Struct DataDesc 

pub struct DataDesc {
    pub size: u64,
    pub pages: Vec<ArenaPageRef>,
}

Page-granular sparse content of a data cap. size is the full logical extent in bytes (a PAGE_SIZE multiple); pages names only the non-zero pages, sorted by page_index (strictly ascending, unique), each backed by an arena window of its non-zero prefix (zero-padded back to PAGE_SIZE at decode) — see ArenaPageRef.

Decodes (via DataDesc::to_data_cap) to a DataCap whose identity is over logical {size, page_index -> content} only — independent of arena layout, page ordering, or page sharing. So eliding zero pages and deduplicating identical pages never change a cap hash.

Fields

size: u64

pages: Vec<ArenaPageRef>

Implementations

impl DataDesc

pub fn page_count(&self) -> u64

Number of logical pages (size / PAGE_SIZE).

pub fn validate(&self, arena_len: usize) -> Result<(), DataDescError>

Eagerly validate this descriptor against an arena of arena_len bytes: size a PAGE_SIZE multiple; every page-ref page-aligned, in-bounds, with page_index < page_count; pages strictly ascending by page_index (canonical, no duplicates). Untrusted wire input is checked here — a loud Err, never a panic — before any arena slice is taken in to_data_cap.

pub fn to_data_cap(&self, arena: &[u8]) -> DataCap

Materialize the runtime DataCap: each named page is Loaded from its PAGE_SIZE arena window at its absolute page_index; omitted pages are the canonical zero page. The result is byte-identical (and hash-identical) to DataCap::from_bytes_sized(equivalent_contiguous_content, size).

Assumes validate has passed (the deblob gate); an out-of-range arena_off panics — the intended loud failure for a producer bug.

Trait Implementations

impl Clone for DataDesc

fn clone(&self) -> DataDesc

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DataDesc

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

Formats the value using the given formatter.

impl Decode for DataDesc

fn is_ssz_fixed_len() -> bool

true iff this type is fixed-length.

fn ssz_fixed_len() -> usize

Number of bytes this type occupies in the fixed-length portion of a container encoding. Variable-length types return [BYTES_PER_LENGTH_OFFSET].

fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, DecodeError>

Decode a full instance from bytes, rejecting trailing input.

impl Default for DataDesc

fn default() -> DataDesc

Returns the “default value” for a type.

impl Encode for DataDesc

fn is_ssz_fixed_len() -> bool

true iff this type is fixed-length (no variable-length fields).

fn ssz_fixed_len() -> usize

Number of bytes this type occupies in the fixed-length portion of a container encoding. For variable-length types this returns [BYTES_PER_LENGTH_OFFSET] (i.e. the size of the offset slot).

fn ssz_bytes_len(&self) -> usize

Total size of self when serialized.

fn ssz_append(&self, buf: &mut Vec<u8>)

Append the encoding of self to buf.

fn is_basic_type() -> bool

true for “basic” SSZ types (uintN, bool), which pack adjacent elements into shared 32-byte chunks for merkleization. Composite types (containers, lists, structs) return false (the default).

fn as_ssz_bytes(&self) -> Vec<u8>

Serialize into a fresh Vec<u8> allocated through the global allocator.

impl HashTreeRoot for DataDesc

fn hash_tree_root<__D: Digest<OutputSize = U32>>(&self) -> [u8; 32]

Compute the hash tree root using D as the underlying hash.

impl PartialEq for DataDesc

fn eq(&self, other: &DataDesc) -> 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 Eq for DataDesc

impl StructuralPartialEq for DataDesc