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use super::LocalInfileHandler;
use lib_futures::IntoFuture;
use mio::{Evented, Poll, PollOpt, Ready, Registration, Token};
use std::collections::HashSet;
use std::fs;
use std::io::{self, Read};
use std::path::PathBuf;
use std::str::from_utf8;
use std::sync::mpsc::{channel, Receiver, Sender, TryRecvError};
use std::thread;
use tokio::reactor::PollEvented2;
use tokio_io::AsyncRead;
use BoxFuture;
#[derive(Debug)]
enum Message {
FillBuf(usize),
BufFilled(io::Result<Vec<u8>>),
Done,
}
pub struct File {
to_thread: Sender<Message>,
from_thread: Receiver<Message>,
registration: Registration,
waiting_for_readiness: bool,
}
impl File {
pub fn new<T>(path: T) -> File
where
T: Into<PathBuf>,
{
let (to_main, from_thread) = channel();
let (to_thread, from_main) = channel();
let (registration, set_readiness) = Registration::new2();
let path = path.into();
thread::spawn(move || {
let mut file = match fs::File::open(path) {
Ok(file) => file,
Err(err) => {
to_main.send(Message::BufFilled(Err(err))).unwrap();
set_readiness.set_readiness(Ready::readable()).unwrap();
return;
}
};
set_readiness.set_readiness(Ready::readable()).unwrap();
loop {
match from_main.recv() {
Ok(Message::FillBuf(size)) => {
let mut buf = Vec::with_capacity(size);
unsafe {
buf.set_len(size);
}
let result = file.read(&mut buf[..]).map(|count| {
unsafe {
buf.set_len(count);
}
buf
});
to_main.send(Message::BufFilled(result)).unwrap();
set_readiness.set_readiness(Ready::readable()).unwrap();
}
Ok(Message::Done) | Err(_) => {
break;
}
Ok(x) => panic!("Unexpected message for file io thread: {:?}", x),
}
}
});
File {
to_thread,
from_thread,
registration,
waiting_for_readiness: false,
}
}
}
impl Read for File {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
match self.from_thread.try_recv() {
Ok(Message::BufFilled(data_buf)) => match data_buf {
Ok(data_buf) => {
self.waiting_for_readiness = false;
if data_buf.len() == 0 && !buf.len() == 0 {
let _ = self.to_thread.send(Message::Done);
}
(&data_buf[..]).read(buf)
}
Err(err) => {
let _ = self.to_thread.send(Message::Done);
Err(err)
}
},
Err(TryRecvError::Empty) => {
if !self.waiting_for_readiness {
self.waiting_for_readiness = true;
match self.to_thread.send(Message::FillBuf(buf.len())) {
Ok(_) => (),
Err(_) => {
return Err(io::Error::new(
io::ErrorKind::Other,
"Read thread disconnected",
))
}
}
}
Err(io::ErrorKind::WouldBlock.into())
}
Err(TryRecvError::Disconnected) => Err(io::Error::new(
io::ErrorKind::Other,
"Read thread disconnected",
)),
_ => panic!("Unexpected message"),
}
}
}
impl Evented for File {
fn register(
&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt,
) -> io::Result<()> {
self.registration.register(poll, token, interest, opts)
}
fn reregister(
&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt,
) -> io::Result<()> {
self.registration.reregister(poll, token, interest, opts)
}
fn deregister(&self, poll: &Poll) -> io::Result<()> {
Evented::deregister(&self.registration, poll)
}
}
#[derive(Clone, Debug)]
pub struct WhiteListFsLocalInfileHandler {
white_list: HashSet<PathBuf>,
}
impl WhiteListFsLocalInfileHandler {
pub fn new<A, B>(white_list: B) -> WhiteListFsLocalInfileHandler
where
A: Into<PathBuf>,
B: IntoIterator<Item = A>,
{
let mut white_list_set = HashSet::new();
for path in white_list.into_iter() {
white_list_set.insert(Into::<PathBuf>::into(path));
}
WhiteListFsLocalInfileHandler {
white_list: white_list_set,
}
}
}
impl LocalInfileHandler for WhiteListFsLocalInfileHandler {
fn handle(&self, file_name: &[u8]) -> BoxFuture<Box<AsyncRead + Send + 'static>> {
let path: PathBuf = match from_utf8(file_name) {
Ok(path_str) => path_str.into(),
Err(_) => return Box::new(Err("Invalid file name".into()).into_future()),
};
if self.white_list.contains(&path) {
let fut = Ok(
Box::new(PollEvented2::new(File::new(path))) as Box<AsyncRead + Send + 'static>
).into_future();
Box::new(fut) as BoxFuture<Box<_>>
} else {
let err_msg = format!("Path `{}' is not in white list", path.display());
return Box::new(Err(err_msg.into()).into_future());
}
}
}