1 | use super::{Body, SizeHint}; |
2 | use bytes::Buf; |
3 | use http::HeaderMap; |
4 | use std::{ |
5 | convert::Infallible, |
6 | fmt, |
7 | marker::PhantomData, |
8 | pin::Pin, |
9 | task::{Context, Poll}, |
10 | }; |
11 | |
12 | /// A body that is always empty. |
13 | pub struct Empty<D> { |
14 | _marker: PhantomData<fn() -> D>, |
15 | } |
16 | |
17 | impl<D> Empty<D> { |
18 | /// Create a new `Empty`. |
19 | pub fn new() -> Self { |
20 | Self::default() |
21 | } |
22 | } |
23 | |
24 | impl<D: Buf> Body for Empty<D> { |
25 | type Data = D; |
26 | type Error = Infallible; |
27 | |
28 | #[inline ] |
29 | fn poll_data( |
30 | self: Pin<&mut Self>, |
31 | _cx: &mut Context<'_>, |
32 | ) -> Poll<Option<Result<Self::Data, Self::Error>>> { |
33 | Poll::Ready(None) |
34 | } |
35 | |
36 | #[inline ] |
37 | fn poll_trailers( |
38 | self: Pin<&mut Self>, |
39 | _cx: &mut Context<'_>, |
40 | ) -> Poll<Result<Option<HeaderMap>, Self::Error>> { |
41 | Poll::Ready(Ok(None)) |
42 | } |
43 | |
44 | fn is_end_stream(&self) -> bool { |
45 | true |
46 | } |
47 | |
48 | fn size_hint(&self) -> SizeHint { |
49 | SizeHint::with_exact(0) |
50 | } |
51 | } |
52 | |
53 | impl<D> fmt::Debug for Empty<D> { |
54 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
55 | f.debug_struct(name:"Empty" ).finish() |
56 | } |
57 | } |
58 | |
59 | impl<D> Default for Empty<D> { |
60 | fn default() -> Self { |
61 | Self { |
62 | _marker: PhantomData, |
63 | } |
64 | } |
65 | } |
66 | |
67 | impl<D> Clone for Empty<D> { |
68 | fn clone(&self) -> Self { |
69 | Self { |
70 | _marker: PhantomData, |
71 | } |
72 | } |
73 | } |
74 | |
75 | impl<D> Copy for Empty<D> {} |
76 | |