#include <stdlib.h>

#include "state_db.h"
#include "memory.h"

StateDB
create_stateDB()
{
    StateDB s = (StateDB)malloc(sizeof(StateNode));
    if (!s) die_exit("Cann't alloc state db node.");
    return s;
}

static MemoryPtr mem_db;

static int state_count0;

void
reset_state_count()
{
    state_count0 = 0;
}

int
state_count()
{
    return state_count0;
}


/*

  lookup_StateDB(struct state *s, StateDB *parent, StatePtr *out)

  s->memory points the real memory
  if s is new, it is copied in the database (parent).
  if s is in the database, existing state is returned.

  if return value is 0, it returns new state.
  if out is null, no copy_state is created. (lookup mode)

  Founded state or newly created state is returned in out.
    
*/

int
lookup_StateDB(StateDB s, StateDB *parent, StateDB *out)
{
    StateDB db;
    int r;

    while(1) {
		db = *parent;
		if (!db) {
			/* not found */
			if (out) {
				db = create_stateDB();
				db->left = db->right = 0;
				db->memory = copy_memory(s->memory,&mem_db);
				db->hash = s->hash;
				state_count0 ++;
				*parent = db;
				*out = db;
			}
			return 0;
		}
		if (s->hash == db->hash) {
			r =  cmp_memory(s->memory,db->memory);
		} else
			r =  (s->hash > db->hash)? 1 : -1;
		if(!r) {
			/* bingo */
			if (out) *out = db;
			return 1;
		} else if (r>0) {
			parent = &db->left;
		} else if (r<0) {
			parent = &db->right;
		}
    }
}

/* end */