def read_utxos():
utxos = []
utxos_append = utxos.append
# Key: b'u' + address_hashX + tx_idx + tx_num
# Value: the UTXO value as a 64-bit unsigned integer
prefix = b'u' + hashX
for db_key, db_value in self.utxo_db.iterator(prefix=prefix):
tx_pos, = unpack_le_uint32(db_key[-9:-5])
tx_num, = unpack_le_uint64(db_key[-5:] + bytes(3))
value, = unpack_le_uint64(db_value)
tx_hash, height = self.fs_tx_hash(tx_num)
utxos_append(UTXO(tx_num, tx_pos, tx_hash, height, value))
return utxos
def read_utxos():
utxos = []
utxos_append = utxos.append
txnum_padding = bytes(8-TXNUM_LEN)
# Key: b'u' + address_hashX + txout_idx + tx_num
# Value: the UTXO value as a 64-bit unsigned integer
prefix = b'u' + hashX
for db_key, db_value in self.utxo_db.iterator(prefix=prefix):
txout_idx, = unpack_le_uint32(db_key[-TXNUM_LEN-4:-TXNUM_LEN])
tx_num, = unpack_le_uint64(db_key[-TXNUM_LEN:] + txnum_padding)
value, = unpack_le_uint64(db_value)
tx_hash, height = self.fs_tx_hash(tx_num)
utxos_append(UTXO(tx_num, txout_idx, tx_hash, height, value))
return utxos
def spend_utxo(self, tx_hash, tx_idx, spend_tx_hash):
'''Spend a UTXO and return the 33-byte value.
If the UTXO is not in the cache it must be on disk. We store
all UTXOs so not finding one indicates a logic error or DB
corruption.
'''
# Fast track is it being in the cache
idx_packed = pack_le_uint32(tx_idx)
cache_value = self.utxo_cache.pop(tx_hash + idx_packed, None)
if cache_value:
return cache_value
# Spend it from the DB.
# Key: b'h' + compressed_tx_hash + tx_idx + tx_num
# Value: hashX
prefix = b'h' + tx_hash[:4] + idx_packed
candidates = {
db_key: hashX
for db_key, hashX in self.db.utxo_db.iterator(prefix=prefix)
}
for hdb_key, hashX in candidates.items():
tx_num_packed = hdb_key[-4:]
if len(candidates) > 1:
tx_num, = unpack_le_uint32(tx_num_packed)
hash, _height = self.db.fs_tx_hash(tx_num)
if hash != tx_hash:
assert hash is not None # Should always be found
continue
# Key: b'u' + address_hashX + tx_idx + tx_num
# Value: the UTXO value as a 64-bit unsigned integer
udb_key = b'u' + hashX + hdb_key[-8:]
utxo_value_packed = self.db.utxo_db.get(udb_key)
if utxo_value_packed:
# Remove both entries for this UTXO
self.db_deletes.append(hdb_key)
self.db_deletes.append(udb_key)
return hashX + tx_num_packed + utxo_value_packed
if spend_tx_hash in self.dup_tx_hashes:
return None
raise ChainError(
'UTXO {}:{:,d} not found in "h" table at height {}, spend tx {}'.
format(hash_to_hex_str(tx_hash), tx_idx, self.height,
hash_to_hex_str(spend_tx_hash)))
def lookup_hashX(tx_hash, tx_idx):
idx_packed = pack_le_uint32(tx_idx)
# Key: b'h' + compressed_tx_hash + tx_idx + tx_num
# Value: hashX
prefix = b'h' + tx_hash[:4] + idx_packed
# Find which entry, if any, the TX_HASH matches.
for db_key, hashX in self.utxo_db.iterator(prefix=prefix):
tx_num_packed = db_key[-4:]
tx_num, = unpack_le_uint32(tx_num_packed)
hash, _height = self.fs_tx_hash(tx_num)
if hash == tx_hash:
return hashX, idx_packed + tx_num_packed
return None, None
def read_utxos():
utxos = []
utxos_append = utxos.append
# Key: b'u' + address_hashX + tx_num + txout_idx
# Value: the UTXO value as a 64-bit unsigned integer
prefix = b'u' + hashX
for db_key, db_value in self.utxo_db.iterator(prefix=prefix):
txout_idx, = unpack_le_uint32(db_key[-TXOUTIDX_LEN:] +
TXOUTIDX_PADDING)
tx_numb = db_key[-TXOUTIDX_LEN - TXNUM_LEN:-TXOUTIDX_LEN]
tx_num = unpack_txnum(tx_numb)
value, = unpack_le_uint64(db_value)
tx_hash, height = self.fs_tx_hash(tx_num)
utxos_append(UTXO(tx_num, txout_idx, tx_hash, height, value))
return utxos
def date_str(self):
timestamp, = unpack_le_uint32(self.header[68:72])
return datetime.utcfromtimestamp(timestamp).strftime(
'%Y-%m-%d %H:%M:%S')