lighthouse/beacon_node/eth2-libp2p/src/rpc/methods.rs
2019-08-25 10:13:17 +10:00

160 lines
4.3 KiB
Rust

//!Available RPC methods types and ids.
use ssz::{impl_decode_via_from, impl_encode_via_from};
use ssz_derive::{Decode, Encode};
use types::{Epoch, Hash256, Slot};
/* Request/Response data structures for RPC methods */
/* Requests */
pub type RequestId = usize;
/// The HELLO request/response handshake message.
#[derive(Encode, Decode, Clone, Debug)]
pub struct HelloMessage {
/// The fork version of the chain we are broadcasting.
pub fork_version: [u8; 4],
/// Latest finalized root.
pub finalized_root: Hash256,
/// Latest finalized epoch.
pub finalized_epoch: Epoch,
/// The latest block root.
pub head_root: Hash256,
/// The slot associated with the latest block root.
pub head_slot: Slot,
}
/// The reason given for a `Goodbye` message.
///
/// Note: any unknown `u64::into(n)` will resolve to `Goodbye::Unknown` for any unknown `n`,
/// however `GoodbyeReason::Unknown.into()` will go into `0_u64`. Therefore de-serializing then
/// re-serializing may not return the same bytes.
#[derive(Debug, Clone)]
pub enum GoodbyeReason {
/// This node has shutdown.
ClientShutdown = 1,
/// Incompatible networks.
IrrelevantNetwork = 2,
/// Error/fault in the RPC.
Fault = 3,
/// Unknown reason.
Unknown = 0,
}
impl From<u64> for GoodbyeReason {
fn from(id: u64) -> GoodbyeReason {
match id {
1 => GoodbyeReason::ClientShutdown,
2 => GoodbyeReason::IrrelevantNetwork,
3 => GoodbyeReason::Fault,
_ => GoodbyeReason::Unknown,
}
}
}
impl Into<u64> for GoodbyeReason {
fn into(self) -> u64 {
self as u64
}
}
impl_encode_via_from!(GoodbyeReason, u64);
impl_decode_via_from!(GoodbyeReason, u64);
/// Request a number of beacon block roots from a peer.
#[derive(Encode, Decode, Clone, Debug, PartialEq)]
pub struct BeaconBlocksRequest {
/// The hash tree root of a block on the requested chain.
pub head_block_root: Hash256,
/// The starting slot to request blocks.
pub start_slot: u64,
/// The number of blocks from the start slot.
pub count: u64,
/// The step increment to receive blocks.
///
/// A value of 1 returns every block.
/// A value of 2 returns every second block.
/// A value of 3 returns every third block and so on.
pub step: u64,
}
/// Request a number of beacon block bodies from a peer.
#[derive(Encode, Decode, Clone, Debug, PartialEq)]
pub struct RecentBeaconBlocksRequest {
/// The list of beacon block bodies being requested.
pub block_roots: Vec<Hash256>,
}
/* RPC Handling and Grouping */
// Collection of enums and structs used by the Codecs to encode/decode RPC messages
#[derive(Debug, Clone)]
pub enum RPCResponse {
/// A HELLO message.
Hello(HelloMessage),
/// A response to a get BEACON_BLOCKS request.
BeaconBlocks(Vec<u8>),
/// A response to a get RECENT_BEACON_BLOCKS request.
RecentBeaconBlocks(Vec<u8>),
}
#[derive(Debug)]
pub enum RPCErrorResponse {
Success(RPCResponse),
InvalidRequest(ErrorMessage),
ServerError(ErrorMessage),
Unknown(ErrorMessage),
}
impl RPCErrorResponse {
/// Used to encode the response.
pub fn as_u8(&self) -> u8 {
match self {
RPCErrorResponse::Success(_) => 0,
RPCErrorResponse::InvalidRequest(_) => 1,
RPCErrorResponse::ServerError(_) => 2,
RPCErrorResponse::Unknown(_) => 255,
}
}
/// Tells the codec whether to decode as an RPCResponse or an error.
pub fn is_response(response_code: u8) -> bool {
match response_code {
0 => true,
_ => false,
}
}
/// Builds an RPCErrorResponse from a response code and an ErrorMessage
pub fn from_error(response_code: u8, err: ErrorMessage) -> Self {
match response_code {
1 => RPCErrorResponse::InvalidRequest(err),
2 => RPCErrorResponse::ServerError(err),
_ => RPCErrorResponse::Unknown(err),
}
}
}
#[derive(Encode, Decode, Debug)]
pub struct ErrorMessage {
/// The UTF-8 encoded Error message string.
pub error_message: Vec<u8>,
}
impl ErrorMessage {
pub fn as_string(&self) -> String {
String::from_utf8(self.error_message.clone()).unwrap_or_else(|_| "".into())
}
}