sbor 1.3.1

Reference implementation of the SBOR binary data format, from the Radix DLT project.
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

use crate::rust::mem::MaybeUninit;
use crate::value_kind::*;
use crate::*;

impl<X: CustomValueKind, T> Categorize<X> for [T] {
    #[inline]
    fn value_kind() -> ValueKind<X> {
        ValueKind::Array
    }
}

impl<X: CustomValueKind, T, const N: usize> Categorize<X> for [T; N] {
    #[inline]
    fn value_kind() -> ValueKind<X> {
        ValueKind::Array
    }
}

impl<X: CustomValueKind, E: Encoder<X>, T: Encode<X, E> + Categorize<X>> Encode<X, E> for [T] {
    #[inline]
    fn encode_value_kind(&self, encoder: &mut E) -> Result<(), EncodeError> {
        encoder.write_value_kind(Self::value_kind())
    }

    #[inline]
    fn encode_body(&self, encoder: &mut E) -> Result<(), EncodeError> {
        encoder.write_value_kind(T::value_kind())?;
        encoder.write_size(self.len())?;
        if T::value_kind() == ValueKind::U8 || T::value_kind() == ValueKind::I8 {
            let ptr = self.as_ptr().cast::<u8>();
            let slice = unsafe { sbor::rust::slice::from_raw_parts(ptr, self.len()) };
            encoder.write_slice(slice)?;
        } else {
            for v in self {
                encoder.encode_deeper_body(v)?;
            }
        }
        Ok(())
    }
}

impl<X: CustomValueKind, E: Encoder<X>, T: Encode<X, E> + Categorize<X>, const N: usize>
    Encode<X, E> for [T; N]
{
    #[inline]
    fn encode_value_kind(&self, encoder: &mut E) -> Result<(), EncodeError> {
        encoder.write_value_kind(Self::value_kind())
    }
    #[inline]
    fn encode_body(&self, encoder: &mut E) -> Result<(), EncodeError> {
        self.as_slice().encode_body(encoder)
    }
}

#[allow(clippy::forget_non_drop)]
impl<X: CustomValueKind, D: Decoder<X>, T: Decode<X, D> + Categorize<X>, const N: usize>
    Decode<X, D> for [T; N]
{
    #[inline]
    fn decode_body_with_value_kind(
        decoder: &mut D,
        value_kind: ValueKind<X>,
    ) -> Result<Self, DecodeError> {
        decoder.check_preloaded_value_kind(value_kind, Self::value_kind())?;
        let element_value_kind = decoder.read_and_check_value_kind(T::value_kind())?;
        decoder.read_and_check_size(N)?;

        // Please read:
        // * https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#initializing-an-array-element-by-element
        // * https://github.com/rust-lang/rust/issues/61956
        //
        // TODO: replace with `uninit_array` and `assume_array_init` once they're stable

        // Create an uninitialized array
        let mut data: [MaybeUninit<T>; N] = unsafe { MaybeUninit::uninit().assume_init() };

        // Decode element by element
        for elem in &mut data[..] {
            elem.write(decoder.decode_deeper_body_with_value_kind(element_value_kind)?);
        }

        // Use &mut as an assertion of unique "ownership"
        let ptr = &mut data as *mut _ as *mut [T; N];
        let res = unsafe { ptr.read() };
        core::mem::forget(data);

        Ok(res)
    }
}

mod schema {
    use super::*;

    impl<C: CustomTypeKind<RustTypeId>, T: Describe<C>> Describe<C> for [T] {
        const TYPE_ID: RustTypeId = match T::TYPE_ID {
            RustTypeId::WellKnown(basic_well_known_types::U8_TYPE) => {
                RustTypeId::WellKnown(basic_well_known_types::BYTES_TYPE)
            }
            _ => RustTypeId::novel("Array", &[T::TYPE_ID]),
        };

        fn type_data() -> TypeData<C, RustTypeId> {
            match T::TYPE_ID {
                RustTypeId::WellKnown(basic_well_known_types::U8_TYPE) => {
                    basic_well_known_types::bytes_type_data()
                }
                _ => TypeData::new(
                    TypeKind::Array {
                        element_type: T::TYPE_ID,
                    },
                    TypeMetadata::unnamed(),
                ),
            }
        }

        fn add_all_dependencies(aggregator: &mut TypeAggregator<C>) {
            aggregator.add_child_type_and_descendents::<T>();
        }
    }

    impl<C: CustomTypeKind<RustTypeId>, T: Describe<C>, const N: usize> Describe<C> for [T; N] {
        const TYPE_ID: RustTypeId = RustTypeId::novel_validated(
            "Array",
            &[T::TYPE_ID],
            &[("min", &N.to_le_bytes()), ("max", &N.to_le_bytes())],
        );

        fn type_data() -> TypeData<C, RustTypeId> {
            let size = N
                .try_into()
                .expect("The array length is too large for a u32 for the SBOR schema");

            TypeData::new(
                TypeKind::Array {
                    element_type: T::TYPE_ID,
                },
                TypeMetadata::unnamed(),
            )
            .with_validation(TypeValidation::Array(LengthValidation {
                min: Some(size),
                max: Some(size),
            }))
        }

        fn add_all_dependencies(aggregator: &mut TypeAggregator<C>) {
            aggregator.add_child_type_and_descendents::<T>();
        }
    }
}