);

/* This message derives from H5O message class */

const H5O_msg_class_t H5O_MSG_LINK[1] = {{

    H5O_LINK_ID,              /*message id number             */

    "link",                   /*message name for debugging    */

    sizeof(H5O_link_t),       /*native message size           */

    0,                        /* messages are shareable?       */

    H5O__link_decode,         /*decode message                */

    H5O__link_encode,         /*encode message                */

    H5O__link_copy,           /*copy the native value         */

    H5O__link_size,           /*size of symbol table entry    */

    H5O__link_reset,          /* reset method     */

    H5O__link_free,           /* free method      */

    H5O_link_delete,          /* file delete method   */

    NULL,                     /* link method      */

    NULL,                     /*set share method    */

    NULL,                     /*can share method    */

    H5O__link_pre_copy_file,  /* pre copy native value to file */

    H5O__link_copy_file,      /* copy native value to file    */

    H5O__link_post_copy_file, /* post copy native value to file    */

    NULL,                     /* get creation index   */

    NULL,                     /* set creation index   */

    H5O__link_debug           /*debug the message             */

}};

/* Current version of link information */

#define H5O_LINK_VERSION 1

/* Flags for link flag encoding */

#define H5O_LINK_NAME_SIZE       0x03 /* 2-bit field for size of name length */

#define H5O_LINK_STORE_CORDER    0x04 /* Whether to store creation index */

#define H5O_LINK_STORE_LINK_TYPE 0x08 /* Whether to store non-default link type */

#define H5O_LINK_STORE_NAME_CSET 0x10 /* Whether to store non-default name character set */

#define H5O_LINK_ALL_FLAGS                                                                                   \

    (H5O_LINK_NAME_SIZE | H5O_LINK_STORE_CORDER | H5O_LINK_STORE_LINK_TYPE | H5O_LINK_STORE_NAME_CSET)

/* Individual definitions of name size values */

#define H5O_LINK_NAME_1 0x00 /* Use 1-byte value for name length */

#define H5O_LINK_NAME_2 0x01 /* Use 2-byte value for name length */

#define H5O_LINK_NAME_4 0x02 /* Use 4-byte value for name length */

#define H5O_LINK_NAME_8 0x03 /* Use 8-byte value for name length */

/* Declare a free list to manage the H5O_link_t struct */

H5FL_DEFINE_STATIC(H5O_link_t);

/*-------------------------------------------------------------------------

 * Function:    H5O__link_decode

 *

 * Purpose:     Decode a message and return a pointer to

 *              a newly allocated one.

 *

 * Return:      Success:    Pointer to new message in native order

 *              Failure:    NULL

 *-------------------------------------------------------------------------

 */

static void *

H5O__link_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh, unsigned H5_ATTR_UNUSED mesg_flags,

                 unsigned H5_ATTR_UNUSED *ioflags, size_t p_size, const uint8_t *p)

{

    H5O_link_t    *lnk = NULL;                 /* Pointer to link message */

    size_t         len = 0;                    /* Length of a string in the message */

    unsigned char  link_flags;                 /* Flags for encoding link info */

    const uint8_t *p_end     = p + p_size - 1; /* End of the p buffer */

    void          *ret_value = NULL;

    FUNC_ENTER_PACKAGE

    assert(f);

    assert(p);

    if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))

        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

    if (*p++ != H5O_LINK_VERSION)

        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for message");

    /* Allocate space for message */

    if (NULL == (lnk = H5FL_CALLOC(H5O_link_t)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* Get the encoding flags for the link */

    if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))

        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

    link_flags = *p++;

    if (link_flags & ~H5O_LINK_ALL_FLAGS)

        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad flag value for message");

    /* Check for non-default link type */

    if (link_flags & H5O_LINK_STORE_LINK_TYPE) {

        /* Get the type of the link */

        if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))

            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

        lnk->type = (H5L_type_t)*p++;

        if (lnk->type < H5L_TYPE_HARD || lnk->type > H5L_TYPE_MAX)

            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad link type");

    }

    else

        lnk->type = H5L_TYPE_HARD;

    /* Get the link creation time from the file */

    if (link_flags & H5O_LINK_STORE_CORDER) {

        if (H5_IS_BUFFER_OVERFLOW(p, 8, p_end))

            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

        INT64DECODE(p, lnk->corder);

        lnk->corder_valid = true;

    }

    else {

        lnk->corder       = 0;

        lnk->corder_valid = false;

    }

    /* Check for non-default name character set */

    if (link_flags & H5O_LINK_STORE_NAME_CSET) {

        /* Get the link name's character set */

        if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))

            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

        lnk->cset = (H5T_cset_t)*p++;

        if (lnk->cset < H5T_CSET_ASCII || lnk->cset > H5T_CSET_UTF8)

            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad cset type");

    }

    else

        lnk->cset = H5T_CSET_ASCII;

    /* Get the length of the link's name */

    switch (link_flags & H5O_LINK_NAME_SIZE) {

        case 0: /* 1 byte size */

            if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            len = *p++;

            break;

        case 1: /* 2 byte size */

            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            UINT16DECODE(p, len);

            break;

        case 2: /* 4 byte size */

            if (H5_IS_BUFFER_OVERFLOW(p, 4, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            UINT32DECODE(p, len);

            break;

        case 3: /* 8 byte size */

            if (H5_IS_BUFFER_OVERFLOW(p, 8, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            UINT64DECODE(p, len);

            break;

        default:

            HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "no appropriate size for name length");

    }

    if (len == 0)

        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid name length");

    /* Get the link's name */

    if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))

        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

    if (NULL == (lnk->name = (char *)H5MM_malloc(len + 1)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    H5MM_memcpy(lnk->name, p, len);

    lnk->name[len] = '\0';

    p += len;

    /* Get the appropriate information for each type of link */

    switch (lnk->type) {

        case H5L_TYPE_HARD:

            /* Get the address of the object the link points to */

            if (H5_IS_BUFFER_OVERFLOW(p, H5F_sizeof_addr(f), p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            H5F_addr_decode(f, &p, &(lnk->u.hard.addr));

            break;

        case H5L_TYPE_SOFT:

            /* Get the link value */

            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            UINT16DECODE(p, len);

            if (len == 0)

                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid link length");

            if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            if (NULL == (lnk->u.soft.name = (char *)H5MM_malloc((size_t)len + 1)))

                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

            H5MM_memcpy(lnk->u.soft.name, p, len);

            lnk->u.soft.name[len] = '\0';

            p += len;

            break;

        /* User-defined links */

        case H5L_TYPE_EXTERNAL:

        case H5L_TYPE_ERROR:

        case H5L_TYPE_MAX:

        default:

            if (lnk->type < H5L_TYPE_UD_MIN || lnk->type > H5L_TYPE_MAX)

                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "unknown link type");

            /* A UD link.  Get the user-supplied data */

            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

            UINT16DECODE(p, len);

            if (lnk->type == H5L_TYPE_EXTERNAL && len < 3)

                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "external link information length < 3");

            lnk->u.ud.size = len;

            if (len > 0) {

                if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))

                    HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");

                if (NULL == (lnk->u.ud.udata = H5MM_malloc((size_t)len)))

                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

                H5MM_memcpy(lnk->u.ud.udata, p, len);

                p += len;

            }

            else

                lnk->u.ud.udata = NULL;

    }

    /* Set return value */

    ret_value = lnk;

done:

    if (!ret_value && lnk) {

        H5MM_xfree(lnk->name);

        if (lnk->type == H5L_TYPE_SOFT && lnk->u.soft.name != NULL)

            H5MM_xfree(lnk->u.soft.name);

        if (lnk->type >= H5L_TYPE_UD_MIN && lnk->u.ud.size > 0 && lnk->u.ud.udata != NULL)

            H5MM_xfree(lnk->u.ud.udata);

        H5FL_FREE(H5O_link_t, lnk);

    }

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5O__link_decode() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_encode

 *

 * Purpose:     Encodes a link message.

 *

 * Return:      Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_encode(H5F_t *f, bool H5_ATTR_UNUSED disable_shared, size_t H5_ATTR_UNUSED p_size, uint8_t *p,

                 const void *_mesg)

{

    const H5O_link_t *lnk = (const H5O_link_t *)_mesg;

    uint64_t          len;        /* Length of a string in the message */

    unsigned char     link_flags; /* Flags for encoding link info */

    FUNC_ENTER_PACKAGE_NOERR

    /* check args */

    assert(f);

    assert(p);

    assert(lnk);

    /* Get length of link's name */

    len = (uint64_t)strlen(lnk->name);

    assert(len > 0);

    /* encode */

    *p++ = H5O_LINK_VERSION;

    /* The encoding flags for the link */

    if (len > 4294967295)

        link_flags = H5O_LINK_NAME_8;

    else if (len > 65535)

        link_flags = H5O_LINK_NAME_4;

    else if (len > 255)

        link_flags = H5O_LINK_NAME_2;

    else

        link_flags = H5O_LINK_NAME_1;

    link_flags = (unsigned char)(link_flags | (lnk->corder_valid ? H5O_LINK_STORE_CORDER : 0));

    link_flags = (unsigned char)(link_flags | ((lnk->type != H5L_TYPE_HARD) ? H5O_LINK_STORE_LINK_TYPE : 0));

    link_flags = (unsigned char)(link_flags | ((lnk->cset != H5T_CSET_ASCII) ? H5O_LINK_STORE_NAME_CSET : 0));

    *p++       = link_flags;

    /* Store the type of a non-default link */

    if (link_flags & H5O_LINK_STORE_LINK_TYPE)

        *p++ = (uint8_t)lnk->type;

    /* Store the link creation order in the file, if its valid */

    if (lnk->corder_valid)

        INT64ENCODE(p, lnk->corder);

    /* Store a non-default link name character set */

    if (link_flags & H5O_LINK_STORE_NAME_CSET)

        *p++ = (uint8_t)lnk->cset;

    /* Store the link name's length */

    switch (link_flags & H5O_LINK_NAME_SIZE) {

        case 0: /* 1 byte size */

            *p++ = (uint8_t)len;

            break;

        case 1: /* 2 byte size */

            UINT16ENCODE(p, len);

            break;

        case 2: /* 4 byte size */

            UINT32ENCODE(p, len);

            break;

        case 3: /* 8 byte size */

            UINT64ENCODE(p, len);

            break;

        default:

            assert(0 && "bad size for name");

    } /* end switch */

    /* Store the link's name */

    H5MM_memcpy(p, lnk->name, (size_t)len);

    p += len;

    /* Store the appropriate information for each type of link */

    switch (lnk->type) {

        case H5L_TYPE_HARD:

            /* Store the address of the object the link points to */

            H5F_addr_encode(f, &p, lnk->u.hard.addr);

            break;

        case H5L_TYPE_SOFT:

            /* Store the link value */

            len = (uint16_t)strlen(lnk->u.soft.name);

            assert(len > 0);

            UINT16ENCODE(p, len);

            H5MM_memcpy(p, lnk->u.soft.name, (size_t)len);

            p += len;

            break;

        /* User-defined links */

        case H5L_TYPE_EXTERNAL:

        case H5L_TYPE_ERROR:

        case H5L_TYPE_MAX:

        default:

            assert(lnk->type >= H5L_TYPE_UD_MIN && lnk->type <= H5L_TYPE_MAX);

            /* Store the user-supplied data, however long it is */

            len = (uint16_t)lnk->u.ud.size;

            UINT16ENCODE(p, len);

            if (len > 0) {

                H5MM_memcpy(p, lnk->u.ud.udata, (size_t)len);

                p += len;

            }

            break;

    } /* end switch */

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5O__link_encode() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_copy

 *

 * Purpose:     Copies a message from _MESG to _DEST, allocating _DEST if

 *              necessary.

 *

 * Return:      Success:        Ptr to _DEST

 *

 *              Failure:        NULL

 *

 *-------------------------------------------------------------------------

 */

static void *

H5O__link_copy(const void *_mesg, void *_dest)

{

    const H5O_link_t *lnk       = (const H5O_link_t *)_mesg;

    H5O_link_t       *dest      = (H5O_link_t *)_dest;

    void             *ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check args */

    assert(lnk);

    if (!dest && NULL == (dest = H5FL_MALLOC(H5O_link_t)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* Copy static information */

    *dest = *lnk;

    /* Duplicate the link's name */

    assert(lnk->name);

    if (NULL == (dest->name = H5MM_xstrdup(lnk->name)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't duplicate link name");

    /* Copy other information needed for different link types */

    if (lnk->type == H5L_TYPE_SOFT) {

        if (NULL == (dest->u.soft.name = H5MM_xstrdup(lnk->u.soft.name)))

            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't duplicate soft link value");

    } /* end if */

    else if (lnk->type >= H5L_TYPE_UD_MIN) {

        if (lnk->u.ud.size > 0) {

            if (NULL == (dest->u.ud.udata = H5MM_malloc(lnk->u.ud.size)))

                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

            H5MM_memcpy(dest->u.ud.udata, lnk->u.ud.udata, lnk->u.ud.size);

        } /* end if */

    }     /* end if */

    /* Set return value */

    ret_value = dest;

done:

    if (NULL == ret_value)

        if (dest) {

            if (dest->name && dest->name != lnk->name)

                dest->name = (char *)H5MM_xfree(dest->name);

            if (NULL == _dest)

                dest = H5FL_FREE(H5O_link_t, dest);

        } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5O__link_copy() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_size

 *

 * Purpose:     Returns the size of the raw message in bytes not counting

 *              the message type or size fields, but only the data fields.

 *              This function doesn't take into account alignment.

 *

 * Return:      Success:        Message data size in bytes without alignment.

 *

 *              Failure:        zero

 *

 *-------------------------------------------------------------------------

 */

static size_t

H5O__link_size(const H5F_t *f, bool H5_ATTR_UNUSED disable_shared, const void *_mesg)

{

    const H5O_link_t *lnk = (const H5O_link_t *)_mesg;

    uint64_t          name_len;      /* Length of name */

    size_t            name_size;     /* Size of encoded name length */

    size_t            ret_value = 0; /* Return value */

    FUNC_ENTER_PACKAGE_NOERR

    /* Sanity check */

    HDcompile_assert(sizeof(uint64_t) >= sizeof(size_t));

    /* Get name's length */

    name_len = (uint64_t)strlen(lnk->name);

    /* Determine correct value for name size bits */

    if (name_len > 4294967295)

        name_size = 8;

    else if (name_len > 65535)

        name_size = 4;

    else if (name_len > 255)

        name_size = 2;

    else

        name_size = 1;

    /* Set return value */

    ret_value = 1 +                                            /* Version */

                1 +                                            /* Link encoding flags */

                (lnk->type != H5L_TYPE_HARD ? (size_t)1 : 0) + /* Link type */

                (lnk->corder_valid ? 8 : 0) +                  /* Creation order */

                (lnk->cset != H5T_CSET_ASCII ? 1 : 0) +        /* Character set */

                name_size +                                    /* Name length */

                name_len;                                      /* Name */

    /* Add the appropriate length for each type of link */

    switch (lnk->type) {

        case H5L_TYPE_HARD:

            ret_value += H5F_SIZEOF_ADDR(f);

            break;

        case H5L_TYPE_SOFT:

            ret_value += 2 +                       /* Link value length */

                         strlen(lnk->u.soft.name); /* Link value */

            break;

        case H5L_TYPE_ERROR:

        case H5L_TYPE_EXTERNAL:

        case H5L_TYPE_MAX:

        default: /* Default is user-defined link type */

            assert(lnk->type >= H5L_TYPE_UD_MIN);

            ret_value += 2 +             /* User-defined data size */

                         lnk->u.ud.size; /* User-defined data */

            break;

    } /* end switch */

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5O__link_size() */

/*-------------------------------------------------------------------------

 * Function:  H5O__link_reset

 *

 * Purpose: Frees resources within a message, but doesn't free

 *    the message itself.

 *

 * Return:  Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_reset(void *_mesg)

{

    H5O_link_t *lnk = (H5O_link_t *)_mesg;

    FUNC_ENTER_PACKAGE_NOERR

    if (lnk) {

        /* Free information for link (but don't free link pointer) */

        if (lnk->type == H5L_TYPE_SOFT)

            lnk->u.soft.name = (char *)H5MM_xfree(lnk->u.soft.name);

        else if (lnk->type >= H5L_TYPE_UD_MIN) {

            if (lnk->u.ud.size > 0)

                lnk->u.ud.udata = H5MM_xfree(lnk->u.ud.udata);

        } /* end if */

        lnk->name = (char *)H5MM_xfree(lnk->name);

    } /* end if */

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5O__link_reset() */

/*-------------------------------------------------------------------------

 * Function:  H5O__link_free

 *

 * Purpose: Frees the message contents and the message itself

 *

 * Return:  Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_free(void *_mesg)

{

    H5O_link_t *lnk = (H5O_link_t *)_mesg;

    FUNC_ENTER_PACKAGE_NOERR

    assert(lnk);

    lnk = H5FL_FREE(H5O_link_t, lnk);

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5O__link_free() */

/*-------------------------------------------------------------------------

 * Function:    H5O_link_delete

 *

 * Purpose:     Free file space referenced by message

 *

 * Return:      Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

herr_t

H5O_link_delete(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh, void *_mesg)

{

    H5O_link_t *lnk       = (H5O_link_t *)_mesg;

    hid_t       file_id   = -1;      /* ID for the file the link is located in (passed to user callback) */

    herr_t      ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* check args */

    assert(f);

    assert(lnk);

    /* Check for adjusting the link count when the link is removed */

    /* Adjust the reference count of the object when a hard link is removed */

    if (lnk->type == H5L_TYPE_HARD) {

        H5O_loc_t oloc;

        /* Construct object location for object, in order to decrement it's ref count */

        H5O_loc_reset(&oloc);

        oloc.file = f;

        assert(H5_addr_defined(lnk->u.hard.addr));

        oloc.addr = lnk->u.hard.addr;

        /* Decrement the ref count for the object */

        if (H5O_link(&oloc, -1) < 0)

            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to decrement object link count");

    } /* end if */

    /* Perform the "delete" callback when a user-defined link is removed */

    else if (lnk->type >= H5L_TYPE_UD_MIN) {

        const H5L_class_t *link_class; /* User-defined link class */

        /* Get the link class for this type of link. */

        if (NULL == (link_class = H5L_find_class(lnk->type)))

            HGOTO_ERROR(H5E_OHDR, H5E_NOTREGISTERED, FAIL, "link class not registered");

        /* Check for delete callback */

        if (link_class->del_func) {

            /* Get a file ID for the file the link is in */

            if ((file_id = H5F_get_id(f)) < 0)

                HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get file ID");

            /* Prepare & restore library for user callback */

            H5_BEFORE_USER_CB(FAIL)

                {

                    /* Call user-defined link's 'delete' callback */

                    ret_value = (link_class->del_func)(lnk->name, file_id, lnk->u.ud.udata, lnk->u.ud.size);

                }

            H5_AFTER_USER_CB(FAIL)

            if (ret_value < 0)

                HGOTO_ERROR(H5E_OHDR, H5E_CALLBACK, FAIL, "link deletion callback returned failure");

        } /* end if */

    }     /* end if */

done:

    /* Release the file ID */

    if (file_id > 0 && H5I_dec_ref(file_id) < 0)

        HDONE_ERROR(H5E_OHDR, H5E_CANTCLOSEFILE, FAIL, "can't close file");

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5O_link_delete() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_pre_copy_file

 *

 * Purpose:     Perform any necessary actions before copying message between

 *              files for link messages.

 *

 * Return:      Success:        Non-negative

 *

 *              Failure:        Negative

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void H5_ATTR_UNUSED *native_src, bool *deleted,

                        const H5O_copy_t *cpy_info, void H5_ATTR_UNUSED *udata)

{

    FUNC_ENTER_PACKAGE_NOERR

    /* check args */

    assert(deleted);

    assert(cpy_info);

    /* If we are performing a 'shallow hierarchy' copy, and this link won't

     *  be included in the final group, indicate that it should be deleted

     *  in the destination object header before performing any other actions

     *  on it.

     */

    if (cpy_info->max_depth >= 0 && cpy_info->curr_depth >= cpy_info->max_depth)

        *deleted = true;

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5O__link_pre_copy_file() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_copy_file

 *

 * Purpose:     Copies a message from _MESG to _DEST in file

 *

 * Return:      Success:        Ptr to _DEST

 *

 *              Failure:        NULL

 *

 *-------------------------------------------------------------------------

 */

static void *

H5O__link_copy_file(H5F_t H5_ATTR_UNUSED *file_src, void *native_src, H5F_t H5_ATTR_UNUSED *file_dst,

                    bool H5_ATTR_UNUSED *recompute_size, unsigned H5_ATTR_UNUSED *mesg_flags,

                    H5O_copy_t H5_ATTR_UNUSED *cpy_info, void H5_ATTR_UNUSED *udata)

{

    H5O_link_t *link_src  = (H5O_link_t *)native_src;

    void       *ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */

    assert(link_src);

    assert(cpy_info);

    assert(cpy_info->max_depth < 0 || cpy_info->curr_depth < cpy_info->max_depth);

    /* Sanity check source link type */

    if (link_src->type > H5L_TYPE_SOFT && link_src->type < H5L_TYPE_UD_MIN)

        HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, NULL, "unrecognized built-in link type");

    /* Allocate "blank" link for destination */

    /* (values will be filled in during 'post copy' operation) */

    if (NULL == (ret_value = H5FL_CALLOC(H5O_link_t)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5O__link_copy_file() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_post_copy_file

 *

 * Purpose:     Finish copying a message from between files

 *

 * Return:      Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src, H5O_loc_t *dst_oloc, void *mesg_dst,

                         unsigned H5_ATTR_UNUSED *mesg_flags, H5O_copy_t *cpy_info)

{

    const H5O_link_t *link_src  = (const H5O_link_t *)mesg_src;

    H5O_link_t       *link_dst  = (H5O_link_t *)mesg_dst;

    herr_t            ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */

    assert(link_src);

    assert(dst_oloc);

    assert(H5_addr_defined(dst_oloc->addr));

    assert(dst_oloc->file);

    assert(link_dst);

    assert(cpy_info);

    assert(cpy_info->max_depth < 0 || cpy_info->curr_depth < cpy_info->max_depth);

    /* Copy the link (and the object it points to) */

    if (H5L__link_copy_file(dst_oloc->file, link_src, src_oloc, link_dst, cpy_info) < 0)

        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, FAIL, "unable to copy link");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5O__link_post_copy_file() */

/*-------------------------------------------------------------------------

 * Function:    H5O__link_debug

 *

 * Purpose:     Prints debugging info for a message.

 *

 * Return:      Non-negative on success/Negative on failure

 *

 *-------------------------------------------------------------------------

 */

static herr_t

H5O__link_debug(H5F_t H5_ATTR_UNUSED *f, const void *_mesg, FILE *stream, int indent, int fwidth)

{

    const H5O_link_t *lnk       = (const H5O_link_t *)_mesg;

    herr_t            ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */

    assert(f);

    assert(lnk);

    assert(stream);

    assert(indent >= 0);

    assert(fwidth >= 0);

    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "Link Type:",

            (lnk->type == H5L_TYPE_HARD

                 ? "Hard"

                 : (lnk->type == H5L_TYPE_SOFT

                        ? "Soft"

                        : (lnk->type == H5L_TYPE_EXTERNAL

                               ? "External"

                               : (lnk->type >= H5L_TYPE_UD_MIN ? "User-defined" : "Unknown")))));

    if (lnk->corder_valid)

        fprintf(stream, "%*s%-*s %" PRId64 "\n", indent, "", fwidth, "Creation Order:", lnk->corder);

    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "Link Name Character Set:",

            (lnk->cset == H5T_CSET_ASCII ? "ASCII" : (lnk->cset == H5T_CSET_UTF8 ? "UTF-8" : "Unknown")));

    fprintf(stream, "%*s%-*s '%s'\n", indent, "", fwidth, "Link Name:", lnk->name);

    /* Display link-specific information */

    switch (lnk->type) {

        case H5L_TYPE_HARD:

            fprintf(stream, "%*s%-*s %" PRIuHADDR "\n", indent, "", fwidth,

                    "Object address:", lnk->u.hard.addr);

            break;

        case H5L_TYPE_SOFT:

            fprintf(stream, "%*s%-*s '%s'\n", indent, "", fwidth, "Link Value:", lnk->u.soft.name);

            break;

        case H5L_TYPE_ERROR:

        case H5L_TYPE_EXTERNAL:

        case H5L_TYPE_MAX:

        default:

            if (lnk->type >= H5L_TYPE_UD_MIN) {

                if (lnk->type == H5L_TYPE_EXTERNAL) {

                    const char *objname =

                        (const char *)lnk->u.ud.udata + (strlen((const char *)lnk->u.ud.udata) + 1);

                    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,

                            "External File Name:", (const char *)lnk->u.ud.udata);

                    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "External Object Name:", objname);

                } /* end if */

                else {

                    fprintf(stream, "%*s%-*s %zu\n", indent, "", fwidth,

                            "User-Defined Link Size:", lnk->u.ud.size);

                } /* end else */

            }     /* end if */

            else

                HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "unrecognized link type");

            break;

    } /* end switch */

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5O__link_debug() */