Newer
Older
// 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/>.
//! Fetchable Dapps support.
//! Manages downloaded (cached) Dapps and downloads them when necessary.
//! Uses `URLHint` to resolve addresses into Dapps bundle file location.
mod installers;
use std::{fs, env};
use std::path::PathBuf;
use std::sync::Arc;
use futures::{future, Future};
use futures_cpupool::CpuPool;
use fetch::{Client as FetchClient, Fetch};
use hash_fetch::urlhint::{URLHintContract, URLHint, URLHintResult};
use hyper::StatusCode;
use {Embeddable, SyncStatus, random_filename};
use page::local;
use handlers::{ContentHandler, ContentFetcherHandler};
use endpoint::{self, Endpoint, EndpointPath};
use apps::cache::{ContentCache, ContentStatus};
/// Limit of cached dapps/content
const MAX_CACHED_DAPPS: usize = 20;
pub trait Fetcher: Endpoint + 'static {
fn contains(&self, content_id: &str) -> bool;
}
pub struct ContentFetcher<F: Fetch = FetchClient, R: URLHint + 'static = URLHintContract> {
resolver: R,
cache: Arc<Mutex<ContentCache>>,
sync: Arc<SyncStatus>,
pool: CpuPool,
impl<R: URLHint + 'static, F: Fetch> Drop for ContentFetcher<F, R> {
fn drop(&mut self) {
// Clear cache path
let _ = fs::remove_dir_all(&self.cache_path);
impl<R: URLHint + 'static, F: Fetch> ContentFetcher<F, R> {
sync: Arc<SyncStatus>,
pool: CpuPool,
let mut cache_path = env::temp_dir();
cache_path.push(random_filename());
cache_path,
resolver,
sync,
cache: Arc::new(Mutex::new(ContentCache::default())),
fetch,
pool,
pub fn allow_dapps(mut self, dapps: bool) -> Self {
self.only_content = !dapps;
self
}
pub fn embeddable_on(mut self, embeddable_on: Embeddable) -> Self {
self.embeddable_on = embeddable_on;
self
}
fn not_found(embeddable: Embeddable) -> endpoint::Response {
Box::new(future::ok(ContentHandler::error(
StatusCode::NotFound,
"Resource Not Found",
"Requested resource was not found.",
None,
embeddable,
).into()))
}
fn still_syncing(embeddable: Embeddable) -> endpoint::Response {
Box::new(future::ok(ContentHandler::error(
StatusCode::ServiceUnavailable,
"Sync In Progress",
"Your node is still syncing. We cannot resolve any content before it's fully synced.",
Some("<a href=\"javascript:window.location.reload()\">Refresh</a>"),
).into()))
fn dapps_disabled(address: Embeddable) -> endpoint::Response {
Box::new(future::ok(ContentHandler::error(
StatusCode::ServiceUnavailable,
"Network Dapps Not Available",
"This interface doesn't support network dapps for security reasons.",
None,
address,
).into()))
#[cfg(test)]
fn set_status(&self, content_id: &str, status: ContentStatus) {
self.cache.lock().insert(content_id.to_owned(), status);
}
// resolve contract call synchronously.
// TODO: port to futures-based hyper and make it all async.
fn resolve(&self, content_id: Vec<u8>) -> Option<URLHintResult> {
self.resolver.resolve(content_id)
.wait()
.unwrap_or_else(|e| { warn!("Error resolving content-id: {}", e); None })
}
impl<R: URLHint + 'static, F: Fetch> Fetcher for ContentFetcher<F, R> {
fn contains(&self, content_id: &str) -> bool {
{
let mut cache = self.cache.lock();
// Check if we already have the app
if cache.get(content_id).is_some() {
return true;
}
}
// fallback to resolver
if let Ok(content_id) = content_id.from_hex() {
// if there is content or we are syncing return true
self.sync.is_major_importing() || self.resolve(content_id).is_some()
impl<R: URLHint + 'static, F: Fetch> Endpoint for ContentFetcher<F, R> {
fn respond(&self, path: EndpointPath, req: endpoint::Request) -> endpoint::Response {
let mut cache = self.cache.lock();
let content_id = path.app_id.clone();
let (new_status, handler) = {
let status = cache.get(&content_id);
match status {
// Just serve the content
Some(&mut ContentStatus::Ready(ref endpoint)) => {
(None, endpoint.to_response(&path))
},
// Content is already being fetched
Some(&mut ContentStatus::Fetching(ref fetch_control)) if !fetch_control.is_deadline_reached() => {
trace!(target: "dapps", "Content fetching in progress. Waiting...");
(None, fetch_control.to_response(path))
},
// We need to start fetching the content
trace!(target: "dapps", "Content unavailable. Fetching... {:?}", content_id);
let content_hex = content_id.from_hex().expect("to_handler is called only when `contains` returns true.");
let content = self.resolve(content_hex);
let cache = self.cache.clone();
let id = content_id.clone();
let on_done = move |result: Option<local::Dapp>| {
let mut cache = cache.lock();
match result {
Some(endpoint) => cache.insert(id.clone(), ContentStatus::Ready(endpoint)),
// In case of error
None => cache.remove(&id),
};
};
match content {
// Don't serve dapps if we are still syncing (but serve content)
Some(URLHintResult::Dapp(_)) if self.sync.is_major_importing() => {
(None, Self::still_syncing(self.embeddable_on.clone()))
},
Some(URLHintResult::Dapp(_)) if self.only_content => {
(None, Self::dapps_disabled(self.embeddable_on.clone()))
},
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
Some(content) => {
let handler = match content {
URLHintResult::Dapp(dapp) => {
ContentFetcherHandler::new(
req.method(),
&dapp.url(),
path,
installers::Dapp::new(
content_id.clone(),
self.cache_path.clone(),
Box::new(on_done),
self.embeddable_on.clone(),
self.pool.clone(),
),
self.embeddable_on.clone(),
self.fetch.clone(),
)
},
URLHintResult::GithubDapp(content) => {
ContentFetcherHandler::new(
req.method(),
&content.url,
path,
installers::Dapp::new(
content_id.clone(),
self.cache_path.clone(),
Box::new(on_done),
self.embeddable_on.clone(),
self.pool.clone(),
),
self.embeddable_on.clone(),
self.fetch.clone(),
)
},
URLHintResult::Content(content) => {
ContentFetcherHandler::new(
req.method(),
&content.url,
path,
installers::Content::new(
content_id.clone(),
content.mime,
self.cache_path.clone(),
Box::new(on_done),
self.pool.clone(),
),
self.embeddable_on.clone(),
self.fetch.clone(),
)
},
};
(Some(ContentStatus::Fetching(handler.fetch_control())), Box::new(handler) as endpoint::Response)
},
None if self.sync.is_major_importing() => {
(None, Self::still_syncing(self.embeddable_on.clone()))
},
None => {
// This may happen when sync status changes in between
// `contains` and `to_handler`
(None, Self::not_found(self.embeddable_on.clone()))
},
}
},
}
};
if let Some(status) = new_status {
cache.clear_garbage(MAX_CACHED_DAPPS);
cache.insert(content_id, status);
}
handler
}
}
#[cfg(test)]
mod tests {
use std::env;
use std::sync::Arc;
use bytes::Bytes;
use futures::future;
use hash_fetch::urlhint::{URLHint, URLHintResult, BoxFuture};
use apps::cache::ContentStatus;
use endpoint::EndpointInfo;
use page::local;
struct FakeResolver;
impl URLHint for FakeResolver {
fn resolve(&self, _id: Bytes) -> BoxFuture<Option<URLHintResult>, String> {
Box::new(future::ok(None))
struct FakeSync(bool);
impl SyncStatus for FakeSync {
fn is_major_importing(&self) -> bool { self.0 }
fn peers(&self) -> (usize, usize) { (0, 5) }
}
#[test]
fn should_true_if_contains_the_app() {
// given
let pool = ::futures_cpupool::CpuPool::new(1);
let fetcher = ContentFetcher::new(
FakeResolver,
Arc::new(FakeSync(false)),
Client::new().unwrap(),
pool.clone(),
).allow_dapps(true);
let handler = local::Dapp::new(pool, path, EndpointInfo {
name: "fake".into(),
description: "".into(),
version: "".into(),
author: "".into(),
icon_url: "".into(),
}, Default::default(), None);
// when
fetcher.set_status("test", ContentStatus::Ready(handler));
fetcher.set_status("test2", ContentStatus::Fetching(Default::default()));
// then
assert_eq!(fetcher.contains("test"), true);
assert_eq!(fetcher.contains("test2"), true);
assert_eq!(fetcher.contains("test3"), false);
}
}