Zebra/tower-batch/src/layer.rs

57 lines
1.7 KiB
Rust

use super::{service::Batch, BatchControl};
use std::{fmt, marker::PhantomData};
use tower::layer::Layer;
use tower::Service;
/// Adds a layer performing batch processing of requests.
///
/// The default Tokio executor is used to run the given service,
/// which means that this layer can only be used on the Tokio runtime.
///
/// See the module documentation for more details.
pub struct BatchLayer<Request> {
max_items: usize,
max_latency: std::time::Duration,
_p: PhantomData<fn(Request)>,
}
impl<Request> BatchLayer<Request> {
/// Creates a new `BatchLayer`.
///
/// The wrapper is responsible for telling the inner service when to flush a
/// batch of requests. Two parameters control this policy:
///
/// * `max_items` gives the maximum number of items per batch.
/// * `max_latency` gives the maximum latency for a batch item.
pub fn new(max_items: usize, max_latency: std::time::Duration) -> Self {
BatchLayer {
max_items,
max_latency,
_p: PhantomData,
}
}
}
impl<S, Request> Layer<S> for BatchLayer<Request>
where
S: Service<BatchControl<Request>> + Send + 'static,
S::Future: Send,
S::Error: Into<crate::BoxError> + Send + Sync,
Request: Send + 'static,
{
type Service = Batch<S, Request>;
fn layer(&self, service: S) -> Self::Service {
Batch::new(service, self.max_items, self.max_latency)
}
}
impl<Request> fmt::Debug for BatchLayer<Request> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("BufferLayer")
.field("max_items", &self.max_items)
.field("max_latency", &self.max_latency)
.finish()
}
}