Struct ChunkLayout 

pub struct ChunkLayout { /* private fields */ }

The chunk boundaries of a resource: the per-chunk ciphertext lengths and their cumulative byte offsets. Built from the chunk_lens a peer reports in the first range frame (or the availability answer), this is the map from a byte range to the chunk(s) it covers.

Implementations

impl ChunkLayout

pub fn new(chunk_lens: Vec<u64>) -> Self

Build a layout from TRUSTED per-chunk lengths. Zero-length chunks are permitted (an empty resource has no chunks; a resource with content has ≥1).

Overflow SATURATES here, which is safe only because the caller already knows the lengths are real. For lengths off the wire use try_new: a saturating sum lets a hostile [1, u64::MAX] land on exactly u64::MAX and pass a consistency check against a declared total (#1608).

pub fn try_new(chunk_lens: Vec<u64>) -> Result<Self, VerifyError>

Build a layout from UNTRUSTED per-chunk lengths — the peer-facing constructor.

Every step is total over a hostile input: the chunk COUNT is bounded before any allocation, the offset reservation is FALLIBLE (an infallible Vec::with_capacity sized by wire input aborts the process via the uncatchable handle_alloc_error), and the cumulative offsets are CHECKED so an overflow is a typed rejection instead of a silent wrap or saturation. A library must never delegate this to [profile.release] overflow-checks: only the ROOT package’s profile applies, so in a consumer build a wrapping add is a silent ACCEPT, not a panic (#1608).

Errors

VerifyError::Metadata when the declared chunk count exceeds MAX_RESOURCE_CHUNK_COUNT, the offsets cannot be allocated, or the cumulative length overflows u64.

pub fn chunk_count(&self) -> usize

The number of chunks.

pub fn chunk_lens(&self) -> &[u64]

The per-chunk lengths.

pub fn total_length(&self) -> u64

The total ciphertext length (sum of all chunk lengths).

pub fn chunk_offset(&self, index: usize) -> Option<u64>

The byte start offset of chunk index, or None if out of range.

pub fn chunk_len(&self, index: usize) -> Option<u64>

The length of chunk index, or None if out of range.

pub fn chunks_for_range( &self, offset: u64, length: u64, ) -> Result<(usize, usize), VerifyError>

The chunk index range [start, end) that a byte range [offset, offset+length) covers, requiring the byte range to be chunk-aligned (start on a chunk boundary, end on a chunk boundary). Returns VerifyError::Alignment otherwise — an unaligned range is not a verifiable unit.

Trait Implementations

impl Clone for ChunkLayout

fn clone(&self) -> ChunkLayout

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChunkLayout

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

Formats the value using the given formatter.

impl Eq for ChunkLayout

impl PartialEq for ChunkLayout

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ChunkLayout