obj *
slab_alloc(slab* slab_allocator)
{
if (0 >= slab_allocator->size) {
_alloc_chunk(slab_allocator);
}
slab_allocator->size--;
obj *object = slab_allocator->head;
slab_allocator->head = object->next;
return object;
}
slab *
create_slab_allocator(int size)
{
if (0 >= size) {
perror("Size is less than or equal to 0");
exit(-1);
} else {
slab *slab_allocator = malloc(sizeof(slab));
slab_allocator->size = size;
slab_allocator->chunk_size = size;
_alloc_chunk(slab_allocator);
}
}
static uint32_t _split_table(struct btree *btree, struct btree_table *table, char *key, uint32_t *offset)
{
memcpy(key, table->items[TABLE_SIZE / 2].key, KEY_MAX_LENGTH);
*offset = table->items[TABLE_SIZE / 2].offset;
struct btree_table *new_table = _alloc_table();
new_table->size = table->size - TABLE_SIZE / 2 - 1;
table->size = TABLE_SIZE / 2;
memcpy(new_table->items, &table->items[TABLE_SIZE / 2 + 1],
(new_table->size + 1) * sizeof(struct btree_item));
uint32_t new_table_offset = _alloc_chunk(btree, sizeof *new_table);
_flush_table(btree, new_table, new_table_offset);
return new_table_offset;
}
uint32_t _insert_toplevel(struct btree *btree, uint32_t *table_offset, struct slice *sk, struct slice *sv)
{
uint32_t offset = 0;
uint32_t ret = 0;
uint32_t right_child = 0;
if (*table_offset != 0) {
ret = _insert_table(btree, *table_offset, sk, sv);
struct btree_table *table = _get_table(btree, *table_offset);
if (table->size < TABLE_SIZE-1) {
_put_table(btree, table, *table_offset);
return ret;
}
right_child = _split_table(btree, table, sk->data, &offset);
_flush_table(btree, table, *table_offset);
} else {
ret = offset = _insert_data(btree, sv);
}
/* create new top level table */
struct btree_table *new_table = _alloc_table();
new_table->size = 1;
memcpy(new_table->items[0].key, sk->data, sk->len);
new_table->items[0].offset = offset;
new_table->items[0].child = *table_offset;
new_table->items[1].child = right_child;
uint32_t new_table_offset = _alloc_chunk(btree, sizeof *new_table);
_flush_table(btree, new_table, new_table_offset);
*table_offset = new_table_offset;
return ret;
}