#include "inc/priv.h"
#include "inc/htable.h"
#include "inc/hashing.h"

sl_htable *
htable_new(sl_htable *h, usize numpairs)
{
	usize size;
	if(numpairs <= HT_N_INLINE_PAIRS){
		size = HT_N_INLINE;
		h->table = &h->local[0];
	}else{
		size = nextipow2(numpairs);
		size *= 2; // 2 pointers per key/value pair
		size *= 2; // aim for 50% occupancy
		if((h->table = MEM_ALLOC(size * sizeof(*h->table))) == nil)
			return nil;
		slvm.malloc_pressure += size * sizeof(*h->table);
	}
	h->size = size;
	h->i = 0;
	h->num = 0;
	h->live = 0;
	memset(h->table, 0xff, size*sizeof(*h->table));
	return h;
}

void
htable_free(sl_htable *h)
{
	if(h != nil && h->table != &h->local[0])
		MEM_FREE(h->table);
}

// empty and reduce size
void
htable_reset(sl_htable *h, usize sz)
{
	sz = nextipow2(sz);
	if(h->size > sz*4 && h->table != &h->local[0]){
		MEM_FREE(h->table);
		htable_new(h, sz);
	}else if(h->num > 0 || h->live > 0){
		memset(h->table, 0xff, h->size*sizeof(*h->table));
		h->num = 0;
		h->live = 0;
	}
}