Struct BlobBuilder 

pub struct BlobBuilder { /* private fields */ }

BlobBuilder provides an incremental way to construct a Blob from a stream of data.

This builder handles the division of input data into fixed-size ChunkSets, prepares RLNC-based erasure-coded chunks, computes BLAKE3 digest of blob, and generates Merkle inclusion (in respective Chunksets) proof for proof-carrying chunks.

Implementations

impl BlobBuilder

pub fn init() -> Self

Initializes a new BlobBuilder - ready to build a blob.

pub fn num_bytes_absorbed_so_far(&self) -> usize

pub fn update(&mut self, data: &[u8]) -> Option<Vec<ProofCarryingChunk>>

Updates the BlobBuilder with new data.

This method absorbs the provided data into the internal buffer. If enough data accumulates to form a complete ChunkSet, it is processed (erasure-coded, Merkle-proofed) and its resulting ProofCarryingChunks are returned.

You can call this method arbitrary number of times, before calling Self::finalize. Note, you must call this method atleast once with non-empty input data, to not get an error from Self::finalize - as you can’t build a blob over empty input data.

Arguments

• data - A byte slice containing the new data to be processed.

Returns

An Option<Vec<ProofCarryingChunk>>.

• Some(Vec<ProofCarryingChunk>) if one or more ChunkSets were completed and their chunks generated. These chunks carry Merkle proof-of-inclusion in respective Chunkset.
• None if no complete ChunkSet was formed or if the input data was empty.

pub fn finalize( self, ) -> Result<(Vec<ProofCarryingChunk>, BlobHeader), DecdsError>

Finalizes the BlobBuilder, processing any remaining buffered data and constructing the BlobHeader.

This method pads any incomplete ChunkSet in the buffer with zeros, processes it, computes the final blob digest, and builds the top-level Merkle tree over chunkset root commitments, yielding the BlobHeader and at max 16 proof-carrying chunks, if there was an incomplete chunkset, which needed to be built.

Returns

Returns a Result which is:

• Ok((Vec<ProofCarryingChunk>, BlobHeader)) containing either 0 or 16 ProofCarryingChunks from last chunkset and the BlobHeader for the complete blob.
• Err(DecdsError::EmptyDataForBlob) if no data was ever absorbed by the builder.
• Other DecdsError types may be returned from underlying MerkleTree::new calls.