def advance(self):
page_num = self.page_num
page = self.table.pager.get_page(page_num)
node = Node.deserialize_from(page)
self.cell_num += 1
if self.cell_num >= node.num_cells:
self.is_at_end_of_table = True
def insert_leaf_node(self, key, row):
current_page = self.table.pager.get_page(self.page_num)
current_node = Node.deserialize_from(current_page)
num_cells = current_node.num_cells
if num_cells >= LEAF_NODE_MAX_CELLS:
# node is full
raise NotImplementedError("need to implement splitting leaf nodes")
exit(0)
def __init__(self, table, page_num, is_at_end_of_table):
# type: (Table, int, bool) -> None
self.table = table
self.page_num = table.root_page_num
self.cell_num = 0
root_node_page = table.pager.get_page(table.root_page_num)
root_node = Node.deserialize_from(root_node_page)
num_cells = root_node.num_cells
self.is_at_end_of_table = num_cells == 0
def table_end(cls, table):
# type: (Table) -> Cursor
page_num = table.root_page_num
root_node_page = table.pager.get_page(table.root_page_num)
root_node = Node.deserialize_from(root_node_page)
num_cells = root_node.num_cells
is_at_end_of_table = True
return cls(table, num_cells, is_at_end_of_table)
def table_start(cls, table):
# type: (Table) -> Cursor
page_num = table.root_page_num
cell_num = 0
root_node_page = table.pager.get_page(table.root_page_num)
root_node = Node.deserialize_from(root_node_page)
num_cells = root_node.num_cells
is_at_end_of_table = num_cells == 0
return cls(table, cell_num, is_at_end_of_table)
def location(self):
# type: () -> Tuple[Page, int]
page_num = self.page_num
page = self.table.pager.get_page(page_num)
return Node.deserialize_from(page).value(self.cell_num)