def test_find_consensus(self):
tester_node = Node("Tester")
blockchain1 = Blockchain(diff_threshold=10, g_data="Fiat Lux!")
blockchain2 = Blockchain(diff_threshold=7, g_data="Fiat Lux!")
for i in range(100):
tester_node.write_data(data=str(i), chain=blockchain1)
for i in range(80):
tester_node.write_data(data=str(i), chain=blockchain2)
# Blockchain 2 has a higher difficulty threshold, thus it will have a
# higher cumulative proof-of-work despite mining fewer blocks:
self.assertFalse(blockchain2.find_consensus(blockchain1))
self.assertTrue(blockchain1.find_consensus(blockchain2))
self.assertEqual(blockchain1.get_last_block(),
blockchain2.get_last_block())
node_addr=user.get_node_addr())
# Mine 100 blocks on the first chain and 80 blocks on the second chain:
for i in range(100):
if i < 80: user.write_data(data=str(i), chain=second_chain)
user.write_data(data=str(i), chain=first_chain)
print(
f"Last Block ID of first chain (before consensus): {first_chain.get_last_block().get_block_id()}"
)
print(
f"Last Block ID of second chain (before consensus): {second_chain.get_last_block().get_block_id()}\n"
)
print("Finding consensus...\n")
# Even though there are more blocks in the first chain,
# the ledger of this chain will be replaced by the second ledger.
# This is because the second chain has a higher cumulative proof-of-work,
# since the difficulty is raised more often:
if not second_chain.find_consensus(f_chain=first_chain):
first_chain.find_consensus(f_chain=second_chain)
""" We've found the consensus and brought both chains into the same state! """
print(
f"Last Block ID of first chain (after consensus): {first_chain.get_last_block().get_block_id()}"
)
print(
f"Last Block ID of second chain (after consensus): {second_chain.get_last_block().get_block_id()}"
)