class UTXOSet(object):
db_file = 'blockchain.db'
utxo_bucket = 'utxo'
def __init__(self, blockchain):
self._bucket = Bucket(UTXOSet.db_file, UTXOSet.utxo_bucket)
self._bc = blockchain
@property
def blockchain(self):
return self._bc
def reindex(self):
# Rebuilds the UTXO set
self._bucket.reset()
utxos = self._bc.find_utxo()
for tx_id, outs in utxos.items():
self._bucket.put(tx_id, utils.serialize(outs))
self._bucket.commit()
def find_spendable_outputs(self, pubkey_hash, amount):
# Finds and returns unspent outputs to reference in inputs
accumulated = 0
unspent_outputs = defaultdict(list)
for tx_id, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out_idx, out in enumerate(outs):
if out.is_locked_with_key(pubkey_hash) and accumulated < amount:
accumulated += out.value
unspent_outputs[tx_id].append(out_idx)
return accumulated, unspent_outputs
def find_utxo(self, pubkey_hash):
# Finds UTXO for a public key hash
utxos = []
for _, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out in outs:
if out.is_locked_with_key(pubkey_hash):
utxos.append(out)
return utxos
def print_utxo(self):
utxos = []
for _, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out in outs:
print(out)
def count_transactions(self):
# Returns the number of transactions in the UTXO set
return len(self._bucket)
def update(self, block):
# Updates the UTXO set with transactions from the Block
for tx in block.transactions:
if not isinstance(tx, CoinbaseTx):
for vin in tx.vin:
update_outs = []
outs_bytes = self._bucket.get(vin.tx_id)
outs = utils.deserialize(outs_bytes)
for out_idx, out in enumerate(outs):
if out_idx != vin.vout:
update_outs.append(out)
if len(update_outs) == 0:
self._bucket.delete(vin.tx_id)
else:
self._bucket.put(
vin.tx_id, utils.serialize(update_outs))
# Add new outputs
new_outputs = [out for out in tx.vout]
self._bucket.put(tx.ID, utils.serialize(new_outputs))
self._bucket.commit()
@property
def utxo_set(self):
return {k: utils.deserialize(v) for k, v in self._bucket.kv.items()}
class UTXOSet():
db_file = "utxo.db"
utxo_bucket = "utxo"
def __init__(self, blockchain):
self._bucket = Bucket(UTXOSet.db_file, UTXOSet.utxo_bucket)
self._bc = blockchain
def reindex(self):
self._bucket.reset()
utxos = self._bc.find_utxo()
for txid, outs in utxos.items():
self._bucket.put(txid, utils.serialize(outs))
self._bucket.save()
def find_spendable_outputs(self, pubkey_hash, amount):
account_amount = 0
unspent_outputs = defaultdict(list)
for tx_id, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out_idx, out in enumerate(outs):
if out.is_locked_with_key(
pubkey_hash) and account_amount < amount:
account_amount += out.value
unspent_outputs[tx_id].append(out_idx)
return account_amount, unspent_outputs
def update(self, block):
for tx in block.transactions:
if not isinstance(tx, CoinbaseTx):
for vin in tx.vin:
update_outs = []
outs_bytes = self._bucket.get(vin.txid)
outs = utils.deserialize(outs_bytes)
for out_idx, out in enumerate(outs):
if out_idx != vin.vout:
update_outs.append(out)
if len(update_outs) == 0:
self._bucket.delete(vin.txid)
else:
self._bucket.put(vin.txid,
utils.serialize(update_outs))
# Add new outputs
new_outputs = [out for out in tx.vout]
self._bucket.put(tx.id, utils.serialize(new_outputs))
self._bucket.save()
def print_utxo(self):
utxos = []
for _, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out in outs:
print(out.value)
def find_utxo(self, pubkey_hash):
utxos = []
for _, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out in outs:
if out.is_locked_with_key(pubkey_hash):
utxos.append(out)
return utxos
@property
def blockchain(self):
return self._bc
class UTXOSet(object):
'''
Maintain all UTXOs in current blockchain
'''
db_file = 'block_chain.db'
bucket = 'utxo'
def __init__(self, block_chain):
self._bucket = Bucket(UTXOSet.db_file, UTXOSet.bucket)
self._bc = block_chain
def reset(self):
self._bucket = Bucket(UTXOSet.db_file, UTXOSet.bucket)
self._bucket.reset()
utxos = self._bc.find_all_utxo()
for tx_id, vout_idx in utxos.items():
self._bucket.put(tx_id, utils.serialize(vout_idx))
self._bucket.commit()
def update(self, block):
self._bucket = Bucket(UTXOSet.db_file, UTXOSet.bucket)
transactions = block.transactions
for tx in transactions:
if not isinstance(tx, CoinBaseTx):
for vin in tx.vin:
update_outs = []
encoded_outs = self._bucket.get(vin.txid)
outs = utils.deserialize(encoded_outs)
for out_idx, out in enumerate(outs):
if out_idx != vin.vout_idx:
update_outs.append(out)
if len(update_outs) == 0:
self._bucket.delete(vin.txid)
else:
self._bucket.put(
vin.txid, utils.serialize(update_outs))
new_output = [out for out in tx.vout]
self._bucket.put(tx.id, utils.serialize(new_output))
self._bucket.commit()
def find_spendable_output(self, address, amount):
accumulate = 0
spendable_output = defaultdict(list)
for tx_id, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out_idx, out in enumerate(outs):
if out.address == address:
accumulate += out.value
spendable_output[tx_id].append(out_idx)
if accumulate >= amount:
return accumulate, spendable_output
return accumulate, spendable_output
def find_utxo_by_address(self, address):
accumulate = 0
utxos = defaultdict(list)
for tx_id, outs in self._bucket.kv.items():
outs = utils.deserialize(outs)
for out_idx, out in enumerate(outs):
if out.address == address:
accumulate += out.value
utxos[tx_id].append(out_idx)
return accumulate, utxos