Struct StorageBlob 

pub struct StorageBlob { /* private fields */ }

A persistent variable-length byte storage.

StorageBlob stores arbitrary-length byte arrays by chunking them into 32-byte segments. Useful for storing strings, serialized structs, or large data.

Storage Layout

• derive_slot(namespace, ["blob:len"]) - Length in bytes as u64
• derive_slot(namespace, ["blob:chunk", i]) - Chunk i (32 bytes)

Example

const NS_METADATA: Namespace = Namespace([1u8; 32]);
let metadata = StorageBlob::new(NS_METADATA);

// Write raw bytes
metadata.write(b"Hello, TruthLinked!")?;

// Read raw bytes
let data = metadata.read()?;

// Write typed value
let config = Config { version: 1, enabled: true };
metadata.put(&config)?;

// Read typed value
let config: Config = metadata.get()?;

Implementations

impl StorageBlob

pub const fn new(namespace: Namespace) -> Self

Creates a new blob with the specified namespace.

pub fn len_slot(&self) -> [u8; 32]

Returns the storage slot for the length counter.

pub fn slot_for_chunk(&self, index: u64) -> [u8; 32]

Returns the storage slot for a chunk at the given index.

pub fn write_in<B: StorageBackend>( &self, backend: &mut B, data: &[u8], ) -> Result<()>

Writes raw bytes to storage (with explicit backend).

Data is chunked into 32-byte segments. The length is stored separately.

pub fn read_in<B: StorageBackend>(&self, backend: &B) -> Result<Vec<u8>>

Reads raw bytes from storage (with explicit backend).

Reconstructs the original byte array from stored chunks.

pub fn clear_in<B: StorageBackend>(&self, backend: &mut B) -> Result<()>

Clears the blob by setting length to 0 (with explicit backend).

pub fn put_in<B: StorageBackend, T: BytesCodec>( &self, backend: &mut B, value: &T, ) -> Result<()>

Writes a typed value to storage (with explicit backend).

The value is encoded using BytesCodec before storage.

pub fn get_in<B: StorageBackend, T: BytesCodec>(&self, backend: &B) -> Result<T>

Reads a typed value from storage (with explicit backend).

The bytes are decoded using BytesCodec.

pub fn write(&self, data: &[u8]) -> Result<()>

Writes raw bytes to storage (production, uses HostStorage).

pub fn read(&self) -> Result<Vec<u8>>

Reads raw bytes from storage (production, uses HostStorage).

pub fn put<T: BytesCodec>(&self, value: &T) -> Result<()>

Writes a typed value to storage (production, uses HostStorage).

pub fn get<T: BytesCodec>(&self) -> Result<T>

Reads a typed value from storage (production, uses HostStorage).

pub fn clear(&self) -> Result<()>

Clears the blob (production, uses HostStorage).