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core.messaging.dispatchers.command_dispatcher

CommandDispatcher Objects​

class CommandDispatcher(MessageDispatcher[Command])

Message dispatcher specific to Command.

process​

def process() -> None

Takes care of checking whether issued commands have already timed out.

pre_dispatch​

def pre_dispatch(msg: Command, msg_meta: CommandMetaInformation) -> None

Adds command meta information to a global list so that command replies can be handled properly.

Arguments:

  • msg - The command that is about to be dispatched.
  • msg_meta - The command meta information.

invoke_reply_callbacks​

@staticmethod
def invoke_reply_callbacks(
        unique: Trace,
        *,
        reply: CommandReply | None = None,
        reply_meta: CommandReplyMetaInformation | None = None,
        fail_type: CommandReply.FailType = CommandReply.FailType.NONE,
        fail_msg: str = "") -> None

Invokes command reply callbacks.

When emitting a command, it is possible to specify reply callbacks that are invoked beside message handlers. This method will call the correct callback and take care of intercepting exceptions.

Arguments:

  • unique - The unique trace of the command.
  • reply - The received command reply (if any).
  • reply_meta - The reply meta information (if any).
  • fail_type - The type of the command failure (in case of a timeout or exception).
  • fail_msg - The failure message.