Function write_frame

nodedb-cluster/src/rpc_codec/header.rs:36–49

Write a framed v3 header + payload into `out`. `rpc_type` is the discriminant byte; `payload` is the already-serialized body. The current cluster epoch (read from [`current_local_cluster_epoch`]) is stamped into the header.

(rpc_type: u8, payload: &[u8], out: &mut Vec<u8>)

/// body. The current cluster epoch (read from
/// [`current_local_cluster_epoch`]) is stamped into the header.
pub fn write_frame(rpc_type: u8, payload: &[u8], out: &mut Vec<u8>) -> Result<()> {
    let payload_len: u32 = payload.len().try_into().map_err(|_| ClusterError::Codec {
        detail: format!("payload too large: {} bytes", payload.len()),
    })?;
    let crc = crc32c::crc32c(payload);
    let epoch = current_local_cluster_epoch();
    out.push(RPC_FRAME_VERSION);
    out.push(rpc_type);
    out.extend_from_slice(&payload_len.to_le_bytes());
    out.extend_from_slice(&crc.to_le_bytes());
    out.extend_from_slice(&epoch.to_le_bytes());
    out.extend_from_slice(payload);
    Ok(())
}

/// Validate the CRC32C of an inbound frame and return the payload slice.
///