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use crate::{ctx::*, DekuError, DekuRead, DekuWrite};
use bitvec::prelude::*;
use std::ffi::CString;
impl<Ctx: Copy> DekuWrite<Ctx> for CString
where
u8: DekuWrite<Ctx>,
{
fn write(&self, output: &mut BitVec<u8, Msb0>, ctx: Ctx) -> Result<(), DekuError> {
let bytes = self.as_bytes_with_nul();
bytes.write(output, ctx)
}
}
impl<'a, Ctx: Copy> DekuRead<'a, Ctx> for CString
where
u8: DekuRead<'a, Ctx>,
{
fn read(
input: &'a BitSlice<u8, Msb0>,
ctx: Ctx,
) -> Result<(&'a BitSlice<u8, Msb0>, Self), DekuError>
where
Self: Sized,
{
let (rest, mut bytes) = Vec::read(input, (Limit::from(|b: &u8| *b == 0x00), ctx))?;
let nul_byte = bytes.pop();
if nul_byte != Some(0x00) {
return Err(DekuError::Unexpected("Expected nul byte".to_string()));
}
let value = CString::new(bytes)
.map_err(|e| DekuError::Parse(format!("Failed to convert Vec to CString: {}", e)))?;
Ok((rest, value))
}
}
#[cfg(test)]
mod tests {
use super::*;
use rstest::rstest;
#[rstest(input, expected, expected_rest,
case(
&[b't', b'e', b's', b't', b'\0'],
CString::new("test").unwrap(),
bits![u8, Msb0;]
),
case(
&[b't', b'e', b's', b't', b'\0', b'a'],
CString::new("test").unwrap(),
[b'a'].view_bits::<Msb0>(),
),
#[should_panic(expected = "Incomplete(NeedSize { bits: 8 })")]
case(&[b't', b'e', b's', b't'], CString::new("test").unwrap(), bits![u8, Msb0;]),
)]
fn test_cstring(input: &[u8], expected: CString, expected_rest: &BitSlice<u8, Msb0>) {
let bit_slice = input.view_bits::<Msb0>();
let (rest, res_read) = CString::read(bit_slice, ()).unwrap();
assert_eq!(expected, res_read);
assert_eq!(expected_rest, rest);
let mut res_write = bitvec![u8, Msb0;];
res_read.write(&mut res_write, ()).unwrap();
assert_eq!(vec![b't', b'e', b's', b't', b'\0'], res_write.into_vec());
}
}