Pavel Patsey
104 lines
3.0 KiB
Python
104 lines
3.0 KiB
Python
import cProfile
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from .util import cidr4_to_node, get_data, make_cidr4
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Node = tuple[int, int]
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class Cidr4MergerError(Exception):
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pass
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def find_parent(a: Node, b: Node) -> Node:
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ip_a, mask_len_a = a
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ip_b, mask_len_b = b
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mask_len = min(mask_len_a, mask_len_b)
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mask = ((1 << mask_len) - 1) << (32 - mask_len)
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while ip_a & mask != ip_b & mask:
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mask_len -= 1
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mask = (mask << 1) & ((1 << 32) - 1)
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ip = ip_a & mask
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parent_node = ip, mask_len
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return parent_node
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def calc_dip(mask_len_a: int, mask_len_b: int, mask_len_p: int) -> int:
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def dip(mla, mlp):
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m = mlp + 1
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res = 1 << (mla - m)
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res -= 1
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res <<= 32 - mla
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return res
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return dip(mask_len_a, mask_len_p) + dip(mask_len_b, mask_len_p)
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def merge_two_nodes(node_a: Node, node_b: Node) -> tuple[Node, int]:
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parent_node = find_parent(node_a, node_b)
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dip = calc_dip(node_a[1], node_b[1], parent_node[1])
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return parent_node, dip
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def merge_nodes(nodes: list[Node], required_len: int) -> tuple[list[Node], int]:
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sum_dip = 0
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while len(nodes) > required_len:
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min_tuple = None, None, float("inf")
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for i, (a, b) in enumerate(zip(nodes, nodes[1:])):
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parent_node, dip = merge_two_nodes(a, b)
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if dip < min_tuple[2]:
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min_tuple = i, parent_node, dip
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idx, parent_node, dip = min_tuple
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nodes = nodes[:idx] + [parent_node] + nodes[idx + 2 :]
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sum_dip += dip
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while neighbors := find_neighbors(nodes):
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idx, a, b = neighbors[0]
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parent_node, dip = merge_two_nodes(a, b)
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nodes = nodes[:idx] + [parent_node] + nodes[idx + 2 :]
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sum_dip += dip
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return nodes, sum_dip
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def find_subnets(nodes: list[Node]) -> list[tuple[Node, Node]]:
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subnets = []
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for i, (a, b) in enumerate(zip(nodes, nodes[1:])):
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parent_node, dip = merge_two_nodes(a, b)
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if parent_node == a or parent_node == b:
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subnets.append((a, b))
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return subnets
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def ensure_no_subnets(nodes: list[Node]):
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if subnets := find_subnets(nodes):
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raise Cidr4MergerError(f"There are subnets! {subnets=}")
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def find_neighbors(nodes: list[Node]) -> list[tuple[int, Node, Node]]:
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neighbors = []
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for i, (a, b) in enumerate(zip(nodes, nodes[1:])):
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parent_node, dip = merge_two_nodes(a, b)
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if parent_node[1] + 1 == a[1] == b[1]:
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neighbors.append((i, a, b))
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return neighbors
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def ensure_no_neighbors(nodes: list[Node]):
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if neighbors := find_neighbors(nodes):
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raise Cidr4MergerError(f"There are neighbors! {neighbors=}")
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def main():
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required_len = 20
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data = get_data()
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nodes = sorted(map(cidr4_to_node, data))
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ensure_no_subnets(nodes)
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ensure_no_neighbors(nodes)
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merged_nodes, sum_dip = merge_nodes(nodes, required_len)
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cidr4s = [make_cidr4(ip, mask_len) for ip, mask_len in merged_nodes]
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print(cidr4s, sum_dip, sep="\n")
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if __name__ == "__main__":
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cProfile.run("main()")
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