subtle_encoding/
identity.rs

1//! Identity `Encoding`: output is identical to input
2
3use super::{
4    Encoding,
5    Error::{self, LengthInvalid},
6};
7
8/// `Encoding` which does not transform data and returns the original input.
9#[derive(Copy, Clone, Debug, Default, Eq, Hash, PartialEq, PartialOrd, Ord)]
10pub struct Identity {}
11
12/// Constant `Identity` encoding that can be used in lieu of calling `default()`
13pub const IDENTITY: &Identity = &Identity {};
14
15impl Encoding for Identity {
16    fn encode_to_slice(&self, src: &[u8], dst: &mut [u8]) -> Result<usize, Error> {
17        ensure!(self.encoded_len(src) == dst.len(), LengthInvalid);
18        dst.copy_from_slice(src);
19        Ok(src.len())
20    }
21
22    fn encoded_len(&self, bytes: &[u8]) -> usize {
23        bytes.len()
24    }
25
26    fn decode_to_slice(&self, src: &[u8], dst: &mut [u8]) -> Result<usize, Error> {
27        ensure!(self.decoded_len(src)? == dst.len(), LengthInvalid);
28        dst.copy_from_slice(src);
29        Ok(src.len())
30    }
31
32    fn decoded_len(&self, bytes: &[u8]) -> Result<usize, Error> {
33        Ok(bytes.len())
34    }
35}
36
37// TODO(tarcieri): `no_std` tests
38#[cfg(feature = "alloc")]
39#[cfg(test)]
40mod tests {
41    use super::*;
42
43    const TEST_DATA: &[u8] = b"Testing 1, 2, 3...";
44
45    #[test]
46    fn test_encode() {
47        assert_eq!(IDENTITY.encode(TEST_DATA), TEST_DATA);
48    }
49
50    #[test]
51    fn test_decode() {
52        assert_eq!(IDENTITY.decode(TEST_DATA).unwrap(), TEST_DATA);
53    }
54}
subtle_encoding/identity.rs

subtle_encoding/
identity.rs
