91 lines
2.7 KiB
Rust
91 lines
2.7 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/>.
|
||
|
|
|
||
|
|
use std::sync::{Arc, Weak};
|
||
|
|
|
||
|
|
use ethcore::encoded;
|
||
|
|
use ethcore::engines::{Engine, StateDependentProof};
|
||
|
|
use ethcore::header::Header;
|
||
|
|
use ethcore::receipt::Receipt;
|
||
|
|
use ethsync::LightSync;
|
||
|
|
|
||
|
|
use futures::{future, Future, BoxFuture};
|
||
|
|
|
||
|
|
use light::client::fetch::ChainDataFetcher;
|
||
|
|
use light::on_demand::{request, OnDemand};
|
||
|
|
|
||
|
|
use parking_lot::RwLock;
|
||
|
|
use bigint::hash::H256;
|
||
|
|
|
||
|
|
const ALL_VALID_BACKREFS: &str = "no back-references, therefore all back-references valid; qed";
|
||
|
|
|
||
|
|
/// Allows on-demand fetch of data useful for the light client.
|
||
|
|
pub struct EpochFetch {
|
||
|
|
/// A handle to the sync service.
|
||
|
|
pub sync: Arc<RwLock<Weak<LightSync>>>,
|
||
|
|
/// The on-demand request service.
|
||
|
|
pub on_demand: Arc<OnDemand>,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl EpochFetch {
|
||
|
|
fn request<T>(&self, req: T) -> BoxFuture<T::Out, &'static str>
|
||
|
|
where T: Send + request::RequestAdapter + 'static, T::Out: Send + 'static
|
||
|
|
{
|
||
|
|
match self.sync.read().upgrade() {
|
||
|
|
Some(sync) => {
|
||
|
|
let on_demand = &self.on_demand;
|
||
|
|
let maybe_future = sync.with_context(move |ctx| {
|
||
|
|
on_demand.request(ctx, req).expect(ALL_VALID_BACKREFS)
|
||
|
|
});
|
||
|
|
|
||
|
|
match maybe_future {
|
||
|
|
Some(x) => x.map_err(|_| "Request canceled").boxed(),
|
||
|
|
None => future::err("Unable to access network.").boxed(),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
None => future::err("Unable to access network").boxed(),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl ChainDataFetcher for EpochFetch {
|
||
|
|
type Error = &'static str;
|
||
|
|
|
||
|
|
type Body = BoxFuture<encoded::Block, &'static str>;
|
||
|
|
type Receipts = BoxFuture<Vec<Receipt>, &'static str>;
|
||
|
|
type Transition = BoxFuture<Vec<u8>, &'static str>;
|
||
|
|
|
||
|
|
fn block_body(&self, header: &Header) -> Self::Body {
|
||
|
|
self.request(request::Body(header.encoded().into()))
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Fetch block receipts.
|
||
|
|
fn block_receipts(&self, header: &Header) -> Self::Receipts {
|
||
|
|
self.request(request::BlockReceipts(header.encoded().into()))
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Fetch epoch transition proof at given header.
|
||
|
|
fn epoch_transition(&self, hash: H256, engine: Arc<Engine>, checker: Arc<StateDependentProof>)
|
||
|
|
-> Self::Transition
|
||
|
|
{
|
||
|
|
self.request(request::Signal {
|
||
|
|
hash: hash,
|
||
|
|
engine: engine,
|
||
|
|
proof_check: checker,
|
||
|
|
})
|
||
|
|
}
|
||
|
|
}
|