field_block 0.3.0

A definition language for buffer parsing
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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159

mod block;
mod field;
mod value;

use std::hash::Hash;

pub use block::*;
pub use field::*;
pub use value::*;

pub trait FieldName: PartialEq + Eq + Hash + Clone {}

#[derive(Debug, PartialEq)]
pub enum ToBytesError<F>
where
    F: FieldName,
{
    NoValueProvided(F),
    InvalidValue(F),
    NotEnoughSpace(F),
}

#[derive(Debug, PartialEq)]
pub enum ToValuesError<F>
where
    F: FieldName,
{
    InvalidValue(F),
    NotEnoughData(F),
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;

    use super::*;

    #[test]
    fn test_to_bytes() {
        let block = get_block();

        let mut values = HashMap::new();
        values.insert(Name::VarInt, Val::VarInt(0x1234));
        let vec = vec![1];
        values.insert(Name::BytesFixedLen, Val::Bytes(&vec));
        let vec = vec![1, 2, 3];
        values.insert(Name::BytesVarLen, Val::Bytes(&vec));

        let mut vec = vec![0; 1024];

        let end = block.to_bytes(&values, &mut vec).unwrap();

        assert_eq!(end, 19);

        assert_eq!(
            &vec[..end],
            &vec![
                // fixed varint
                0 | 0xc0,
                0,
                0,
                0,
                0xde,
                0xad,
                0xbe,
                0xef,
                // varint
                0x12 | 0x40,
                0x34,
                // bytes with fixed len
                1,
                // bytes with var len
                3,
                1,
                2,
                3,
                // fixed bytes
                0xba,
                0xad,
                0xf0,
                0x0d
            ]
        );
    }

    #[test]
    fn test_to_values() {
        let block = get_block();

        let vec = vec![
            // fixed varint
            0 | 0xc0,
            0,
            0,
            0,
            0xde,
            0xad,
            0xbe,
            0xef,
            // varint
            0x12 | 0x40,
            0x34,
            // bytes with fixed len
            1,
            // bytes with var len
            3,
            1,
            2,
            3,
            // fixed bytes
            0xba,
            0xad,
            0xf0,
            0x0d,
        ];

        let mut values = HashMap::new();

        let end = block.to_values(&vec, &mut values).unwrap();

        assert_eq!(end, vec.len());

        let ValInfo { value, pos } = values.get(&Name::VarInt).unwrap();
        assert_eq!(value.varint().unwrap(), 0x1234);
        assert_eq!(*pos, 8);

        let ValInfo { value, pos } = values.get(&Name::BytesFixedLen).unwrap();
        assert_eq!(value.bytes().unwrap(), vec![1]);
        assert_eq!(*pos, 10);

        let ValInfo { value, pos } = values.get(&Name::BytesVarLen).unwrap();
        assert_eq!(value.bytes().unwrap(), vec![1, 2, 3]);
        assert_eq!(*pos, 11);
    }

    fn get_block() -> Block<Name> {
        let mut block = Block::new();
        block.add_field(Name::FixedVarInt, Def::VarInt(U64::Fixed(0xdeadbeef)));
        block.add_field(Name::VarInt, Def::VarInt(U64::Var));
        block.add_field(Name::BytesFixedLen, Def::Bytes(Len::Fixed(1)));
        block.add_field(Name::BytesVarLen, Def::Bytes(Len::Var));
        block.add_field(
            Name::FixedBytes,
            Def::FixedBytes(vec![0xba, 0xad, 0xf0, 0x0d]),
        );
        block
    }

    #[derive(Debug, PartialEq, Eq, Hash, Clone)]
    enum Name {
        FixedVarInt,
        VarInt,
        BytesFixedLen,
        BytesVarLen,
        FixedBytes,
    }

    impl FieldName for Name {}
}