/* Copyright (c) 1986 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "@(#)modobject.c 2.1 11/12/91 LBL";
#endif

/*
 *  Routines for tracking object modifiers
 */

#include  "standard.h"

#include  "object.h"

#include  "otypes.h"


extern int  (*addobjnotify[])();	/* people to notify of new objects */

static struct ohtab {
	int  hsiz;			/* current table size */
	OBJECT  *htab;			/* table, if allocated */
}  modtab = {100, NULL}, objtab = {1000, NULL};	/* modifiers and objects */

static int  otndx();


#ifdef  GETOBJ
int
object(oname)			/* get an object number from its name */
char  *oname;
{
	register int  ndx;

	ndx = otndx(oname, &objtab);
	return(objtab.htab[ndx]);
}
#endif


int
modifier(mname)			/* get a modifier number from its name */
char  *mname;
{
	register int  ndx;

	ndx = otndx(mname, &modtab);
	return(modtab.htab[ndx]);
}


insertobject(obj)		/* insert new object into our list */
register OBJECT  obj;
{
	register int  i;

#ifdef  GETOBJ
	i = otndx(objptr(obj)->oname, &objtab);
	objtab.htab[i] = obj;
#endif
	if (ismodifier(objptr(obj)->otype)) {
		i = otndx(objptr(obj)->oname, &modtab);
		modtab.htab[i] = obj;
	}
	for (i = 0; addobjnotify[i] != NULL; i++)
		(*addobjnotify[i])(obj);
}


static int
nexthsiz(oldsiz)		/* return next hash table size */
int  oldsiz;
{
	static int  hsiztab[] = {
		251, 509, 1021, 2039, 4093, 8191, 16381, 0
	};
	register int  *hsp;

	for (hsp = hsiztab; *hsp; hsp++)
		if (*hsp > oldsiz)
			return(*hsp);
	return(oldsiz*2 + 1);		/* not always prime */
}


static int
shash(s)			/* hash a string */
register char  *s;
{
	register int  h = 0;

	while (*s)
		h = (h<<1 & 0x7fff) ^ *s++;
	return(h);
}


static int
otndx(name, tab)		/* get object table index for name */
char  *name;
register struct ohtab  *tab;
{
	OBJECT  *oldhtab;
	int  hval, i;
	register int  ndx;

	if (tab->htab == NULL) {		/* new table */
		tab->hsiz = nexthsiz(tab->hsiz);
		tab->htab = (OBJECT *)malloc(tab->hsiz*sizeof(OBJECT));
		if (tab->htab == NULL)
			error(SYSTEM, "out of memory in otndx");
		ndx = tab->hsiz;
		while (ndx--)			/* empty it */
			tab->htab[ndx] = OVOID;
	}
					/* look up object */
	hval = shash(name);
tryagain:
	for (i = 0; i < tab->hsiz; i++) {
		ndx = (hval + i*i) % tab->hsiz;
		if (tab->htab[ndx] == OVOID ||
				!strcmp(objptr(tab->htab[ndx])->oname, name))
			return(ndx);
	}
					/* table is full, reallocate */
	oldhtab = tab->htab;
	ndx = tab->hsiz;
	tab->htab = NULL;
	while (ndx--)
		if (oldhtab[ndx] != OVOID) {
			i = otndx(objptr(oldhtab[ndx])->oname, tab);
			tab->htab[i] = oldhtab[ndx];
		}
	free((char *)oldhtab);
	goto tryagain;			/* should happen only once! */
}