Struct Prepared 

pub struct Prepared { /* private fields */ }

A plan with every operator’s code prepared: one per program, shared by every subscription.

The split between this and Engine is the difference between a plan and an arrangement, and it is load-bearing for §5.3’s fanout. Preparing an operator means asking the backend to turn Core into something callable, which a compiling backend does expensively and even a tree-walker does by cloning the expression; doing it per subscriber cost about 90 KB of a subscription that then held 60 entries. A thousand subscribers share one of these.

Implementations

impl Prepared

pub fn new( plan: Arc<Plan>, backend: &dyn Backend, ) -> Result<Prepared, ExecError>

pub fn compile( placed: &Placed, backend: &dyn Backend, ) -> Result<Prepared, ExecError>

Compile and prepare a sliced program’s view in one step.

pub fn plan(&self) -> &Arc<Plan>