Enum StringLayerHeader 

#[non_exhaustive]
pub enum StringLayerHeader {
    SingleString {
        version: u8,
    },
    Chunked {
        version: u8,
        chunk_set_id: u32,
        total_chunks: u8,
        chunk_index: u8,
    },
}

String-layer header for one mk1 chunk.

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.

SingleString

Card fits in one mk1 string; no chunking. Carries no chunk-set identifier or index because the format is unambiguous.

Fields

version: u8

5-bit format version (0 in v0.1).

Chunked

One chunk in a multi-chunk encoding. All chunks of one card share the same version, chunk_set_id, and total_chunks; only chunk_index varies.

Fields

version: u8

5-bit format version (0 in v0.1).

chunk_set_id: u32

20-bit per-encoding random tag for reassembly mismatch detection. Decoders compare across chunks; mismatch is rejected with Error::ChunkSetIdMismatch.

total_chunks: u8

Total number of chunks in this set, in 1..=MAX_CHUNKS.

chunk_index: u8

Zero-based index of this chunk within the set.

Implementations

impl StringLayerHeader

pub fn to_5bit_symbols(self) -> Vec<u8>

Emit this header as a sequence of 5-bit symbols.

The output length is SINGLE_HEADER_SYMBOLS (= 2) for StringLayerHeader::SingleString and CHUNKED_HEADER_SYMBOLS (= 8) for StringLayerHeader::Chunked. The caller prepends these symbols to bytes_to_5bit(fragment) to form a chunk’s data part before BCH checksumming.

pub fn from_5bit_symbols(symbols: &[u8]) -> Result<(Self, usize)>

Parse a header off the front of a 5-bit-symbol stream.

Returns the parsed header and the number of symbols consumed (2 for SingleString, 8 for Chunked). The caller slices off the remainder as the fragment-payload symbols.

Errors

• Error::UnexpectedEnd if symbols is shorter than the minimum 2-symbol single-string header.
• Error::UnsupportedVersion if the version field is non-zero in v0.1.
• Error::UnsupportedCardType if the type field is not in {0x00, 0x01} (the reserved range 0x02..=0x1F is rejected).
• Error::ChunkedHeaderMalformed if a chunked header has total_chunks == 0, total_chunks > MAX_CHUNKS, or chunk_index >= total_chunks.

pub fn is_chunked(self) -> bool

Returns true if this header is the Chunked variant.

Trait Implementations

impl Clone for StringLayerHeader

fn clone(&self) -> StringLayerHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StringLayerHeader

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

Formats the value using the given formatter.

impl PartialEq for StringLayerHeader

fn eq(&self, other: &StringLayerHeader) -> 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 StringLayerHeader

impl Eq for StringLayerHeader

impl StructuralPartialEq for StringLayerHeader