text: #!/usr/bin/env python3
  # Copyright (c) 2020 The Samcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  """Test block-relay-only anchors functionality"""
  
  import os
  
  from test_framework.p2p import P2PInterface
  from test_framework.test_framework import SamcoinTestFramework
  from test_framework.util import assert_equal
  
  INBOUND_CONNECTIONS = 5
  BLOCK_RELAY_CONNECTIONS = 2
  
  
  def check_node_connections(*, node, num_in, num_out):
      info = node.getnetworkinfo()
      assert_equal(info["connections_in"], num_in)
      assert_equal(info["connections_out"], num_out)
  
  
  class AnchorsTest(SamcoinTestFramework):
      def set_test_params(self):
          self.num_nodes = 1
  
      def setup_network(self):
          self.setup_nodes()
  
      def run_test(self):
          node_anchors_path = os.path.join(
              self.nodes[0].datadir, "regtest", "anchors.dat"
          )
  
          self.log.info("When node starts, check if anchors.dat doesn't exist")
          assert not os.path.exists(node_anchors_path)
  
          self.log.info(f"Add {BLOCK_RELAY_CONNECTIONS} block-relay-only connections to node")
          for i in range(BLOCK_RELAY_CONNECTIONS):
              self.log.debug(f"block-relay-only: {i}")
              self.nodes[0].add_outbound_p2p_connection(
                  P2PInterface(), p2p_idx=i, connection_type="block-relay-only"
              )
  
          self.log.info(f"Add {INBOUND_CONNECTIONS} inbound connections to node")
          for i in range(INBOUND_CONNECTIONS):
              self.log.debug(f"inbound: {i}")
              self.nodes[0].add_p2p_connection(P2PInterface())
  
          self.log.info("Check node connections")
          check_node_connections(node=self.nodes[0], num_in=5, num_out=2)
  
          # 127.0.0.1
          ip = "7f000001"
  
          # Since the ip is always 127.0.0.1 for this case,
          # we store only the port to identify the peers
          block_relay_nodes_port = []
          inbound_nodes_port = []
          for p in self.nodes[0].getpeerinfo():
              addr_split = p["addr"].split(":")
              if p["connection_type"] == "block-relay-only":
                  block_relay_nodes_port.append(hex(int(addr_split[1]))[2:])
              else:
                  inbound_nodes_port.append(hex(int(addr_split[1]))[2:])
  
          self.log.info("Stop node 0")
          self.stop_node(0)
  
          # It should contain only the block-relay-only addresses
          self.log.info("Check the addresses in anchors.dat")
  
          with open(node_anchors_path, "rb") as file_handler:
              anchors = file_handler.read().hex()
  
          for port in block_relay_nodes_port:
              ip_port = ip + port
              assert ip_port in anchors
          for port in inbound_nodes_port:
              ip_port = ip + port
              assert ip_port not in anchors
  
          self.log.info("Start node")
          self.start_node(0)
  
          self.log.info("When node starts, check if anchors.dat doesn't exist anymore")
          assert not os.path.exists(node_anchors_path)
  
  
  if __name__ == "__main__":
      AnchorsTest().main()
  