netcdf-c/libsrc/nclistmgr.c
2010-06-03 13:24:43 +00:00

79 lines
1.7 KiB
C

/*********************************************************************
Copyright 2010, UCAR/Unidata See netcdf/COPYRIGHT file for
copying and redistribution conditions.
$Id: nclistmgr.c,v 2.3 2010/05/26 11:11:26 ed Exp $
*********************************************************************/
#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "nc.h"
#define ID_SHIFT (16)
#define NCFILELISTLENGTH 0x10000
/* Version one just allocates the max space (sizeof(NC*)*2^16)*/
static NC** nc_filelist = NULL;
static int numfiles = 0;
/* Common */
int
count_NCList(void)
{
return numfiles;
}
void
free_NCList(void)
{
if(numfiles > 0) return; /* not empty */
if(nc_filelist != NULL) free(nc_filelist);
nc_filelist = NULL;
}
int
add_to_NCList(NC* ncp)
{
int i;
int new_id;
if(nc_filelist == NULL) {
if (!(nc_filelist = calloc(1, sizeof(NC*)*NCFILELISTLENGTH)))
return NC_ENOMEM;
numfiles = 0;
}
new_id = 0; /* id's begin at 1 */
for(i=1;i<0x10000;i++) {
if(nc_filelist[i] == NULL) {new_id = i; break;}
}
if(new_id == 0) return NC_ENOMEM; /* no more slots */
nc_filelist[new_id] = ncp;
numfiles++;
new_id = (new_id << ID_SHIFT);
ncp->ext_ncid = new_id;
return NC_NOERR;
}
void
del_from_NCList(NC* ncp)
{
unsigned int ncid = ((unsigned int)ncp->ext_ncid) >> ID_SHIFT;
if(numfiles == 0 || ncid == 0 || nc_filelist == NULL) return;
if(nc_filelist[ncid] != ncp) return;
nc_filelist[ncid] = NULL;
numfiles--;
}
NC*
find_in_NCList(int ext_ncid)
{
NC* f = NULL;
unsigned int ncid = ((unsigned int)ext_ncid) >> ID_SHIFT;
if(numfiles > 0 && nc_filelist != NULL && ncid < NCFILELISTLENGTH)
f = nc_filelist[ncid];
return f;
}