sethtitem(3) test and set an item in an hash table.

SYNOPSYS

#include "mut.h"
int sethtitem(table, key)
ht *table;
void *key;

PARAMETERS

table
Hash table pointer
key
Key used by the hash coding function to set an item

DESCRIPTION

sethtitem() adds an item in the hash table pointed to by table, whether it existed or not, and returns an appropriate value. This is kind of a test and set operator.

RETURN VALUE

If the key exists, the funtion return 1, if it doesn't, the item is stored and the function returns 0.

EXAMPLE

#include <stdio.h>
#include "mut.h"
checksigname(p)
lofig_list *p;
{
int i;
losig_list *ptsig;
locon_list *ptcon;
ht *h;
char *amatla;
   for (i = 0, ptsig = p->LOSIG; ptsig; i++, ptsig = ptsig->NEXT);
   h = addht(i << 1); /* half empty hash tables are faster! */
   for (ptcon = p->LOCON; ptcon; ptcon = ptcon->NEXT)
      addhtitem(h, ptcon->NAME, 0);
   for (ptsig = p->LOSIG; ptsig; ptsig = ptsig->NEXT) {
      if (ptsig->TYPE == INTERNAL) {
         amatla = getsigname(ptsig);
         if (!sethtitem(h, amatla, 0))
            printf("node %s is now unique\n", amatla);
      }
   }
   delht(h);
}

ERRORS

"*** mbk error *** sethtitem impossible : value is EMPTYHT or DELETEHT"
The values EMPTYHT, -1, and DELETEHT, -2, are reserved for internal use, sorry.

DIAGNOSTICS

The value must be distinct from -1 and -2.