Files
dify/api/graphon/graph_engine/command_processing/command_processor.py

80 lines
2.4 KiB
Python

"""
Main command processor for handling external commands.
"""
import logging
from typing import Protocol, final
from ..domain.graph_execution import GraphExecution
from ..entities.commands import GraphEngineCommand
from ..protocols.command_channel import CommandChannel
logger = logging.getLogger(__name__)
class CommandHandler(Protocol):
"""Protocol for command handlers."""
def handle(self, command: GraphEngineCommand, execution: GraphExecution) -> None: ...
@final
class CommandProcessor:
"""
Processes external commands sent to the engine.
This polls the command channel and dispatches commands to
appropriate handlers.
"""
def __init__(
self,
command_channel: CommandChannel,
graph_execution: GraphExecution,
) -> None:
"""
Initialize the command processor.
Args:
command_channel: Channel for receiving commands
graph_execution: Graph execution aggregate
"""
self._command_channel = command_channel
self._graph_execution = graph_execution
self._handlers: dict[type[GraphEngineCommand], CommandHandler] = {}
def register_handler(self, command_type: type[GraphEngineCommand], handler: CommandHandler) -> None:
"""
Register a handler for a command type.
Args:
command_type: Type of command to handle
handler: Handler for the command
"""
self._handlers[command_type] = handler
def process_commands(self) -> None:
"""Check for and process any pending commands."""
try:
commands = self._command_channel.fetch_commands()
for command in commands:
self._handle_command(command)
except Exception as e:
logger.warning("Error processing commands: %s", e)
def _handle_command(self, command: GraphEngineCommand) -> None:
"""
Handle a single command.
Args:
command: The command to handle
"""
handler = self._handlers.get(type(command))
if handler:
try:
handler.handle(command, self._graph_execution)
except Exception:
logger.exception("Error handling command %s", command.__class__.__name__)
else:
logger.warning("No handler registered for command: %s", command.__class__.__name__)