ax-codec-core 0.1.6

Core binary codec library with zero-copy decoding, varint encoding, and configurable decode limits
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

use ax_codec_core::buffer::{SliceReader, VecWriter};
use ax_codec_core::{Decode, Encode, Validate, View};
use ax_codec_derive::{Decode, Encode, View};

#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
struct NamedStruct {
    id: u32,
    name: String,
    active: bool,
}

#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
struct UnnamedStruct(u16, u32);

#[derive(Debug, Clone, PartialEq, Eq, Encode, View)]
struct SimpleViewStruct {
    id: u32,
    active: bool,
}

#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode, View)]
enum SimpleEnum {
    A,
    B(u32),
    C { x: u16, y: u16 },
}

#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
struct WithSkip {
    id: u32,
    #[ax_codec(skip)]
    cached: String,
}

impl Default for WithSkip {
    fn default() -> Self {
        Self {
            id: 0,
            cached: String::new(),
        }
    }
}

fn roundtrip_encode_decode<T: Encode + Decode + PartialEq + std::fmt::Debug>(val: T) {
    let mut w = VecWriter::new();
    val.encode(&mut w).unwrap();
    let mut r = SliceReader::new(w.as_slice());
    let decoded = T::decode(&mut r).unwrap();
    assert_eq!(val, decoded);
}

#[test]
fn named_struct_roundtrip() {
    roundtrip_encode_decode(NamedStruct {
        id: 42,
        name: "hello".into(),
        active: true,
    });
}

#[test]
fn unnamed_struct_roundtrip() {
    roundtrip_encode_decode(UnnamedStruct(0x1234, 0xDEADBEEF));
}

#[test]
fn view_struct_roundtrip() {
    let mut w = VecWriter::new();
    let val = SimpleViewStruct {
        id: 99,
        active: true,
    };
    val.encode(&mut w).unwrap();
    let mut r = SliceReader::new(w.as_slice());
    let decoded: SimpleViewStruct = View::view(&mut r).unwrap();
    assert_eq!(decoded.id, 99);
    assert_eq!(decoded.active, true);
}

#[test]
fn enum_roundtrip() {
    roundtrip_encode_decode(SimpleEnum::A);
    roundtrip_encode_decode(SimpleEnum::B(42));
    roundtrip_encode_decode(SimpleEnum::C { x: 1, y: 2 });
}

#[test]
fn skip_attribute_roundtrip() {
    let val = WithSkip {
        id: 42,
        cached: "should be ignored".into(),
    };
    let mut w = VecWriter::new();
    val.encode(&mut w).unwrap();
    let mut r = SliceReader::new(w.as_slice());
    let decoded = WithSkip::decode(&mut r).unwrap();
    assert_eq!(val.id, decoded.id);
    assert_eq!(decoded.cached, "");
}

#[test]
fn validate_struct_ok() {
    let mut w = VecWriter::new();
    let val = SimpleViewStruct {
        id: 99,
        active: true,
    };
    val.encode(&mut w).unwrap();
    let mut r = SliceReader::new(w.as_slice());
    SimpleViewStruct::validate(&mut r).unwrap();
}

#[test]
fn validate_struct_truncated_fails() {
    let mut w = VecWriter::new();
    let val = SimpleViewStruct {
        id: 99,
        active: true,
    };
    val.encode(&mut w).unwrap();
    let mut r = SliceReader::new(&w.as_slice()[..2]);
    assert!(SimpleViewStruct::validate(&mut r).is_err());
}

#[test]
fn validate_enum_ok() {
    let mut w = VecWriter::new();
    SimpleEnum::B(42).encode(&mut w).unwrap();
    let mut r = SliceReader::new(w.as_slice());
    SimpleEnum::validate(&mut r).unwrap();
}

#[test]
fn validate_enum_bad_discriminant_fails() {
    let buf = [0xffu8];
    let mut r = SliceReader::new(&buf);
    assert!(SimpleEnum::validate(&mut r).is_err());
}

#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
struct WithDefault {
    id: u32,
    #[ax_codec(default)]
    extra: String,
}

#[test]
fn default_attribute_uses_default_on_eof() {
    let mut w = VecWriter::new();
    42u32.encode(&mut w).unwrap();

    let mut r = SliceReader::new(w.as_slice());
    let decoded = WithDefault::decode(&mut r).unwrap();
    assert_eq!(decoded.id, 42);
    assert_eq!(decoded.extra, "");
}