Update backend

Author: 15Dkatz

.gitignore

@@ -2,3 +2,5 @@
 *__pycache__*
 *node_modules*
 blockchain-env/lib/python3.7
+*.DS_Store*
+

backend/app/__init__.py

@@ -3,7 +3,6 @@
 import random
 
 from flask import Flask, jsonify, request
-from flask_cors import CORS
 
 from backend.blockchain.blockchain import Blockchain
 from backend.wallet.wallet import Wallet
@@ -12,9 +11,8 @@
 from backend.pubsub import PubSub
 
 app = Flask(__name__)
-CORS(app, resources={ r'/*': { 'origins': 'http://localhost:3000' } })
 blockchain = Blockchain()
-wallet = Wallet(blockchain)
+wallet = Wallet()
 transaction_pool = TransactionPool()
 pubsub = PubSub(blockchain, transaction_pool)
 
@@ -26,23 +24,9 @@ def route_default():
 def route_blockchain():
     return jsonify(blockchain.to_json())
 
-@app.route('/blockchain/range')
-def route_blockchain_range():
-    # http://localhost:5000/blockchain/range?start=2&end=5
-    start = int(request.args.get('start'))
-    end = int(request.args.get('end'))
-
-    return jsonify(blockchain.to_json()[::-1][start:end])
-
-@app.route('/blockchain/length')
-def route_blockchain_length():
-    return jsonify(len(blockchain.chain))
-
 @app.route('/blockchain/mine')
 def route_blockchain_mine():
-    transaction_data = transaction_pool.transaction_data()
-    transaction_data.append(Transaction.reward_transaction(wallet).to_json())
-    blockchain.add_block(transaction_data)
+    blockchain.add_block(transaction_pool.transaction_data())
     block = blockchain.chain[-1]
     pubsub.broadcast_block(block)
     transaction_pool.clear_blockchain_transactions(blockchain)
@@ -68,33 +52,14 @@ def route_wallet_transact():
         )
 
     pubsub.broadcast_transaction(transaction)
-    transaction_pool.set_transaction(transaction)
 
     return jsonify(transaction.to_json())
 
-@app.route('/wallet/info')
-def route_wallet_info():
-    return jsonify({ 'address': wallet.address, 'balance': wallet.balance })
-
-@app.route('/known-addresses')
-def route_known_addresses():
-    known_addresses = set()
-
-    for block in blockchain.chain:
-        for transaction in block.data:
-            known_addresses.update(transaction['output'].keys())
-
-    return jsonify(list(known_addresses))
-
-@app.route('/transactions')
-def route_transactions():
-    return jsonify(transaction_pool.transaction_data())
-
-ROOT_PORT = 5000
+ROOT_PORT = 5050
 PORT = ROOT_PORT
 
 if os.environ.get('PEER') == 'True':
-    PORT = random.randint(5001, 6000)
+    PORT = random.randint(5051, 6000)
 
     result = requests.get(f'http://localhost:{ROOT_PORT}/blockchain')
     result_blockchain = Blockchain.from_json(result.json())
@@ -105,16 +70,5 @@ def route_transactions():
     except Exception as e:
         print(f'\n -- Error synchronizing: {e}')
 
-if os.environ.get('SEED_DATA') == 'True':
-    for i in range(10):
-        blockchain.add_block([
-            Transaction(Wallet(), Wallet().address, random.randint(2, 50)).to_json(),
-            Transaction(Wallet(), Wallet().address, random.randint(2, 50)).to_json()
-        ])
-
-    for i in range(3):
-        transaction_pool.set_transaction(
-            Transaction(Wallet(), Wallet().address, random.randint(2, 50))
-        )
+app.run(port=5050)
 
-app.run(port=PORT)

backend/blockchain/blockchain.py

@@ -1,7 +1,4 @@
 from backend.blockchain.block import Block
-from backend.wallet.transaction import Transaction
-from backend.wallet.wallet import Wallet
-from backend.config import MINING_REWARD_INPUT
 
 class Blockchain:
     """
@@ -68,53 +65,6 @@ def is_valid_chain(chain):
             last_block = chain[i-1]
             Block.is_valid_block(last_block, block)
 
-        Blockchain.is_valid_transaction_chain(chain)
-
-    @staticmethod
-    def is_valid_transaction_chain(chain):
-        """
-        Enforce the rules of a chain composed of blocks of transactions.
-            - Each transaction must only appear once in the chain.
-            - There can only be one mining reward per block.
-            - Each transaction must be valid.
-        """
-        transaction_ids = set()
-
-        for i in range(len(chain)):
-            block = chain[i]
-            has_mining_reward = False
-
-            for transaction_json in block.data:
-                transaction = Transaction.from_json(transaction_json)
-
-                if transaction.id in transaction_ids:
-                    raise Exception(f'Transaction {transaction.id} is not unique')
-
-                transaction_ids.add(transaction.id)
-
-                if transaction.input == MINING_REWARD_INPUT:
-                    if has_mining_reward:
-                        raise Exception(
-                            'There can only be one mining reward per block. '\
-                            f'Check block with hash: {block.hash}'
-                        )
-
-                    has_mining_reward = True
-                else:
-                    historic_blockchain = Blockchain()
-                    historic_blockchain.chain = chain[0:i]
-                    historic_balance = Wallet.calculate_balance(
-                        historic_blockchain,
-                        transaction.input['address']
-                    )
-
-                    if historic_balance != transaction.input['amount']:
-                        raise Exception(
-                            f'Transaction {transaction.id} has an invalid '\
-                            'input amount'
-                        )
-
-                Transaction.is_valid_transaction(transaction)
 
 def main():
     blockchain = Blockchain()

backend/config.py

@@ -6,6 +6,3 @@
 MINE_RATE = 4 * SECONDS
 
 STARTING_BALANCE = 1000
-
-MINING_REWARD = 50
-MINING_REWARD_INPUT = { 'address': '*--official-mining-reward--*' }

backend/pubsub.py

@@ -8,8 +8,10 @@
 from backend.wallet.transaction import Transaction
 
 pnconfig = PNConfiguration()
-pnconfig.subscribe_key = 'sub-c-666638f6-ec63-11e9-b715-9abbdb5d0da2'
-pnconfig.publish_key = 'pub-c-82bf7695-ce5e-4bc5-9cd9-a8f8147dc2a8'
+# NOTE: these keys have been retired.
+pnconfig.subscribe_key = 'sub-c-448d1fb4-5f47-4e56-a496-e4588e0808a7'
+pnconfig.publish_key = 'pub-c-691add7b-2cc0-42c8-96f9-7edf786b5b4b'
+pnconfig.user_id = 'test-1'
 
 CHANNELS = {
     'TEST': 'TEST',
@@ -32,9 +34,11 @@ def message(self, pubnub, message_object):
 
             try:
                 self.blockchain.replace_chain(potential_chain)
+
                 self.transaction_pool.clear_blockchain_transactions(
                     self.blockchain
                 )
+
                 print('\n -- Successfully replaced the local chain')
             except Exception as e:
                 print(f'\n -- Did not replace chain: {e}')
@@ -57,9 +61,7 @@ def publish(self, channel, message):
         """
         Publish the message object to the channel.
         """
-        self.pubnub.unsubscribe().channels([channel]).execute()
         self.pubnub.publish().channel(channel).message(message).sync()
-        self.pubnub.subscribe().channels([channel]).execute()
 
     def broadcast_block(self, block):
         """

backend/scripts/average_block_rate.py

@@ -19,4 +19,4 @@
 
     print(f'New block difficulty: {blockchain.chain[-1].difficulty}')
     print(f'Time to mine new block: {time_to_mine}s')
-    print(f'Average time to add blocks: {average_time}s\n')
+    print(f'Average time to add blocks: {average_time}s\n')

backend/scripts/test_app.py

@@ -3,23 +3,20 @@
 
 from backend.wallet.wallet import Wallet
 
-BASE_URL = 'http://127.0.0.1:5000'
+BASE_URL = 'http://localhost:5050'
 
 def get_blockchain():
     return requests.get(f'{BASE_URL}/blockchain').json()
 
 def get_blockchain_mine():
     return requests.get(f'{BASE_URL}/blockchain/mine').json()   
 
-def post_wallet_transact(recipient, amount):
+def post_wallet_transact(recipient, amount): 
     return requests.post(
         f'{BASE_URL}/wallet/transact',
         json={ 'recipient': recipient, 'amount': amount }
     ).json()
 
-def get_wallet_info():
-    return requests.get(f'{BASE_URL}/wallet/info').json()
-
 start_blockchain = get_blockchain()
 print(f'start_blockchain: {start_blockchain}')
 
@@ -34,6 +31,3 @@ def get_wallet_info():
 time.sleep(1)
 mined_block = get_blockchain_mine()
 print(f'\nmined_block: {mined_block}')
-
-wallet_info = get_wallet_info()
-print(f'\nwallet_info: {wallet_info}')

backend/tests/blockchain/test_block.py

@@ -85,4 +85,4 @@ def test_is_valid_block_bad_block_hash(last_block, block):
 	block.hash = '0000000000000000bbbabc'
 
 	with pytest.raises(Exception, match='block hash must be correct'):
-		Block.is_valid_block(last_block, block)
+		Block.is_valid_block(last_block, block)

backend/tests/blockchain/test_blockchain.py

@@ -1,9 +1,5 @@
-import pytest
-
 from backend.blockchain.blockchain import Blockchain
 from backend.blockchain.block import GENESIS_DATA
-from backend.wallet.wallet import Wallet
-from backend.wallet.transaction import Transaction
 
 def test_blockchain_instance():
     blockchain = Blockchain()
@@ -15,76 +11,3 @@ def test_add_block():
     blockchain.add_block(data)
 
     assert blockchain.chain[-1].data == data
-
-@pytest.fixture
-def blockchain_three_blocks():
-    blockchain = Blockchain()
-    for i in range(3):
-        blockchain.add_block([Transaction(Wallet(), 'recipient', i).to_json()])
-    return blockchain
-
-def test_is_valid_chain(blockchain_three_blocks):
-    Blockchain.is_valid_chain(blockchain_three_blocks.chain)
-
-def test_is_valid_chain_bad_genesis(blockchain_three_blocks):
-    blockchain_three_blocks.chain[0].hash = 'evil_hash'
-
-    with pytest.raises(Exception, match='genesis block must be valid'):
-        Blockchain.is_valid_chain(blockchain_three_blocks.chain)
-
-def test_replace_chain(blockchain_three_blocks):
-    blockchain = Blockchain()
-    blockchain.replace_chain(blockchain_three_blocks.chain)
-
-    assert blockchain.chain == blockchain_three_blocks.chain
-
-def test_replace_chain_not_longer(blockchain_three_blocks):
-    blockchain = Blockchain()
-
-    with pytest.raises(Exception, match='The incoming chain must be longer'):
-        blockchain_three_blocks.replace_chain(blockchain.chain)
-
-def test_replace_chain_bad_chain(blockchain_three_blocks):
-    blockchain = Blockchain()
-    blockchain_three_blocks.chain[1].hash = 'evil_hash'
-
-    with pytest.raises(Exception, match='The incoming chain is invalid'):
-        blockchain.replace_chain(blockchain_three_blocks.chain)
-
-def test_valid_transaction_chain(blockchain_three_blocks):
-    Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)
-
-def test_is_valid_transaction_chain_duplicate_transactions(blockchain_three_blocks):
-    transaction = Transaction(Wallet(), 'recipient', 1).to_json()
-    blockchain_three_blocks.add_block([transaction, transaction])
-
-    with pytest.raises(Exception, match='is not unique'):
-        Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)
-
-def test_is_valid_transaction_chain_multiple_rewards(blockchain_three_blocks):
-    reward_1 = Transaction.reward_transaction(Wallet()).to_json()
-    reward_2 = Transaction.reward_transaction(Wallet()).to_json()
-    blockchain_three_blocks.add_block([reward_1, reward_2])
-
-    with pytest.raises(Exception, match='one mining reward per block'):
-        Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)
-
-def test_is_valid_transaction_chain_bad_transaction(blockchain_three_blocks):
-    bad_transaction = Transaction(Wallet(), 'recipient', 1)
-    bad_transaction.input['signature'] = Wallet().sign(bad_transaction.output)
-    blockchain_three_blocks.add_block([bad_transaction.to_json()])
-
-    with pytest.raises(Exception):
-        Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)
-
-def test_is_valid_transaction_chain_bad_historic_balance(blockchain_three_blocks):
-    wallet = Wallet()
-    bad_transaction = Transaction(wallet, 'recipient', 1)
-    bad_transaction.output[wallet.address] = 9000
-    bad_transaction.input['amount'] = 9001
-    bad_transaction.input['signature'] = wallet.sign(bad_transaction.output)
-
-    blockchain_three_blocks.add_block([bad_transaction.to_json()])
-
-    with pytest.raises(Exception, match='has an invalid input amount'):
-        Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)

backend/tests/util/test_crypto_hash.py

@@ -1,7 +1,7 @@
 from backend.util.crypto_hash import crypto_hash
 
 def test_crypto_hash():
-    # It should create the same hash with arguments of different data types
-    # in any order
+    # It should create the same hash with arguments of different data types in
+    # any order
     assert crypto_hash(1, [2], 'three') == crypto_hash('three', 1, [2])
-    assert crypto_hash('foo') == 'b2213295d564916f89a6a42455567c87c3f480fcd7a1c15e220f17d7169a790b'
+    assert crypto_hash('foo') == 'b2213295d564916f89a6a42455567c87c3f480fcd7a1c15e220f17d7169a790b'