Trait packing::Endian

pub trait Endian {
    const IS_LITTLE: bool;

    fn align_field_bits<S: Bit, E: Bit>(
        input_bytes: &[u8], 
        output_bytes: &mut [u8]
    );
    fn restore_field_bits<S: Bit, E: Bit>(
        input_bytes: &[u8], 
        output_bytes: &mut [u8]
    );
}

Trait that covers functionality required to deal with non aligned endian sensitive fields in packed structs

For example, 10 bits LE offset by 2:

byte	7	6	5	4	3	2	1	0
0	0	0	F	E	D	C	B	A
1	J	I	H	G	0	0	0	0

Should become:

byte	7	6	5	4	3	2	1	0
0	H	G	F	E	D	C	B	A
1	0	0	0	0	0	0	J	I

Associated Constants

const IS_LITTLE: bool

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Required methods

fn align_field_bits<S: Bit, E: Bit>(input_bytes: &[u8], output_bytes: &mut [u8])

Align the bits in slice to usual 8 bit byte boundaries in the endianness represented by the implementing type

Also masks away bytes outside the range specified by S and E. Simple memcopy if S == 7 and E == 0.

S and E type parameters represent bit positions with 7 being the most significant bit and 0 being the least significant bit. S is the first included bit in the first byte of the slice. E is the last included bit in the last byte of the slice.

fn restore_field_bits<S: Bit, E: Bit>(
    input_bytes: &[u8],
    output_bytes: &mut [u8]
)

Take nice 8 bit aligned bytes and shift them to align with the bits specified by S and E in an endian aware way - this means the most significant bits will be masked away rather than the least significant bits. Does not perform any range checks to determine if data is being truncated.

Data is ORed into the output byte slice so it is acceptable for there to be data already in the slice outside of the field defined by S and E. Bits within the field must be set to 0 prior to calling this function. TODO: Clear out data inside the field so dirty buffers can be reused.

S and E type parameters represent bit positions with 7 being the most significant bit and 0 being the least significant bit. S is the first included bit in the first byte of the slice. E is the last included bit in the last byte of the slice.

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Implementors

impl Endian for BigEndian

const IS_LITTLE: bool

fn align_field_bits<S: Bit, E: Bit>(input_bytes: &[u8], output_bytes: &mut [u8])

fn restore_field_bits<S: Bit, E: Bit>(
    input_bytes: &[u8],
    output_bytes: &mut [u8]
)

impl Endian for LittleEndian

const IS_LITTLE: bool

fn align_field_bits<S: Bit, E: Bit>(input_bytes: &[u8], output_bytes: &mut [u8])

fn restore_field_bits<S: Bit, E: Bit>(
    input_bytes: &[u8],
    output_bytes: &mut [u8]
)

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