openethereum/util/fetch/src/client.rs
2016-12-11 19:30:54 +01:00

147 lines
4.1 KiB
Rust

// Copyright 2015, 2016 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/>.
//! Fetching
use std::{env, io};
use std::sync::{mpsc, Arc};
use std::sync::atomic::AtomicBool;
use std::path::PathBuf;
use hyper;
use https_fetch as https;
use fetch_file::{FetchHandler, Error as HttpFetchError};
pub type FetchResult = Result<PathBuf, FetchError>;
#[derive(Debug)]
pub enum FetchError {
InvalidUrl,
Http(HttpFetchError),
Https(https::FetchError),
Io(io::Error),
Other(String),
}
impl From<HttpFetchError> for FetchError {
fn from(e: HttpFetchError) -> Self {
FetchError::Http(e)
}
}
impl From<io::Error> for FetchError {
fn from(e: io::Error) -> Self {
FetchError::Io(e)
}
}
pub trait Fetch: Default + Send {
/// Fetch URL and get the result in callback.
fn request_async(&mut self, url: &str, abort: Arc<AtomicBool>, on_done: Box<Fn(FetchResult) + Send>) -> Result<(), FetchError>;
/// Fetch URL and get a result Receiver. You will be notified when receiver is ready by `on_done` callback.
fn request(&mut self, url: &str, abort: Arc<AtomicBool>, on_done: Box<Fn() + Send>) -> Result<mpsc::Receiver<FetchResult>, FetchError> {
let (tx, rx) = mpsc::channel();
try!(self.request_async(url, abort, Box::new(move |result| {
let res = tx.send(result);
if let Err(_) = res {
warn!("Fetch finished, but no one was listening");
}
on_done();
})));
Ok(rx)
}
/// Closes this client
fn close(self) {}
/// Returns a random filename
fn random_filename() -> String {
use ::rand::Rng;
let mut rng = ::rand::OsRng::new().unwrap();
rng.gen_ascii_chars().take(12).collect()
}
}
pub struct Client {
http_client: hyper::Client<FetchHandler>,
https_client: https::Client,
limit: Option<usize>,
}
impl Default for Client {
fn default() -> Self {
// Max 15MB will be downloaded.
Client::with_limit(Some(15*1024*1024))
}
}
impl Client {
fn with_limit(limit: Option<usize>) -> Self {
Client {
http_client: hyper::Client::new().expect("Unable to initialize http client."),
https_client: https::Client::with_limit(limit).expect("Unable to initialize https client."),
limit: limit,
}
}
fn convert_url(url: hyper::Url) -> Result<https::Url, FetchError> {
let host = format!("{}", try!(url.host().ok_or(FetchError::InvalidUrl)));
let port = try!(url.port_or_known_default().ok_or(FetchError::InvalidUrl));
https::Url::new(&host, port, url.path()).map_err(|_| FetchError::InvalidUrl)
}
fn temp_path() -> PathBuf {
let mut dir = env::temp_dir();
dir.push(Self::random_filename());
dir
}
}
impl Fetch for Client {
fn close(self) {
self.http_client.close();
self.https_client.close();
}
fn request_async(&mut self, url: &str, abort: Arc<AtomicBool>, on_done: Box<Fn(FetchResult) + Send>) -> Result<(), FetchError> {
let is_https = url.starts_with("https://");
let url = try!(url.parse().map_err(|_| FetchError::InvalidUrl));
let temp_path = Self::temp_path();
trace!(target: "fetch", "Fetching from: {:?}", url);
if is_https {
let url = try!(Self::convert_url(url));
try!(self.https_client.fetch_to_file(
url,
temp_path.clone(),
abort,
move |result| on_done(result.map(|_| temp_path).map_err(FetchError::Https)),
).map_err(|e| FetchError::Other(format!("{:?}", e))));
} else {
try!(self.http_client.request(
url,
FetchHandler::new(temp_path, abort, Box::new(move |result| on_done(result)), self.limit.map(|v| v as u64).clone()),
).map_err(|e| FetchError::Other(format!("{:?}", e))));
}
Ok(())
}
}