Enum LengthForm 

#[non_exhaustive]
pub enum LengthForm {
    Minimal,
    Long {
        octets: u8,
    },
}

How a length_field is — or is to be — coded on the wire.

A CAM may code a length in a longer form than necessary (82 00 09 for the value 9, captured raw on hardware, dvb-ci-runtime #337). parse is tolerant and records the coding here; serialize re-emits exactly that coding, so a parsed APDU/SPDU/TPDU round-trips byte-for-byte. A value built by hand uses LengthForm::Minimal (the Default): the shortest legal form.

parse only ever produces LengthForm::Long for a non-minimal coding, so a parsed object equals the same object built with the default form whenever the wire used the minimal coding.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Minimal

The shortest legal coding for the value: the 1-byte short form for 0..=127, otherwise the long form with the fewest length octets.

Long

A non-minimal long form (size_indicator = 1) with exactly octets length octets (1..=MAX_LENGTH_OCTETS), e.g. 82 00 09.

Fields

octets: u8

length_field_size: the number of length octets that follow the size-indicator byte.

Implementations

impl LengthForm

pub const fn is_minimal(&self) -> bool

true for LengthForm::Minimal (used to skip the field in serde).

pub fn name(&self) -> &'static str

Short label (issue #204 convention).

Trait Implementations

impl Clone for LengthForm

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LengthForm

impl Debug for LengthForm

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

Formats the value using the given formatter.

impl Default for LengthForm

fn default() -> Self

Returns the “default value” for a type.

impl Display for LengthForm

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

Formats the value using the given formatter.

impl Eq for LengthForm

impl Hash for LengthForm

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LengthForm

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for LengthForm

Available on crate feature serde only.

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for LengthForm