mirror of
https://github.com/pezkuwichain/pezkuwi-subxt.git
synced 2026-05-07 07:18:03 +00:00
Alin Dima
f2a750ee86
Previously, it was only possible to retry the same request on a different protocol name that had the exact same binary payloads. Introduce a way of trying a different request on a different protocol if the first one fails with Unsupported protocol. This helps with adding new req-response versions in polkadot while preserving compatibility with unupgraded nodes. The way req-response protocols were bumped previously was that they were bundled with some other notifications protocol upgrade, like for async backing (but that is more complicated, especially if the feature does not require any changes to a notifications protocol). Will be needed for implementing https://github.com/polkadot-fellows/RFCs/pull/47 TODO: - [x] add tests - [x] add guidance docs in polkadot about req-response protocol versioning
76 lines
2.7 KiB
Rust
76 lines
2.7 KiB
Rust
// Copyright Parity Technologies (UK) Ltd.
|
|
// This file is part of Substrate.
|
|
|
|
// Substrate is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
|
|
// Substrate is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with Substrate. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
//! Block relay protocol related definitions.
|
|
|
|
use futures::channel::oneshot;
|
|
use libp2p::PeerId;
|
|
use sc_network::{
|
|
request_responses::{ProtocolConfig, RequestFailure},
|
|
ProtocolName,
|
|
};
|
|
use sc_network_common::sync::message::{BlockData, BlockRequest};
|
|
use sp_runtime::traits::Block as BlockT;
|
|
use std::sync::Arc;
|
|
|
|
/// The serving side of the block relay protocol. It runs a single instance
|
|
/// of the server task that processes the incoming protocol messages.
|
|
#[async_trait::async_trait]
|
|
pub trait BlockServer<Block: BlockT>: Send {
|
|
/// Starts the protocol processing.
|
|
async fn run(&mut self);
|
|
}
|
|
|
|
/// The client side stub to download blocks from peers. This is a handle
|
|
/// that can be used to initiate concurrent downloads.
|
|
#[async_trait::async_trait]
|
|
pub trait BlockDownloader<Block: BlockT>: Send + Sync {
|
|
/// Performs the protocol specific sequence to fetch the blocks from the peer.
|
|
/// Output: if the download succeeds, the response is a `Vec<u8>` which is
|
|
/// in a format specific to the protocol implementation. The block data
|
|
/// can be extracted from this response using [`BlockDownloader::block_response_into_blocks`].
|
|
async fn download_blocks(
|
|
&self,
|
|
who: PeerId,
|
|
request: BlockRequest<Block>,
|
|
) -> Result<Result<(Vec<u8>, ProtocolName), RequestFailure>, oneshot::Canceled>;
|
|
|
|
/// Parses the protocol specific response to retrieve the block data.
|
|
fn block_response_into_blocks(
|
|
&self,
|
|
request: &BlockRequest<Block>,
|
|
response: Vec<u8>,
|
|
) -> Result<Vec<BlockData<Block>>, BlockResponseError>;
|
|
}
|
|
|
|
/// Errors returned by [`BlockDownloader::block_response_into_blocks`].
|
|
#[derive(Debug)]
|
|
pub enum BlockResponseError {
|
|
/// Failed to decode the response bytes.
|
|
DecodeFailed(String),
|
|
|
|
/// Failed to extract the blocks from the decoded bytes.
|
|
ExtractionFailed(String),
|
|
}
|
|
|
|
/// Block relay specific params for network creation, specified in
|
|
/// ['sc_service::BuildNetworkParams'].
|
|
pub struct BlockRelayParams<Block: BlockT> {
|
|
pub server: Box<dyn BlockServer<Block>>,
|
|
pub downloader: Arc<dyn BlockDownloader<Block>>,
|
|
pub request_response_config: ProtocolConfig,
|
|
}
|