netcdf-c/libhdf5/hdf5file.c

/* Copyright 2003-2018, University Corporation for Atmospheric
 * Research. See COPYRIGHT file for copying and redistribution
 * conditions. */
/**
 * @file
 * @internal The netCDF-4 file functions.
 *
 * This file is part of netcdf-4, a netCDF-like interface for HDF5, or
 * a HDF5 backend for netCDF, depending on your point of view.
 *
 * @author Ed Hartnett
 */

#include "config.h"
#include "hdf5internal.h"
#include "ncrc.h"

extern int NC4_extract_file_image(NC_FILE_INFO_T* h5); /* In nc4memcb.c */

static void dumpopenobjects(NC_FILE_INFO_T* h5);

/** @internal When we have open objects at file close, should
    we log them or print to stdout. Default is to log. */
#define LOGOPEN 1

/** @internal Number of reserved attributes. These attributes are
 * hidden from the netcdf user, but exist in the HDF5 file to help
 * netcdf read the file. */
#define NRESERVED 11 /*|NC_reservedatt|*/

/** @internal List of reserved attributes. This list must be in sorted
 * order for binary search. */
static const NC_reservedatt NC_reserved[NRESERVED] = {
    {NC_ATT_CLASS, READONLYFLAG|DIMSCALEFLAG},            /*CLASS*/
    {NC_ATT_DIMENSION_LIST, READONLYFLAG|DIMSCALEFLAG},   /*DIMENSION_LIST*/
    {NC_ATT_NAME, READONLYFLAG|DIMSCALEFLAG},             /*NAME*/
    {NC_ATT_REFERENCE_LIST, READONLYFLAG|DIMSCALEFLAG},   /*REFERENCE_LIST*/
    {NC_ATT_FORMAT, READONLYFLAG},                        /*_Format*/
    {ISNETCDF4ATT, READONLYFLAG|NAMEONLYFLAG},            /*_IsNetcdf4*/
    {NCPROPS, READONLYFLAG|NAMEONLYFLAG|MATERIALIZEDFLAG},/*_NCProperties*/
    {NC_ATT_COORDINATES, READONLYFLAG|DIMSCALEFLAG|MATERIALIZEDFLAG},/*_Netcdf4Coordinates*/
    {NC_DIMID_ATT_NAME, READONLYFLAG|DIMSCALEFLAG|MATERIALIZEDFLAG},/*_Netcdf4Dimid*/
    {SUPERBLOCKATT, READONLYFLAG|NAMEONLYFLAG},/*_SuperblockVersion*/
    {NC3_STRICT_ATT_NAME, READONLYFLAG|MATERIALIZEDFLAG},  /*_nc3_strict*/
};

/* Forward */
static int NC4_enddef(int ncid);
static void dumpopenobjects(NC_FILE_INFO_T* h5);

/**
 * @internal Define a binary searcher for reserved attributes
 * @param name for which to search
 * @return pointer to the matchig NC_reservedatt structure.
 * @return NULL if not found.
 * @author Dennis Heimbigner
 */
const NC_reservedatt*
NC_findreserved(const char* name)
{
    int n = NRESERVED;
    int L = 0;
    int R = (n - 1);
    for(;;) {
        if(L > R) break;
        int m = (L + R) / 2;
        const NC_reservedatt* p = &NC_reserved[m];
        int cmp = strcmp(p->name,name);
        if(cmp == 0) return p;
        if(cmp < 0)
            L = (m + 1);
        else /*cmp > 0*/
            R = (m - 1);
    }
    return NULL;
}

/**
 * @internal Recursively determine if there is a mismatch between
 * order of coordinate creation and associated dimensions in this
 * group or any subgroups, to find out if we have to handle that
 * situation.  Also check if there are any multidimensional coordinate
 * variables defined, which require the same treatment to fix a
 * potential bug when such variables occur in subgroups.
 *
 * @param grp Pointer to group info struct.
 * @param bad_coord_orderp Pointer that gets 1 if there is a bad
 * coordinate order.
 *
 * @returns NC_NOERR No error.
 * @returns NC_EHDFERR HDF5 returned an error.
 * @author Ed Hartnett
 */
static int
detect_preserve_dimids(NC_GRP_INFO_T *grp, nc_bool_t *bad_coord_orderp)
{
    NC_VAR_INFO_T *var;
    NC_GRP_INFO_T *child_grp;
    int last_dimid = -1;
    int retval;
    int i;

    /* Iterate over variables in this group */
    for (i=0; i < ncindexsize(grp->vars); i++)
    {
        NC_HDF5_VAR_INFO_T *hdf5_var;
        var = (NC_VAR_INFO_T*)ncindexith(grp->vars,i);
        if (var == NULL) continue;
	hdf5_var = (NC_HDF5_VAR_INFO_T*)var->format_var_info;
        /* Only matters for dimension scale variables, with non-scalar dimensionality */
        if (hdf5_var->dimscale && var->ndims)
        {
            /* If the user writes coord vars in a different order then he
             * defined their dimensions, then, when the file is reopened, the
             * order of the dimids will change to match the order of the coord
             * vars. Detect if this is about to happen. */
            if (var->dimids[0] < last_dimid)
            {
                LOG((5, "%s: %s is out of order coord var", __func__, var->hdr.name));
                *bad_coord_orderp = NC_TRUE;
                return NC_NOERR;
            }
            last_dimid = var->dimids[0];

            /* If there are multidimensional coordinate variables defined, then
             * it's also necessary to preserve dimension IDs when the file is
             * reopened ... */
            if (var->ndims > 1)
            {
                LOG((5, "%s: %s is multidimensional coord var", __func__, var->hdr.name));
                *bad_coord_orderp = NC_TRUE;
                return NC_NOERR;
            }

            /* Did the user define a dimension, end define mode, reenter define
             * mode, and then define a coordinate variable for that dimension?
             * If so, dimensions will be out of order. */
            if (var->is_new_var || var->became_coord_var)
            {
                LOG((5, "%s: coord var defined after enddef/redef", __func__));
                *bad_coord_orderp = NC_TRUE;
                return NC_NOERR;
            }
        }
    }

    /* If there are any child groups, check them also for this condition. */
    for (i = 0; i < ncindexsize(grp->children); i++)
    {
        if (!(child_grp = (NC_GRP_INFO_T *)ncindexith(grp->children, i)))
            continue;
        if ((retval = detect_preserve_dimids(child_grp, bad_coord_orderp)))
            return retval;
    }
    return NC_NOERR;
}

/**
 * @internal This function will write all changed metadata and flush
 * HDF5 file to disk.
 *
 * @param h5 Pointer to HDF5 file info struct.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EINDEFINE Classic model file in define mode.
 * @return ::NC_EHDFERR HDF5 error.
 * @author Ed Hartnett
 */
static int
sync_netcdf4_file(NC_FILE_INFO_T *h5)
{
    NC_HDF5_FILE_INFO_T *hdf5_info;
    int retval;

    assert(h5 && h5->format_file_info);
    LOG((3, "%s", __func__));

    /* If we're in define mode, that's an error, for strict nc3 rules,
     * otherwise, end define mode. */
    if (h5->flags & NC_INDEF)
    {
        if (h5->cmode & NC_CLASSIC_MODEL)
            return NC_EINDEFINE;

        /* Turn define mode off. */
        h5->flags ^= NC_INDEF;

        /* Redef mode needs to be tracked separately for nc_abort. */
        h5->redef = NC_FALSE;
    }

#ifdef LOGGING
    /* This will print out the names, types, lens, etc of the vars and
       atts in the file, if the logging level is 2 or greater. */
    log_metadata_nc(h5);
#endif

    /* Write any metadata that has changed. */
    if (!h5->no_write)
    {
        nc_bool_t bad_coord_order = NC_FALSE;

        /* Write any user-defined types. */
        if ((retval = nc4_rec_write_groups_types(h5->root_grp)))
            return retval;

        /* Check to see if the coordinate order is messed up. If
         * detected, propagate to all groups to consistently store
         * dimids. */
        if ((retval = detect_preserve_dimids(h5->root_grp, &bad_coord_order)))
            return retval;

        /* Write all the metadata. */
        if ((retval = nc4_rec_write_metadata(h5->root_grp, bad_coord_order)))
            return retval;

        /* Write out provenance*/
        if((retval = NC4_write_provenance(h5)))
            return retval;
    }

    /* Tell HDF5 to flush all changes to the file. */
    hdf5_info = (NC_HDF5_FILE_INFO_T *)h5->format_file_info;
    if (H5Fflush(hdf5_info->hdfid, H5F_SCOPE_GLOBAL) < 0)
        return NC_EHDFERR;

    return NC_NOERR;
}

/**
 * @internal This function will free all allocated metadata memory,
 * and close the HDF5 file. The group that is passed in must be the
 * root group of the file. If inmemory is used, then save
 * the final memory in mem.memio.
 *
 * @param h5 Pointer to HDF5 file info struct.
 * @param abort True if this is an abort.
 * @param memio the place to return a core image if not NULL
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EHDFERR HDF5 could not close the file.
 * @return ::NC_EINDEFINE Classic model file is in define mode.
 * @author Ed Hartnett, Dennis Heimbigner
 */
int
nc4_close_netcdf4_file(NC_FILE_INFO_T *h5, int abort, NC_memio *memio)
{
    NC_HDF5_FILE_INFO_T *hdf5_info;
    int retval;

    assert(h5 && h5->root_grp && h5->format_file_info);
    LOG((3, "%s: h5->path %s abort %d", __func__, h5->controller->path, abort));

    /* Get HDF5 specific info. */
    hdf5_info = (NC_HDF5_FILE_INFO_T *)h5->format_file_info;

#ifdef USE_PARALLEL4
    /* Free the MPI Comm & Info objects, if we opened the file in
     * parallel. */
    if (h5->parallel)
    {
        if (h5->comm != MPI_COMM_NULL)
            MPI_Comm_free(&h5->comm);
        if (h5->info != MPI_INFO_NULL)
            MPI_Info_free(&h5->info);
    }
#endif

    /* Free the fileinfo struct, which holds info from the fileinfo
     * hidden attribute. */
    NC4_clear_provenance(&h5->provenance);

    /* Close hdf file. It may not be open, since this function is also
     * called by NC_create() when a file opening is aborted. */
    if (hdf5_info->hdfid > 0 && H5Fclose(hdf5_info->hdfid) < 0)
    {
        dumpopenobjects(h5);
        return NC_EHDFERR;
    }

    /* If inmemory is used and user wants the final memory block,
       then capture and return the final memory block else free it */
    if (h5->mem.inmemory)
    {
        /* Pull out the final memory */
        (void)NC4_extract_file_image(h5);
        if (!abort && memio != NULL)
        {
            *memio = h5->mem.memio; /* capture it */
            h5->mem.memio.memory = NULL; /* avoid duplicate free */
        }
        /* If needed, reclaim extraneous memory */
        if (h5->mem.memio.memory != NULL)
        {
            /* If the original block of memory is not resizeable, then
               it belongs to the caller and we should not free it. */
            if(!h5->mem.locked)
                free(h5->mem.memio.memory);
        }
        h5->mem.memio.memory = NULL;
        h5->mem.memio.size = 0;
        NC4_image_finalize(h5->mem.udata);
    }

    /* Free the HDF5-specific info. */
    if (h5->format_file_info) {
	NC_HDF5_FILE_INFO_T* hdf5_file = (NC_HDF5_FILE_INFO_T*)h5->format_file_info;
	free(hdf5_file);
    }
    
    /* Free the NC_FILE_INFO_T struct. */
    if ((retval = nc4_nc4f_list_del(h5)))
        return retval;

    return NC_NOERR;
}

/**
 * @internal This function will recurse through an open HDF5 file and
 * release resources. All open HDF5 objects in the file will be
 * closed.
 *
 * @param h5 Pointer to HDF5 file info struct.
 * @param abort True if this is an abort.
 * @param memio the place to return a core image if not NULL
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EHDFERR HDF5 could not close the file.
 * @author Ed Hartnett
 */
int
nc4_close_hdf5_file(NC_FILE_INFO_T *h5, int abort,  NC_memio *memio)
{
    int retval;

    assert(h5 && h5->root_grp && h5->format_file_info);
    LOG((3, "%s: h5->path %s abort %d", __func__, h5->controller->path, abort));

    /* According to the docs, always end define mode on close. */
    if (h5->flags & NC_INDEF)
        h5->flags ^= NC_INDEF;

    /* Sync the file, unless we're aborting, or this is a read-only
     * file. */
    if (!h5->no_write && !abort)
        if ((retval = sync_netcdf4_file(h5)))
            return retval;

    /* Close all open HDF5 objects within the file. */
    if ((retval = nc4_rec_grp_HDF5_del(h5->root_grp)))
        return retval;

    /* Release all internal lists and metadata associated with this
     * file. All HDF5 objects have already been released. */
    if ((retval = nc4_close_netcdf4_file(h5, abort, memio)))
        return retval;

    return NC_NOERR;
}

/**
 * @internal Output a list of still-open objects in the HDF5
 * file. This is only called if the file fails to close cleanly.
 *
 * @param h5 Pointer to file info.
 *
 * @author Dennis Heimbigner
 */
static void
dumpopenobjects(NC_FILE_INFO_T* h5)
{
    NC_HDF5_FILE_INFO_T *hdf5_info;
    int nobjs;

    assert(h5 && h5->format_file_info);
    hdf5_info = (NC_HDF5_FILE_INFO_T *)h5->format_file_info;

    if(hdf5_info->hdfid <= 0)
        return; /* File was never opened */

    nobjs = H5Fget_obj_count(hdf5_info->hdfid, H5F_OBJ_ALL);

    /* Apparently we can get an error even when nobjs == 0 */
    if(nobjs < 0) {
        return;
    } else if(nobjs > 0) {
        char msg[1024];
        int logit = 0;
        /* If the close doesn't work, probably there are still some HDF5
         * objects open, which means there's a bug in the library. So
         * print out some info on to help the poor programmer figure it
         * out. */
        snprintf(msg,sizeof(msg),"There are %d HDF5 objects open!", nobjs);
#ifdef LOGGING
#ifdef LOGOPEN
        LOG((0, msg));
        logit = 1;
#endif
#else
        fprintf(stdout,"%s\n",msg);
        logit = 0;
#endif
        reportopenobjects(logit,hdf5_info->hdfid);
        fflush(stderr);
    }

    return;
}

/**
 * @internal Unfortunately HDF only allows specification of fill value
 * only when a dataset is created. Whereas in netcdf, you first create
 * the variable and then (optionally) specify the fill value. To
 * accomplish this in HDF5 I have to delete the dataset, and recreate
 * it, with the fill value specified.
 *
 * @param ncid File and group ID.
 * @param fillmode File mode.
 * @param old_modep Pointer that gets old mode. Ignored if NULL.
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4_set_fill(int ncid, int fillmode, int *old_modep)
{
    NC_FILE_INFO_T *nc4_info;
    int retval;

    LOG((2, "%s: ncid 0x%x fillmode %d", __func__, ncid, fillmode));

    /* Get pointer to file info. */
    if ((retval = nc4_find_grp_h5(ncid, NULL, &nc4_info)))
        return retval;
    assert(nc4_info);

    /* Trying to set fill on a read-only file? You sicken me! */
    if (nc4_info->no_write)
        return NC_EPERM;

    /* Did you pass me some weird fillmode? */
    if (fillmode != NC_FILL && fillmode != NC_NOFILL)
        return NC_EINVAL;

    /* If the user wants to know, tell him what the old mode was. */
    if (old_modep)
        *old_modep = nc4_info->fill_mode;

    nc4_info->fill_mode = fillmode;

    return NC_NOERR;
}

/**
 * @internal Put the file back in redef mode. This is done
 * automatically for netcdf-4 files, if the user forgets.
 *
 * @param ncid File and group ID.
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4_redef(int ncid)
{
    NC_FILE_INFO_T *nc4_info;
    int retval;

    LOG((1, "%s: ncid 0x%x", __func__, ncid));

    /* Find this file's metadata. */
    if ((retval = nc4_find_grp_h5(ncid, NULL, &nc4_info)))
        return retval;
    assert(nc4_info);

    /* If we're already in define mode, return an error. */
    if (nc4_info->flags & NC_INDEF)
        return NC_EINDEFINE;

    /* If the file is read-only, return an error. */
    if (nc4_info->no_write)
        return NC_EPERM;

    /* Set define mode. */
    nc4_info->flags |= NC_INDEF;

    /* For nc_abort, we need to remember if we're in define mode as a
       redef. */
    nc4_info->redef = NC_TRUE;

    return NC_NOERR;
}

/**
 * @internal For netcdf-4 files, this just calls nc_enddef, ignoring
 * the extra parameters.
 *
 * @param ncid File and group ID.
 * @param h_minfree Ignored for netCDF-4 files.
 * @param v_align Ignored for netCDF-4 files.
 * @param v_minfree Ignored for netCDF-4 files.
 * @param r_align Ignored for netCDF-4 files.
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4__enddef(int ncid, size_t h_minfree, size_t v_align,
            size_t v_minfree, size_t r_align)
{
    return NC4_enddef(ncid);
}

/**
 * @internal Take the file out of define mode. This is called
 * automatically for netcdf-4 files, if the user forgets.
 *
 * @param ncid File and group ID.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_EBADGRPID Bad group ID.
 * @author Ed Hartnett
 */
static int
NC4_enddef(int ncid)
{
    NC_FILE_INFO_T *nc4_info;
    NC_GRP_INFO_T *grp;
    NC_VAR_INFO_T *var;
    int i;
    int retval;

    LOG((1, "%s: ncid 0x%x", __func__, ncid));

    /* Find pointer to group and nc4_info. */
    if ((retval = nc4_find_grp_h5(ncid, &grp, &nc4_info)))
        return retval;

    /* When exiting define mode, mark all variable written. */
    for (i = 0; i < ncindexsize(grp->vars); i++)
    {
        var = (NC_VAR_INFO_T *)ncindexith(grp->vars, i);
        assert(var);
        var->written_to = NC_TRUE;
    }

    return nc4_enddef_netcdf4_file(nc4_info);
}

/**
 * @internal Flushes all buffers associated with the file, after
 * writing all changed metadata. This may only be called in data mode.
 *
 * @param ncid File and group ID.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_EINDEFINE Classic model file is in define mode.
 * @author Ed Hartnett
 */
int
NC4_sync(int ncid)
{
    NC_FILE_INFO_T *nc4_info;
    int retval;

    LOG((2, "%s: ncid 0x%x", __func__, ncid));

    if ((retval = nc4_find_grp_h5(ncid, NULL, &nc4_info)))
        return retval;
    assert(nc4_info);

    /* If we're in define mode, we can't sync. */
    if (nc4_info->flags & NC_INDEF)
    {
        if (nc4_info->cmode & NC_CLASSIC_MODEL)
            return NC_EINDEFINE;
        if ((retval = NC4_enddef(ncid)))
            return retval;
    }

    return sync_netcdf4_file(nc4_info);
}

/**
 * @internal From the netcdf-3 docs: The function nc_abort just closes
 * the netCDF dataset, if not in define mode. If the dataset is being
 * created and is still in define mode, the dataset is deleted. If
 * define mode was entered by a call to nc_redef, the netCDF dataset
 * is restored to its state before definition mode was entered and the
 * dataset is closed.
 *
 * @param ncid File and group ID.
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4_abort(int ncid)
{
    NC *nc;
    NC_FILE_INFO_T *nc4_info;
    int delete_file = 0;
    char path[NC_MAX_NAME + 1];
    int retval;

    LOG((2, "%s: ncid 0x%x", __func__, ncid));

    /* Find metadata for this file. */
    if ((retval = nc4_find_nc_grp_h5(ncid, &nc, NULL, &nc4_info)))
        return retval;
    assert(nc4_info);

    /* If we're in define mode, but not redefing the file, delete it. */
    if (nc4_info->flags & NC_INDEF && !nc4_info->redef)
    {
        delete_file++;
        strncpy(path, nc->path, NC_MAX_NAME);
    }

    /* Free any resources the netcdf-4 library has for this file's
     * metadata. */
    if ((retval = nc4_close_hdf5_file(nc4_info, 1, NULL)))
        return retval;

    /* Delete the file, if we should. */
    if (delete_file)
        if (remove(path) < 0)
            return NC_ECANTREMOVE;

    return NC_NOERR;
}

/**
 * @internal Close the netcdf file, writing any changes first.
 *
 * @param ncid File and group ID.
 * @param params any extra parameters in/out of close
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4_close(int ncid, void* params)
{
    NC_GRP_INFO_T *grp;
    NC_FILE_INFO_T *h5;
    int retval;
    int inmemory;
    NC_memio* memio = NULL;

    LOG((1, "%s: ncid 0x%x", __func__, ncid));

    /* Find our metadata for this file. */
    if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
        return retval;

    assert(h5 && grp);

    /* This must be the root group. */
    if (grp->parent)
        return NC_EBADGRPID;

    inmemory = ((h5->cmode & NC_INMEMORY) == NC_INMEMORY);

    if(inmemory && params != NULL) {
        memio = (NC_memio*)params;
    }

    /* Call the nc4 close. */
    if ((retval = nc4_close_hdf5_file(grp->nc4_info, 0, memio)))
        return retval;

    return NC_NOERR;
}

/**
 * @internal Learn number of dimensions, variables, global attributes,
 * and the ID of the first unlimited dimension (if any).
 *
 * @note It's possible for any of these pointers to be NULL, in which
 * case don't try to figure out that value.
 *
 * @param ncid File and group ID.
 * @param ndimsp Pointer that gets number of dimensions.
 * @param nvarsp Pointer that gets number of variables.
 * @param nattsp Pointer that gets number of global attributes.
 * @param unlimdimidp Pointer that gets first unlimited dimension ID,
 * or -1 if there are no unlimied dimensions.
 *
 * @return ::NC_NOERR No error.
 * @author Ed Hartnett
 */
int
NC4_inq(int ncid, int *ndimsp, int *nvarsp, int *nattsp, int *unlimdimidp)
{
    NC *nc;
    NC_FILE_INFO_T *h5;
    NC_GRP_INFO_T *grp;
    int retval;
    int i;

    LOG((2, "%s: ncid 0x%x", __func__, ncid));

    /* Find file metadata. */
    if ((retval = nc4_find_nc_grp_h5(ncid, &nc, &grp, &h5)))
        return retval;

    assert(h5 && grp && nc);

    /* Count the number of dims, vars, and global atts; need to iterate
     * because of possible nulls. */
    if (ndimsp)
    {
        *ndimsp = ncindexcount(grp->dim);
    }
    if (nvarsp)
    {
        *nvarsp = ncindexcount(grp->vars);
    }
    if (nattsp)
    {
        /* Do we need to read the atts? */
        if (!grp->atts_read)
            if ((retval = nc4_read_atts(grp, NULL)))
                return retval;

        *nattsp = ncindexcount(grp->att);
    }

    if (unlimdimidp)
    {
        /* Default, no unlimited dimension */
        *unlimdimidp = -1;

        /* If there's more than one unlimited dim, which was not possible
           with netcdf-3, then only the last unlimited one will be reported
           back in xtendimp. */
        /* Note that this code is inconsistent with nc_inq_unlimid() */
        for(i=0;i<ncindexsize(grp->dim);i++) {
            NC_DIM_INFO_T* d = (NC_DIM_INFO_T*)ncindexith(grp->dim,i);
            if(d == NULL) continue;
            if(d->unlimited) {
                *unlimdimidp = d->hdr.id;
                break;
            }
        }
    }

    return NC_NOERR;
}

/**
 * @internal This function will do the enddef stuff for a netcdf-4 file.
 *
 * @param h5 Pointer to HDF5 file info struct.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_ENOTINDEFINE Not in define mode.
 * @author Ed Hartnett
 */
int
nc4_enddef_netcdf4_file(NC_FILE_INFO_T *h5)
{
    assert(h5);
    LOG((3, "%s", __func__));

    /* If we're not in define mode, return an error. */
    if (!(h5->flags & NC_INDEF))
        return NC_ENOTINDEFINE;

    /* Turn define mode off. */
    h5->flags ^= NC_INDEF;

    /* Redef mode needs to be tracked separately for nc_abort. */
    h5->redef = NC_FALSE;

    return sync_netcdf4_file(h5);
}