zeropod 0.3.3

Zero-copy pod types with derive macros. Alignment-1 representations for zero-overhead data access.
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

use zeropod::{pod::*, ZeroPod, ZeroPodFixed};

#[allow(dead_code)]
#[derive(ZeroPod)]
struct Simple {
    pub value: u64,
    pub flag: bool,
}

#[test]
fn fixed_size() {
    assert_eq!(<Simple as zeropod::ZeroPodFixed>::SIZE, 8 + 1);
}

#[test]
fn fixed_alignment() {
    assert_eq!(
        core::mem::align_of::<<Simple as zeropod::ZeroPodFixed>::Zc>(),
        1
    );
}

#[test]
fn fixed_read() {
    let mut buf = [0u8; 9];
    buf[0..8].copy_from_slice(&42u64.to_le_bytes());
    buf[8] = 1;
    let zc = Simple::from_bytes(&buf).unwrap();
    assert_eq!(zc.value.get(), 42);
    assert!(zc.flag.get());
}

#[test]
fn fixed_write() {
    let mut buf = [0u8; 9];
    let zc = Simple::from_bytes_mut(&mut buf).unwrap();
    zc.value = 100.into();
    zc.flag = true.into();
    assert_eq!(buf[0..8], 100u64.to_le_bytes());
    assert_eq!(buf[8], 1);
}

#[test]
fn fixed_validate_bad_bool() {
    let mut buf = [0u8; 9];
    buf[8] = 2;
    assert!(Simple::from_bytes(&buf).is_err());
}

#[test]
fn fixed_buffer_too_small() {
    let buf = [0u8; 4];
    assert!(Simple::from_bytes(&buf).is_err());
}

#[test]
fn fixed_unchecked() {
    let buf = [0u8; 9];
    let zc = unsafe { Simple::from_bytes_unchecked(&buf) };
    assert_eq!(zc.value.get(), 0);
}

#[allow(dead_code)]
#[derive(ZeroPod)]
struct WithCollections {
    pub authority: [u8; 32],
    pub name: zeropod::String<32>,
    pub scores: zeropod::Vec<u8, 10>,
    pub active: bool,
    pub maybe: Option<u64>,
}

#[allow(dead_code)]
#[derive(ZeroPod)]
struct WideOptions {
    pub authority: PodOption<[u8; 32], 4>,
    pub amount: PodOption<PodU64, 4>,
}

#[test]
fn fixed_collections_size() {
    // [u8;32](32) + PodString<32,1>(1+32=33) + PodVec<u8,10,2>(2+10=12) +
    // PodBool(1) + PodOption<PodU64>(1+8=9) = 87
    assert_eq!(<WithCollections as zeropod::ZeroPodFixed>::SIZE, 87);
}

#[test]
fn fixed_collections_alignment() {
    assert_eq!(
        core::mem::align_of::<<WithCollections as zeropod::ZeroPodFixed>::Zc>(),
        1
    );
}

#[test]
fn fixed_pfx4_pod_option_accessors_borrow() {
    let mut buf = vec![0u8; <WideOptions as zeropod::ZeroPodFixed>::SIZE];
    let authority = [7u8; 32];

    {
        let zc = WideOptions::from_bytes_mut(&mut buf).unwrap();
        zc.authority = PodOption::<[u8; 32], 4>::some(authority);
        zc.amount = PodOption::<PodU64, 4>::some(PodU64::from(123));
    }

    let zc = WideOptions::from_bytes(&buf).unwrap();
    assert_eq!(zc.authority(), Some(&authority));
    assert_eq!(zc.amount().map(|value| value.get()), Some(123));
}

#[test]
fn fixed_string_field() {
    let mut buf = [0u8; 87];
    let zc = WithCollections::from_bytes_mut(&mut buf).unwrap();
    let _ = zc.name.set("hello");
    assert_eq!(zc.name.as_str(), "hello");
}

#[test]
fn fixed_vec_field() {
    let mut buf = [0u8; 87];
    let zc = WithCollections::from_bytes_mut(&mut buf).unwrap();
    let _ = zc.scores.push(1);
    let _ = zc.scores.push(2);
    assert_eq!(zc.scores.as_slice(), &[1, 2]);
}

#[test]
fn fixed_option_field() {
    let mut buf = [0u8; 87];
    let zc = WithCollections::from_bytes_mut(&mut buf).unwrap();
    assert!(zc.maybe.is_none());
    zc.maybe.set(Some(PodU64::from(42u64)));
    assert_eq!(zc.maybe.get(), Some(PodU64::from(42u64)));
}

#[test]
fn fixed_zc_is_zc_elem() {
    fn assert_zc_elem<T: zeropod::ZcElem>() {}
    assert_zc_elem::<SimpleZc>();
}