def refresh(self, transaction_data, last_update_timestamp):
updated, my_ledger_path = blockchain.ledger_updated(
self.blockchain.cnx, self.blockchain.client, self.blockchain.gpg)
if not updated:
self.blockchain = blockchain.download_ledger(
self.blockchain.cnx, self.blockchain.client,
self.blockchain.gpg)
ipfs_hash = blockchain.insert_transaction(
self.blockchain.cnx,
self.blockchain.client,
self.blockchain.gpg,
self.contract_id,
transaction_data,
recipients=[
self.contract_header['engineer_email'],
self.contract_header['technician_email']
])
blockdata = self.contract_header
blockdata['ipfs_hash'] = ipfs_hash
block = Blockchain.hash(blockdata)
blockchain.update_world_state(self.blockchain.cnx, self.contract_id,
last_update_timestamp,
self.contract_header['current_state'])
block_added, self.blockchain.ledger_path = new_block(
self.blockchain, block, ipfs_hash)
self.blockchain.chain = self.blockchain.load_blockchain(
self.blockchain.ledger_path)
print('Transaction block added to blockchain at ',
self.blockchain.ledger_path, '\n', block_added)
return block_added
def mine():
# We run the proof of work algorithm to get the next proof...
last_block = blockchain.last_block
last_proof = last_block['proof']
proof = blockchain.proof_of_work(last_proof)
# We must receive a reward for finding the proof.
# The sender is "0" to signify that this node has mined a new coin.
blockchain.new_transaction(
sender="0",
recipient=node_identifier,
amount=1,
)
# Forge the new Block by adding it to the chain
previous_hash = blockchain.hash(last_block)
block = blockchain.new_block(proof, previous_hash)
response = {
'message': "New Block Forged",
'index': block['index'],
'transactions': block['transactions'],
'proof': block['proof'],
'previous_hash': block['previous_hash'],
}
return jsonify(response), 200
def thread_mine(current_index):
# sleep for a random number of seconds from 10 to 60 seconds to simulate mining
time.sleep(random.randint(1, 6))
last_block = blockchain.last_block
last_proof = last_block['proof']
proof = blockchain.proof_of_work(last_proof)
# if faulty, edit the hash to be incorrect
if blockchain.faulty:
proof = 0
previous_hash = blockchain.hash(last_block)
# if the blockchain is still the same length as when we started, add the new block
if len(blockchain.chain) == current_index:
# reward miner
blockchain.new_transaction(
1,
"0",
node_identifier,
1,
False,
)
blockchain.new_block(proof, previous_hash)
# print the new block mined
b_index = blockchain.last_block["index"]
b_hash = blockchain.last_block["previous_hash"]
b_proof = blockchain.last_block["proof"]
b_timestamp = blockchain.last_block["timestamp"]
mine_log.write(f"{b_index}, {b_hash}, {b_proof}, {b_timestamp}\n")
for transaction in blockchain.last_block["transactions"]:
mine_log.write(f"\t{transaction['trans_id']}\n")
# if we are proactively telling other nodes of the new chain
if blockchain.proactive:
proactive_consensus()
blockchain.mining = False
def create_blockchain():
# Our block chain is a list
blockchain = [create_genesis_block()]
previous_block = blockchain[0]
# Total blocks in chain
number_of_blocks = 20
for each_block in range(0, number_of_blocks):
next_block = new_block(previous_block)
blockchain.append(next_block)
previous_block = next_block
# Print details
print("New block: Block {} added!! ".format(previous_block.index))
print("Block data: {}".format(previous_block.data))
print("Block hash: {}".format(previous_block.hash))
def mine():
req = request.form.get('mine')
lt_block = blockchain.last_block
lt_proof = lt_block['proof']
proof = blockchain.proof_of_work(lt_proof, lt_block)
blockchain.new_transaction(sender='0', receiver=node_id, amount=1)
previous_hash = blockchain.hash(lt_block)
block = blockchain.new_block(proof, previous_hash)
response = {
'message': "Block created",
'index': block['index'],
'proof': block['proof'],
'previous_hash': block['previous_hash']
}
return render_template('/mine.html', response=response)
def mine():
last_block = blockchain.last_block
last_proof = last_block['proof']
proof = blockchain.proof_of_work(last_proof)
blockchain.new_transaction(sender="0", recipient=node_identifier, amount=1)
previous_hash = blockchain.hash(last_block)
block = blockchain.new_block(proof, previous_hash)
response = {
'message': "New block Forged",
'index': block['index'],
'transactions': block['transactions'],
'proof': block['proof'],
'previous_hash': block['previous_hash'],
}
return jsonify(response), 200
def mine():
# We run the proof of work algorithm to get the next proof...
last_block = blockchain.last_block
last_proof = last_block['proof']
proof = blockchain.proof_of_work(last_proof)
# 给工作量证明的节点提供奖励.
# 发送者为 "0" 表明是新挖出的币
blockchain.new_transaction(
sender="0",
recipient=node_identifier,
amount=1,
)
# Forge the new Block by adding it to the chain
block = blockchain.new_block(proof)
response = {
'message': "New Block Forged",
'index': block['index'],
'transactions': block['transactions'],
'proof': block['proof'],
'previous_hash': block['previous_hash'],
}
return jsonify(response), 200
import blockchain as bc
blockchain = [bc.create_genesis_block()]
previous_block = blockchain[0]
num_of_blocks = 30
for i in range(0, num_of_blocks):
current_block = bc.new_block(previous_block)
blockchain.append(current_block)
previous_block = current_block
print("Block " + str(current_block.counter) + " has been added\n")
print("Transactoin info:")
print("Sender - " + current_block.data.sender)
print("Recipient - " + current_block.data.recipient)
print("Amount of transaction - " + str(current_block.data.amount))
print("\nHash - " + current_block.hash + "\n\n\n")
blockchain = blockchain.Blockchain() # the blockchain used in this test
# create a test record for a patient
patient_test_vc = [
"Administration Date: MAY-01-2021 10:00 AM", "Patient ID: 10132",
"Patient Name: John Doe", "Patient Address: 10 Example St. NE",
"Administered by: Dr. Jill Fakeington"
]
# additional info is non-personally identifying info stored with transaction
additional_data = ["Vaccine Type: Pfizer", "Vaccine ID: 1234"]
# create the provider
provider = Provider.Provider(provider_key)
# create the patient
patient = Patient.Patient(patient_key)
# create the third party verifier
verifier = Verifier.Verifier(verifier_key, blockchain)
# generate patient vaccine card
provider.generate_card(patient_test_vc)
# provider posts the transaction to the blockchain
provider.post_transaction(blockchain, patient_key.public_key(),
additional_data)
# a new block is created
blockchain.new_block()
# provider sends encrypted vaccine care to the patient
provider.send_patient_info(patient)
# Patient sends encrypted record to the verifier to prove his vaccination
patient.send_records(verifier, verifier.get_pub_key())
# verifier verifies the record is in the blockchain
verifier.verify_record(blockchain)