class BlockchainManager(object):
"""Client to synchronise blockchain headers."""
def __init__(self):
"""Initialise the blockchain manager."""
self.bcs = BlockChainStore(data_dir)
self.client = None
def _blockchain_change_callback(self, blockchain, ops):
pass
def _sync_loop(self, timeout, length_change_callback):
interval_time = 1
current_length = 0
time_elapsed_since_length_change = 0
while True:
new_length = self.blockchain().length()
if current_length == new_length:
time_elapsed_since_length_change += interval_time
if time_elapsed_since_length_change > timeout:
self.event_loop.stop()
break
else:
time_elapsed_since_length_change = 0
current_length = new_length
if length_change_callback:
length_change_callback(current_length)
time.sleep(interval_time)
def sync(self, timeout, length_change_callback=None):
"""
Synchronise the blockchain to the latest headers.
Args:
timeout: the timeout to stop after not receiving any new blocks.
length_change_callback: a function to call with arg (length) when the blockchain length changes.
"""
self.client = Client(
network=MAINNET,
host_port_q=dns_bootstrap_host_port_q(MAINNET),
should_download_block_f=should_download_block_false,
block_chain_store=self.bcs,
blockchain_change_callback=self._blockchain_change_callback,
)
self.event_loop = asyncio.get_event_loop()
t = threading.Thread(target=self._sync_loop,
args=(timeout, length_change_callback))
t.start()
self.event_loop.run_forever()
def blockchain(self):
"""Returns the current Blockchain object."""
if self.client:
return self.client.blockhandler.block_chain
else:
blockchain = BlockChain(
did_lock_to_index_f=self.bcs.did_lock_to_index)
blockchain.preload_locked_blocks(self.bcs.headers())
return blockchain
def test_BlockChainStore():
with TemporaryDirectory() as the_dir:
db = BlockChainStore(dir_path=the_dir, parent_to_0=h_f(-1))
check_prepopulate(db)
check_postpopulate(db)
db1 = BlockChainStore(dir_path=the_dir, parent_to_0=h_f(-1))
check_postpopulate(db1)
BHOS1 = [FakeHeader(h_f(i), h_f(i-1)) for i in range(10000,10050)]
db2 = BlockChainStore(dir_path=the_dir, parent_to_0=h_f(-1))
check_postpopulate(db2)
db2.did_lock_to_index(BHOS1, len(BHOS))
assert list(db2.headers()) == BHOS + BHOS1
db3 = BlockChainStore(dir_path=the_dir, parent_to_0=h_f(-1))
assert list(db3.headers()) == BHOS + BHOS1