113 lines
3.2 KiB
Rust
113 lines
3.2 KiB
Rust
// Copyright 2015-2017 Parity Technologies (UK) Ltd.
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// This file is part of Parity.
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// Parity is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// Parity is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with Parity. If not, see <http://www.gnu.org/licenses/>.
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//! Async Content Handler
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//! Temporary solution until we switch to future-based server.
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//! Wraps a future and converts it to hyper::server::Handler;
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use std::{mem, time};
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use std::sync::mpsc;
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use futures::Future;
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use hyper::{server, Decoder, Encoder, Next, Control};
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use hyper::net::HttpStream;
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use handlers::ContentHandler;
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use parity_reactor::Remote;
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const TIMEOUT_SECS: u64 = 15;
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enum State<F, T, M> {
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Initial(F, M, Remote, Control),
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Waiting(mpsc::Receiver<Result<T, ()>>, M),
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Done(ContentHandler),
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Invalid,
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}
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pub struct AsyncHandler<F, T, M> {
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state: State<F, T, M>,
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}
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impl<F, T, M> AsyncHandler<F, T, M> {
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pub fn new(future: F, map: M, remote: Remote, control: Control) -> Self {
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AsyncHandler {
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state: State::Initial(future, map, remote, control),
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}
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}
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}
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impl<F, T, E, M> server::Handler<HttpStream> for AsyncHandler<F, Result<T, E>, M> where
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F: Future<Item=T, Error=E> + Send + 'static,
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M: FnOnce(Result<Result<T, E>, ()>) -> ContentHandler,
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T: Send + 'static,
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E: Send + 'static,
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{
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fn on_request(&mut self, _request: server::Request<HttpStream>) -> Next {
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if let State::Initial(future, map, remote, control) = mem::replace(&mut self.state, State::Invalid) {
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let (tx, rx) = mpsc::sync_channel(1);
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let control2 = control.clone();
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let tx2 = tx.clone();
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remote.spawn_with_timeout(move || future.then(move |result| {
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// Send a result (ignore errors if the connection was dropped)
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let _ = tx.send(Ok(result));
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// Resume handler
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let _ = control.ready(Next::read());
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Ok(())
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}), time::Duration::from_secs(TIMEOUT_SECS), move || {
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// Notify about error
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let _ = tx2.send(Err(()));
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// Resume handler
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let _ = control2.ready(Next::read());
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});
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self.state = State::Waiting(rx, map);
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}
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Next::wait()
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}
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fn on_request_readable(&mut self, _decoder: &mut Decoder<HttpStream>) -> Next {
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if let State::Waiting(rx, map) = mem::replace(&mut self.state, State::Invalid) {
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match rx.try_recv() {
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Ok(result) => {
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self.state = State::Done(map(result));
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},
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Err(err) => {
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warn!("Resuming handler in incorrect state: {:?}", err);
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}
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}
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}
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Next::write()
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}
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fn on_response(&mut self, res: &mut server::Response) -> Next {
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if let State::Done(ref mut handler) = self.state {
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handler.on_response(res)
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} else {
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Next::end()
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}
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}
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fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
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if let State::Done(ref mut handler) = self.state {
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handler.on_response_writable(encoder)
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} else {
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Next::end()
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}
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}
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}
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