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

 * 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:     H5B2cache.c

 *

 * Purpose:     Implement v2 B-tree metadata cache methods

 *

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

 */

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

/* Module Setup */

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

#include "H5B2module.h" /* This source code file is part of the H5B2 module */

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

/* Headers */

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

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

#include "H5ACprivate.h" /* Metadata Cache                           */

#include "H5B2pkg.h"     /* B-Trees (Version 2)                      */

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

#include "H5Fprivate.h"  /* Files                                    */

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

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

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

/* Local Macros */

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

/* B-tree format version #'s */

#define H5B2_HDR_VERSION  0 /* Header */

#define H5B2_INT_VERSION  0 /* Internal node */

#define H5B2_LEAF_VERSION 0 /* Leaf node */

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

/* Local Typedefs */

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

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

/* Package Typedefs */

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

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

/* Local Prototypes */

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

/* Metadata cache callbacks */

static herr_t H5B2__cache_hdr_get_initial_load_size(void *udata, size_t *image_len);

static htri_t H5B2__cache_hdr_verify_chksum(const void *image_ptr, size_t len, void *udata);

static void  *H5B2__cache_hdr_deserialize(const void *image, size_t len, void *udata, bool *dirty);

static herr_t H5B2__cache_hdr_image_len(const void *thing, size_t *image_len);

static herr_t H5B2__cache_hdr_serialize(const H5F_t *f, void *image, size_t len, void *thing);

static herr_t H5B2__cache_hdr_notify(H5AC_notify_action_t action, void *thing);

static herr_t H5B2__cache_hdr_free_icr(void *thing);

static herr_t H5B2__cache_int_get_initial_load_size(void *udata, size_t *image_len);

static htri_t H5B2__cache_int_verify_chksum(const void *image_ptr, size_t len, void *udata);

static void  *H5B2__cache_int_deserialize(const void *image, size_t len, void *udata, bool *dirty);

static herr_t H5B2__cache_int_image_len(const void *thing, size_t *image_len);

static herr_t H5B2__cache_int_serialize(const H5F_t *f, void *image, size_t len, void *thing);

static herr_t H5B2__cache_int_notify(H5AC_notify_action_t action, void *thing);

static herr_t H5B2__cache_int_free_icr(void *thing);

static herr_t H5B2__cache_leaf_get_initial_load_size(void *udata, size_t *image_len);

static htri_t H5B2__cache_leaf_verify_chksum(const void *image_ptr, size_t len, void *udata);

static void  *H5B2__cache_leaf_deserialize(const void *image, size_t len, void *udata, bool *dirty);

static herr_t H5B2__cache_leaf_image_len(const void *thing, size_t *image_len);

static herr_t H5B2__cache_leaf_serialize(const H5F_t *f, void *image, size_t len, void *thing);

static herr_t H5B2__cache_leaf_notify(H5AC_notify_action_t action, void *thing);

static herr_t H5B2__cache_leaf_free_icr(void *thing);

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

/* Package Variables */

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

/* H5B2 inherits cache-like properties from H5AC */

const H5AC_class_t H5AC_BT2_HDR[1] = {{

    H5AC_BT2_HDR_ID,                       /* Metadata client ID */

    "v2 B-tree header",                    /* Metadata client name (for debugging) */

    H5FD_MEM_BTREE,                        /* File space memory type for client */

    H5AC__CLASS_NO_FLAGS_SET,              /* Client class behavior flags */

    H5B2__cache_hdr_get_initial_load_size, /* 'get_initial_load_size' callback */

    NULL,                                  /* 'get_final_load_size' callback */

    H5B2__cache_hdr_verify_chksum,         /* 'verify_chksum' callback */

    H5B2__cache_hdr_deserialize,           /* 'deserialize' callback */

    H5B2__cache_hdr_image_len,             /* 'image_len' callback */

    NULL,                                  /* 'pre_serialize' callback */

    H5B2__cache_hdr_serialize,             /* 'serialize' callback */

    H5B2__cache_hdr_notify,                /* 'notify' callback */

    H5B2__cache_hdr_free_icr,              /* 'free_icr' callback */

    NULL,                                  /* 'fsf_size' callback */

}};

/* H5B2 inherits cache-like properties from H5AC */

const H5AC_class_t H5AC_BT2_INT[1] = {{

    H5AC_BT2_INT_ID,                       /* Metadata client ID */

    "v2 B-tree internal node",             /* Metadata client name (for debugging) */

    H5FD_MEM_BTREE,                        /* File space memory type for client */

    H5AC__CLASS_NO_FLAGS_SET,              /* Client class behavior flags */

    H5B2__cache_int_get_initial_load_size, /* 'get_initial_load_size' callback */

    NULL,                                  /* 'get_final_load_size' callback */

    H5B2__cache_int_verify_chksum,         /* 'verify_chksum' callback */

    H5B2__cache_int_deserialize,           /* 'deserialize' callback */

    H5B2__cache_int_image_len,             /* 'image_len' callback */

    NULL,                                  /* 'pre_serialize' callback */

    H5B2__cache_int_serialize,             /* 'serialize' callback */

    H5B2__cache_int_notify,                /* 'notify' callback */

    H5B2__cache_int_free_icr,              /* 'free_icr' callback */

    NULL,                                  /* 'fsf_size' callback */

}};

/* H5B2 inherits cache-like properties from H5AC */

const H5AC_class_t H5AC_BT2_LEAF[1] = {{

    H5AC_BT2_LEAF_ID,                       /* Metadata client ID */

    "v2 B-tree leaf node",                  /* Metadata client name (for debugging) */

    H5FD_MEM_BTREE,                         /* File space memory type for client */

    H5AC__CLASS_NO_FLAGS_SET,               /* Client class behavior flags */

    H5B2__cache_leaf_get_initial_load_size, /* 'get_initial_load_size' callback */

    NULL,                                   /* 'get_final_load_size' callback */

    H5B2__cache_leaf_verify_chksum,         /* 'verify_chksum' callback */

    H5B2__cache_leaf_deserialize,           /* 'deserialize' callback */

    H5B2__cache_leaf_image_len,             /* 'image_len' callback */

    NULL,                                   /* 'pre_serialize' callback */

    H5B2__cache_leaf_serialize,             /* 'serialize' callback */

    H5B2__cache_leaf_notify,                /* 'notify' callback */

    H5B2__cache_leaf_free_icr,              /* 'free_icr' callback */

    NULL,                                   /* 'fsf_size' callback */

}};

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

/* Library Private Variables */

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

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

/* Local Variables */

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

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

 * Function:    H5B2__cache_hdr_get_initial_load_size

 *

 * Purpose:     Compute the size of the data structure on disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_hdr_get_initial_load_size(void *_udata, size_t *image_len)

{

    H5B2_hdr_cache_ud_t *udata = (H5B2_hdr_cache_ud_t *)_udata; /* User data for callback */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check arguments */

    assert(udata);

    assert(udata->f);

    assert(image_len);

    /* Set the image length size */

    *image_len = H5B2_HEADER_SIZE_FILE(udata->f);

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5B2__cache_hdr_get_initial_load_size() */

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

 * Function:  H5B2__cache_hdr_verify_chksum

 *

 * Purpose:     Verify the computed checksum of the data structure is the

 *              same as the stored chksum.

 *

 * Return:      Success:        true/false

 *              Failure:        Negative

 *

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

 */

static htri_t

H5B2__cache_hdr_verify_chksum(const void *_image, size_t len, void H5_ATTR_UNUSED *_udata)

{

    const uint8_t *image = (const uint8_t *)_image; /* Pointer into raw data buffer */

    uint32_t       stored_chksum;                   /* Stored metadata checksum value */

    uint32_t       computed_chksum;                 /* Computed metadata checksum value */

    htri_t         ret_value = true;                /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(image);

    /* Get stored and computed checksums */

    if (H5F_get_checksums(image, len, &stored_chksum, &computed_chksum) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't get checksums");

    if (stored_chksum != computed_chksum)

        ret_value = false;

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5B2__cache_hdr_verify_chksum() */

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

 * Function:  H5B2__cache_hdr_deserialize

 *

 * Purpose: Loads a B-tree header from the disk.

 *

 * Return:  Success:  Pointer to a new B-tree.

 *    Failure:  NULL

 *

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

 */

static void *

H5B2__cache_hdr_deserialize(const void *_image, size_t H5_ATTR_UNUSED len, void *_udata,

                            bool H5_ATTR_UNUSED *dirty)

{

    H5B2_hdr_t          *hdr   = NULL; /* B-tree header */

    H5B2_hdr_cache_ud_t *udata = (H5B2_hdr_cache_ud_t *)_udata;

    H5B2_create_t        cparam;                              /* B-tree creation parameters */

    H5B2_subid_t         id;                                  /* ID of B-tree class, as found in file */

    uint16_t             depth;                               /* Depth of B-tree */

    uint32_t             stored_chksum;                       /* Stored metadata checksum value */

    const uint8_t       *image     = (const uint8_t *)_image; /* Pointer into raw data buffer */

    H5B2_hdr_t          *ret_value = NULL;                    /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(image);

    assert(udata);

    /* Allocate new B-tree header and reset cache info */

    if (NULL == (hdr = H5B2__hdr_alloc(udata->f)))

        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "allocation failed for B-tree header");

    /* Magic number */

    if (memcmp(image, H5B2_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC) != 0)

        HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, NULL, "wrong B-tree header signature");

    image += H5_SIZEOF_MAGIC;

    /* Version */

    if (*image++ != H5B2_HDR_VERSION)

        HGOTO_ERROR(H5E_BTREE, H5E_BADRANGE, NULL, "wrong B-tree header version");

    /* B-tree class */

    id = (H5B2_subid_t)*image++;

    if (id >= H5B2_NUM_BTREE_ID)

        HGOTO_ERROR(H5E_BTREE, H5E_BADTYPE, NULL, "incorrect B-tree type");

    /* Node size (in bytes) */

    UINT32DECODE(image, cparam.node_size);

    /* Raw key size (in bytes) */

    UINT16DECODE(image, cparam.rrec_size);

    /* Depth of tree */

    UINT16DECODE(image, depth);

    /* Split & merge %s */

    cparam.split_percent = *image++;

    cparam.merge_percent = *image++;

    /* Root node pointer */

    H5F_addr_decode(udata->f, (const uint8_t **)&image, &(hdr->root.addr));

    UINT16DECODE(image, hdr->root.node_nrec);

    H5F_DECODE_LENGTH(udata->f, image, hdr->root.all_nrec);

    /* checksum verification already done in verify_chksum cb */

    /* Metadata checksum */

    UINT32DECODE(image, stored_chksum);

    /* Sanity check */

    assert((size_t)(image - (const uint8_t *)_image) == hdr->hdr_size);

    /* Initialize B-tree header info */

    cparam.cls = H5B2_client_class_g[id];

    if (H5B2__hdr_init(hdr, &cparam, udata->ctx_udata, depth) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, NULL, "can't initialize B-tree header info");

    /* Set the B-tree header's address */

    hdr->addr = udata->addr;

    /* Sanity check */

    assert((size_t)(image - (const uint8_t *)_image) <= len);

    /* Set return value */

    ret_value = hdr;

done:

    if (!ret_value && hdr)

        if (H5B2__hdr_free(hdr) < 0)

            HDONE_ERROR(H5E_BTREE, H5E_CANTRELEASE, NULL, "can't release v2 B-tree header");

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5B2__cache_hdr_deserialize() */

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

 * Function:    H5B2__cache_hdr_image_len

 *

 * Purpose:     Compute the size of the data structure on disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_hdr_image_len(const void *_thing, size_t *image_len)

{

    const H5B2_hdr_t *hdr = (const H5B2_hdr_t *)_thing; /* Pointer to the B-tree header */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check arguments */

    assert(hdr);

    assert(image_len);

    /* Set the image length size */

    *image_len = hdr->hdr_size;

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5B2__cache_hdr_image_len() */

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

 * Function:  H5B2__cache_hdr_serialize

 *

 * Purpose: Flushes a dirty B-tree header to disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_hdr_serialize(const H5F_t *f, void *_image, size_t H5_ATTR_UNUSED len, void *_thing)

{

    H5B2_hdr_t *hdr   = (H5B2_hdr_t *)_thing; /* Pointer to the B-tree header */

    uint8_t    *image = (uint8_t *)_image;    /* Pointer into raw data buffer */

    uint32_t    metadata_chksum;              /* Computed metadata checksum value */

    FUNC_ENTER_PACKAGE_NOERR

    /* check arguments */

    assert(f);

    assert(image);

    assert(hdr);

    /* Magic number */

    H5MM_memcpy(image, H5B2_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC);

    image += H5_SIZEOF_MAGIC;

    /* Version # */

    *image++ = H5B2_HDR_VERSION;

    /* B-tree type */

    assert(hdr->cls->id <= 255);

    *image++ = (uint8_t)hdr->cls->id;

    /* Node size (in bytes) */

    UINT32ENCODE(image, hdr->node_size);

    /* Raw key size (in bytes) */

    UINT16ENCODE(image, hdr->rrec_size);

    /* Depth of tree */

    UINT16ENCODE(image, hdr->depth);

    /* Split & merge %s */

    H5_CHECK_OVERFLOW(hdr->split_percent, /* From: */ unsigned, /* To: */ uint8_t);

    *image++ = (uint8_t)hdr->split_percent;

    H5_CHECK_OVERFLOW(hdr->merge_percent, /* From: */ unsigned, /* To: */ uint8_t);

    *image++ = (uint8_t)hdr->merge_percent;

    /* Root node pointer */

    H5F_addr_encode(f, &image, hdr->root.addr);

    UINT16ENCODE(image, hdr->root.node_nrec);

    H5F_ENCODE_LENGTH(f, image, hdr->root.all_nrec);

    /* Compute metadata checksum */

    metadata_chksum = H5_checksum_metadata(_image, (hdr->hdr_size - H5B2_SIZEOF_CHKSUM), 0);

    /* Metadata checksum */

    UINT32ENCODE(image, metadata_chksum);

    /* Sanity check */

    assert((size_t)(image - (uint8_t *)_image) == len);

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* H5B2__cache_hdr_serialize() */

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

 * Function:    H5B2__cache_hdr_notify

 *

 * Purpose:     Handle cache action notifications

 *

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

 *

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

 */

static herr_t

H5B2__cache_hdr_notify(H5AC_notify_action_t action, void *_thing)

{

    H5B2_hdr_t *hdr       = (H5B2_hdr_t *)_thing;

    herr_t      ret_value = SUCCEED;

    FUNC_ENTER_PACKAGE

    /*

     * Check arguments.

     */

    assert(hdr);

    /* Check if the file was opened with SWMR-write access */

    if (hdr->swmr_write) {

        switch (action) {

            case H5AC_NOTIFY_ACTION_AFTER_INSERT:

            case H5AC_NOTIFY_ACTION_AFTER_LOAD:

                /* do nothing */

                break;

            case H5AC_NOTIFY_ACTION_AFTER_FLUSH:

                /* Increment the shadow epoch, forcing new modifications to

                 * internal and leaf nodes to create new shadow copies */

                hdr->shadow_epoch++;

                break;

            case H5AC_NOTIFY_ACTION_ENTRY_DIRTIED:

            case H5AC_NOTIFY_ACTION_ENTRY_CLEANED:

            case H5AC_NOTIFY_ACTION_CHILD_DIRTIED:

            case H5AC_NOTIFY_ACTION_CHILD_CLEANED:

            case H5AC_NOTIFY_ACTION_CHILD_UNSERIALIZED:

            case H5AC_NOTIFY_ACTION_CHILD_SERIALIZED:

                /* do nothing */

                break;

            case H5AC_NOTIFY_ACTION_BEFORE_EVICT:

                /* If hdr->parent != NULL, hdr->parent is used to destroy

                 * the flush dependency before the header is evicted.

                 */

                if (hdr->parent) {

                    /* Sanity check */

                    assert(hdr->top_proxy);

                    /* Destroy flush dependency on object header proxy */

                    if (H5AC_proxy_entry_remove_child((H5AC_proxy_entry_t *)hdr->parent,

                                                      (void *)hdr->top_proxy) < 0)

                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL,

                                    "unable to destroy flush dependency between v2 B-tree and proxy");

                    hdr->parent = NULL;

                } /* end if */

                /* Detach from 'top' proxy for extensible array */

                if (hdr->top_proxy) {

                    if (H5AC_proxy_entry_remove_child(hdr->top_proxy, hdr) < 0)

                        HGOTO_ERROR(

                            H5E_BTREE, H5E_CANTUNDEPEND, FAIL,

                            "unable to destroy flush dependency between header and v2 B-tree 'top' proxy");

                    /* Don't reset hdr->top_proxy here, it's destroyed when the header is freed -QAK */

                } /* end if */

                break;

            default:

#ifdef NDEBUG

                HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "unknown action from metadata cache");

#else     /* NDEBUG */

                assert(0 && "Unknown action?!?");

#endif    /* NDEBUG */

        } /* end switch */

    }     /* end if */

    else

        assert(NULL == hdr->parent);

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5B2__cache_hdr_notify() */

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

 * Function:  H5B2__cache_hdr_free_icr

 *

 * Purpose: Destroy/release an "in core representation" of a data

 *              structure

 *

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

 *

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

 */

static herr_t

H5B2__cache_hdr_free_icr(void *thing)

{

    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(thing);

    /* Destroy v2 B-tree header */

    if (H5B2__hdr_free((H5B2_hdr_t *)thing) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL, "unable to free v2 B-tree header");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5B2__cache_hdr_free_icr() */

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

 * Function:    H5B2__cache_int_get_initial_load_size

 *

 * Purpose:     Compute the size of the data structure on disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_int_get_initial_load_size(void *_udata, size_t *image_len)

{

    H5B2_internal_cache_ud_t *udata = (H5B2_internal_cache_ud_t *)_udata; /* User data for callback */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check arguments */

    assert(udata);

    assert(udata->hdr);

    assert(image_len);

    /* Set the image length size */

    *image_len = udata->hdr->node_size;

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5B2__cache_int_get_initial_load_size() */

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

 * Function:  H5B2__cache_int_verify_chksum

 *

 * Purpose:     Verify the computed checksum of the data structure is the

 *              same as the stored chksum.

 *

 * Return:      Success:        true/false

 *              Failure:        Negative

 *

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

 */

static htri_t

H5B2__cache_int_verify_chksum(const void *_image, size_t H5_ATTR_UNUSED len, void *_udata)

{

    const uint8_t            *image = (const uint8_t *)_image;            /* Pointer into raw data buffer */

    H5B2_internal_cache_ud_t *udata = (H5B2_internal_cache_ud_t *)_udata; /* Pointer to user data */

    size_t                    chk_size;         /* Exact size of the node with checksum at the end */

    uint32_t                  stored_chksum;    /* Stored metadata checksum value */

    uint32_t                  computed_chksum;  /* Computed metadata checksum value */

    htri_t                    ret_value = true; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(image);

    assert(udata);

    /* Internal node prefix header + records + child pointer triplets: size with checksum at the end */

    chk_size = H5B2_INT_PREFIX_SIZE + (udata->nrec * udata->hdr->rrec_size) +

               ((size_t)(udata->nrec + 1) * H5B2_INT_POINTER_SIZE(udata->hdr, udata->depth));

    /* Get stored and computed checksums */

    if (H5F_get_checksums(image, chk_size, &stored_chksum, &computed_chksum) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't get checksums");

    if (stored_chksum != computed_chksum)

        ret_value = false;

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5B2__cache_int_verify_chksum() */

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

 * Function:  H5B2__cache_int_deserialize

 *

 * Purpose: Deserialize a B-tree internal node from the disk.

 *

 * Return:  Success:  Pointer to a new B-tree internal node.

 *              Failure:        NULL

 *

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

 */

static void *

H5B2__cache_int_deserialize(const void *_image, size_t H5_ATTR_UNUSED len, void *_udata,

                            bool H5_ATTR_UNUSED *dirty)

{

    H5B2_internal_cache_ud_t *udata    = (H5B2_internal_cache_ud_t *)_udata; /* Pointer to user data */

    H5B2_internal_t          *internal = NULL;                               /* Internal node read */

    const uint8_t            *image    = (const uint8_t *)_image; /* Pointer into raw data buffer */

    uint8_t                  *native;                             /* Pointer to native record info */

    H5B2_node_ptr_t          *int_node_ptr;                       /* Pointer to node pointer info */

    uint32_t                  stored_chksum;                      /* Stored metadata checksum value */

    unsigned                  u;                                  /* Local index variable */

    H5B2_internal_t          *ret_value = NULL;                   /* Return value */

    int                       node_nrec = 0;

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(image);

    assert(udata);

    /* Allocate new internal node and reset cache info */

    if (NULL == (internal = H5FL_CALLOC(H5B2_internal_t)))

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

    /* Increment ref. count on B-tree header */

    if (H5B2__hdr_incr(udata->hdr) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTINC, NULL, "can't increment ref. count on B-tree header");

    /* Share B-tree information */

    internal->hdr          = udata->hdr;

    internal->parent       = udata->parent;

    internal->shadow_epoch = udata->hdr->shadow_epoch;

    /* Magic number */

    if (memcmp(image, H5B2_INT_MAGIC, (size_t)H5_SIZEOF_MAGIC) != 0)

        HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, NULL, "wrong B-tree internal node signature");

    image += H5_SIZEOF_MAGIC;

    /* Version */

    if (*image++ != H5B2_INT_VERSION)

        HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, NULL, "wrong B-tree internal node version");

    /* B-tree type */

    if (*image++ != (uint8_t)udata->hdr->cls->id)

        HGOTO_ERROR(H5E_BTREE, H5E_BADTYPE, NULL, "incorrect B-tree type");

    /* Allocate space for the native keys in memory */

    if (NULL ==

        (internal->int_native = (uint8_t *)H5FL_FAC_MALLOC(udata->hdr->node_info[udata->depth].nat_rec_fac)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,

                    "memory allocation failed for B-tree internal native keys");

    /* Allocate space for the node pointers in memory */

    if (NULL == (internal->node_ptrs =

                     (H5B2_node_ptr_t *)H5FL_FAC_MALLOC(udata->hdr->node_info[udata->depth].node_ptr_fac)))

        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,

                    "memory allocation failed for B-tree internal node pointers");

    /* Set the number of records in the leaf & it's depth */

    internal->nrec  = udata->nrec;

    internal->depth = udata->depth;

    /* Deserialize records for internal node */

    native = internal->int_native;

    for (u = 0; u < internal->nrec; u++) {

        /* Decode record */

        if ((udata->hdr->cls->decode)(image, native, udata->hdr->cb_ctx) < 0)

            HGOTO_ERROR(H5E_BTREE, H5E_CANTDECODE, NULL, "unable to decode B-tree record");

        /* Move to next record */

        image += udata->hdr->rrec_size;

        native += udata->hdr->cls->nrec_size;

    } /* end for */

    /* Deserialize node pointers for internal node */

    int_node_ptr = internal->node_ptrs;

    for (u = 0; u < (unsigned)(internal->nrec + 1); u++) {

        /* Decode node pointer */

        H5F_addr_decode(udata->f, (const uint8_t **)&image, &(int_node_ptr->addr));

        UINT64DECODE_VAR(image, node_nrec, udata->hdr->max_nrec_size);

        H5_CHECKED_ASSIGN(int_node_ptr->node_nrec, uint16_t, node_nrec, int);

        if (udata->depth > 1)

            UINT64DECODE_VAR(image, int_node_ptr->all_nrec,

                             udata->hdr->node_info[udata->depth - 1].cum_max_nrec_size);

        else

            int_node_ptr->all_nrec = int_node_ptr->node_nrec;

        /* Move to next node pointer */

        int_node_ptr++;

    } /* end for */

    /* checksum verification already done in verify_chksum cb */

    /* Metadata checksum */

    UINT32DECODE(image, stored_chksum);

    /* Sanity check parsing */

    assert((size_t)(image - (const uint8_t *)_image) <= len);

    /* Set return value */

    ret_value = internal;

done:

    if (!ret_value && internal)

        if (H5B2__internal_free(internal) < 0)

            HDONE_ERROR(H5E_BTREE, H5E_CANTFREE, NULL, "unable to destroy B-tree internal node");

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5B2__cache_int_deserialize() */

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

 * Function:    H5B2__cache_int_image_len

 *

 * Purpose:     Compute the size of the data structure on disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_int_image_len(const void *_thing, size_t *image_len)

{

    const H5B2_internal_t *internal =

        (const H5B2_internal_t *)_thing; /* Pointer to the B-tree internal node */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check arguments */

    assert(internal);

    assert(internal->hdr);

    assert(image_len);

    /* Set the image length size */

    *image_len = internal->hdr->node_size;

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5B2__cache_int_image_len() */

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

 * Function:  H5B2__cache_int_serialize

 *

 * Purpose: Serializes a B-tree internal node for writing to disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_int_serialize(const H5F_t *f, void *_image, size_t H5_ATTR_UNUSED len, void *_thing)

{

    H5B2_internal_t *internal = (H5B2_internal_t *)_thing; /* Pointer to the B-tree internal node */

    uint8_t         *image    = (uint8_t *)_image;         /* Pointer into raw data buffer */

    uint8_t         *native;                               /* Pointer to native record info */

    H5B2_node_ptr_t *int_node_ptr;                         /* Pointer to node pointer info */

    uint32_t         metadata_chksum;                      /* Computed metadata checksum value */

    unsigned         u;                                    /* Local index variable */

    herr_t           ret_value = SUCCEED;                  /* Return value */

    FUNC_ENTER_PACKAGE

    /* check arguments */

    assert(f);

    assert(image);

    assert(internal);

    assert(internal->hdr);

    /* Magic number */

    H5MM_memcpy(image, H5B2_INT_MAGIC, (size_t)H5_SIZEOF_MAGIC);

    image += H5_SIZEOF_MAGIC;

    /* Version # */

    *image++ = H5B2_INT_VERSION;

    /* B-tree type */

    assert(internal->hdr->cls->id <= 255);

    *image++ = (uint8_t)internal->hdr->cls->id;

    assert((size_t)(image - (uint8_t *)_image) == (H5B2_INT_PREFIX_SIZE - H5B2_SIZEOF_CHKSUM));

    /* Serialize records for internal node */

    native = internal->int_native;

    for (u = 0; u < internal->nrec; u++) {

        /* Encode record */

        if ((internal->hdr->cls->encode)(image, native, internal->hdr->cb_ctx) < 0)

            HGOTO_ERROR(H5E_BTREE, H5E_CANTENCODE, FAIL, "unable to encode B-tree record");

        /* Move to next record */

        image += internal->hdr->rrec_size;

        native += internal->hdr->cls->nrec_size;

    } /* end for */

    /* Serialize node pointers for internal node */

    int_node_ptr = internal->node_ptrs;

    for (u = 0; u < (unsigned)(internal->nrec + 1); u++) {

        /* Encode node pointer */

        H5F_addr_encode(f, &image, int_node_ptr->addr);

        UINT64ENCODE_VAR(image, int_node_ptr->node_nrec, internal->hdr->max_nrec_size);

        if (internal->depth > 1)

            UINT64ENCODE_VAR(image, int_node_ptr->all_nrec,

                             internal->hdr->node_info[internal->depth - 1].cum_max_nrec_size);

        /* Move to next node pointer */

        int_node_ptr++;

    } /* end for */

    /* Compute metadata checksum */

    metadata_chksum = H5_checksum_metadata(_image, (size_t)(image - (uint8_t *)_image), 0);

    /* Metadata checksum */

    UINT32ENCODE(image, metadata_chksum);

    /* Sanity check */

    assert((size_t)(image - (uint8_t *)_image) <= len);

    /* Clear rest of internal node */

    memset(image, 0, len - (size_t)(image - (uint8_t *)_image));

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5B2__cache_int_serialize() */

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

 * Function:    H5B2__cache_int_notify

 *

 * Purpose:     Handle cache action notifications

 *

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

 *

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

 */

static herr_t

H5B2__cache_int_notify(H5AC_notify_action_t action, void *_thing)

{

    H5B2_internal_t *internal  = (H5B2_internal_t *)_thing;

    herr_t           ret_value = SUCCEED;

    FUNC_ENTER_PACKAGE

    /*

     * Check arguments.

     */

    assert(internal);

    assert(internal->hdr);

    /* Check if the file was opened with SWMR-write access */

    if (internal->hdr->swmr_write) {

        switch (action) {

            case H5AC_NOTIFY_ACTION_AFTER_INSERT:

            case H5AC_NOTIFY_ACTION_AFTER_LOAD:

                /* Create flush dependency on parent */

                if (H5B2__create_flush_depend((H5AC_info_t *)internal->parent, (H5AC_info_t *)internal) < 0)

                    HGOTO_ERROR(H5E_BTREE, H5E_CANTDEPEND, FAIL, "unable to create flush dependency");

                break;

            case H5AC_NOTIFY_ACTION_AFTER_FLUSH:

            case H5AC_NOTIFY_ACTION_ENTRY_DIRTIED:

            case H5AC_NOTIFY_ACTION_ENTRY_CLEANED:

            case H5AC_NOTIFY_ACTION_CHILD_DIRTIED:

            case H5AC_NOTIFY_ACTION_CHILD_CLEANED:

            case H5AC_NOTIFY_ACTION_CHILD_UNSERIALIZED:

            case H5AC_NOTIFY_ACTION_CHILD_SERIALIZED:

                /* do nothing */

                break;

            case H5AC_NOTIFY_ACTION_BEFORE_EVICT:

                /* Destroy flush dependency on parent */

                if (H5B2__destroy_flush_depend((H5AC_info_t *)internal->parent, (H5AC_info_t *)internal) < 0)

                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL, "unable to destroy flush dependency");

                /* Detach from 'top' proxy for v2 B-tree */

                if (internal->top_proxy) {

                    if (H5AC_proxy_entry_remove_child(internal->top_proxy, internal) < 0)

                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNDEPEND, FAIL,

                                    "unable to destroy flush dependency between internal node and v2 B-tree "

                                    "'top' proxy");

                    internal->top_proxy = NULL;

                } /* end if */

                break;

            default:

#ifdef NDEBUG

                HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "unknown action from metadata cache");

#else     /* NDEBUG */

                assert(0 && "Unknown action?!?");

#endif    /* NDEBUG */

        } /* end switch */

    }     /* end if */

    else

        assert(NULL == internal->top_proxy);

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5B2__cache_int_notify() */

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

 * Function:  H5B2__cache_int_free_icr

 *

 * Purpose: Destroy/release an "in core representation" of a data

 *              structure

 *

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

 *

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

 */

static herr_t

H5B2__cache_int_free_icr(void *_thing)

{

    H5B2_internal_t *internal  = (H5B2_internal_t *)_thing;

    herr_t           ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */

    assert(internal);

    /* Release v2 B-tree internal node */

    if (H5B2__internal_free(internal) < 0)

        HGOTO_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL, "unable to release v2 B-tree internal node");

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* H5B2__cache_int_free_icr() */

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

 * Function:    H5B2__cache_leaf_get_initial_load_size

 *

 * Purpose:     Compute the size of the data structure on disk.

 *

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

 *

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

 */

static herr_t

H5B2__cache_leaf_get_initial_load_size(void *_udata, size_t *image_len)

{

    H5B2_leaf_cache_ud_t *udata = (H5B2_leaf_cache_ud_t *)_udata; /* User data for callback */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check arguments */

    assert(udata);

    assert(udata->hdr);

    assert(image_len);

    /* Set the image length size */

    *image_len = udata->hdr->node_size;

    FUNC_LEAVE_NOAPI(SUCCEED)

} /* end H5B2__cache_leaf_get_initial_load_size() */

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

 * Function:  H5B2__cache_leaf_verify_chksum

 *

 * Purpose:     Verify the computed checksum of the data structure is the

 *              same as the stored chksum.

 *

 * Return:      Success:        true/false

 *              Failure:        Negative

 *

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

 */

static htri_t

H5B2__cache_leaf_verify_chksum(const void *_image, size_t H5_ATTR_UNUSED len, void *_udata)

{

    const uint8_t            *image = (const uint8_t *)_image;            /* Pointer into raw data buffer */

    H5B2_internal_cache_ud_t *udata = (H5B2_internal_cache_ud_t *)_udata; /* Pointer to user data */