commonware_codec/types/
vec.rs

1//! Codec implementation for [`Vec<T>`].
2//!
3//! For portability and consistency between architectures,
4//! the length of the vector must fit within a [u32].
5
6use crate::{EncodeSize, Error, RangeCfg, Read, Write};
7#[cfg(not(feature = "std"))]
8use alloc::vec::Vec;
9use bytes::{Buf, BufMut};
10
11impl<T: Write> Write for Vec<T> {
12    #[inline]
13    fn write(&self, buf: &mut impl BufMut) {
14        self.len().write(buf);
15        for item in self {
16            item.write(buf);
17        }
18    }
19}
20
21impl<T: EncodeSize> EncodeSize for Vec<T> {
22    #[inline]
23    fn encode_size(&self) -> usize {
24        self.len().encode_size() + self.iter().map(EncodeSize::encode_size).sum::<usize>()
25    }
26}
27
28impl<T: Read> Read for Vec<T> {
29    type Cfg = (RangeCfg, T::Cfg);
30
31    #[inline]
32    fn read_cfg(buf: &mut impl Buf, (range, cfg): &Self::Cfg) -> Result<Self, Error> {
33        let len = usize::read_cfg(buf, range)?;
34        let mut vec = Vec::with_capacity(len);
35        for _ in 0..len {
36            vec.push(T::read_cfg(buf, cfg)?);
37        }
38        Ok(vec)
39    }
40}
41
42#[cfg(test)]
43mod tests {
44    use super::*;
45    use crate::{DecodeRangeExt, Encode};
46    #[cfg(not(feature = "std"))]
47    use alloc::vec;
48
49    #[test]
50    fn test_vec() {
51        let vec_values = [vec![], vec![1u8], vec![1u8, 2u8, 3u8]];
52        for value in vec_values {
53            let encoded = value.encode();
54            assert_eq!(encoded.len(), value.len() * core::mem::size_of::<u8>() + 1);
55
56            // Valid decoding
57            let len = value.len();
58            let decoded = Vec::<u8>::decode_range(encoded, len..=len).unwrap();
59            assert_eq!(value, decoded);
60
61            // Failure for too long
62            assert!(matches!(
63                Vec::<u8>::decode_range(value.encode(), 0..len),
64                Err(Error::InvalidLength(_))
65            ));
66
67            // Failure for too short
68            assert!(matches!(
69                Vec::<u8>::decode_range(value.encode(), len + 1..),
70                Err(Error::InvalidLength(_))
71            ));
72        }
73    }
74
75    #[test]
76    fn test_conformity() {
77        assert_eq!(Vec::<u8>::new().encode(), &[0x00][..]);
78        assert_eq!(
79            vec![0x01u8, 0x02u8, 0x03u8].encode(),
80            &[0x03, 0x01, 0x02, 0x03][..]
81        );
82
83        let v_u16: Vec<u16> = vec![0x1234, 0xABCD];
84        assert_eq!(v_u16.encode(), &[0x02, 0x12, 0x34, 0xAB, 0xCD][..]);
85
86        let v_bool: Vec<bool> = vec![true, false, true];
87        assert_eq!(v_bool.encode(), &[0x03, 0x01, 0x00, 0x01][..]);
88
89        let v_empty_u32: Vec<u32> = Vec::new();
90        assert_eq!(v_empty_u32.encode(), &[0x00][..]);
91
92        // Test with a length that requires a multi-byte varint
93        let v_long_u8: Vec<u8> = vec![0xCC; 200]; // 200 = 0xC8 = 0x80 + 0x48 -> 0xC8 0x01
94        let mut expected_long_u8 = vec![0xC8, 0x01];
95        expected_long_u8.extend_from_slice(&[0xCC; 200]);
96        assert_eq!(v_long_u8.encode(), expected_long_u8.as_slice());
97    }
98}
commonware_codec/types/vec.rs

commonware_codec/types/
vec.rs
