Trait OffloadPolicy

Source

pub trait OffloadPolicy<T: BlockMetadata>: Send + Sync {
    // Required methods
    fn name(&self) -> &str;
    fn evaluate<'a>(&'a self, ctx: &'a EvalContext<T>) -> PolicyFuture<'a>;

    // Provided method
    fn evaluate_batch<'a>(
        &'a self,
        contexts: &'a [EvalContext<T>],
    ) -> PolicyBatchFuture<'a> { ... }
}

Expand description

Trait for offload policies that filter blocks.

Policies are evaluated as a chain - a block must pass ALL policies to proceed. Each policy receives an EvalContext with block information and returns Ok(true) to pass or Ok(false) to filter out.

§Performance

This trait uses Either<Ready, BoxFuture> instead of #[async_trait] to avoid heap allocations for synchronous policies. Implement using:

sync_result(Ok(true)) for synchronous policies (zero allocation)
async_result(async { ... }) for async policies (boxes the future)

§Batch Evaluation

The evaluate_batch method provides a default implementation that calls evaluate for each block. Override for efficiency when the policy can benefit from batching (e.g., batch registry lookups).