use crate::client::RowStream;
use crate::error::OrmResult;
use crate::row::FromRow;
use futures_core::Stream;
use std::marker::PhantomData;
use std::pin::Pin;
use std::task::{Context, Poll};
#[must_use]
pub struct FromRowStream<T> {
inner: RowStream,
_marker: PhantomData<fn() -> T>,
}
impl<T> FromRowStream<T> {
pub(crate) fn new(inner: RowStream) -> Self {
Self {
inner,
_marker: PhantomData,
}
}
}
impl<T: FromRow> Stream for FromRowStream<T> {
type Item = OrmResult<T>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
match Pin::new(&mut self.inner).poll_next(cx) {
Poll::Ready(Some(Ok(row))) => Poll::Ready(Some(T::from_row(&row))),
Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(e))),
Poll::Ready(None) => Poll::Ready(None),
Poll::Pending => Poll::Pending,
}
}
}