rabuf 0.3.0

randome access buffer for io
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

#[macro_use]
mod helper;

#[cfg(test)]
mod test7 {
    use function_name::named;
    use rabuf::{BufFile, FileSetLen};
    use std::io::{Read, Seek, SeekFrom, Write};

    #[named]
    #[test]
    fn test_set_len_truncate_1() {
        let f = open_test_file!(function_name!());
        let mut bf = BufFile::new("test_set_len_truncate", f).unwrap();

        let initial_data = b"1234567890";
        bf.write_all(initial_data).unwrap();
        assert_eq!(bf.seek(SeekFrom::End(0)).unwrap(), 10);

        // Truncate the file
        bf.set_len(5).unwrap();
        assert_eq!(bf.seek(SeekFrom::End(0)).unwrap(), 5);

        // Check content
        bf.rewind().unwrap();
        let mut content = Vec::new();
        bf.read_to_end(&mut content).unwrap();
        assert_eq!(content, b"12345");
    }

    #[named]
    #[test]
    fn test_set_len_truncate_2() {
        let bw = b"ABCEDFG\nhijklmn\n";
        let f = open_test_file!(function_name!());
        let mut bf = BufFile::new("tes", f).unwrap();
        bf.write_all(bw).unwrap();

        // Truncate the file
        let new_len = 5;
        bf.set_len(new_len).unwrap();

        bf.rewind().unwrap();

        let mut br = Vec::new();
        bf.read_to_end(&mut br).unwrap();
        assert_eq!(br.len() as u64, new_len);
        assert_eq!(&br, &bw[..new_len as usize]);
    }

    #[named]
    #[test]
    fn test_set_len_extend_1() {
        let f = open_test_file!(function_name!());
        let mut bf = BufFile::new("test_set_len_extend", f).unwrap();

        let initial_data = b"12345";
        bf.write_all(initial_data).unwrap();
        assert_eq!(bf.seek(SeekFrom::End(0)).unwrap(), 5);

        // Extend the file
        bf.set_len(10).unwrap();
        assert_eq!(bf.seek(SeekFrom::End(0)).unwrap(), 10);

        // Check content
        bf.rewind().unwrap();
        let mut content = Vec::new();
        bf.read_to_end(&mut content).unwrap();
        let mut expected_content = initial_data.to_vec();
        expected_content.resize(10, 0);
        assert_eq!(content, expected_content);

        // Write to the extended part
        bf.seek(SeekFrom::Start(7)).unwrap();
        bf.write_all(b"abc").unwrap();

        bf.rewind().unwrap();
        let mut content = Vec::new();
        bf.read_to_end(&mut content).unwrap();
        assert_eq!(content, b"12345abc");
    }

    #[named]
    #[test]
    fn test_set_len_extend_2() {
        let f = open_test_file!(function_name!());
        let mut bf = BufFile::new("tes", f).unwrap();

        let initial_size = 10;
        let extended_size = 20;
        bf.write_all(&vec![1u8; initial_size]).unwrap();
        bf.set_len(extended_size).unwrap();

        bf.rewind().unwrap();

        let mut br = Vec::new();
        bf.read_to_end(&mut br).unwrap();

        let mut expected_data = vec![1u8; initial_size];
        expected_data.extend_from_slice(&vec![0u8; extended_size as usize - initial_size]);

        assert_eq!(br, expected_data);
    }

    #[named]
    #[test]
    fn test_set_len_smaller_and_write() {
        let f = open_test_file!(function_name!());
        let mut bf = BufFile::new("tes", f).unwrap();

        let initial_data = b"0123456789abcdef";
        bf.write_all(initial_data).unwrap();

        let new_len = 8;
        bf.set_len(new_len).unwrap();

        let new_data = b"ghij";
        bf.seek(std::io::SeekFrom::Start(new_len)).unwrap();
        bf.write_all(new_data).unwrap();

        bf.rewind().unwrap();

        let mut br = Vec::new();
        bf.read_to_end(&mut br).unwrap();

        let mut expected_data = initial_data[..new_len as usize].to_vec();
        expected_data.extend_from_slice(new_data);

        assert_eq!(br, expected_data);
    }
}