From 1fd4140ecf6795807f4b69034c0d802c10f74613 Mon Sep 17 00:00:00 2001 From: KOSASIH Date: Fri, 10 May 2024 20:53:03 +0700 Subject: [PATCH] Create chain.py --- blockchain/chain.py | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 blockchain/chain.py diff --git a/blockchain/chain.py b/blockchain/chain.py new file mode 100644 index 000000000..ad5ad80d5 --- /dev/null +++ b/blockchain/chain.py @@ -0,0 +1,35 @@ +import hashlib + +class Blockchain: + def __init__(self): + self.chain = [self.create_genesis_block()] + self.difficulty = 2 + + def create_genesis_block(self): + return Block(0, '0' * 64, int(time.time()), 'Genesis Block', self.calculate_hash(0, '0' * 64, int(time.time()), 'Genesis Block')) + + def calculate_hash(self, index, previous_hash, timestamp, data): + value = str(index) + str(previous_hash) + str(timestamp) + str(data) + return hashlib.sha256(value.encode('utf-8')).hexdigest() + + def is_chain_valid(self, chain): + for i in range(1, len(chain)): + current_block = chain[i] + previous_block = chain[i - 1] + + if current_block.hash != self.calculate_hash(current_block.index, current_block.previous_hash, current_block.timestamp, current_block.data): + return False + + if current_block.previous_hash != previous_block.hash: + return False + + return True + + def add_block(self, data): + new_block = Block(len(self.chain), self.chain[-1].hash, int(time.time()), data, None) + new_block.hash = self.calculate_hash(new_block.index, new_block.previous_hash, new_block.timestamp, new_block.data) + self.chain.append(new_block) + + def replace_chain(self, chain): + if self.is_chain_valid(chain) and len(chain) > len(self.chain): + self.chain = chain