Struct Blob

pub struct Blob { /* private fields */ }

Represents a complete, erasure-coded blob of data, consisting of a BlobHeader and a collection of ChunkSets, each of which are holding 16 erasure-coded proof-of-inclusion carrying chunks.

Implementations

impl Blob

pub fn new(data: Vec<u8>) -> Result<Self, DecdsError>

Creates a new Blob from raw byte data.

This involves:

1. Calculating the blob’s digest and padding its length to a multiple of ChunkSet::BYTE_LENGTH.
2. Dividing the data into ChunkSets and erasure-coding them individually.
3. Building a Merkle tree over the chunksets’ root commitments to create the blob’s root commitment.
4. Appending blob-level Merkle proofs to each chunk within the chunksets.

Arguments

• data - The raw Vec<u8> representing the blob’s content.

Returns

Returns a Result which is:

• Ok(Self) containing the newly created Blob if successful.
• Err(DecdsError::EmptyDataForBlob) if the input data is empty.
• Other DecdsError types may be returned from underlying ChunkSet::new or MerkleTree::new calls.

pub fn get_blob_header(&self) -> &BlobHeader

Returns a reference to the BlobHeader of this blob.

pub fn get_share( &self, share_id: usize, ) -> Result<Vec<ProofCarryingChunk>, DecdsError>

Retrieves a specific “share” (a collection of erasure-coded chunks, one from each chunkset) based on the share_id.

Each share represents a vertical slice through the blob’s chunksets.

Arguments

• share_id - The ID of the share to retrieve (0 to DECDS_NUM_ERASURE_CODED_SHARES - 1).

Returns

Returns a Result which is:

• Ok(Vec<ProofCarryingChunk>) containing a vector of proof-carrying chunks for the requested share.
• Err(DecdsError::InvalidErasureCodedShareId) if share_id is out of bounds.