Class HookFunctionReference

src/diffusers/hooks/hooks.py:144–164

class HookFunctionReference:
    def __init__(self) -> None:
        """A container class that maintains mutable references to forward pass functions in a hook chain.

        Its mutable nature allows the hook system to modify the execution chain dynamically without rebuilding the
        entire forward pass structure.

        Attributes:
            pre_forward: A callable that processes inputs before the main forward pass.
            post_forward: A callable that processes outputs after the main forward pass.
            forward: The current forward function in the hook chain.
            original_forward: The original forward function, stored when a hook provides a custom new_forward.

        The class enables hook removal by allowing updates to the forward chain through reference modification rather
        than requiring reconstruction of the entire chain. When a hook is removed, only the relevant references need to
        be updated, preserving the execution order of the remaining hooks.
        """
        self.pre_forward = None
        self.post_forward = None
        self.forward = None
        self.original_forward = None


class HookRegistry: