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use std::sync::{Arc, RwLock};
use futures::*;
use log::*;
use log::Level::Debug;
use tokio::io::WriteHalf;
use tokio::net::TcpStream;
use tokio::prelude::*;
use tokio::prelude::future::Future;
use crate::init::CONFIG;
use crate::session::stomp_session::{StompSession, FLAG_WEB_SOCKETS};
use crate::message::serializer::MessageSerializer;
use crate::web_socket::ws_response::ECG_FRAME;
/// responsible for sending data to the Tcp Connections WriteHalf
/// xtomp_send()
pub struct Writer {
session: Arc<RwLock<StompSession>>,
session_id: usize,
write_half: Arc<RwLock<WriteHalf<TcpStream>>>,
pos: usize,
end: usize,
out: Box<[u8]>,
first_poll: bool,
serializer: MessageSerializer,
web_socket: bool,
}
impl Writer {
pub fn new(session: Arc<RwLock<StompSession>>, session_id: usize, write_half: Arc<RwLock<WriteHalf<TcpStream>>>) -> Writer {
Writer {
session,
session_id,
write_half,
pos: 0,
end: 0,
out: vec![0 as u8; CONFIG.response_client_buffer].into_boxed_slice(),
first_poll: true,
serializer: MessageSerializer::new(),
web_socket: false,
}
}
/// poll Mq via session until it has a message to write, or it has been drained or closed
fn poll_mq(&self) -> Result<Async<()>, ()> {
match self.session.read().unwrap().poll_mq() {
Ok(Async::Ready(())) => Ok(Async::Ready(())),
Ok(Async::NotReady) => Ok(Async::NotReady),
Err(_) => Err(()),
}
}
fn pop_mq(&mut self) {
let session = self.session.read().unwrap();
match session.pop() {
Some(message) => {
if session.get_flag(FLAG_WEB_SOCKETS) {
self.serializer.ws_upgrade();
self.web_socket = true;
}
self.serializer.set_message(message);
}
_ => {
warn!("unreachable, pop_mq() should be called after poll() returns");
}
}
}
/// write the contents of self.out to the network
fn write_buf(&mut self) -> Result<Async<()>, ()> {
if self.pos == self.end {
return Ok(Async::Ready(()));
}
let mut write_half = self.write_half.write().unwrap();
while self.pos < self.end {
let out_buf = &self.out[self.pos..self.end];
let n = try_ready!(write_half.poll_write(out_buf).map_err(|_e| ()));
self.pos += n;
//debug!("WRITE CHUNK '{}'", String::from_utf8_lossy(out_buf));
//debug!("WRITE CHUNK '{:x?}'", out_buf);
//debug!("WRITE CHUNK {} bytes", self.pos);
{
self.session.read().unwrap().wrote_something();
}
if self.pos == self.end {
// wrote the whole buffer
if self.pos > 0 {
debug!("wrote whole out_buf last char '{}'", self.out[self.pos - 1]);
}
self.pos = 0;
self.end = 0;
return Ok(Async::Ready(()));
}
if n == 0 {
debug!("write of zero len is error");
self.session.write().unwrap().write_error();
debug!("writer closed");
return Err(());
}
}
Ok(Async::NotReady)
}
}
impl Future for Writer {
type Item = ();
type Error = ();
/// handles writing from mq to self.out and from self.out to the network.
fn poll(&mut self) -> Result<Async<Self::Item>, Self::Error> {
debug!("write polled");
if self.first_poll {
let session = self.session.write().unwrap();
session.set_mq_task(futures::task::current());
self.first_poll = false;
}
// if there is anything left in out, write it
match self.write_buf() {
Ok(Async::Ready(())) => {
// able to write
},
Ok(Async::NotReady) => {
return Ok(Async::NotReady);
},
Err(_) => {
// write_error() was called
return Err(());
},
}
// if we are currently processing a message, write the next chunk
while self.serializer.is_serializing() {
match self.serializer.write_chunk(&mut self.out) {
Ok(0) => {
warn!("unreachable? zero write_chunk()");
},
Ok(writ) => {
self.pos = 0;
self.end = writ;
debug!("prepared some");
match self.write_buf() {
Ok(Async::Ready(())) => {
// able to write
},
Ok(Async::NotReady) => {
return Ok(Async::NotReady);
},
Err(_) => {
// write_error() was called
return Err(());
}
}
},
Err(_) => {
warn!("discarding message");
},
}
}
if log_enabled!(Debug) {
debug!("looking for more {}", self.session.read().unwrap().len());
}
match self.poll_mq() {
Ok(Async::Ready(())) => {
self.pop_mq();
return self.poll();
},
Ok(Async::NotReady) => {
debug!("no more messages");
// heart-beat
if self.session.read().unwrap().should_heart_beat() {
debug!("sending heart-beat");
if self.web_socket {
self.out[self.pos] = ECG_FRAME[0];
self.out[self.pos + 1] = ECG_FRAME[1];
self.out[self.pos + 2] = ECG_FRAME[2];
self.end += 3;
} else {
self.out[self.pos] = b'\n';
self.end += 1;
}
match self.write_buf() {
Ok(Async::Ready(())) => {
// able to write
},
Ok(Async::NotReady) => {
return Ok(Async::NotReady);
},
Err(_) => {
// write_error() was called
return Err(());
}
}
}
Ok(Async::NotReady)
},
Err(_) => {
self.write_half.write().unwrap().shutdown().ok();
debug!("writer closed id={}" , self.session_id);
self.session.write().unwrap().write_terminated();
return Err(());
},
}
}
}