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// Copyright 2022 Palantir Technologies, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use crate::service::{Layer, Service};
use http::Request;
use std::fmt;
#[derive(Copy, Clone)]
pub struct RequestId {
id: [u8; 8],
}
impl RequestId {
pub fn random() -> Self {
RequestId { id: rand::random() }
}
}
impl fmt::Display for RequestId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for b in &self.id {
write!(f, "{b:02x}")?;
}
Ok(())
}
}
/// A layer which adds a unique [`RequestId`] to each request's extensions.
pub struct RequestIdLayer;
impl<S> Layer<S> for RequestIdLayer {
type Service = RequestIdService<S>;
fn layer(self, inner: S) -> Self::Service {
RequestIdService { inner }
}
}
pub struct RequestIdService<S> {
inner: S,
}
impl<S, B> Service<Request<B>> for RequestIdService<S>
where
S: Service<Request<B>> + Sync,
B: Send,
{
type Response = S::Response;
async fn call(&self, mut req: Request<B>) -> Self::Response {
req.extensions_mut().insert(RequestId::random());
self.inner.call(req).await
}
}