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use crate::api::context::Context as OpenTelemetryContext;
use pin_project::pin_project;
use std::{
pin::Pin,
task::{Context as TaskContext, Poll},
};
#[pin_project]
#[derive(Clone, Debug)]
pub struct WithContext<T> {
#[pin]
inner: T,
otel_cx: OpenTelemetryContext,
}
impl<T: Sized> FutureExt for T {}
impl<T: std::future::Future> std::future::Future for WithContext<T> {
type Output = T::Output;
fn poll(self: Pin<&mut Self>, task_cx: &mut TaskContext<'_>) -> Poll<Self::Output> {
let this = self.project();
let _guard = this.otel_cx.clone().attach();
this.inner.poll(task_cx)
}
}
impl<T: futures::Stream> futures::Stream for WithContext<T> {
type Item = T::Item;
fn poll_next(self: Pin<&mut Self>, task_cx: &mut TaskContext<'_>) -> Poll<Option<Self::Item>> {
let this = self.project();
let _guard = this.otel_cx.clone().attach();
T::poll_next(this.inner, task_cx)
}
}
impl<I, T: futures::Sink<I>> futures::Sink<I> for WithContext<T>
where
T: futures::Sink<I>,
{
type Error = T::Error;
fn poll_ready(
self: Pin<&mut Self>,
task_cx: &mut TaskContext<'_>,
) -> Poll<Result<(), Self::Error>> {
let this = self.project();
let _guard = this.otel_cx.clone().attach();
T::poll_ready(this.inner, task_cx)
}
fn start_send(self: Pin<&mut Self>, item: I) -> Result<(), Self::Error> {
let this = self.project();
let _guard = this.otel_cx.clone().attach();
T::start_send(this.inner, item)
}
fn poll_flush(
self: Pin<&mut Self>,
task_cx: &mut TaskContext<'_>,
) -> Poll<Result<(), Self::Error>> {
let this = self.project();
let _guard = this.otel_cx.clone().attach();
T::poll_flush(this.inner, task_cx)
}
fn poll_close(
self: Pin<&mut Self>,
task_cx: &mut TaskContext<'_>,
) -> futures::task::Poll<Result<(), Self::Error>> {
let this = self.project();
let _enter = this.otel_cx.clone().attach();
T::poll_close(this.inner, task_cx)
}
}
pub trait FutureExt: Sized {
fn with_context(self, otel_cx: OpenTelemetryContext) -> WithContext<Self> {
WithContext {
inner: self,
otel_cx,
}
}
fn with_current_context(self) -> WithContext<Self> {
let otel_cx = OpenTelemetryContext::current();
self.with_context(otel_cx)
}
}