def genesis_block(self):
"""
Creates genesis block and appends it to chain. The block has
index 0, previous_hash as 0, and a valid given hash.
"""
transactions = {}
genesis_block = Block(0, [], datetime.datetime.now(), "0")
genesis_block.hash = genesis_block.compute_hash()
self.chain.append(genesis_block)
def getUserBlockThreads(db, latest = False):
try:
logging.info("getting block threads")
uid = session['uid']
curTime = db.query("""select logout_time from user_info where uid = %s""", [uid])
logout_time = curTime.fetchone()[0]
logging.info(logout_time)
cur2 = db.query("""select block_id from user_info where uid = %s""", [uid])
bid = cur2.fetchone()[0]
logging.info(bid)
blockUsers = Block.getBlockUsersResidents(db, bid)
logging.info(blockUsers)
tids = []
for user in blockUsers:
blockTids = getCommentTIDs(db, user, logout_time, latest)
if blockTids:
for b in blockTids:
tids.append(b)
tids.append(getLatestThreads(db, logout_time, user, 'b'))
logging.info("tids")
logging.info(tids)
threads = []
for tid in tids:
threads.append(tid)
logging.info("threads")
logging.info(threads)
return threads
except:
logging.info("error fetching user threads")
return None
def verify_and_add_block():
block_data = request.get_json()
block = Block(block_data["index"],
block_data["transactions"],
block_data["timestamp"],
block_data["previous_hash"])
proof = block_data['hash']
added = blockchain.add_block(block, proof)
if not added:
return "The block was discarded by the node", 400
return "Block added to the chain", 201
def create_chain_from_dump(chain_dump):
blockchain = Blockchain()
for idx, block_data in enumerate(chain_dump):
block = Block(block_data["index"],
block_data["transactions"],
block_data["timestamp"],
block_data["previous_hash"])
proof = block_data['hash']
if idx > 0:
added = blockchain.add_block(block, proof)
if not added:
raise Exception("The chain dump is tampered!!")
else: # the block is a genesis block, no verification needed
blockchain.chain.append(block)
return blockchain
def getHoodResidents(db, hid):
logging.info("getting hood residents")
error = None
try:
blocks = getAllBlocksInHood(db,hid)
logging.info("blocks in hood")
logging.info(blocks)
hoodResidents = []
for block in blocks:
blockResidents = Block.getBlockUsersResidents(db, block)
for resident in blockResidents:
hoodResidents.append(resident)
logging.info(hoodResidents)
return hoodResidents
except:
logging.error("error fetching residents of same block")
error = "error"
return error
def profile():
if 'uid' not in session:
return redirect(url_for('login'))
profile = []
if request.method == 'GET':
logging.info("Get profile")
profile_data = Users.view_profile(db.conn, request.form)
if profile_data[10]:
block_id = profile_data[10]
block_name = Block.getBlockNameFromBid(db, block_id)
logging.info(profile_data)
else:
block_name = "block approval pending"
if profile_data:
profile.append({"Fname": profile_data[1], "LName": profile_data[2], "email": profile_data[3], "Username": profile_data[5], "apt": profile_data[5],\
"street": profile_data[6], "city": profile_data[7], "state": profile_data[8], "zip": profile_data[9],"block_name" : block_name, "email_preference": profile_data[14]})
logging.info(profile)
return render_template('show_profile.html', profileInfo=profile)
def interface(self):
"""Serves as an interface to add pending transactions to blockchain
by adding them to block and verifying Proof of Work algorithm.
"""
if not self.unconfirmed_transactions:
return False
last_block = self.last_block
new_block = Block(index=last_block.index + 1,
transactions=self.unconfirmed_transactions,
timestamp=datetime.datetime.now(),
previous_hash=last_block.hash)
proof = self.proof_of_work(new_block)
self.add_block(new_block, proof)
# reset unconfirmed transactions
self.unconfirmed_transactions = []
return new_block.index
def getBlockListForHood():
hoodid = request.args.get('selectedHoodId')
blocklist = Block.getBlockListForHood(db, hoodid)
return blocklist