openethereum/parity/light_helpers/queue_cull.rs
Robert Habermeier 386cdb830d Back-references for the on-demand service (#5573)
* header back-references for on demand

* initial back-reference implementation for on demand requests

* answer requests from cache

* answer requests from cache, add tests

* strongly typed responses for vectors of homogeneous requests

* fix fallout in RPC without optimizing
2017-05-23 12:39:25 +02:00

106 lines
3.4 KiB
Rust

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity 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.
// Parity 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 Parity. If not, see <http://www.gnu.org/licenses/>.
//! Service for culling the light client's transaction queue.
use std::sync::Arc;
use std::time::Duration;
use ethcore::service::ClientIoMessage;
use ethsync::LightSync;
use io::{IoContext, IoHandler, TimerToken};
use light::client::Client;
use light::on_demand::{request, OnDemand};
use light::TransactionQueue;
use futures::{future, Future};
use parity_reactor::Remote;
use util::RwLock;
// Attepmt to cull once every 10 minutes.
const TOKEN: TimerToken = 1;
const TIMEOUT_MS: u64 = 1000 * 60 * 10;
// But make each attempt last only 9 minutes
const PURGE_TIMEOUT_MS: u64 = 1000 * 60 * 9;
/// Periodically culls the transaction queue of mined transactions.
pub struct QueueCull {
/// A handle to the client, for getting the latest block header.
pub client: Arc<Client>,
/// A handle to the sync service.
pub sync: Arc<LightSync>,
/// The on-demand request service.
pub on_demand: Arc<OnDemand>,
/// The transaction queue.
pub txq: Arc<RwLock<TransactionQueue>>,
/// Event loop remote.
pub remote: Remote,
}
impl IoHandler<ClientIoMessage> for QueueCull {
fn initialize(&self, io: &IoContext<ClientIoMessage>) {
io.register_timer(TOKEN, TIMEOUT_MS).expect("Error registering timer");
}
fn timeout(&self, _io: &IoContext<ClientIoMessage>, timer: TimerToken) {
if timer != TOKEN { return }
let senders = self.txq.read().queued_senders();
if senders.is_empty() { return }
let (sync, on_demand, txq) = (self.sync.clone(), self.on_demand.clone(), self.txq.clone());
let best_header = self.client.best_block_header();
let start_nonce = self.client.engine().account_start_nonce();
info!(target: "cull", "Attempting to cull queued transactions from {} senders.", senders.len());
self.remote.spawn_with_timeout(move || {
let maybe_fetching = sync.with_context(move |ctx| {
// fetch the nonce of each sender in the queue.
let nonce_reqs = senders.iter()
.map(|&address| request::Account { header: best_header.clone().into(), address: address })
.collect::<Vec<_>>();
// when they come in, update each sender to the new nonce.
on_demand.request(ctx, nonce_reqs)
.expect("No back-references; therefore all back-references are valid; qed")
.map(move |accs| {
let txq = txq.write();
let _ = accs.into_iter()
.map(|maybe_acc| maybe_acc.map_or(start_nonce, |acc| acc.nonce))
.zip(senders)
.fold(txq, |mut txq, (nonce, addr)| {
txq.cull(addr, nonce);
txq
});
})
.map_err(|_| debug!(target: "cull", "OnDemand prematurely closed channel."))
});
match maybe_fetching {
Some(fut) => fut.boxed(),
None => {
debug!(target: "cull", "Unable to acquire network context; qed");
future::ok(()).boxed()
}
}
}, Duration::from_millis(PURGE_TIMEOUT_MS), || {})
}
}