/*
* NROOT -- Create the root of a new tree.
*
* Parameters:
* t: tree
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
static int
nroot(BTREE *t)
{
PAGE *meta, *root;
pgno_t npg;
if ((meta = mpool_get(t->bt_mp, 0, 0)) != NULL) {
mpool_put(t->bt_mp, meta, 0);
return (RET_SUCCESS);
}
if (errno != EINVAL) /* It's OK to not exist. */
return (RET_ERROR);
errno = 0;
if ((meta = mpool_new(t->bt_mp, &npg)) == NULL)
return (RET_ERROR);
if ((root = mpool_new(t->bt_mp, &npg)) == NULL)
return (RET_ERROR);
if (npg != P_ROOT)
return (RET_ERROR);
root->pgno = npg;
root->prevpg = root->nextpg = P_INVALID;
root->lower = BTDATAOFF;
root->upper = t->bt_psize;
root->flags = P_BLEAF;
memset(meta, 0, t->bt_psize);
mpool_put(t->bt_mp, meta, MPOOL_DIRTY);
mpool_put(t->bt_mp, root, MPOOL_DIRTY);
return (RET_SUCCESS);
}
/*
* __bt_new --
* Get a new page, preferably from the freelist.
*
* Parameters:
* t: tree
* npg: storage for page number.
*
* Returns:
* Pointer to a page, NULL on error.
*/
PAGE *
__bt_new(BTREE *t, pgno_t *npg)
{
PAGE *h;
if (t->bt_free != P_INVALID &&
(h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) {
*npg = t->bt_free;
t->bt_free = h->nextpg;
F_SET(t, B_METADIRTY);
return (h);
}
return (mpool_new(t->bt_mp, npg, MPOOL_PAGE_NEXT));
}
void test_mpool() {
struct mpool* m = mpool_new(1024);
int i;
void* last_p = NULL;
for (i=0; i<1024/4; ++i) {
void *p = mpool_alloc(m, 4);
if (last_p) {
assert((p-last_p) == 4);
}
last_p = p;
}
void* p = mpool_alloc(m, 1024);
p = mpool_alloc(m, 1025);
p = mpool_alloc(m, 1020);
p = mpool_alloc(m, 10240);
mpool_dump(m);
mpool_delete(m);
}
void *
__mpool_new__44bsd(MPOOL *mp, pgno_t *pgnoaddr)
{
return (mpool_new(mp, pgnoaddr, MPOOL_PAGE_NEXT));
}
