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use crate::thread::{self, Joiner};
use std::borrow::Borrow;
use std::collections::VecDeque;
use std::convert::From;
use std::io;
use std::sync::mpsc;
use std::sync::mpsc::Sender;
use std::time::{Duration, Instant};
use url::Url;
use ws::{self, CloseCode, Handler, Handshake, Message, Request};
#[cfg(not(test))]
const RECONNECT_PERIOD: u64 = 10;
#[cfg(test)]
const RECONNECT_PERIOD: u64 = 0;
const MAX_BUFFERED_MESSAGES: usize = 500_000;
const SESSION_ID_HEADER: &str = "SessionId";
pub struct WebSocket {
url: String,
session_id: Option<String>,
socket: ws::Result<(ws::Sender, Joiner)>,
last_reconnect: Instant,
message_buffer: VecDeque<Message>,
}
impl WebSocket {
pub fn new<U: Borrow<str>>(url_borrow: U, session_id: Option<String>) -> Self {
let url = url_borrow.borrow().to_owned();
let last_reconnect = Instant::now() - Duration::from_secs(RECONNECT_PERIOD);
let socket = Self::connect(url.clone(), session_id.clone());
WebSocket {
url,
session_id,
socket,
last_reconnect,
message_buffer: VecDeque::new(),
}
}
pub fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
self.queue_message(Message::Binary(buf.to_owned()));
while let Some(msg) = self.message_buffer.pop_front() {
let to_send = msg.clone();
if self
.get_sender()
.and_then(|sender| sender.send(to_send))
.is_err()
{
self.message_buffer.push_front(msg);
let now = Instant::now();
if now - self.last_reconnect >= Duration::from_secs(RECONNECT_PERIOD) {
self.last_reconnect = now;
self.socket = Self::connect(self.url.clone(), self.session_id.clone());
}
if self.socket.is_err() {
break;
}
}
}
Ok(())
}
fn get_sender(&self) -> ws::Result<&ws::Sender> {
self.socket
.as_ref()
.map(|&(ref sender, _)| sender)
.map_err(|_| ws::Error::new(ws::ErrorKind::Internal, "No web socket thread running"))
}
fn queue_message(&mut self, msg: Message) {
if self.message_buffer.len() < MAX_BUFFERED_MESSAGES {
self.message_buffer.push_back(msg);
}
}
pub fn connect(
url: String,
mut session_id: Option<String>,
) -> ws::Result<(ws::Sender, Joiner)> {
let (tx, rx) = mpsc::channel();
let joiner = thread::named("WebSocketLogger", move || {
struct Client<'a> {
ws_tx: ws::Sender,
tx: &'a Sender<ws::Result<ws::Sender>>,
session_id: Option<String>,
}
impl<'a> Client<'a> {
fn new(
ws_tx: ws::Sender,
tx: &'a Sender<ws::Result<ws::Sender>>,
session_id: Option<String>,
) -> Self {
Client {
ws_tx,
tx,
session_id,
}
}
}
impl<'a> Handler for Client<'a> {
fn build_request(&mut self, url: &Url) -> ws::Result<Request> {
let mut req = Request::from_url(url)?;
if let Some(ref session_id) = self.session_id {
req.headers_mut()
.push((SESSION_ID_HEADER.into(), session_id.clone().into()));
}
Ok(req)
}
fn on_open(&mut self, _: Handshake) -> ws::Result<()> {
if self.tx.send(Ok(self.ws_tx.clone())).is_err() {
Err(ws::Error {
kind: ws::ErrorKind::Internal,
details: From::from("Channel error - Could not send ws_tx."),
})
} else {
Ok(())
}
}
fn on_error(&mut self, _: ws::Error) {
}
}
if let Err(e) = ws::connect(url, |ws_tx| Client::new(ws_tx, &tx, session_id.take())) {
let _ = tx.send(Err(e));
}
});
match rx.recv() {
Ok(Ok(ws_tx)) => Ok((ws_tx, joiner)),
Ok(Err(e)) => Err(e),
Err(e) => Err(ws::Error::new(
ws::ErrorKind::Internal,
format!("WebSocket Logger Error: {:?}", e),
)),
}
}
}
impl Drop for WebSocket {
fn drop(&mut self) {
let _ = self
.get_sender()
.and_then(|sender| sender.close(CloseCode::Normal));
}
}
pub fn validate_request(req: &Request, expected_id: Option<&str>) -> ws::Result<ws::Response> {
match (expected_id, req.header(SESSION_ID_HEADER)) {
(Some(exp), Some(obs)) if &obs[..] == exp.as_bytes() => ws::Response::from_request(req),
(None, _) => ws::Response::from_request(req),
_ => Err(ws::Error::new(ws::ErrorKind::Internal, "Invalid SessionId")),
}
}