countio 0.3.0

Byte counting for std::io::{Read, Write, Seek} and its async variants from futures and tokio.
Documentation 
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

use std::io::{BufRead, Read, Result, Seek, SeekFrom, Write};

use crate::Counter;

impl<R: Read> Read for Counter<R> {
    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
        let bytes = self.inner.read(buf)?;
        self.reader_bytes += bytes;
        Ok(bytes)
    }
}

impl<R: BufRead> BufRead for Counter<R> {
    fn fill_buf(&mut self) -> Result<&[u8]> {
        self.inner.fill_buf()
    }

    fn consume(&mut self, amt: usize) {
        self.reader_bytes += amt;
        self.inner.consume(amt);
    }
}

impl<W: Write> Write for Counter<W> {
    fn write(&mut self, buf: &[u8]) -> Result<usize> {
        let bytes = self.inner.write(buf)?;
        self.writer_bytes += bytes;
        Ok(bytes)
    }

    #[inline]
    fn flush(&mut self) -> Result<()> {
        self.inner.flush()
    }
}

impl<D: Seek> Seek for Counter<D> {
    #[inline]
    fn seek(&mut self, pos: SeekFrom) -> Result<u64> {
        self.inner.seek(pos)
    }
}

#[cfg(test)]
mod test {
    use std::io::{BufReader, BufWriter};

    use super::*;

    #[test]
    fn test_reader() -> Result<()> {
        let mut reader = Counter::new(&b"Hello World!"[..]);

        let mut buf = Vec::new();
        let len = reader.read_to_end(&mut buf)?;

        assert_eq!(len, reader.reader_bytes());
        assert_eq!(len as u128, reader.total_bytes());

        Ok(())
    }

    #[test]
    fn test_buf_reader() -> Result<()> {
        let reader = BufReader::new(&b"Hello World!"[..]);
        let mut reader = Counter::new(reader);

        let mut buf = String::new();
        let len = reader.read_line(&mut buf)?;

        assert_eq!(len, reader.reader_bytes());
        assert_eq!(len as u128, reader.total_bytes());

        Ok(())
    }

    #[test]
    fn test_writer() -> Result<()> {
        let writer = Vec::new();
        let writer = BufWriter::new(writer);
        let mut writer = Counter::new(writer);

        let len = writer.write(b"Hello World!")?;
        writer.flush()?;

        assert_eq!(len, writer.writer_bytes());
        assert_eq!(len as u128, writer.total_bytes());

        Ok(())
    }

    #[test]
    fn test_debug() {
        let writer = Vec::<u8>::new();
        let writer = Counter::new(writer);

        let fmt = "Counter { inner: [], read: 0, written: 0 }";
        assert_eq!(format!("{writer:?}"), fmt);
    }

    #[test]
    fn test_seek() -> Result<()> {
        use std::io::{Cursor, SeekFrom};

        let data = b"Hello, World!".to_vec();
        let cursor = Cursor::new(data);
        let mut counter = Counter::new(cursor);

        let pos = counter.seek(SeekFrom::Start(0))?;
        assert_eq!(pos, 0);

        let pos = counter.seek(SeekFrom::End(0))?;
        assert_eq!(pos, 13);

        let pos = counter.seek(SeekFrom::Current(-5))?;
        assert_eq!(pos, 8);

        assert_eq!(counter.reader_bytes(), 0);
        assert_eq!(counter.writer_bytes(), 0);
        assert_eq!(counter.total_bytes(), 0);

        Ok(())
    }

    #[test]
    fn test_zero_byte_ops() -> Result<()> {
        let mut counter = Counter::new(Vec::new());

        let len = counter.write(&[])?;
        assert_eq!(len, 0);
        assert_eq!(counter.writer_bytes(), 0);
        assert_eq!(counter.total_bytes(), 0);

        let mut reader = Counter::new(&b""[..]);
        let mut buf = [0u8; 10];
        let len = reader.read(&mut buf)?;
        assert_eq!(len, 0);
        assert_eq!(reader.reader_bytes(), 0);
        assert_eq!(reader.total_bytes(), 0);

        Ok(())
    }
}