bin_layout/record/
mod.rs

1// #[cfg(feature = "nightly")]
2// mod specialize;
3
4mod collection;
5mod string;
6
7use crate::*;
8use std::{
9    convert::{TryFrom, TryInto},
10    fmt,
11    iter::FromIterator,
12    marker::PhantomData,
13    ops::{Deref, DerefMut},
14};
15
16/// [Record](https://docs.rs/bin-layout/latest/bin_layout/struct.Record.html) can be used to
17/// encode collections where the size of the length is known.
18///
19/// For example, `Record<u8, String>` here the maximum allowed payload length is 255 (`u8::MAX`)
20///
21/// ### Example
22///
23/// ```rust
24/// use bin_layout::*;
25///
26/// let record: Record<u8, String> = "very long string!".repeat(15).into();
27/// let bytes = record.encode();
28/// assert_eq!(record.len(), 255);
29/// assert_eq!(bytes.len(), 256);
30/// ```
31#[derive(Default, Clone, PartialEq, Eq, PartialOrd, Ord)]
32pub struct Record<Len: LenType, T> {
33    _marker: PhantomData<Len>,
34    pub data: T,
35}
36
37impl<Len: LenType, T> Record<Len, T> {
38    #[inline]
39    pub const fn new(data: T) -> Self {
40        Self {
41            data,
42            _marker: PhantomData,
43        }
44    }
45}
46
47impl<Len: LenType, T> From<T> for Record<Len, T> {
48    #[inline]
49    fn from(data: T) -> Self {
50        Self::new(data)
51    }
52}
53
54impl<Len: LenType, T, V: FromIterator<T>> FromIterator<T> for Record<Len, V> {
55    #[inline]
56    fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
57        Record::new(V::from_iter(iter))
58    }
59}
60
61impl<Len: LenType, T: fmt::Debug> fmt::Debug for Record<Len, T> {
62    #[inline]
63    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
64        self.data.fmt(f)
65    }
66}
67impl<Len: LenType, T> Deref for Record<Len, T> {
68    type Target = T;
69    #[inline]
70    fn deref(&self) -> &Self::Target {
71        &self.data
72    }
73}
74impl<Len: LenType, T> DerefMut for Record<Len, T> {
75    #[inline]
76    fn deref_mut(&mut self) -> &mut Self::Target {
77        &mut self.data
78    }
79}
80
81/// Supported length type for [Record](https://docs.rs/bin-layout/latest/bin_layout/struct.Record.html)
82pub trait LenType:
83    fmt::Display + TryFrom<usize> + TryInto<usize> + Encoder + for<'de> Decoder<'de>
84{
85    fn max() -> Self;
86    fn bits() -> u32;
87    fn ty_str() -> &'static str;
88}
89
90macro_rules! impl_len_ty {
91    [$($ty:ty),*] => {$(
92        impl LenType for $ty {
93            #[inline] fn max() -> Self { <$ty>::MAX }
94            #[inline] fn bits() -> u32 { <$ty>::BITS }
95            #[inline] fn ty_str() -> &'static str { stringify!($ty) }
96        }
97    )*};
98}
99impl_len_ty!(u8, u16, u32, u64, usize, L2, L3);
100macro_rules! encode_len {
101    [$data:expr, $c: expr] => {
102        let len = $data.len();
103        Len::try_from(len).map_err(|_| invalid_input(format!("Max payload length is {} ({}), But got {len}", Len::max(), Len::ty_str())))?.encoder($c)?;
104    };
105}
106macro_rules! decode_len {
107    [$c: expr] => ({
108        let len: usize = Len::decoder($c)?.try_into().map_err(|_| DynErr::from("Invalid length"))?;
109        len
110    });
111}
112pub(crate) use decode_len;
113pub(crate) use encode_len;
bin_layout/record/mod.rs

bin_layout/record/
mod.rs
