1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
use bytes::{Buf, Bytes};
use http_body::{Body, Frame, SizeHint};
use pin_project_lite::pin_project;
use std::borrow::Cow;
use std::convert::{Infallible, TryFrom};
use std::pin::Pin;
use std::task::{Context, Poll};

pin_project! {
    /// A body that consists of a single chunk.
    #[derive(Clone, Copy, Debug)]
    pub struct Full<D> {
        data: Option<D>,
    }
}

impl<D> Full<D>
where
    D: Buf,
{
    /// Create a new `Full`.
    pub fn new(data: D) -> Self {
        let data = if data.has_remaining() {
            Some(data)
        } else {
            None
        };
        Full { data }
    }
}

impl<D> Body for Full<D>
where
    D: Buf,
{
    type Data = D;
    type Error = Infallible;

    fn poll_frame(
        mut self: Pin<&mut Self>,
        _cx: &mut Context<'_>,
    ) -> Poll<Option<Result<Frame<D>, Self::Error>>> {
        Poll::Ready(self.data.take().map(|d| Ok(Frame::data(d))))
    }

    fn is_end_stream(&self) -> bool {
        self.data.is_none()
    }

    fn size_hint(&self) -> SizeHint {
        self.data
            .as_ref()
            .map(|data| SizeHint::with_exact(u64::try_from(data.remaining()).unwrap()))
            .unwrap_or_else(|| SizeHint::with_exact(0))
    }
}

impl<D> Default for Full<D>
where
    D: Buf,
{
    /// Create an empty `Full`.
    fn default() -> Self {
        Full { data: None }
    }
}

impl<D> From<Bytes> for Full<D>
where
    D: Buf + From<Bytes>,
{
    fn from(bytes: Bytes) -> Self {
        Full::new(D::from(bytes))
    }
}

impl<D> From<Vec<u8>> for Full<D>
where
    D: Buf + From<Vec<u8>>,
{
    fn from(vec: Vec<u8>) -> Self {
        Full::new(D::from(vec))
    }
}

impl<D> From<&'static [u8]> for Full<D>
where
    D: Buf + From<&'static [u8]>,
{
    fn from(slice: &'static [u8]) -> Self {
        Full::new(D::from(slice))
    }
}

impl<D, B> From<Cow<'static, B>> for Full<D>
where
    D: Buf + From<&'static B> + From<B::Owned>,
    B: ToOwned + ?Sized,
{
    fn from(cow: Cow<'static, B>) -> Self {
        match cow {
            Cow::Borrowed(b) => Full::new(D::from(b)),
            Cow::Owned(o) => Full::new(D::from(o)),
        }
    }
}

impl<D> From<String> for Full<D>
where
    D: Buf + From<String>,
{
    fn from(s: String) -> Self {
        Full::new(D::from(s))
    }
}

impl<D> From<&'static str> for Full<D>
where
    D: Buf + From<&'static str>,
{
    fn from(slice: &'static str) -> Self {
        Full::new(D::from(slice))
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::BodyExt;

    #[tokio::test]
    async fn full_returns_some() {
        let mut full = Full::new(&b"hello"[..]);
        assert_eq!(full.size_hint().exact(), Some(b"hello".len() as u64));
        assert_eq!(
            full.frame().await.unwrap().unwrap().into_data().unwrap(),
            &b"hello"[..]
        );
        assert!(full.frame().await.is_none());
    }

    #[tokio::test]
    async fn empty_full_returns_none() {
        assert!(Full::<&[u8]>::default().frame().await.is_none());
        assert!(Full::new(&b""[..]).frame().await.is_none());
    }
}