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Refactor `link` module for use in one thread

While `link` module is still spawning new threads to handle new
connections and reading data from connected clients - it now collects
all the received messages in one thread, simplifying their handling.
feature_link
Anton Tarasenko 3 years ago
parent
commit
cfe680d770
  1. 31
      Cargo.lock
  2. 4
      Cargo.toml
  3. 38
      src/link/message.rs
  4. 139
      src/link/mod.rs
  5. 106
      src/link/network.rs
  6. 15
      src/main.rs

31
Cargo.lock generated

@ -5,6 +5,8 @@ name = "avarice"
version = "0.1.0"
dependencies = [
"custom_error 1.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
"serde 1.0.126 (registry+https://github.com/rust-lang/crates.io-index)",
"serde_json 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
@ -12,5 +14,34 @@ name = "custom_error"
version = "1.9.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "itoa"
version = "0.4.7"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "ryu"
version = "1.0.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "serde"
version = "1.0.126"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "serde_json"
version = "1.0.66"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"itoa 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
"ryu 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
"serde 1.0.126 (registry+https://github.com/rust-lang/crates.io-index)",
]
[metadata]
"checksum custom_error 1.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4f8a51dd197fa6ba5b4dc98a990a43cc13693c23eb0089ebb0fcc1f04152bca6"
"checksum itoa 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
"checksum ryu 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
"checksum serde 1.0.126 (registry+https://github.com/rust-lang/crates.io-index)" = "ec7505abeacaec74ae4778d9d9328fe5a5d04253220a85c4ee022239fc996d03"
"checksum serde_json 1.0.66 (registry+https://github.com/rust-lang/crates.io-index)" = "336b10da19a12ad094b59d870ebde26a45402e5b470add4b5fd03c5048a32127"

4
Cargo.toml

@ -7,4 +7,6 @@ edition = "2018"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
custom_error="1.9.2"
custom_error="1.*"
serde ="1.*"
serde_json="1.*"

38
src/link/message.rs

@ -0,0 +1,38 @@
//! Implements Avarice message: target service, message type, json parameters
use serde_json;
use serde_json::json;
use std::fmt;
pub struct AvariceMessage {
pub service: String,
pub message_type: String,
pub parameters: serde_json::Value,
}
impl AvariceMessage {
/// Parses JSON form of a message into `AvariceMessage` struct
pub fn from(message_str: &str) -> Option<AvariceMessage> {
let mut message_json: serde_json::Value = serde_json::from_str(message_str).unwrap();
let message_json = message_json.as_object_mut()?;
Some(AvariceMessage {
service: message_json.remove("s")?.as_str()?.to_owned(),
message_type: message_json.remove("t")?.as_str()?.to_owned(),
parameters: message_json.remove("p")?,
})
}
}
impl fmt::Display for AvariceMessage {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"{}",
json!({
"s": self.service,
"t": self.message_type,
"p": self.parameters,
})
.to_string()
)
}
}

139
src/link/mod.rs

@ -1,62 +1,111 @@
//! Implements reader and writer to use when talking to UE2 game server.
//! This module provides a simple interface to exchange messages (`message::AvariceMessage`) between
//! Avarice and ue-server. The model is simple - we create an mpsc-channel of `Sender` and
//! `Receiver`, then pass `Sender` to the `network` sub-module and wait for its messages about
//! ue-servers' connections using `Receiver`.
use std::collections::HashMap;
use std::error::Error;
use std::io::{Read, Write};
use std::net::{SocketAddr, TcpListener};
use std::sync::Arc;
use std::{str, thread};
use std::io::Write;
use std::net::{SocketAddr, TcpStream};
use std::sync::mpsc::{channel, Receiver};
pub use writer::MessageWriter;
mod message;
mod network;
mod reader;
mod writer;
pub use reader::MessageReader;
pub use writer::MessageWriter;
pub use message::AvariceMessage;
pub use network::{run_server, NetworkMessage};
/// For collecting messages from all connected ue-servers and providing a way to reply back.
pub struct AvariceServer {
connected_links: HashMap<SocketAddr, Link>,
receiver: Receiver<NetworkMessage>,
}
/// For representing a link to one of the connected ue-servers, can be used to send messages back.
/// To receive messages use `AvariceServer`'s `next()` method instead.
pub struct Link {
reader: MessageReader,
ue_server_address: SocketAddr,
writer: MessageWriter,
writing_stream: TcpStream,
}
impl Link {
pub fn run<F>(port: u16, handler: F) -> Result<(), Box<dyn Error>>
where
F: Fn(&mut Link, &str) -> () + Send + Sync + 'static,
{
let address = SocketAddr::from(([0, 0, 0, 0], port));
let listener = TcpListener::bind(address)?;
let handler = Arc::new(handler);
impl AvariceServer {
/// Blocks until a new message arrives from one of the ue-servers. Returns a pair of `Link`,
/// corresponding to the ue-server that sent next message and `AvariceMessage`,
/// representing that message.
pub fn next(&mut self) -> Option<(&mut Link, AvariceMessage)> {
loop {
// Listen to new (multiple) connection
let mut reading_stream = listener.accept()?.0;
let mut writing_stream = reading_stream.try_clone()?;
let mut avarice_link = Link {
reader: MessageReader::new(),
writer: MessageWriter::new(),
};
let handler_clone = handler.clone();
// On connection - spawn a new thread
thread::spawn(move || loop {
let mut buffer = [0; 1024];
// Reading cycle
match reading_stream.read(&mut buffer) {
Ok(n) => avarice_link.reader.push(&buffer[..n]).unwrap(),
_ => panic!("Connection issue!"),
};
// Handling cycle
while let Some(message) = avarice_link.reader.pop() {
handler_clone(&mut avarice_link, &message);
match self.receiver.recv() {
Ok(NetworkMessage::ConnectionEstablished(ue_server_address, writing_stream)) => {
// If `ue_server_address` was already present in `self.connected_links`
// hash map, then it means we have failed to clean it up after it
// has disconnected. We can just throw away the old value here.
self.connected_links.insert(
ue_server_address,
Link {
ue_server_address,
writing_stream,
writer: MessageWriter::new(),
},
);
continue;
}
Ok(NetworkMessage::ConnectionLost(ue_server_address)) => {
self.connected_links.remove(&ue_server_address);
continue;
}
Ok(NetworkMessage::InvalidDataReceived(ue_server_address)) => {
self.connected_links.remove(&ue_server_address);
continue;
}
// Writing
avarice_link
.writer
.update_ue_received_bytes(avarice_link.reader.ue_received_bytes());
if let Some(bytes) = avarice_link.writer.try_pop() {
writing_stream.write_all(&bytes).unwrap();
Ok(NetworkMessage::UEReceivedUpdate(ue_server_address, ue_received_bytes)) => {
if let Some(link) = self.connected_links.get_mut(&ue_server_address) {
link.update_ue_received_bytes(ue_received_bytes)
}
continue;
}
});
Ok(NetworkMessage::MessageReceived(ue_server_address, message)) => {
// Not having a link with key `ue_server_address` should be impossible here
return self
.connected_links
.get_mut(&ue_server_address)
.and_then(|x| Some((x, message)));
}
_ => return None,
}
}
}
}
impl Link {
pub fn send(&mut self, message: AvariceMessage) {
self.writer.push(&message.to_string());
self.flush();
}
pub fn socket_address(&self) -> SocketAddr {
self.ue_server_address
}
pub fn write(&mut self, message: &str) {
self.writer.push(message);
fn update_ue_received_bytes(&mut self, ue_received_bytes: u64) {
self.writer.update_ue_received_bytes(ue_received_bytes);
self.flush();
}
fn flush(&mut self) {
if let Some(bytes) = self.writer.try_pop() {
self.writing_stream.write_all(&bytes).unwrap();
}
}
}
/// Creates a new `AvariceServer` that will listen for ue-server connections on the specified port.
pub fn start_avarice(port: u16) -> Result<AvariceServer, Box<dyn Error>> {
let (sender, receiver) = channel();
run_server(port, sender)?;
Ok(AvariceServer {
connected_links: HashMap::new(),
receiver,
})
}

106
src/link/network.rs

@ -0,0 +1,106 @@
//! Implements a network model where messages from all the ue-servers are collected in a single
//! main thread. For that we spawn a new thread that listens for new connections, which in turn
//! spawns a new thread for every connected ue-server to handle reading data from it.
//! Since all reading is handled in ue-servers' own threads, to collect messages they have
//! received in the main thread we use `std::sync::mpsc::Sender`. Conversely, all the writing to
//! ue-server is handled in the main thread itself. Writing `TcpStream` is sent to the main thread
//! by the same `std::sync::mpsc::Sender` object.
use super::message::AvariceMessage;
pub use super::reader::MessageReader;
use std::error::Error;
use std::io::Read;
use std::net::{SocketAddr, TcpListener, TcpStream};
use std::sync::mpsc::Sender;
use std::thread;
pub struct UEConnection {
pub address: SocketAddr,
pub reader: MessageReader,
pub reading_stream: TcpStream,
pub message_sender: Sender<NetworkMessage>,
}
/// Possible messages to the main thread
pub enum NetworkMessage {
ConnectionEstablished(SocketAddr, TcpStream),
InvalidDataReceived(SocketAddr),
ConnectionLost(SocketAddr),
MessageReceived(SocketAddr, AvariceMessage),
UEReceivedUpdate(SocketAddr, u64),
}
pub fn run_server(port: u16, message_sender: Sender<NetworkMessage>) -> Result<(), Box<dyn Error>> {
let address = SocketAddr::from(([0, 0, 0, 0], port));
let listener = TcpListener::bind(address)?;
thread::spawn(move || loop {
// Listen to new (multiple) connection
let (reading_stream, address) = listener.accept().unwrap();
let writing_stream = reading_stream.try_clone().unwrap();
message_sender
.send(NetworkMessage::ConnectionEstablished(
address,
writing_stream,
))
.unwrap();
// On connection - spawn a new thread
let sender_clone = message_sender.clone();
thread::spawn(move || {
manage_connection(UEConnection {
reader: MessageReader::new(),
message_sender: sender_clone,
reading_stream,
address,
})
});
});
Ok(())
}
fn manage_connection(mut connection: UEConnection) {
let mut buffer = [0; 1024];
loop {
// Reading cycle
match connection.reading_stream.read(&mut buffer) {
Ok(n) => connection.reader.push(&buffer[..n]).unwrap(),
_ => {
connection
.message_sender
.send(NetworkMessage::ConnectionLost(connection.address))
.unwrap();
return;
}
};
if connection.reader.is_broken() {
connection
.message_sender
.send(NetworkMessage::InvalidDataReceived(connection.address))
.unwrap();
return;
}
// Decoding cycle
while let Some(text_message) = connection.reader.pop() {
if let Some(avarice_message) = AvariceMessage::from(&text_message) {
connection
.message_sender
.send(NetworkMessage::MessageReceived(
connection.address,
avarice_message,
))
.unwrap();
} else {
connection
.message_sender
.send(NetworkMessage::InvalidDataReceived(connection.address))
.unwrap();
return;
}
}
connection
.message_sender
.send(NetworkMessage::UEReceivedUpdate(
connection.address,
connection.reader.ue_received_bytes(),
))
.unwrap();
}
}

15
src/main.rs

@ -1,9 +1,14 @@
// ! This utility provides a way to communicate with Unreal Engine 2 servers running Acedia mutator.
mod link;
use link::Link;
use link::start_avarice;
fn main() {
match Link::run(1234, |link, message| { link.write(message);}) {
Ok(_) => print!("Connect!"),
_ => print!("Connection error!"),
};
let mut server = start_avarice(1234).unwrap();
while let Some((link, message)) = server.next() {
println!("{}: {}", link.socket_address(), message.to_string());
if message.message_type != "end" {
link.send(message);
}
}
println!("Avarice has shut down!");
}

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