Struct FabricMem 

pub struct FabricMem { /* private fields */ }

Safe handle to fabric memory via FBMU host functions.

Created by FabricMem::hello, which performs the FBMU HELLO handshake to establish a memory data-plane session. Once created, the handle can be used for byte-addressable reads and writes within the arena.

Examples

use grafos_std::mem::FabricMem;

let mem = FabricMem::hello()?;

// Write and read back
mem.write(0, b"test data")?;
let data = mem.read(0, 9)?;
assert_eq!(&data, b"test data");

// Check arena capacity
let size = mem.arena_size()?;
assert_eq!(size, 4096);

Implementations

impl FabricMem

pub fn hello() -> Result<FabricMem>

Perform the FBMU HELLO handshake and return a memory handle.

This establishes the memory data-plane session with the host. On WASM targets, this calls the real fbmu_hello host import. On native targets, it initializes the mock state.

Errors

• FabricError::Disconnected if the host connection is unavailable.
• Other FabricError variants based on the host status code.

pub fn write(&self, offset: u64, data: &[u8]) -> Result<()>

Write data at the given byte offset in the arena.

Errors

Returns a FabricError if the host reports a write failure.

pub fn read(&self, offset: u64, len: u32) -> Result<Vec<u8>>

Read len bytes starting at offset from the arena.

Returns a Vec<u8> containing the data read. The returned vector may be shorter than len if the host returned fewer bytes.

Errors

Returns a FabricError if the host reports a read failure.

pub fn arena_size(&self) -> Result<u64>

Query the total arena size in bytes.

Errors

Returns FabricError::IoError if the host returns a negative value.

impl FabricMem

pub fn write_struct<T: Serialize>(&self, offset: u64, val: &T) -> Result<usize>

Serialize val and write it to fabric memory at offset.

Uses postcard encoding, which is compact and no_std-compatible. Returns the number of bytes written.

Errors

• FabricError::IoError if serialization fails (e.g. the type cannot be serialized by postcard).
• Any FabricError from the underlying FabricMem::write call.

pub fn read_struct<T: DeserializeOwned>( &self, offset: u64, max_len: u32, ) -> Result<T>

Read and deserialize a T from fabric memory at offset.

Reads up to max_len bytes from the arena and attempts to deserialize them as T using postcard.

Errors

• FabricError::IoError if deserialization fails (e.g. the data does not match the expected type layout).
• Any FabricError from the underlying FabricMem::read call.

Trait Implementations

impl Debug for FabricMem

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

Formats the value using the given formatter.