def get_changefeed():
"""Create and return ordered changefeed of blocks starting from
last voted block"""
b = Bigchain()
last_block_id = b.get_last_voted_block().id
feed = backend.query.get_new_blocks_feed(b.connection, last_block_id)
return Node(feed.__next__, name='changefeed')
def get_changefeed():
"""Create and return ordered changefeed of blocks starting from
last voted block"""
b = Bigchain()
last_block_id = b.get_last_voted_block().id
feed = backend.query.get_new_blocks_feed(b.connection, last_block_id)
return Node(feed.__next__, name='changefeed')
def bft():
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
print(" ")
# Digital Asset Definition (e.g. bicycle)
asset = Asset(data={
"bicycle": {
"manufacturer": "bkfab",
"serial_number": "abcd1234"
}
})
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)],
metadata=metadata,
asset=asset)
# sign with private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
print("tx_id : ", tx_id)
# create block
b = Bigchain()
block = b.create_block([tx])
print("valid block timestamp : ",
block.to_dict()['block']['timestamp'])
# tamper block
block.timestamp = '1'
print("tamper block.timestamp to 1 : ")
block_id = block.to_dict()['id']
block_voters = block.to_dict()['block']['voters']
print("invalid block timestamp : ",
block.to_dict()['block']['timestamp'])
print("tamper_block_id : ", block_id)
print("db response of block : ", b.write_block(block))
sleep(0)
last_voted_id = b.get_last_voted_block().id
vote = b.vote(block_id, last_voted_id, True)
print("crate vote 'True' : ", vote)
print("db response of vote : ", b.write_vote(vote))
print("tamper_block status : ",
b.block_election_status(block_id, block_voters))
print("blocks_status_containing_tx : ",
b.get_blocks_status_containing_tx(tx_id))
print("wait for 20 sec : ")
sleep(20)
print("blocks_status_containing_tx : ",
b.get_blocks_status_containing_tx(tx_id))
print(" ")
def bootstrap(self):
"""
Before starting handling the new blocks received by the changefeed we need to handle unvoted blocks
added to the bigchain while the process was down
We also need to set the previous_block_id.
"""
b = Bigchain()
last_voted = b.get_last_voted_block()
self.v_previous_block_id.value = last_voted['id'].encode()
def bootstrap(self):
"""
Before starting handling the new blocks received by the changefeed we need to handle unvoted blocks
added to the bigchain while the process was down
We also need to set the previous_block_id.
"""
b = Bigchain()
last_voted = b.get_last_voted_block()
self.v_previous_block_id.value = last_voted['id'].encode()
