Struct VarHeader

pub struct VarHeader {
    pub key: VarKey,
    pub seq_no: VarSeq,
}

A variably sized message header

NOTE: We use the standard PartialEq here as it will do the correct things.

Sequence numbers must be EXACTLY the same, and keys must be equivalent when degraded to the smaller of the two.

We DO NOT impl Serialize/Deserialize for this type because we use non-postcard-compatible format (externally tagged)

Fields

key: VarKey

The variably sized Key

seq_no: VarSeq

The variably sized Sequence Number

Implementations

impl VarHeader

pub const KEY_ONE_BITS: u8 = 0u8

Bits for a key of ONE byte

pub const KEY_TWO_BITS: u8 = 64u8

Bits for a key of TWO bytes

pub const KEY_FOUR_BITS: u8 = 128u8

Bits for a key of FOUR bytes

pub const KEY_EIGHT_BITS: u8 = 192u8

Bits for a key of EIGHT bytes

pub const KEY_MASK_BITS: u8 = 192u8

Mask bits

pub const SEQ_ONE_BITS: u8 = 0u8

Bits for a sequence number of ONE bytes

pub const SEQ_TWO_BITS: u8 = 16u8

Bits for a sequence number of TWO bytes

pub const SEQ_FOUR_BITS: u8 = 32u8

Bits for a sequence number of FOUR bytes

pub const SEQ_MASK_BITS: u8 = 48u8

Mask bits

pub const VER_ZERO_BITS: u8 = 0u8

Bits for a version number of ZERO

pub const VER_MASK_BITS: u8 = 15u8

Mask bits

pub fn write_to_vec(&self) -> Vec<u8>

Encode the header to a Vec of bytes

pub fn write_to_slice<'a>( &self, buf: &'a mut [u8], ) -> Option<(&'a mut [u8], &'a mut [u8])>

Attempt to write the header to the given slice

If the slice is large enough, a Some will be returned with the bytes used to encode the header, as well as the remaining unused bytes.

If the slice is not large enough, a None will be returned, and some bytes of the buffer may have been modified.

pub fn take_from_slice(buf: &[u8]) -> Option<(Self, &[u8])>

Attempt to decode a header from the given bytes.

If a well-formed header was found, a Some will be returned with the decoded header and unused remaining bytes.

If no well-formed header was found, a None will be returned.

Trait Implementations

impl Clone for VarHeader

fn clone(&self) -> VarHeader

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for VarHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for VarHeader

fn eq(&self, other: &VarHeader) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for VarHeader

impl StructuralPartialEq for VarHeader