stellar-xdr 30.0.0

Stellar XDR types, encoding, and decoding.
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

#[allow(unused_imports, clippy::wildcard_imports)]
use super::*;

/// ScpStatementPledges is a borrowing equivalent of [`ScpStatementPledges`](super::super::ScpStatementPledges)
/// over `'static` data, for const XDR encoding.
#[derive(Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
#[allow(clippy::large_enum_variant)]
pub enum ScpStatementPledges {
    Prepare(ScpStatementPrepare),
    Confirm(ScpStatementConfirm),
    Externalize(ScpStatementExternalize),
    Nominate(ScpNomination),
}

impl ScpStatementPledges {
    #[must_use]
    pub const fn discriminant(&self) -> ScpStatementType {
        #[allow(clippy::match_same_arms)]
        match self {
            Self::Prepare(_) => ScpStatementType::Prepare,
            Self::Confirm(_) => ScpStatementType::Confirm,
            Self::Externalize(_) => ScpStatementType::Externalize,
            Self::Nominate(_) => ScpStatementType::Nominate,
        }
    }
}

impl ScpStatementPledges {
    /// The exact XDR-encoded length of this value, in bytes.
    ///
    /// Evaluable in a const context, so a caller (such as a proc-macro) can
    /// size a buffer for [`Self::const_to_xdr`] at compile time.
    #[must_use]
    pub const fn const_xdr_len(&self) -> usize {
        let mut empty: [u8; 0] = [];
        let mut w = ConstWriter::new(&mut empty);
        w.write_type_scp_statement_pledges(self);
        w.len()
    }

    /// Serialize this value as XDR into a fixed-size `[u8; N]` using only const
    /// operations. This is the const counterpart to
    /// [`WriteXdr::to_xdr`](super::super::WriteXdr::to_xdr).
    ///
    /// `N` must equal [`Self::const_xdr_len`]. It is intended for callers, such
    /// as a proc-macro, that compute the length with `const_xdr_len` and pass
    /// it as `N`; `const_to_xdr` itself does not need to call `const_xdr_len`.
    ///
    /// # Panics
    ///
    /// Panics if `N` does not equal the value's [`Self::const_xdr_len`].
    #[must_use]
    pub const fn const_to_xdr<const N: usize>(&self) -> [u8; N] {
        let mut buf = [0u8; N];
        let mut w = ConstWriter::new(&mut buf);
        w.write_type_scp_statement_pledges(self);
        assert!(
            w.len() == N,
            "const_to_xdr: N does not equal the XDR-encoded length"
        );
        buf
    }
}

impl ConstWriter<'_> {
    /// Serializes a [`ScpStatementPledges`], mirroring `<ScpStatementPledges as WriteXdr>::write_xdr`.
    pub const fn write_type_scp_statement_pledges(&mut self, v: &ScpStatementPledges) {
        let d = v.discriminant();
        self.write_type_scp_statement_type(&d);
        #[allow(clippy::match_same_arms)]
        match v {
            ScpStatementPledges::Prepare(value) => {
                self.write_type_scp_statement_prepare(value);
            }
            ScpStatementPledges::Confirm(value) => {
                self.write_type_scp_statement_confirm(value);
            }
            ScpStatementPledges::Externalize(value) => {
                self.write_type_scp_statement_externalize(value);
            }
            ScpStatementPledges::Nominate(value) => {
                self.write_type_scp_nomination(value);
            }
        }
    }
}