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
148
149
150
151
152
153
154
155
156
157

use super::{
    io, ready, AsyncRead, Context, End, ErrorKind, FixedLength, Ready, ReceivedBody, StateOutput,
};

impl<'conn, Transport> ReceivedBody<'conn, Transport>
where
    Transport: AsyncRead + Unpin + Send + Sync + 'static,
{
    #[inline]
    pub(super) fn handle_fixed_length(
        &mut self,
        cx: &mut Context<'_>,
        buf: &mut [u8],
        current_index: u64,
        total_length: u64,
    ) -> StateOutput {
        let len = buf.len();
        let remaining = usize::try_from(total_length - current_index).unwrap_or(usize::MAX);
        let buf = &mut buf[..len.min(remaining)];
        let bytes = ready!(self.read_raw(cx, buf)?);
        let current_index = current_index + bytes as u64;
        if current_index == total_length {
            Ready(Ok((End, bytes)))
        } else if bytes == 0 {
            Ready(Err(io::Error::from(ErrorKind::ConnectionAborted)))
        } else {
            Ready(Ok((
                FixedLength {
                    current_index,
                    total: total_length,
                },
                bytes,
            )))
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::{http_config::DEFAULT_CONFIG, Buffer, HttpConfig, ReceivedBody, ReceivedBodyState};
    use encoding_rs::UTF_8;
    use futures_lite::{future::block_on, io::Cursor, AsyncRead, AsyncReadExt};

    fn new_with_config(
        input: String,
        config: &HttpConfig,
    ) -> ReceivedBody<'static, Cursor<String>> {
        ReceivedBody::new_with_config(
            Some(input.len() as u64),
            Buffer::with_capacity(100),
            Cursor::new(input),
            ReceivedBodyState::Start,
            None,
            UTF_8,
            config,
        )
    }

    fn decode_with_config(
        input: String,
        poll_size: usize,
        config: &HttpConfig,
    ) -> crate::Result<String> {
        let mut rb = new_with_config(input, config);

        block_on(read_with_buffers_of_size(&mut rb, poll_size))
    }

    async fn read_with_buffers_of_size<R>(reader: &mut R, size: usize) -> crate::Result<String>
    where
        R: AsyncRead + Unpin,
    {
        let mut return_buffer = vec![];
        loop {
            let mut buf = vec![0; size];
            match reader.read(&mut buf).await? {
                0 => break Ok(String::from_utf8_lossy(&return_buffer).into()),
                bytes_read => return_buffer.extend_from_slice(&buf[..bytes_read]),
            }
        }
    }

    #[test]
    fn test() {
        for size in 3..50 {
            let input = "12345abcdef";
            let output = decode_with_config(input.into(), size, &DEFAULT_CONFIG).unwrap();
            assert_eq!(output, "12345abcdef", "size: {size}");

            let input = "MozillaDeveloperNetwork";
            let output = decode_with_config(input.into(), size, &DEFAULT_CONFIG).unwrap();
            assert_eq!(output, "MozillaDeveloperNetwork", "size: {size}");

            assert!(decode_with_config(String::new(), size, &DEFAULT_CONFIG).is_ok());

            let input = "MozillaDeveloperNetwork";
            assert!(decode_with_config(
                input.into(),
                size,
                &DEFAULT_CONFIG.with_received_body_max_len(5)
            )
            .is_err());
        }
    }

    #[test]
    fn read_string_and_read_bytes() {
        block_on(async {
            let content = "test ".repeat(1000);
            assert_eq!(
                new_with_config(content.clone(), &DEFAULT_CONFIG)
                    .read_string()
                    .await
                    .unwrap()
                    .len(),
                5000
            );

            assert_eq!(
                new_with_config(content.clone(), &DEFAULT_CONFIG)
                    .read_bytes()
                    .await
                    .unwrap()
                    .len(),
                5000
            );

            assert!(new_with_config(
                content.clone(),
                &DEFAULT_CONFIG.with_received_body_max_len(750)
            )
            .read_string()
            .await
            .is_err());

            assert!(new_with_config(
                content.clone(),
                &DEFAULT_CONFIG.with_received_body_max_len(750)
            )
            .read_bytes()
            .await
            .is_err());

            assert!(new_with_config(content.clone(), &DEFAULT_CONFIG)
                .with_max_len(750)
                .read_bytes()
                .await
                .is_err());

            assert!(new_with_config(content.clone(), &DEFAULT_CONFIG)
                .with_max_len(750)
                .read_string()
                .await
                .is_err());
        });
    }
}