import asyncio import hashlib import json import re from datetime import datetime from pathlib import Path from typing import Callable, ContextManager, Optional from sqlmodel import Session, select from ..gossip import gossip_broker from ..logger import get_logger from ..state.merkle_patricia_trie import StateManager logger = get_logger(__name__) from ..state.state_transition import get_state_transition from ..config import ProposerConfig from ..metrics import metrics_registry from ..models import Block, Account _METRIC_KEY_SANITIZE = re.compile(r"[^a-zA-Z0-9_]") def _sanitize_metric_suffix(value: str) -> str: sanitized = _METRIC_KEY_SANITIZE.sub("_", value).strip("_") return sanitized or "unknown" def _compute_state_root(session: Session, chain_id: str) -> str: """Compute state root from current account state.""" try: state_manager = StateManager() # Get all accounts for this chain accounts = session.exec( select(Account).where(Account.chain_id == chain_id) ).all() # Convert to dictionary account_dict = {acc.address: acc for acc in accounts} # Compute state root root = state_manager.compute_state_root(account_dict) # Return as hex string return '0x' + root.hex() except Exception as e: # If state root computation fails, return None for now # This can happen during genesis block creation when accounts don't exist yet logger.warning(f"Failed to compute state root: {e}") return None import time class CircuitBreaker: def __init__(self, threshold: int, timeout: int): self._threshold = threshold self._timeout = timeout self._failures = 0 self._last_failure_time = 0.0 self._state = "closed" @property def state(self) -> str: if self._state == "open": if time.time() - self._last_failure_time > self._timeout: self._state = "half-open" return self._state def allow_request(self) -> bool: state = self.state if state == "closed": return True if state == "half-open": return True return False def record_failure(self) -> None: self._failures += 1 self._last_failure_time = time.time() if self._failures >= self._threshold: self._state = "open" def record_success(self) -> None: self._failures = 0 self._state = "closed" class PoAProposer: """Proof-of-Authority block proposer. Responsible for periodically proposing blocks if this node is configured as a proposer. In the real implementation, this would involve checking the mempool, validating transactions, and signing the block. """ def __init__( self, *, config: ProposerConfig, session_factory: Callable[[], ContextManager[Session]], ) -> None: self._config = config self._session_factory = session_factory self._logger = get_logger(__name__) self._stop_event = asyncio.Event() self._task: Optional[asyncio.Task[None]] = None self._last_proposer_id: Optional[str] = None self._last_block_timestamp: Optional[datetime] = None async def start(self) -> None: if self._task is not None: return self._logger.info("Starting PoA proposer loop", extra={"interval": self._config.interval_seconds}) await self._ensure_genesis_block() # Initialize last block timestamp from head block for heartbeat logic head = self._fetch_chain_head() if head is not None: self._last_block_timestamp = head.timestamp self._logger.info("Initialized last block timestamp from head", extra={"height": head.height}) self._stop_event.clear() self._task = asyncio.create_task(self._run_loop()) async def stop(self) -> None: if self._task is None: return self._logger.info("Stopping PoA proposer loop") self._stop_event.set() await self._task self._task = None async def _run_loop(self) -> None: # Initial sleep so we don't start proposing immediately await asyncio.sleep(self._config.interval_seconds) from ..config import settings block_generation_mode = getattr(settings, "block_generation_mode", "hybrid") while not self._stop_event.is_set(): if self._stop_event.is_set(): break try: proposed = await self._propose_block() if proposed: await self._wait_until_next_slot() else: # If we skipped proposing, wait based on mode if block_generation_mode == "hybrid": # Check more frequently in hybrid mode to catch heartbeat timing # Use 1/4 of normal interval for responsive heartbeat checks check_interval = self._config.interval_seconds / 4 try: await asyncio.wait_for(self._stop_event.wait(), timeout=check_interval) except asyncio.TimeoutError: pass else: # Regular interval for other modes try: await asyncio.wait_for(self._stop_event.wait(), timeout=self._config.interval_seconds) except asyncio.TimeoutError: pass except Exception as exc: # pragma: no cover - defensive logging self._logger.exception("Failed to propose block", extra={"error": str(exc)}) await asyncio.sleep(1.0) async def _wait_until_next_slot(self) -> None: head = self._fetch_chain_head() if head is None: return now = datetime.utcnow() elapsed = (now - head.timestamp).total_seconds() sleep_for = max(self._config.interval_seconds - elapsed, 0.1) if sleep_for <= 0: sleep_for = 0.1 try: await asyncio.wait_for(self._stop_event.wait(), timeout=sleep_for) except asyncio.TimeoutError: return async def _propose_block(self) -> bool: # Check internal mempool and include transactions from ..mempool import get_mempool from ..models import Transaction, Account from ..config import settings mempool = get_mempool() # Hybrid block generation logic block_generation_mode = getattr(settings, "block_generation_mode", "hybrid") max_empty_block_interval = getattr(settings, "max_empty_block_interval", 60) if block_generation_mode in ["mempool-only", "hybrid"]: mempool_size = mempool.size(self._config.chain_id) if block_generation_mode == "mempool-only": # Strict mempool-only mode: skip if empty if mempool_size == 0: self._logger.info(f"[PROPOSE] Skipping block proposal: mempool is empty (chain={self._config.chain_id}, mode=mempool-only)") metrics_registry.increment("sync_empty_blocks_skipped_total") return False elif block_generation_mode == "hybrid": # Hybrid mode: check heartbeat interval if self._last_block_timestamp: time_since_last_block = (datetime.utcnow() - self._last_block_timestamp).total_seconds() if mempool_size == 0 and time_since_last_block < max_empty_block_interval: self._logger.info(f"[PROPOSE] Skipping block proposal: mempool empty, heartbeat not yet due (chain={self._config.chain_id}, mode=hybrid, idle_time={time_since_last_block:.1f}s)") metrics_registry.increment("sync_empty_blocks_skipped_total") return False elif mempool_size == 0 and time_since_last_block >= max_empty_block_interval: self._logger.info(f"[PROPOSE] Forcing heartbeat block: idle for {time_since_last_block:.1f}s (chain={self._config.chain_id}, mode=hybrid)") metrics_registry.increment("sync_heartbeat_blocks_forced_total") metrics_registry.observe("sync_time_since_last_block_seconds", time_since_last_block) elif mempool_size == 0: # No previous block timestamp, skip (will be set after genesis) self._logger.info(f"[PROPOSE] Skipping block proposal: no previous block timestamp (chain={self._config.chain_id}, mode=hybrid)") metrics_registry.increment("sync_empty_blocks_skipped_total") return False with self._session_factory() as session: head = session.exec(select(Block).where(Block.chain_id == self._config.chain_id).order_by(Block.height.desc()).limit(1)).first() next_height = 0 parent_hash = "0x00" interval_seconds: Optional[float] = None if head is not None: next_height = head.height + 1 parent_hash = head.hash interval_seconds = (datetime.utcnow() - head.timestamp).total_seconds() timestamp = datetime.utcnow() # Pull transactions from mempool max_txs = self._config.max_txs_per_block max_bytes = self._config.max_block_size_bytes pending_txs = mempool.drain(max_txs, max_bytes, self._config.chain_id) self._logger.info(f"[PROPOSE] drained {len(pending_txs)} txs from mempool, chain={self._config.chain_id}") # Process transactions and update balances processed_txs = [] for tx in pending_txs: try: # Parse transaction data tx_data = tx.content sender = tx_data.get("from") recipient = tx_data.get("to") value = tx_data.get("amount", 0) fee = tx_data.get("fee", 0) self._logger.info(f"[PROPOSE] Processing tx {tx.tx_hash}: from={sender}, to={recipient}, amount={value}, fee={fee}") if not sender or not recipient: self._logger.warning(f"[PROPOSE] Skipping tx {tx.tx_hash}: missing sender or recipient") continue # Get sender account sender_account = session.get(Account, (self._config.chain_id, sender)) if not sender_account: self._logger.warning(f"[PROPOSE] Skipping tx {tx.tx_hash}: sender account not found for {sender}") continue # Check sufficient balance total_cost = value + fee if sender_account.balance < total_cost: self._logger.warning(f"[PROPOSE] Skipping tx {tx.tx_hash}: insufficient balance (has {sender_account.balance}, needs {total_cost})") continue # Get or create recipient account recipient_account = session.get(Account, (self._config.chain_id, recipient)) if not recipient_account: self._logger.info(f"[PROPOSE] Creating recipient account for {recipient}") recipient_account = Account(chain_id=self._config.chain_id, address=recipient, balance=0, nonce=0) session.add(recipient_account) session.flush() else: self._logger.info(f"[PROPOSE] Recipient account exists for {recipient}") # Apply state transition through validated transaction state_transition = get_state_transition() # Use original tx_data from mempool to preserve type and payload tx_data_for_transition = tx.content.copy() tx_data_for_transition["nonce"] = sender_account.nonce success, error_msg = state_transition.apply_transaction( session, self._config.chain_id, tx_data_for_transition, tx.tx_hash ) if not success: self._logger.warning(f"[PROPOSE] Failed to apply transaction {tx.tx_hash}: {error_msg}") continue # Check if transaction already exists in database existing_tx = session.exec( select(Transaction).where( Transaction.chain_id == self._config.chain_id, Transaction.tx_hash == tx.tx_hash ) ).first() if existing_tx: self._logger.warning(f"[PROPOSE] Skipping tx {tx.tx_hash}: already exists in database at block {existing_tx.block_height}") continue # Create transaction record # Extract type from normalized tx_data (which should have the type field) tx_type = tx.content.get("type", "TRANSFER") if tx_type: tx_type = tx_type.upper() else: tx_type = "TRANSFER" # Store only the original payload, not the full normalized data original_payload = tx.content.get("payload", {}) transaction = Transaction( chain_id=self._config.chain_id, tx_hash=tx.tx_hash, sender=sender, recipient=recipient, payload=original_payload, value=value, fee=fee, nonce=sender_account.nonce - 1, timestamp=timestamp, block_height=next_height, status="confirmed", type=tx_type ) session.add(transaction) processed_txs.append(tx) self._logger.info(f"[PROPOSE] Successfully processed tx {tx.tx_hash}: updated balances") except Exception as e: self._logger.warning(f"Failed to process transaction {tx.tx_hash}: {e}") continue if pending_txs and not processed_txs and getattr(settings, "propose_only_if_mempool_not_empty", True): self._logger.warning( f"[PROPOSE] Skipping block proposal: all drained transactions were invalid (count={len(pending_txs)}, chain={self._config.chain_id})" ) return False # Compute block hash with transaction data block_hash = self._compute_block_hash(next_height, parent_hash, timestamp, processed_txs) # Compute state root from account state state_root = _compute_state_root(session, self._config.chain_id) block = Block( chain_id=self._config.chain_id, height=next_height, hash=block_hash, parent_hash=parent_hash, proposer=self._config.proposer_id, timestamp=timestamp, tx_count=len(processed_txs), state_root=state_root, ) session.add(block) session.commit() metrics_registry.increment("blocks_proposed_total") metrics_registry.set_gauge("chain_head_height", float(next_height)) if interval_seconds is not None and interval_seconds >= 0: metrics_registry.observe("block_interval_seconds", interval_seconds) metrics_registry.set_gauge("poa_last_block_interval_seconds", float(interval_seconds)) proposer_suffix = _sanitize_metric_suffix(self._config.proposer_id) metrics_registry.increment(f"poa_blocks_proposed_total_{proposer_suffix}") if self._last_proposer_id is not None and self._last_proposer_id != self._config.proposer_id: metrics_registry.increment("poa_proposer_switches_total") self._last_proposer_id = self._config.proposer_id # Update last block timestamp for heartbeat logic self._last_block_timestamp = timestamp self._logger.info( "Proposed block", extra={ "height": block.height, "hash": block.hash, "proposer": block.proposer, }, ) # Broadcast the new block tx_list = [tx.content for tx in processed_txs] if processed_txs else [] await gossip_broker.publish( "blocks", { "chain_id": self._config.chain_id, "height": block.height, "hash": block.hash, "parent_hash": block.parent_hash, "proposer": block.proposer, "timestamp": block.timestamp.isoformat(), "tx_count": block.tx_count, "state_root": block.state_root, "transactions": tx_list, }, ) return True async def _ensure_genesis_block(self) -> None: with self._session_factory() as session: # Check if genesis block already exists genesis = session.exec(select(Block).where(Block.chain_id == self._config.chain_id).where(Block.height == 0).limit(1)).first() if genesis is not None: self._logger.info(f"Genesis block already exists: height={genesis.height}, hash={genesis.hash}, proposer={genesis.proposer}") return # Use a deterministic genesis timestamp so all nodes agree on the genesis block hash timestamp = datetime(2025, 1, 1, 0, 0, 0) block_hash = self._compute_block_hash(0, "0x00", timestamp) # Check if block with this hash already exists (duplicate check) existing = session.exec(select(Block).where(Block.chain_id == self._config.chain_id).where(Block.hash == block_hash).limit(1)).first() if existing is not None: self._logger.info(f"Genesis block with hash {block_hash} already exists, skipping creation") return # Compute state root for genesis block state_root = _compute_state_root(session, self._config.chain_id) genesis = Block( chain_id=self._config.chain_id, height=0, hash=block_hash, parent_hash="0x00", proposer="genesis", # Use "genesis" as the proposer for genesis block to avoid hash conflicts timestamp=timestamp, tx_count=0, state_root=state_root, ) session.add(genesis) try: session.commit() except Exception as e: self._logger.warning(f"Failed to create genesis block: {e}") session.rollback() return # Initialize accounts from genesis allocations file (if present) await self._initialize_genesis_allocations(session) # Recompute state root after accounts are initialized new_state_root = _compute_state_root(session, self._config.chain_id) if new_state_root: genesis.state_root = new_state_root session.add(genesis) session.commit() self._logger.info(f"Updated genesis block state_root: {new_state_root}") # Broadcast genesis block for initial sync await gossip_broker.publish( "blocks", { "chain_id": self._config.chain_id, "height": genesis.height, "hash": genesis.hash, "parent_hash": genesis.parent_hash, "proposer": genesis.proposer, "timestamp": genesis.timestamp.isoformat(), "tx_count": genesis.tx_count, "state_root": genesis.state_root, } ) async def _initialize_genesis_allocations(self, session: Session) -> None: """Create Account entries from the genesis allocations file.""" # Use standardized data directory from configuration from ..config import settings genesis_paths = [ Path(f"/var/lib/aitbc/data/{self._config.chain_id}/genesis.json"), # Standard location ] genesis_path = None for path in genesis_paths: if path.exists(): genesis_path = path break if not genesis_path: self._logger.warning("Genesis allocations file not found; skipping account initialization", extra={"paths": str(genesis_paths)}) return with open(genesis_path) as f: genesis_data = json.load(f) allocations = genesis_data.get("allocations", []) created = 0 for alloc in allocations: addr = alloc["address"] balance = int(alloc["balance"]) nonce = int(alloc.get("nonce", 0)) # Check if account already exists (idempotent) acct = session.get(Account, (self._config.chain_id, addr)) if acct is None: acct = Account(chain_id=self._config.chain_id, address=addr, balance=balance, nonce=nonce) session.add(acct) created += 1 session.commit() self._logger.info("Initialized genesis accounts", extra={"count": created, "total": len(allocations), "path": str(genesis_path)}) def _fetch_chain_head(self) -> Optional[Block]: with self._session_factory() as session: return session.exec( select(Block) .where(Block.chain_id == self._config.chain_id) .order_by(Block.height.desc()) .limit(1) ).first() def _compute_block_hash(self, height: int, parent_hash: str, timestamp: datetime, transactions: list = None) -> str: # Include transaction hashes in block hash computation tx_hashes = [] if transactions: tx_hashes = [tx.tx_hash for tx in transactions] payload = f"{self._config.chain_id}|{height}|{parent_hash}|{timestamp.isoformat()}|{'|'.join(sorted(tx_hashes))}".encode() return "0x" + hashlib.sha256(payload).hexdigest()