use crate::{ctx::*, DekuError, DekuRead, DekuWrite};
use bitvec::prelude::*;
use core::convert::TryInto;
#[cfg(feature = "alloc")]
use alloc::format;
macro_rules! ImplDekuTraits {
($typ:ty) => {
impl DekuRead<'_, (Endian, Size)> for $typ {
fn read(
input: &BitSlice<Msb0, u8>,
(endian, size): (Endian, Size),
) -> Result<(&BitSlice<Msb0, u8>, Self), DekuError> {
let max_type_bits: usize = Size::of::<$typ>().bit_size();
let bit_size: usize = size.bit_size();
let input_is_le = endian.is_le();
if bit_size > max_type_bits {
return Err(DekuError::Parse(format!(
"too much data: container of {} bits cannot hold {} bits",
max_type_bits, bit_size
)));
}
if input.len() < bit_size {
return Err(DekuError::Incomplete(crate::error::NeedSize::new(bit_size)));
}
let (bit_slice, rest) = input.split_at(bit_size);
let pad = 8 * ((bit_slice.len() + 7) / 8) - bit_slice.len();
let value = if pad == 0 && bit_slice.len() == max_type_bits {
let bytes: &[u8] = bit_slice.as_raw_slice();
if input_is_le {
<$typ>::from_le_bytes(bytes.try_into()?)
} else {
<$typ>::from_be_bytes(bytes.try_into()?)
}
} else {
let bits: BitVec<Msb0, u8> = {
let mut bits = BitVec::with_capacity(bit_slice.len() + pad);
bits.extend_from_bitslice(bit_slice);
bits.force_align();
let index = if input_is_le {
bits.len() - (8 - pad)
} else {
0
};
for _ in 0..pad {
bits.insert(index, false);
}
for _ in 0..(max_type_bits - bits.len()) {
if input_is_le {
bits.push(false);
} else {
bits.insert(0, false);
}
}
bits
};
let bytes: &[u8] = bits.as_raw_slice();
if input_is_le {
<$typ>::from_le_bytes(bytes.try_into()?)
} else {
<$typ>::from_be_bytes(bytes.try_into()?)
}
};
Ok((rest, value))
}
}
impl DekuRead<'_, Endian> for $typ {
fn read(
input: &BitSlice<Msb0, u8>,
endian: Endian,
) -> Result<(&BitSlice<Msb0, u8>, Self), DekuError> {
let max_type_bits = Size::of::<$typ>();
<$typ>::read(input, (endian, max_type_bits))
}
}
impl DekuRead<'_, Size> for $typ {
fn read(
input: &BitSlice<Msb0, u8>,
bit_size: Size,
) -> Result<(&BitSlice<Msb0, u8>, Self), DekuError> {
let endian = Endian::default();
<$typ>::read(input, (endian, bit_size))
}
}
impl DekuRead<'_> for $typ {
fn read(
input: &BitSlice<Msb0, u8>,
_: (),
) -> Result<(&BitSlice<Msb0, u8>, Self), DekuError> {
<$typ>::read(input, Endian::default())
}
}
impl DekuWrite<(Endian, Size)> for $typ {
fn write(
&self,
output: &mut BitVec<Msb0, u8>,
(endian, size): (Endian, Size),
) -> Result<(), DekuError> {
let input = match endian {
Endian::Little => self.to_le_bytes(),
Endian::Big => self.to_be_bytes(),
};
let bit_size: usize = size.bit_size();
let input_bits = input.view_bits::<Msb0>();
if bit_size > input_bits.len() {
return Err(DekuError::InvalidParam(format!(
"bit size {} is larger then input {}",
bit_size,
input_bits.len()
)));
}
if matches!(endian, Endian::Little) {
let mut remaining_bits = bit_size;
for chunk in input_bits.chunks(8) {
if chunk.len() > remaining_bits {
output.extend_from_bitslice(&chunk[chunk.len() - remaining_bits..]);
break;
} else {
output.extend_from_bitslice(chunk)
}
remaining_bits -= chunk.len();
}
} else {
output.extend_from_bitslice(&input_bits[input_bits.len() - bit_size..]);
}
Ok(())
}
}
impl DekuWrite<Endian> for $typ {
fn write(
&self,
output: &mut BitVec<Msb0, u8>,
endian: Endian,
) -> Result<(), DekuError> {
let input = match endian {
Endian::Little => self.to_le_bytes(),
Endian::Big => self.to_be_bytes(),
};
output.extend_from_bitslice(input.view_bits::<Msb0>());
Ok(())
}
}
impl DekuWrite<Size> for $typ {
fn write(
&self,
output: &mut BitVec<Msb0, u8>,
bit_size: Size,
) -> Result<(), DekuError> {
<$typ>::write(self, output, (Endian::default(), bit_size))
}
}
impl DekuWrite for $typ {
fn write(&self, output: &mut BitVec<Msb0, u8>, _: ()) -> Result<(), DekuError> {
<$typ>::write(self, output, Endian::default())
}
}
};
}
ImplDekuTraits!(u8);
ImplDekuTraits!(u16);
ImplDekuTraits!(u32);
ImplDekuTraits!(u64);
ImplDekuTraits!(u128);
ImplDekuTraits!(usize);
ImplDekuTraits!(i8);
ImplDekuTraits!(i16);
ImplDekuTraits!(i32);
ImplDekuTraits!(i64);
ImplDekuTraits!(i128);
ImplDekuTraits!(isize);
ImplDekuTraits!(f32);
ImplDekuTraits!(f64);
#[cfg(test)]
mod tests {
use super::*;
use rstest::rstest;
static ENDIAN: Endian = Endian::new();
macro_rules! TestPrimitive {
($test_name:ident, $typ:ty, $input:expr, $expected:expr) => {
#[test]
fn $test_name() {
let input = $input;
let bit_slice = input.view_bits::<Msb0>();
let (_rest, res_read) = <$typ>::read(bit_slice, ENDIAN).unwrap();
assert_eq!($expected, res_read);
let mut res_write = bitvec![Msb0, u8;];
res_read.write(&mut res_write, ENDIAN).unwrap();
assert_eq!(input, res_write.into_vec());
}
};
}
TestPrimitive!(test_u8, u8, vec![0xAAu8], 0xAAu8);
TestPrimitive!(test_u16, u16, vec![0xABu8, 0xCD], 0xCDAB);
TestPrimitive!(test_u32, u32, vec![0xABu8, 0xCD, 0xEF, 0xBE], 0xBEEFCDAB);
TestPrimitive!(
test_u64,
u64,
vec![0xABu8, 0xCD, 0xEF, 0xBE, 0xAB, 0xCD, 0xFE, 0xC0],
0xC0FECDABBEEFCDAB
);
TestPrimitive!(
test_u128,
u128,
vec![
0xABu8, 0xCD, 0xEF, 0xBE, 0xAB, 0xCD, 0xFE, 0xC0, 0xAB, 0xCD, 0xEF, 0xBE, 0xAB, 0xCD,
0xFE, 0xC0
],
0xC0FECDABBEEFCDABC0FECDABBEEFCDAB
);
TestPrimitive!(
test_usize,
usize,
vec![0xABu8, 0xCD, 0xEF, 0xBE, 0xAB, 0xCD, 0xFE, 0xC0],
if core::mem::size_of::<usize>() == 8 {
0xC0FECDABBEEFCDAB
} else {
0xBEEFCDAB
}
);
TestPrimitive!(test_i8, i8, vec![0xFBu8], -5);
TestPrimitive!(test_i16, i16, vec![0xFDu8, 0xFE], -259);
TestPrimitive!(test_i32, i32, vec![0x02u8, 0x3F, 0x01, 0xEF], -0x10FEC0FE);
TestPrimitive!(
test_i64,
i64,
vec![0x02u8, 0x3F, 0x01, 0xEF, 0x01, 0x3F, 0x01, 0xEF],
-0x10FEC0FE10FEC0FE
);
TestPrimitive!(
test_i128,
i128,
vec![
0x02u8, 0x3F, 0x01, 0xEF, 0x01, 0x3F, 0x01, 0xEF, 0x01, 0x3F, 0x01, 0xEF, 0x01, 0x3F,
0x01, 0xEF
],
-0x10FEC0FE10FEC0FE10FEC0FE10FEC0FE
);
TestPrimitive!(
test_isize,
isize,
vec![0x02u8, 0x3F, 0x01, 0xEF, 0x01, 0x3F, 0x01, 0xEF],
if core::mem::size_of::<isize>() == 8 {
-0x10FEC0FE10FEC0FE
} else {
-0x10FEC0FE
}
);
TestPrimitive!(test_f32, f32, vec![0xA6u8, 0x9B, 0xC4, 0xBB], -0.006);
TestPrimitive!(
test_f64,
f64,
vec![0xFAu8, 0x7E, 0x6A, 0xBC, 0x74, 0x93, 0x78, 0xBF],
-0.006
);
#[rstest(input, endian, bit_size, expected, expected_rest,
case::normal([0xDD, 0xCC, 0xBB, 0xAA].as_ref(), Endian::Little, Some(32), 0xAABB_CCDD, bits![Msb0, u8;]),
case::normal_bits_12_le([0b1001_0110, 0b1110_0000, 0xCC, 0xDD ].as_ref(), Endian::Little, Some(12), 0b1110_1001_0110, bits![Msb0, u8; 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1]),
case::normal_bits_12_be([0b1001_0110, 0b1110_0000, 0xCC, 0xDD ].as_ref(), Endian::Big, Some(12), 0b1001_0110_1110, bits![Msb0, u8; 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1]),
case::normal_bit_6([0b1001_0110].as_ref(), Endian::Little, Some(6), 0b1001_01, bits![Msb0, u8; 1, 0,]),
#[should_panic(expected = "Incomplete(NeedSize { bits: 32 })")]
case::not_enough_data([].as_ref(), Endian::Little, Some(32), 0xFF, bits![Msb0, u8;]),
#[should_panic(expected = "Incomplete(NeedSize { bits: 32 })")]
case::not_enough_data([0xAA, 0xBB].as_ref(), Endian::Little, Some(32), 0xFF, bits![Msb0, u8;]),
#[should_panic(expected = "Parse(\"too much data: container of 32 bits cannot hold 64 bits\")")]
case::too_much_data([0xAA, 0xBB, 0xCC, 0xDD, 0xAA, 0xBB, 0xCC, 0xDD].as_ref(), Endian::Little, Some(64), 0xFF, bits![Msb0, u8;]),
)]
fn test_bit_read(
input: &[u8],
endian: Endian,
bit_size: Option<usize>,
expected: u32,
expected_rest: &BitSlice<Msb0, u8>,
) {
let bit_slice = input.view_bits::<Msb0>();
let (rest, res_read) = match bit_size {
Some(bit_size) => u32::read(bit_slice, (endian, Size::Bits(bit_size))).unwrap(),
None => u32::read(bit_slice, endian).unwrap(),
};
assert_eq!(expected, res_read);
assert_eq!(expected_rest, rest);
}
#[rstest(input, endian, bit_size, expected,
case::normal_le(0xDDCC_BBAA, Endian::Little, None, vec![0xAA, 0xBB, 0xCC, 0xDD]),
case::normal_be(0xDDCC_BBAA, Endian::Big, None, vec![0xDD, 0xCC, 0xBB, 0xAA]),
case::bit_size_le_smaller(0x03AB, Endian::Little, Some(10), vec![0xAB, 0b11_000000]),
case::bit_size_be_smaller(0x03AB, Endian::Big, Some(10), vec![0b11_1010_10, 0b11_000000]),
#[should_panic(expected = "InvalidParam(\"bit size 100 is larger then input 32\")")]
case::bit_size_le_bigger(0x03AB, Endian::Little, Some(100), vec![0xAB, 0b11_000000]),
)]
fn test_bit_write(input: u32, endian: Endian, bit_size: Option<usize>, expected: Vec<u8>) {
let mut res_write = bitvec![Msb0, u8;];
match bit_size {
Some(bit_size) => input
.write(&mut res_write, (endian, Size::Bits(bit_size)))
.unwrap(),
None => input.write(&mut res_write, endian).unwrap(),
};
assert_eq!(expected, res_write.into_vec());
}
#[rstest(input, endian, bit_size, expected, expected_rest, expected_write,
case::normal([0xDD, 0xCC, 0xBB, 0xAA].as_ref(), Endian::Little, Some(32), 0xAABB_CCDD, bits![Msb0, u8;], vec![0xDD, 0xCC, 0xBB, 0xAA]),
)]
fn test_bit_read_write(
input: &[u8],
endian: Endian,
bit_size: Option<usize>,
expected: u32,
expected_rest: &BitSlice<Msb0, u8>,
expected_write: Vec<u8>,
) {
let bit_slice = input.view_bits::<Msb0>();
let (rest, res_read) = match bit_size {
Some(bit_size) => u32::read(bit_slice, (endian, Size::Bits(bit_size))).unwrap(),
None => u32::read(bit_slice, endian).unwrap(),
};
assert_eq!(expected, res_read);
assert_eq!(expected_rest, rest);
let mut res_write = bitvec![Msb0, u8;];
match bit_size {
Some(bit_size) => res_read
.write(&mut res_write, (endian, Size::Bits(bit_size)))
.unwrap(),
None => res_read.write(&mut res_write, endian).unwrap(),
};
assert_eq!(expected_write, res_write.into_vec());
}
}