def test_invalid_rev_block_3():
utxo_set = UTXOSet()
rev_block = RevBlock("", [], [])
rev_block.pow = "00" * 32
rev_block.removable = [OutPoint("aa" * 32, 0).hex]
with pytest.raises(Exception):
utxo_set.reverse_block(rev_block)
def test_invalid_rev_block_2():
utxo_set = UTXOSet()
rev_block = RevBlock("", [], [])
rev_block.pow = "00" * 32
rev_block.old_txout = [[OutPoint("00" * 32, 0).hex, TxOut()]]
with pytest.raises(Exception):
utxo_set.reverse_block(rev_block)
def test_invalid_tx():
utxo_set = UTXOSet()
tx = Tx(
[
TxIn(OutPoint("00" * 32, 0), Script()),
TxIn(OutPoint("00" * 32, 0), Script()),
],
[TxOut(10**10, Script())],
)
assert not utxo_set.validate_transaction(tx)
def __init__(self, name="regtest"):
self.base_dir = os.path.join(os.path.expanduser("~"), ".toykoin", name)
os.makedirs(self.base_dir, exist_ok=True)
os.makedirs(os.path.join(self.base_dir, "blocks"), exist_ok=True)
os.makedirs(os.path.join(self.base_dir, "rev"), exist_ok=True)
self.__utxo_set = UTXOSet(self.base_dir)
self.db = sqlite3.connect(os.path.join(self.base_dir, "chainstate.sqlite"))
self.cursor = self.db.cursor()
try: # initializing db
self.cursor.execute("CREATE TABLE header (pow, previous_pow, id)")
except:
pass
class Blockchain:
def __init__(self, name="regtest"):
self.base_dir = os.path.join(os.path.expanduser("~"), ".toykoin", name)
os.makedirs(self.base_dir, exist_ok=True)
os.makedirs(os.path.join(self.base_dir, "blocks"), exist_ok=True)
os.makedirs(os.path.join(self.base_dir, "rev"), exist_ok=True)
self.__utxo_set = UTXOSet(self.base_dir)
self.db = sqlite3.connect(os.path.join(self.base_dir, "chainstate.sqlite"))
self.cursor = self.db.cursor()
try: # initializing db
self.cursor.execute("CREATE TABLE header (pow, previous_pow, id)")
except:
pass
def get_utxo_set(self):
return self.__utxo_set
def get_block(self, pow):
self.cursor.execute("SELECT * FROM header WHERE pow = ?", (pow,))
block = self.cursor.fetchall()
return block[0] if block else None
def get_last_blocks(self, n=1):
self.cursor.execute(
"SELECT * FROM header WHERE id > (SELECT MAX(id) FROM header) -?", (n,)
)
last_pow = self.cursor.fetchall()
if not last_pow:
return [[None, None, -1]]
else:
return last_pow
def _add_block(self, block):
previous_pow = block.header.previous_pow
if previous_pow != "00" * 32 and previous_pow != self.get_last_blocks()[0][0]:
raise Exception
reverse_block = self.__utxo_set.add_block(block)
self.cursor.execute(
"INSERT INTO header VALUES (?, ?, ?)",
(
block.header.pow,
block.header.previous_pow,
self.get_last_blocks()[0][2] + 1,
),
)
filename = os.path.join(self.base_dir, "blocks", block.header.pow + ".block")
with open(filename, "wb") as f:
f.write(block.serialize())
filename = os.path.join(self.base_dir, "rev", block.header.pow + ".rev")
with open(filename, "wb") as f:
f.write(reverse_block.serialize())
return reverse_block
def _reverse_block(self, rev_block):
if rev_block.pow != self.get_last_blocks()[0][0]:
raise Exception
self.__utxo_set.reverse_block(rev_block)
self.cursor.execute("DELETE FROM header WHERE pow = ?", (rev_block.pow,))
# it does not raise exceptions, it return True if the blockchain pow been changed
def add_blocks(self, blocks):
last_block = self.get_last_blocks()
for i, block in enumerate(blocks):
if not self.get_block(block.header.pow): # first new block
blocks = blocks[i:]
break
try: # tries to add enough blocks to be in the best chain
last_valid_block = self.get_block(blocks[0].header.previous_pow)
if last_valid_block: # if it is not the first block
last_valid_index = self.get_block(last_valid_block[0])[2]
last_index = self.get_last_blocks()[0][2]
if last_index - last_valid_index > 0:
reverse_blocks = self.get_last_blocks(last_index - last_valid_index)
for rev_block in reverse_blocks:
filename = os.path.join(
self.base_dir, "rev", rev_block[0] + ".rev"
)
with open(filename, "rb") as f:
rev_block = RevBlock.deserialize(f.read())
self._reverse_block(rev_block)
previous_work = work_from_chain([rev[0] for rev in reverse_blocks])
current_chain = []
blocks = (i for i in blocks) # change to iterator
for block in blocks:
self._add_block(block)
current_chain.append(block.header.pow)
if work_from_chain(current_chain) > previous_work:
break # already in best chain
self.__utxo_set.db.commit()
self.db.commit()
except:
self.__utxo_set.db.rollback()
self.db.rollback()
return False
for block in blocks:
try:
self._add_block(block)
self.__utxo_set.db.commit()
self.db.commit()
except:
self.__utxo_set.db.rollback()
self.db.rollback()
if last_block == self.get_last_blocks():
return False
else:
return True