// Copyright 2019 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 .
use crate::ChainSpec;
use futures01::{prelude::*, sync::oneshot, sync::mpsc};
use libp2p::wasm_ext;
use log::{debug, info};
use std::sync::Arc;
use service::{AbstractService, Roles as ServiceRoles};
use substrate_service::{RpcSession, Configuration, config::DatabaseConfig};
use wasm_bindgen::prelude::*;
/// Starts the client.
///
/// You must pass a libp2p transport that supports .
#[wasm_bindgen]
pub fn start_client(wasm_ext: wasm_ext::ffi::Transport) -> Result {
start_inner(wasm_ext)
.map_err(|err| JsValue::from_str(&err.to_string()))
}
fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result> {
console_error_panic_hook::set_once();
console_log::init_with_level(log::Level::Info);
// Build the configuration to pass to the service.
let config = {
let wasm_ext = wasm_ext::ExtTransport::new(wasm_ext);
let chain_spec = ChainSpec::Kusama.load().map_err(|e| format!("{:?}", e))?;
let mut config = Configuration::::default_with_spec_and_base_path(chain_spec, None);
config.network.transport = substrate_network::config::TransportConfig::Normal {
wasm_external_transport: Some(wasm_ext.clone()),
allow_private_ipv4: true,
enable_mdns: false,
};
config.telemetry_external_transport = Some(wasm_ext);
config.roles = ServiceRoles::LIGHT;
config.name = "Browser node".to_string();
config.database = {
let db = Arc::new(kvdb_memorydb::create(10));
DatabaseConfig::Custom(db)
};
config
};
info!("Polkadot browser node");
info!(" version {}", config.full_version());
info!(" by Parity Technologies, 2017-2019");
info!("Chain specification: {}", config.chain_spec.name());
if config.chain_spec.name().starts_with("Kusama") {
info!("----------------------------");
info!("This chain is not in any way");
info!(" endorsed by the ");
info!(" KUSAMA FOUNDATION ");
info!("----------------------------");
}
info!("Node name: {}", config.name);
info!("Roles: {:?}", config.roles);
// Create the service. This is the most heavy initialization step.
let mut service = service::new_light(config).map_err(|e| format!("{:?}", e))?;
// We now dispatch a background task responsible for processing the service.
//
// The main action performed by the code below consists in polling the service with
// `service.poll()`.
// The rest consists in handling RPC requests.
let (rpc_send_tx, mut rpc_send_rx) = mpsc::unbounded::();
wasm_bindgen_futures::spawn_local(futures01::future::poll_fn(move || {
loop {
match rpc_send_rx.poll() {
Ok(Async::Ready(Some(message))) => {
let fut = service.rpc_query(&message.session, &message.rpc_json);
let _ = message.send_back.send(Box::new(fut));
},
Ok(Async::NotReady) => break,
Err(_) | Ok(Async::Ready(None)) => return Ok(Async::Ready(())),
}
}
loop {
match service.poll().map_err(|_| ())? {
Async::Ready(()) => return Ok(Async::Ready(())),
Async::NotReady => break
}
}
Ok(Async::NotReady)
}));
Ok(Client {
rpc_send_tx,
})
}
/// A running client.
#[wasm_bindgen]
pub struct Client {
rpc_send_tx: mpsc::UnboundedSender,
}
struct RpcMessage {
rpc_json: String,
session: RpcSession,
send_back: oneshot::Sender, Error = ()>>>,
}
#[wasm_bindgen]
impl Client {
/// Allows starting an RPC request. Returns a `Promise` containing the result of that request.
#[wasm_bindgen(js_name = "rpcSend")]
pub fn rpc_send(&mut self, rpc: &str) -> js_sys::Promise {
let rpc_session = RpcSession::new(mpsc::channel(1).0);
let (tx, rx) = oneshot::channel();
let _ = self.rpc_send_tx.unbounded_send(RpcMessage {
rpc_json: rpc.to_owned(),
session: rpc_session,
send_back: tx,
});
let fut = rx
.map_err(|_| ())
.and_then(|fut| fut)
.map(|s| JsValue::from_str(&s.unwrap_or(String::new())))
.map_err(|_| JsValue::NULL);
wasm_bindgen_futures::future_to_promise(fut)
}
/// Subscribes to an RPC pubsub endpoint.
#[wasm_bindgen(js_name = "rpcSubscribe")]
pub fn rpc_subscribe(&mut self, rpc: &str, callback: js_sys::Function) {
let (tx, rx) = mpsc::channel(4);
let rpc_session = RpcSession::new(tx);
let (fut_tx, fut_rx) = oneshot::channel();
let _ = self.rpc_send_tx.unbounded_send(RpcMessage {
rpc_json: rpc.to_owned(),
session: rpc_session.clone(),
send_back: fut_tx,
});
let fut_rx = fut_rx
.map_err(|_| ())
.and_then(|fut| fut);
wasm_bindgen_futures::spawn_local(fut_rx.then(|_| Ok(())));
wasm_bindgen_futures::spawn_local(rx.for_each(move |s| {
match callback.call1(&callback, &JsValue::from_str(&s)) {
Ok(_) => Ok(()),
Err(_) => Err(()),
}
}).then(move |v| {
// We need to keep `rpc_session` alive.
debug!("RPC subscription has ended");
drop(rpc_session);
v
}));
}
}