netcdf-c/libsrc/nc.c

/*
 *	Copyright 1996, University Corporation for Atmospheric Research
 *      See netcdf/COPYRIGHT file for copying and redistribution conditions.
 */

#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#if defined(LOCKNUMREC) /* && _CRAYMPP */
#  include <mpp/shmem.h>
#  include <intrinsics.h>
#endif
#ifdef HAVE_UNISTD
#include <unistd.h>
#endif

#include "nc.h"
#include "dispatch.h"
#include "rnd.h"
#include "ncx.h"

/* This is the default create format for nc_create and nc__create. */
int default_create_format = NC_FORMAT_CLASSIC;

/* These have to do with version numbers. */
#define MAGIC_NUM_LEN 4
#define VER_CLASSIC 1
#define VER_64BIT_OFFSET 2
#define VER_HDF5 3

int
NC_check_id(int ncid, NC **ncpp)
{
    NC* nc = find_in_NCList(ncid);
    if(nc == NULL) return NC_EBADID;
    if(ncpp) *ncpp = nc;
    return NC_NOERR;
}

void
free_NC(NC *ncp)
{
	if(ncp == NULL)
		return;
	free_NC_dimarrayV(&ncp->dims);
	free_NC_attrarrayV(&ncp->attrs);
	free_NC_vararrayV(&ncp->vars);
#if _CRAYMPP && defined(LOCKNUMREC)
	shfree(ncp);
#else
	free(ncp);
#endif /* _CRAYMPP && LOCKNUMREC */
}

NC *
new_NC(const size_t *chunkp)
{
	NC *ncp;

#if _CRAYMPP && defined(LOCKNUMREC)
	ncp = (NC *) shmalloc(sizeof(NC));
#else
	ncp = (NC *) malloc(sizeof(NC));
#endif /* _CRAYMPP && LOCKNUMREC */
	if(ncp == NULL)
		return NULL;
	(void) memset(ncp, 0, sizeof(NC));

	ncp->xsz = MIN_NC_XSZ;
	assert(ncp->xsz == ncx_len_NC(ncp,0));
	
	ncp->chunk = chunkp != NULL ? *chunkp : NC_SIZEHINT_DEFAULT;

	return ncp;
}

static NC *
dup_NC(const NC *ref)
{
	NC *ncp;

#if _CRAYMPP && defined(LOCKNUMREC)
	ncp = (NC *) shmalloc(sizeof(NC));
#else
	ncp = (NC *) malloc(sizeof(NC));
#endif /* _CRAYMPP && LOCKNUMREC */
	if(ncp == NULL)
		return NULL;
	(void) memset(ncp, 0, sizeof(NC));

	if(dup_NC_dimarrayV(&ncp->dims, &ref->dims) != NC_NOERR)
		goto err;
	if(dup_NC_attrarrayV(&ncp->attrs, &ref->attrs) != NC_NOERR)
		goto err;
	if(dup_NC_vararrayV(&ncp->vars, &ref->vars) != NC_NOERR)
		goto err;

	ncp->xsz = ref->xsz;
	ncp->begin_var = ref->begin_var;
	ncp->begin_rec = ref->begin_rec;
	ncp->recsize = ref->recsize;
	NC_set_numrecs(ncp, NC_get_numrecs(ref));
	return ncp;
err:
	free_NC(ncp);
	return NULL;
}


/*
 *  Verify that this is a user nc_type
 * Formerly
NCcktype()
 * Sense of the return is changed.
 */
int
nc_cktype(nc_type type)
{
	switch((int)type){
	case NC_BYTE:
	case NC_CHAR:
	case NC_SHORT:
	case NC_INT:
	case NC_FLOAT:
	case NC_DOUBLE:
		return(NC_NOERR);
	}
	return(NC_EBADTYPE);
}


/*
 * How many objects of 'type'
 * will fit into xbufsize?
 */
size_t
ncx_howmany(nc_type type, size_t xbufsize)
{
	switch(type){
	case NC_BYTE:
	case NC_CHAR:
		return xbufsize;
	case NC_SHORT:
		return xbufsize/X_SIZEOF_SHORT;
	case NC_INT:
		return xbufsize/X_SIZEOF_INT;
	case NC_FLOAT:
		return xbufsize/X_SIZEOF_FLOAT;
	case NC_DOUBLE:
		return xbufsize/X_SIZEOF_DOUBLE;
	default:
	        assert("ncx_howmany: Bad type" == 0);
		return(0);
	}
}

#define	D_RNDUP(x, align) _RNDUP(x, (off_t)(align))

/*
 * Compute each variable's 'begin' offset,
 * update 'begin_rec' as well.
 */
static int
NC_begins(NC *ncp,
	size_t h_minfree, size_t v_align,
	size_t v_minfree, size_t r_align)
{
	size_t ii;
	int sizeof_off_t;
	off_t index = 0;
	NC_var **vpp;
	NC_var *last = NULL;

	if(v_align == NC_ALIGN_CHUNK)
		v_align = ncp->chunk;
	if(r_align == NC_ALIGN_CHUNK)
		r_align = ncp->chunk;

	if (fIsSet(ncp->flags, NC_64BIT_OFFSET)) {
	  sizeof_off_t = 8;
	} else {
	  sizeof_off_t = 4;
	}
	
	ncp->xsz = ncx_len_NC(ncp,sizeof_off_t);

	if(ncp->vars.nelems == 0) 
		return NC_NOERR;

	/* only (re)calculate begin_var if there is not sufficient space in header
	   or start of non-record variables is not aligned as requested by valign */
	if (ncp->begin_var < ncp->xsz + h_minfree ||
	    ncp->begin_var != D_RNDUP(ncp->begin_var, v_align) ) 
	{
	  index = (off_t) ncp->xsz;
	  ncp->begin_var = D_RNDUP(index, v_align);
	  if(ncp->begin_var < index + h_minfree)
	  {
	    ncp->begin_var = D_RNDUP(index + (off_t)h_minfree, v_align);
	  }
	}
	index = ncp->begin_var;

	/* loop thru vars, first pass is for the 'non-record' vars */
	vpp = ncp->vars.value;
	for(ii = 0; ii < ncp->vars.nelems ; ii++, vpp++)
	{
		if( IS_RECVAR(*vpp) )
		{
			/* skip record variables on this pass */
			continue;
		}
#if 0
fprintf(stderr, "    VAR %d %s: %ld\n", ii, (*vpp)->name->cp, (long)index);
#endif
                if( sizeof_off_t == 4 && (index > X_OFF_MAX || index < 0) ) 
		{
		    return NC_EVARSIZE;
                }
		(*vpp)->begin = index;
		index += (*vpp)->len;
	}

	/* only (re)calculate begin_rec if there is not sufficient
	   space at end of non-record variables or if start of record
	   variables is not aligned as requested by r_align */
	if (ncp->begin_rec < index + v_minfree ||
	    ncp->begin_rec != D_RNDUP(ncp->begin_rec, r_align) )
	{
	  ncp->begin_rec = D_RNDUP(index, r_align);
	  if(ncp->begin_rec < index + v_minfree)
	  {
	    ncp->begin_rec = D_RNDUP(index + (off_t)v_minfree, r_align);
	  }
	}
	index = ncp->begin_rec;

	ncp->recsize = 0;

	/* loop thru vars, second pass is for the 'record' vars */
	vpp = (NC_var **)ncp->vars.value;
	for(ii = 0; ii < ncp->vars.nelems; ii++, vpp++)
	{
		if( !IS_RECVAR(*vpp) )
		{
			/* skip non-record variables on this pass */
			continue;
		}

#if 0
fprintf(stderr, "    REC %d %s: %ld\n", ii, (*vpp)->name->cp, (long)index);
#endif
                if( sizeof_off_t == 4 && (index > X_OFF_MAX || index < 0) ) 
		{
		    return NC_EVARSIZE;
                }
		(*vpp)->begin = index;
		index += (*vpp)->len;
		/* check if record size must fit in 32-bits */
#if SIZEOF_OFF_T == SIZEOF_SIZE_T && SIZEOF_SIZE_T == 4
		if( ncp->recsize > X_UINT_MAX - (*vpp)->len )
		{
		    return NC_EVARSIZE;
		}
#endif
		ncp->recsize += (*vpp)->len;
		last = (*vpp);
	}

	/*
	 * for special case of exactly one record variable, pack value
	 */
	if(last != NULL && ncp->recsize == last->len)
		ncp->recsize = *last->dsizes * last->xsz;

	if(NC_IsNew(ncp))
		NC_set_numrecs(ncp, 0);
	return NC_NOERR;
}


/*
 * Read just the numrecs member.
 * (A relatively expensive way to do things.)
 */
int
read_numrecs(NC *ncp)
{
	int status = NC_NOERR;
	const void *xp = NULL;
	size_t nrecs = NC_get_numrecs(ncp);

	assert(!NC_indef(ncp));

#define NC_NUMRECS_OFFSET 4
#define NC_NUMRECS_EXTENT 4
	status = ncp->nciop->get(ncp->nciop,
		 NC_NUMRECS_OFFSET, NC_NUMRECS_EXTENT, 0, (void **)&xp);
					/* cast away const */
	if(status != NC_NOERR)
		return status;

	status = ncx_get_size_t(&xp, &nrecs);

	(void) ncp->nciop->rel(ncp->nciop, NC_NUMRECS_OFFSET, 0);

	if(status == NC_NOERR)
	{
		NC_set_numrecs(ncp, nrecs);
		fClr(ncp->flags, NC_NDIRTY);
	}

	return status;
}


/*
 * Write out just the numrecs member.
 * (A relatively expensive way to do things.)
 */
int
write_numrecs(NC *ncp)
{
	int status = NC_NOERR;
	void *xp = NULL;

	assert(!NC_readonly(ncp));
	assert(!NC_indef(ncp));

	status = ncp->nciop->get(ncp->nciop,
		 NC_NUMRECS_OFFSET, NC_NUMRECS_EXTENT, RGN_WRITE, &xp);
	if(status != NC_NOERR)
		return status;

	{
		const size_t nrecs = NC_get_numrecs(ncp);
		status = ncx_put_size_t(&xp, &nrecs);
	}

	(void) ncp->nciop->rel(ncp->nciop, NC_NUMRECS_OFFSET, RGN_MODIFIED);

	if(status == NC_NOERR)
		fClr(ncp->flags, NC_NDIRTY);

	return status;
}


/*
 * Read in the header
 * It is expensive.
 */
static int
read_NC(NC *ncp)
{
	int status = NC_NOERR;

	free_NC_dimarrayV(&ncp->dims);
	free_NC_attrarrayV(&ncp->attrs);
	free_NC_vararrayV(&ncp->vars);

	status = nc_get_NC(ncp);

	if(status == NC_NOERR)
		fClr(ncp->flags, NC_NDIRTY | NC_HDIRTY);

	return status;
}


/*
 * Write out the header
 */
static int
write_NC(NC *ncp)
{
	int status = NC_NOERR;

	assert(!NC_readonly(ncp));

	status = ncx_put_NC(ncp, NULL, 0, 0);

	if(status == NC_NOERR)
		fClr(ncp->flags, NC_NDIRTY | NC_HDIRTY);

	return status;
}


/*
 * Write the header or the numrecs if necessary.
 */
int
NC_sync(NC *ncp)
{
	assert(!NC_readonly(ncp));

	if(NC_hdirty(ncp))
	{
		return write_NC(ncp);
	}
	/* else */

	if(NC_ndirty(ncp))
	{
		return write_numrecs(ncp);
	}
	/* else */

	return NC_NOERR;
}


/*
 * Initialize the 'non-record' variables.
 */
static int
fillerup(NC *ncp)
{
	int status = NC_NOERR;
	size_t ii;
	NC_var **varpp;

	assert(!NC_readonly(ncp));
	assert(NC_dofill(ncp));

	/* loop thru vars */
	varpp = ncp->vars.value;
	for(ii = 0; ii < ncp->vars.nelems; ii++, varpp++)
	{
		if(IS_RECVAR(*varpp))
		{
			/* skip record variables */
			continue;
		}

		status = fill_NC_var(ncp, *varpp, (*varpp)->len, 0);
		if(status != NC_NOERR)
			break;
	}
	return status;
}

/* Begin endef */

/*
 */
static int
fill_added_recs(NC *gnu, NC *old)
{
	NC_var ** const gnu_varpp = (NC_var **)gnu->vars.value;

	const int old_nrecs = (int) NC_get_numrecs(old);
	int recno = 0;
	NC_var **vpp = gnu_varpp;
	NC_var *const *const end = &vpp[gnu->vars.nelems];
	int numrecvars = 0;

	/* Determine if there is only one record variable.  If so, we
	   must treat as a special case because there's no record padding */
	for(; vpp < end; vpp++) {
	    if(IS_RECVAR(*vpp)) {
		numrecvars++;
	    }
	}

	for(; recno < old_nrecs; recno++)
	    {
		int varid = (int)old->vars.nelems;
		for(; varid < (int)gnu->vars.nelems; varid++)
		    {
			const NC_var *const gnu_varp = *(gnu_varpp + varid);
			if(!IS_RECVAR(gnu_varp))
			    {
				/* skip non-record variables */
				continue;
			    }
			/* else */
			{
			    size_t varsize = numrecvars == 1 ? gnu->recsize :  gnu_varp->len;
			    const int status = fill_NC_var(gnu, gnu_varp, varsize, recno);
			    if(status != NC_NOERR)
				return status;
			}
		    }
	    }
	return NC_NOERR;
}

/*
 */
static int
fill_added(NC *gnu, NC *old)
{
	NC_var ** const gnu_varpp = (NC_var **)gnu->vars.value;
	int varid = (int)old->vars.nelems;

	for(; varid < (int)gnu->vars.nelems; varid++)
	{
		const NC_var *const gnu_varp = *(gnu_varpp + varid);
		if(IS_RECVAR(gnu_varp))
		{
			/* skip record variables */
			continue;
		}
		/* else */
		{
		const int status = fill_NC_var(gnu, gnu_varp, gnu_varp->len, 0);
		if(status != NC_NOERR)
			return status;
		}
	}

	return NC_NOERR;
}


/*
 * Move the records "out". 
 * Fill as needed.
 */
static int
move_recs_r(NC *gnu, NC *old)
{
	int status;
	int recno;
	int varid;
	NC_var **gnu_varpp = (NC_var **)gnu->vars.value;
	NC_var **old_varpp = (NC_var **)old->vars.value;
	NC_var *gnu_varp;
	NC_var *old_varp;
	off_t gnu_off;
	off_t old_off;
	const size_t old_nrecs = NC_get_numrecs(old);
	
	/* Don't parallelize this loop */
	for(recno = (int)old_nrecs -1; recno >= 0; recno--)
	{
	/* Don't parallelize this loop */
	for(varid = (int)old->vars.nelems -1; varid >= 0; varid--)
	{
		gnu_varp = *(gnu_varpp + varid);
		if(!IS_RECVAR(gnu_varp))
		{
			/* skip non-record variables on this pass */
			continue;
		}
		/* else */

		/* else, a pre-existing variable */
		old_varp = *(old_varpp + varid);
		gnu_off = gnu_varp->begin + (off_t)(gnu->recsize * recno);
		old_off = old_varp->begin + (off_t)(old->recsize * recno);

		if(gnu_off == old_off)
			continue; 	/* nothing to do */

		assert(gnu_off > old_off);
	
		status = gnu->nciop->move(gnu->nciop, gnu_off, old_off,
			 old_varp->len, 0);

		if(status != NC_NOERR)
			return status;
		
	}
	}

	NC_set_numrecs(gnu, old_nrecs);

	return NC_NOERR;
}


/*
 * Move the "non record" variables "out". 
 * Fill as needed.
 */
static int
move_vars_r(NC *gnu, NC *old)
{
	int status;
	int varid;
	NC_var **gnu_varpp = (NC_var **)gnu->vars.value;
	NC_var **old_varpp = (NC_var **)old->vars.value;
	NC_var *gnu_varp;
	NC_var *old_varp;
	off_t gnu_off;
	off_t old_off;
	
	/* Don't parallelize this loop */
	for(varid = (int)old->vars.nelems -1;
		 varid >= 0; varid--)
	{
		gnu_varp = *(gnu_varpp + varid);
		if(IS_RECVAR(gnu_varp))
		{
			/* skip record variables on this pass */
			continue;
		}
		/* else */

		old_varp = *(old_varpp + varid);
		gnu_off = gnu_varp->begin;
		old_off = old_varp->begin;
	
		if(gnu_off == old_off)
			continue; 	/* nothing to do */

		assert(gnu_off > old_off);

		status = gnu->nciop->move(gnu->nciop, gnu_off, old_off,
			 old_varp->len, 0);

		if(status != NC_NOERR)
			return status;
		
	}

	return NC_NOERR;
}


/*
 * Given a valid ncp, return NC_EVARSIZE if any variable has a bad len 
 * (product of non-rec dim sizes too large), else return NC_NOERR.
 */
static int
NC_check_vlens(NC *ncp)
{
    NC_var **vpp;
    /* maximum permitted variable size (or size of one record's worth
       of a record variable) in bytes.  This is different for format 1
       and format 2. */
    size_t vlen_max;
    size_t ii;
    size_t large_vars_count;
    size_t rec_vars_count;
    int last = 0;

    if(ncp->vars.nelems == 0) 
	return NC_NOERR;

    if ((ncp->flags & NC_64BIT_OFFSET) && sizeof(off_t) > 4) {
	/* CDF2 format and LFS */
	vlen_max = X_UINT_MAX - 3; /* "- 3" handles rounded-up size */
    } else {
	/* CDF1 format */
	vlen_max = X_INT_MAX - 3;
    }
    /* Loop through vars, first pass is for non-record variables.   */
    large_vars_count = 0;
    rec_vars_count = 0;
    vpp = ncp->vars.value;
    for (ii = 0; ii < ncp->vars.nelems; ii++, vpp++) {
	if( !IS_RECVAR(*vpp) ) {
	    last = 0;
	    if( NC_check_vlen(*vpp, vlen_max) == 0 ) {
		large_vars_count++;
		last = 1;
	    }
	} else {
	  rec_vars_count++;
	}
    }
    /* OK if last non-record variable size too large, since not used to 
       compute an offset */
    if( large_vars_count > 1) { /* only one "too-large" variable allowed */
      return NC_EVARSIZE;
    }
    /* and it has to be the last one */ 
    if( large_vars_count == 1 && last == 0) { 
      return NC_EVARSIZE;
    }
    if( rec_vars_count > 0 ) {
	/* and if it's the last one, there can't be any record variables */
	if( large_vars_count == 1 && last == 1) {
	    return NC_EVARSIZE;
	}
	/* Loop through vars, second pass is for record variables.   */
	large_vars_count = 0;
	vpp = ncp->vars.value;
	for (ii = 0; ii < ncp->vars.nelems; ii++, vpp++) {
	    if( IS_RECVAR(*vpp) ) {
		last = 0;
		if( NC_check_vlen(*vpp, vlen_max) == 0 ) {
		    large_vars_count++;
		    last = 1;
		}
	    }
	}
	/* OK if last record variable size too large, since not used to 
	   compute an offset */
	if( large_vars_count > 1) { /* only one "too-large" variable allowed */
	    return NC_EVARSIZE;
	}
	/* and it has to be the last one */ 
	if( large_vars_count == 1 && last == 0) { 
	    return NC_EVARSIZE;
	}
    }
    return NC_NOERR;
}


/*
 *  End define mode.
 *  Common code for ncendef, ncclose(endef)
 *  Flushes I/O buffers.
 */
static int
NC_endef(NC *ncp,
	size_t h_minfree, size_t v_align,
	size_t v_minfree, size_t r_align)
{
	int status = NC_NOERR;

	assert(!NC_readonly(ncp));
	assert(NC_indef(ncp));

	status = NC_check_vlens(ncp);
	if(status != NC_NOERR)
	    return status;
	status = NC_begins(ncp, h_minfree, v_align, v_minfree, r_align);
	if(status != NC_NOERR)
	    return status;

	if(ncp->old != NULL)
	{
		/* a plain redef, not a create */
		assert(!NC_IsNew(ncp));
		assert(fIsSet(ncp->flags, NC_INDEF));
		assert(ncp->begin_rec >= ncp->old->begin_rec);
		assert(ncp->begin_var >= ncp->old->begin_var);

		if(ncp->vars.nelems != 0)
		{
		if(ncp->begin_rec > ncp->old->begin_rec)
		{
			status = move_recs_r(ncp, ncp->old);
			if(status != NC_NOERR)
				return status;
			if(ncp->begin_var > ncp->old->begin_var)
			{
				status = move_vars_r(ncp, ncp->old);
				if(status != NC_NOERR)
					return status;
			} 
			/* else if (ncp->begin_var == ncp->old->begin_var) { NOOP } */
		}
		else
		{	/* Even if (ncp->begin_rec == ncp->old->begin_rec)
			   and     (ncp->begin_var == ncp->old->begin_var)
			   might still have added a new record variable */
		        if(ncp->recsize > ncp->old->recsize)
			{
			        status = move_recs_r(ncp, ncp->old);
				if(status != NC_NOERR)
				      return status;
			}
		}
		}
	}

	status = write_NC(ncp);
	if(status != NC_NOERR)
		return status;

	if(NC_dofill(ncp))
	{
		if(NC_IsNew(ncp))
		{
			status = fillerup(ncp);
			if(status != NC_NOERR)
				return status;
			
		}
		else if(ncp->vars.nelems > ncp->old->vars.nelems)
		{
			status = fill_added(ncp, ncp->old);
			if(status != NC_NOERR)
				return status;
			status = fill_added_recs(ncp, ncp->old);
			if(status != NC_NOERR)
				return status;
		}
	}

	if(ncp->old != NULL)
	{
		free_NC(ncp->old);
		ncp->old = NULL;
	}

	fClr(ncp->flags, NC_CREAT | NC_INDEF);

	return ncp->nciop->sync(ncp->nciop);
}

#ifdef LOCKNUMREC
static int
NC_init_pe(NC *ncp, int basepe) {
	if (basepe < 0 || basepe >= _num_pes()) {
		return NC_EINVAL; /* invalid base pe */
	}
	/* initialize common values */
	ncp->lock[LOCKNUMREC_VALUE] = 0;
	ncp->lock[LOCKNUMREC_LOCK] = 0;
	ncp->lock[LOCKNUMREC_SERVING] = 0;
	ncp->lock[LOCKNUMREC_BASEPE] =  basepe;
	return NC_NOERR;
}
#endif


/*
 * Compute the expected size of the file.
 */
int
NC_calcsize(const NC *ncp, off_t *calcsizep)
{
	NC_var **vpp = (NC_var **)ncp->vars.value;
	NC_var *const *const end = &vpp[ncp->vars.nelems];
	NC_var *last_fix = NULL;	/* last "non-record" var */
	int numrecvars = 0;	/* number of record variables */

	if(ncp->vars.nelems == 0) { /* no non-record variables and 
				       no record variables */
	    *calcsizep = ncp->xsz; /* size of header */
	    return NC_NOERR;
	}

	for( /*NADA*/; vpp < end; vpp++) {
	    if(IS_RECVAR(*vpp)) {
		numrecvars++;
	    } else {
		last_fix = *vpp;
	    }
	}

	if(numrecvars == 0) {
	    off_t varsize;
	    assert(last_fix != NULL);
	    varsize = last_fix->len;
	    if(last_fix->len == X_UINT_MAX) { /* huge last fixed var */
		int i;
		varsize = 1;
		    for(i = 0; i < last_fix->ndims; i++ ) {
			varsize *= last_fix->shape[i];
		    }
	    }
	    *calcsizep = last_fix->begin + varsize;
	    /*last_var = last_fix;*/
	} else {       /* we have at least one record variable */
	    *calcsizep = ncp->begin_rec + ncp->numrecs * ncp->recsize;
	}

	return NC_NOERR;
}

/* Public */

/* Expose a couple of extra functions */

NC* dispatch_new_NC(const size_t *chunkp) {return new_NC(chunkp);}

void dispatch_free_NC(NC *ncp) {free_NC(ncp);}

/* WARNING: SIGNATURE CHANGE */
int
NC3_create(const char * path, int ioflags,
		size_t initialsz, int basepe,
		size_t *chunksizehintp,
		int use_parallel, void* parameters,
                NC_Dispatch* dispatch, NC** ncpp)
{
	NC *ncp;
	int status;
	void *xp = NULL;
	int sizeof_off_t = 0;

#if ALWAYS_NC_SHARE /* DEBUG */
	fSet(ioflags, NC_SHARE);
#endif

	ncp = new_NC(chunksizehintp);
	if(ncp == NULL)
		return NC_ENOMEM;

#if defined(LOCKNUMREC) /* && _CRAYMPP */
	if (status = NC_init_pe(ncp, basepe)) {
		return status;
	}
#else
	/*
	 * !_CRAYMPP, only pe 0 is valid
	 */
	if(basepe != 0)
		return NC_EINVAL;
#endif

	assert(ncp->flags == 0);

	/* Apply default create format. */
	if (default_create_format == NC_FORMAT_64BIT)
	  ioflags |= NC_64BIT_OFFSET;

	if (fIsSet(ioflags, NC_64BIT_OFFSET)) {
	  fSet(ncp->flags, NC_64BIT_OFFSET);
	  sizeof_off_t = 8;
	} else {
	  sizeof_off_t = 4;
	}

	assert(ncp->xsz == ncx_len_NC(ncp,sizeof_off_t));
	
	status = ncio_create(path, ioflags,
		initialsz,
		0, ncp->xsz, &ncp->chunk,
		&ncp->nciop, &xp);
	if(status != NC_NOERR)
	{
		/* translate error status */
		if(status == EEXIST)
			status = NC_EEXIST;
		goto unwind_alloc;
	}

	fSet(ncp->flags, NC_CREAT);

	if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
	{
		/*
		 * NC_SHARE implies sync up the number of records as well.
		 * (File format version one.)
		 * Note that other header changes are not shared
		 * automatically.  Some sort of IPC (external to this package)
		 * would be used to trigger a call to nc_sync().
		 */
		fSet(ncp->flags, NC_NSYNC);
	}

	status = ncx_put_NC(ncp, &xp, sizeof_off_t, ncp->xsz);
	if(status != NC_NOERR)
		goto unwind_ioc;

	add_to_NCList(ncp);

	if(chunksizehintp != NULL)
		*chunksizehintp = ncp->chunk;

	ncp->int_ncid = ncp->nciop->fd;

	if(ncpp) *ncpp = ncp;	

	return NC_NOERR;

unwind_ioc:
	(void) ncio_close(ncp->nciop, 1); /* N.B.: unlink */
	ncp->nciop = NULL;
	/*FALLTHRU*/
unwind_alloc:
	free_NC(ncp);
	return status;
}

/* This function sets a default create flag that will be logically
   or'd to whatever flags are passed into nc_create for all future
   calls to nc_create.
   Valid default create flags are NC_64BIT_OFFSET, NC_CLOBBER,
   NC_LOCK, NC_SHARE. */
int
nc_set_default_format(int format, int *old_formatp)
{
    /* Return existing format if desired. */
    if (old_formatp)
      *old_formatp = default_create_format;

    /* Make sure only valid format is set. */
#ifdef USE_NETCDF4
    if (format != NC_FORMAT_CLASSIC && format != NC_FORMAT_64BIT &&
	format != NC_FORMAT_NETCDF4 && format != NC_FORMAT_NETCDF4_CLASSIC)
      return NC_EINVAL;
#else
    if (format != NC_FORMAT_CLASSIC && format != NC_FORMAT_64BIT)
      return NC_EINVAL;
#endif
    default_create_format = format;
    return NC_NOERR;
}

int
NC3_open(const char * path, int ioflags,
               int basepe, size_t *chunksizehintp,
	       int use_parallel,void* parameters,
               NC_Dispatch* dispatch, NC** ncpp)
{
	NC *ncp;
	int status;

#if ALWAYS_NC_SHARE /* DEBUG */
	fSet(ioflags, NC_SHARE);
#endif

	ncp = new_NC(chunksizehintp);
	if(ncp == NULL)
		return NC_ENOMEM;

#if defined(LOCKNUMREC) /* && _CRAYMPP */
	if (status = NC_init_pe(ncp, basepe)) {
		return status;
	}
#else
	/*
	 * !_CRAYMPP, only pe 0 is valid
	 */
	if(basepe != 0)
		return NC_EINVAL;
#endif

	status = ncio_open(path, ioflags,
		0, 0, &ncp->chunk,
		&ncp->nciop, 0);
	if(status)
		goto unwind_alloc;

	assert(ncp->flags == 0);

	if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
	{
		/*
		 * NC_SHARE implies sync up the number of records as well.
		 * (File format version one.)
		 * Note that other header changes are not shared
		 * automatically.  Some sort of IPC (external to this package)
		 * would be used to trigger a call to nc_sync().
		 */
		fSet(ncp->flags, NC_NSYNC);
	}

	status = nc_get_NC(ncp);
	if(status != NC_NOERR)
		goto unwind_ioc;

	add_to_NCList(ncp);

	if(chunksizehintp != NULL)
		*chunksizehintp = ncp->chunk;


	ncp->int_ncid = ncp->nciop->fd;

	if(ncpp) *ncpp = ncp;

	return NC_NOERR;

unwind_ioc:
	(void) ncio_close(ncp->nciop, 0);
	ncp->nciop = NULL;
	/*FALLTHRU*/
unwind_alloc:
	free_NC(ncp);
	return status;
}

int
NC3__enddef(int ncid,
	size_t h_minfree, size_t v_align,
	size_t v_minfree, size_t r_align)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(!NC_indef(ncp))
		return(NC_ENOTINDEFINE);

	return (NC_endef(ncp, h_minfree, v_align, v_minfree, r_align));
}


int
NC3_close(int ncid)
{
	int status = NC_NOERR;
	NC *ncp; 

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(NC_indef(ncp))
	{
		status = NC_endef(ncp, 0, 1, 0, 1); /* TODO: defaults */
		if(status != NC_NOERR )
		{
			(void) nc_abort(ncid);
			return status;
		}
	}
	else if(!NC_readonly(ncp))
	{
		status = NC_sync(ncp);
		/* flush buffers before any filesize comparisons */
		(void) ncp->nciop->sync(ncp->nciop);
	}

	/* 
	 * If file opened for writing and filesize is less than
	 * what it should be (due to previous use of NOFILL mode),
	 * pad it to correct size, as reported by NC_calcsize().
	 */
	if (status == ENOERR) {
	    off_t filesize; 	/* current size of open file */
	    off_t calcsize;	/* calculated file size, from header */
	    status = ncio_filesize(ncp->nciop, &filesize);
	    if(status != ENOERR)
		return status;
	    status = NC_calcsize(ncp, &calcsize);
	    if(status != NC_NOERR)
		return status;
	    if(filesize < calcsize && !NC_readonly(ncp)) {
		status = ncio_pad_length(ncp->nciop, calcsize);
		if(status != ENOERR)
		    return status;
	    }
	}

	(void) ncio_close(ncp->nciop, 0);
	ncp->nciop = NULL;

	del_from_NCList(ncp);

	free_NC(ncp);

	return status;
}

/*
 * In data mode, same as ncclose.
 * In define mode, restore previous definition.
 * In create, remove the file.
 */
int
NC3_abort(int ncid)
{
	int status;
	NC *ncp;
	int doUnlink = 0;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	doUnlink = NC_IsNew(ncp);

	if(ncp->old != NULL)
	{
		/* a plain redef, not a create */
		assert(!NC_IsNew(ncp));
		assert(fIsSet(ncp->flags, NC_INDEF));
		free_NC(ncp->old);
		ncp->old = NULL;
		fClr(ncp->flags, NC_INDEF);
	}
	else if(!NC_readonly(ncp))
	{
		status = NC_sync(ncp);
		if(status != NC_NOERR)
			return status;
	}


	(void) ncio_close(ncp->nciop, doUnlink);
	ncp->nciop = NULL;

	del_from_NCList(ncp);

	free_NC(ncp);

	return NC_NOERR;
}


int
NC3_redef(int ncid)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(NC_readonly(ncp))
		return NC_EPERM;

	if(NC_indef(ncp))
		return NC_EINDEFINE;

	
	if(fIsSet(ncp->nciop->ioflags, NC_SHARE))
	{
		/* read in from disk */
		status = read_NC(ncp);
		if(status != NC_NOERR)
			return status;
	}

	ncp->old = dup_NC(ncp);
	if(ncp->old == NULL)
		return NC_ENOMEM;

	fSet(ncp->flags, NC_INDEF);

	return NC_NOERR;
}


int
NC3_inq(int ncid,
	int *ndimsp,
	int *nvarsp,
	int *nattsp,
	int *xtendimp)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(ndimsp != NULL)
		*ndimsp = (int) ncp->dims.nelems;
	if(nvarsp != NULL)
		*nvarsp = (int) ncp->vars.nelems;
	if(nattsp != NULL)
		*nattsp = (int) ncp->attrs.nelems;
	if(xtendimp != NULL)
		*xtendimp = find_NC_Udim(&ncp->dims, NULL);

	return NC_NOERR;
}

int 
NC3_inq_unlimdim(int ncid, int *xtendimp)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(xtendimp != NULL)
		*xtendimp = find_NC_Udim(&ncp->dims, NULL);

	return NC_NOERR;
}

int
NC3_sync(int ncid)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(NC_indef(ncp))
		return NC_EINDEFINE;

	if(NC_readonly(ncp))
	{
		return read_NC(ncp);
	}
	/* else, read/write */

	status = NC_sync(ncp);
	if(status != NC_NOERR)
		return status;

	status = ncp->nciop->sync(ncp->nciop);
	if(status != NC_NOERR)
		return status;

#ifdef USE_FSYNC
	/* may improve concurrent access, but slows performance if
	 * called frequently */
#ifndef WIN32
	status = fsync(ncp->nciop->fd);
#else
	status = _commit(ncp->nciop->fd);
#endif	/* WIN32 */
#endif	/* USE_FSYNC */

	return status;
}


int
NC3_set_fill(int ncid,
	int fillmode, int *old_mode_ptr)
{
	int status;
	NC *ncp;
	int oldmode;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	if(NC_readonly(ncp))
		return NC_EPERM;

	oldmode = fIsSet(ncp->flags, NC_NOFILL) ? NC_NOFILL : NC_FILL;

	if(fillmode == NC_NOFILL)
	{
		fSet(ncp->flags, NC_NOFILL);
	}
	else if(fillmode == NC_FILL)
	{
		if(fIsSet(ncp->flags, NC_NOFILL))
		{
			/*
			 * We are changing back to fill mode
			 * so do a sync
			 */
			status = NC_sync(ncp);
			if(status != NC_NOERR)
				return status;
		}
		fClr(ncp->flags, NC_NOFILL);
	}
	else
	{
		return NC_EINVAL; /* Invalid fillmode */
	}

	if(old_mode_ptr != NULL)
		*old_mode_ptr = oldmode;

	return NC_NOERR;
}

#ifdef LOCKNUMREC

/* create function versions of the NC_*_numrecs macros */
size_t
NC_get_numrecs(const NC *ncp) {
	shmem_t numrec;
	shmem_short_get(&numrec, (shmem_t *) ncp->lock + LOCKNUMREC_VALUE, 1,
		ncp->lock[LOCKNUMREC_BASEPE]);
	return (size_t) numrec;
}

void
NC_set_numrecs(NC *ncp, size_t nrecs) {
	shmem_t numrec = (shmem_t) nrecs;
	/* update local value too */
	ncp->lock[LOCKNUMREC_VALUE] = (ushmem_t) numrec;
	shmem_short_put((shmem_t *) ncp->lock + LOCKNUMREC_VALUE, &numrec, 1,
		ncp->lock[LOCKNUMREC_BASEPE]);
}

void NC_increase_numrecs(NC *ncp, size_t nrecs) {
	/* this is only called in one place that's already protected
	 * by a lock ... so don't worry about it */
	if (nrecs > NC_get_numrecs(ncp))
		NC_set_numrecs(ncp, nrecs);
}

#endif /* LOCKNUMREC */

/* everyone in communicator group will be executing this */
/*ARGSUSED*/
int
NC3_set_base_pe(int ncid, int pe)
{
#if _CRAYMPP && defined(LOCKNUMREC)
	int status;
	NC *ncp;
	shmem_t numrecs;

	if ((status = NC_check_id(ncid, &ncp)) != NC_NOERR) {
		return status;
	}
	if (pe < 0 || pe >= _num_pes()) {
		return NC_EINVAL; /* invalid base pe */
	}

	numrecs = (shmem_t) NC_get_numrecs(ncp);

	ncp->lock[LOCKNUMREC_VALUE] = (ushmem_t) numrecs;

	/* update serving & lock values for a "smooth" transition */
	/* note that the "real" server will being doing this as well */
	/* as all the rest in the group */
	/* must have syncronization before & after this step */
	shmem_short_get(
		(shmem_t *) ncp->lock + LOCKNUMREC_SERVING,
		(shmem_t *) ncp->lock + LOCKNUMREC_SERVING,
		1, ncp->lock[LOCKNUMREC_BASEPE]);

	shmem_short_get(
		(shmem_t *) ncp->lock + LOCKNUMREC_LOCK,
		(shmem_t *) ncp->lock + LOCKNUMREC_LOCK,
		1, ncp->lock[LOCKNUMREC_BASEPE]);

	/* complete transition */
	ncp->lock[LOCKNUMREC_BASEPE] = (ushmem_t) pe;

#endif /* _CRAYMPP && LOCKNUMREC */
	return NC_NOERR;
}

/*ARGSUSED*/
int
NC3_inq_base_pe(int ncid, int *pe)
{
#if _CRAYMPP && defined(LOCKNUMREC)
	int status;
	NC *ncp;

	if ((status = NC_check_id(ncid, &ncp)) != NC_NOERR) {
		return status;
	}

	*pe = (int) ncp->lock[LOCKNUMREC_BASEPE];
#else
	/*
	 * !_CRAYMPP, only pe 0 is valid
	 */
	*pe = 0;
#endif /* _CRAYMPP && LOCKNUMREC */
	return NC_NOERR;
}

int
NC3_inq_format(int ncid, int *formatp)
{
	int status;
	NC *ncp;

	status = NC_check_id(ncid, &ncp); 
	if(status != NC_NOERR)
		return status;

	/* only need to check for netCDF-3 variants, since this is never called for netCDF-4 
	   files */
	*formatp = fIsSet(ncp->flags, NC_64BIT_OFFSET) ? NC_FORMAT_64BIT 
	    : NC_FORMAT_CLASSIC; 
	return NC_NOERR;
}

/* The sizes of types may vary from platform to platform, but within
 * netCDF files, type sizes are fixed. */
#define NC_BYTE_LEN 1
#define NC_CHAR_LEN 1
#define NC_SHORT_LEN 2
#define NC_INT_LEN 4
#define NC_FLOAT_LEN 4
#define NC_DOUBLE_LEN 8
#define NUM_ATOMIC_TYPES 6

/* This netCDF-4 function proved so popular that a netCDF-classic
 * version is provided. You're welcome. */
int
NC3_inq_type(int ncid, nc_type typeid, char *name, size_t *size)
{
   int atomic_size[NUM_ATOMIC_TYPES] = {NC_BYTE_LEN, NC_CHAR_LEN, NC_SHORT_LEN, 
					NC_INT_LEN, NC_FLOAT_LEN, NC_DOUBLE_LEN};
   char atomic_name[NUM_ATOMIC_TYPES][NC_MAX_NAME + 1] = {"byte", "char", "short", 
							  "int", "float", "double"};
   
   /* Only netCDF classic model needs to be handled. */
   if (typeid < NC_BYTE || typeid > NC_DOUBLE)
      return NC_EBADTYPE;

   /* Give the user the values they want. Subtract one because types
    * are numbered starting at 1, not 0. */
   if (name)
      strcpy(name, atomic_name[typeid - 1]);
   if (size)
      *size = atomic_size[typeid - 1];

   return NC_NOERR;
}

int
nc_delete_mp(const char * path, int basepe)
{
	NC *ncp;
	int status;
	size_t chunk = 512;

	ncp = new_NC(&chunk);
	if(ncp == NULL)
		return NC_ENOMEM;
	
#if defined(LOCKNUMREC) /* && _CRAYMPP */
	if (status = NC_init_pe(ncp, basepe)) {
		return status;
	}
#else
	/*
	 * !_CRAYMPP, only pe 0 is valid
	 */
	if(basepe != 0)
		return NC_EINVAL;
#endif
	status = ncio_open(path, NC_NOWRITE,
		0, 0, &ncp->chunk,
		&ncp->nciop, 0);
	if(status)
		goto unwind_alloc;

	assert(ncp->flags == 0);

	status = nc_get_NC(ncp);
	if(status != NC_NOERR)
	{
		/* Not a netcdf file, don't delete */
		/* ??? is this the right semantic? what if it was just too big? */
		(void) ncio_close(ncp->nciop, 0);
	}
	else
	{
		/* ncio_close does the unlink */
		status = ncio_close(ncp->nciop, 1); /* ncio_close does the unlink */
	}

	ncp->nciop = NULL;
unwind_alloc:
	free_NC(ncp);
	return status;
}

int
nc_delete(const char * path)
{
	return nc_delete_mp(path, 0);
}