netcdf-c/libdispatch/nclistmgr.c
2019-07-04 15:46:15 -06:00

119 lines
2.5 KiB
C

/*********************************************************************
Copyright 2018, UCAR/Unidata See netcdf/COPYRIGHT file for
copying and redistribution conditions.
*********************************************************************/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "ncdispatch.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 < NCFILELISTLENGTH; 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--;
/* If all files have been closed, release the filelist memory. */
if (numfiles == 0)
free_NCList();
}
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];
/* for classic files, ext_ncid must be a multiple of (1<<ID_SHIFT) */
if (f != NULL && f->model->impl == NC_FORMATX_NC3 && (ext_ncid % (1<<ID_SHIFT)))
return NULL;
return f;
}
/*
Added to support open by name
*/
NC*
find_in_NCList_by_name(const char* path)
{
int i;
NC* f = NULL;
if(nc_filelist == NULL)
return NULL;
for(i=1; i < NCFILELISTLENGTH; i++) {
if(nc_filelist[i] != NULL) {
if(strcmp(nc_filelist[i]->path,path)==0) {
f = nc_filelist[i];
break;
}
}
}
return f;
}
int
iterate_NCList(int index, NC** ncp)
{
/* Walk from 0 ...; 0 return => stop */
if(index < 0 || index >= NCFILELISTLENGTH)
return NC_ERANGE;
if(ncp) *ncp = nc_filelist[index];
return NC_NOERR;
}