def _connect_block(block: Block, active_chain: BlockChain, utxo_set: UTXO_Set) -> bool:
"""
Add block after current chain. Return True if block added successfully, else False.
"""
if block.validate_block(active_chain, utxo_set) is None:
return False
logger.info(
f"connecting the {len(active_chain.chain)+1}th block {block.id} to chain {active_chain.idx}"
)
active_chain.chain.append(block)
# Minipulate transactions in this block.
# Remove txin from utxo_set, add txout to utxo_set.
for tx in block.txns:
if not tx.is_coinbase:
for txin in tx.txins:
utxo_set.rm_from_utxo(*txin.to_spend)
for i, txout in enumerate(tx.txouts):
utxo_set.add_to_utxo(
txout, tx, i, tx.is_coinbase, len(active_chain.chain)
)
return True
def disconnect_block(self, mempool: MemPool, utxo_set: UTXO_Set) -> Block:
block = self.chain[-1]
for tx in block.txns:
if tx.txins[0].to_spend is not None:
mempool.mempool[tx.id] = tx
# Restore UTXO set to what it was before this block.
for txin in tx.txins:
if txin.to_spend: # Account for degenerate coinbase txins.
utxo_set.add_to_utxo(*self.find_txout_for_txin(txin))
for i in range(len(tx.txouts)):
utxo_set.rm_from_utxo(tx.id, i)
logger.info(f'[ds] block {block.id} disconnected, recover transactions and UTXOs by it')
return self.chain.pop()
def _connect_block(block: Block, active_chain: BlockChain,
utxo_set: UTXO_Set) -> bool:
if block.validate_block(active_chain, utxo_set) is None:
return False
logger.info(
f'connecting the {len(active_chain.chain)+1}th block {block.id} to chain {active_chain.idx}'
)
active_chain.chain.append(block)
for tx in block.txns:
if not tx.is_coinbase:
for txin in tx.txins:
utxo_set.rm_from_utxo(*txin.to_spend)
for i, txout in enumerate(tx.txouts):
utxo_set.add_to_utxo(txout, tx, i, tx.is_coinbase,
len(active_chain.chain))
return True
def connect_block(self, block: Block, active_chain: BaseBlockChain, side_branches: Iterable[BaseBlockChain],\
mempool: MemPool, utxo_set: UTXO_Set, mine_interrupt: threading.Event,\
doing_reorg=False) -> bool:
def _reorg_and_succeed(active_chain: BaseBlockChain, side_branches: Iterable[BaseBlockChain], \
mempool: MemPool, utxo_set:UTXO_Set, \
mine_interrupt: threading.Event) -> bool:
def _do_reorg(branch_idx: int, side_branches: Iterable[BaseBlockChain], active_chain: BaseBlockChain, \
fork_height: int, mempool: MemPool, utxo_set:UTXO_Set, \
mine_interrupt: threading.Event) -> bool:
branch_chain = side_branches[branch_idx - 1]
fork_block = active_chain.chain[fork_height - 1]
def disconnect_to_fork(active_chain: BaseBlockChain = active_chain, fork_block: Block = fork_block):
while active_chain.chain[-1].id != fork_block.id:
yield active_chain.disconnect_block(mempool, utxo_set)
old_active = list(disconnect_to_fork(active_chain, fork_block))[::-1]
assert branch_chain.chain[0].prev_block_hash == active_chain.chain[-1].id
def rollback_reorg():
list(disconnect_to_fork(active_chain, fork_block))
for block in old_active:
assert active_chain.connect_block(block, active_chain, side_branches, mempool, utxo_set, \
mine_interrupt, \
doing_reorg=True) == True
for block in branch_chain.chain:
if not active_chain.connect_block(block, active_chain, side_branches, mempool, utxo_set, \
mine_interrupt, doing_reorg=True):
logger.info(f'[ds] reorg of branch {branch_idx} to active_chain failed, decide to rollback')
rollback_reorg()
return False
branch_chain.chain = list(old_active)
logger.info(f'[ds] chain reorg successful with new active_chain height {active_chain.height} and top block id {active_chain.chain[-1].id}')
return True
reorged = False
frozen_side_branches = list(side_branches)
for _, branch_chain in enumerate(frozen_side_branches):
branch_idx = branch_chain.idx
fork_block, fork_height, _ = Block.locate_block(branch_chain.chain[0].prev_block_hash, active_chain)
active_height = active_chain.height
branch_height_real = branch_chain.height + fork_height
if branch_height_real > active_height:
logger.info(f'[ds] decide to reorg branch {branch_idx} with height {branch_height_real} to active_chain with real height {active_height}')
reorged |= _do_reorg(branch_idx, side_branches, active_chain, fork_height, mempool, \
utxo_set, mine_interrupt)
if reorged is True:
return reorged
return reorged
if self.idx == Params.ACTIVE_CHAIN_IDX:
logger.info(f'[ds] ##### connecting block at height #{len(self.chain)+1} chain with index #{self.idx}: {block.id} ')
else:
logger.info(f'[ds] ## connecting block to chain with index #{self.idx}: {block.id} ')
self.chain.append(block)
# If we added to the active chain, perform upkeep on utxo_set and mempool.
if self.idx == Params.ACTIVE_CHAIN_IDX:
for tx in block.txns:
mempool.mempool.pop(tx.id, None)
if not tx.is_coinbase:
for txin in tx.txins:
utxo_set.rm_from_utxo(*txin.to_spend)
for i, txout in enumerate(tx.txouts):
# print(txout)
utxo_set.add_to_utxo(txout, tx, i, tx.is_coinbase, self.height)
reorg_and_succeed = False
if doing_reorg == False:
reorg_and_succeed = _reorg_and_succeed(active_chain, side_branches, mempool, utxo_set, mine_interrupt)
if reorg_and_succeed or self.idx == Params.ACTIVE_CHAIN_IDX:
mine_interrupt.set()
return -1 if reorg_and_succeed else True