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#![deny(missing_docs)]
#[macro_use]
extern crate serde_derive;
mod packet;
mod param;
#[cfg(test)]
pub mod test;
pub type Result<T> = std::result::Result<T, failure::Error>;
use self::packet::Packet;
pub use self::param::ConnectorParam;
use std::collections::HashMap;
use std::io::ErrorKind;
use std::net::{SocketAddr, UdpSocket};
use std::num::NonZeroU64;
#[derive(Debug)]
struct ConnectorSend<TParam: ConnectorParam> {
unconfirmed_message_cache: HashMap<NonZeroU64, CachedPacket<TParam::TSend>>,
next_message_id: Option<NonZeroU64>,
last_ping_time: f64,
}
impl<TParam: ConnectorParam> Default for ConnectorSend<TParam> {
fn default() -> Self {
ConnectorSend {
unconfirmed_message_cache: HashMap::new(),
next_message_id: None,
last_ping_time: 0.,
}
}
}
#[derive(Debug)]
struct ConnectorReceive {
last_message_id: Option<NonZeroU64>,
missing_message_id_list: Vec<MissingId>,
last_ping_time: f64,
}
impl Default for ConnectorReceive {
fn default() -> Self {
ConnectorReceive {
last_message_id: None,
missing_message_id_list: Vec::new(),
last_ping_time: 0.,
}
}
}
pub struct Connector<TParam: ConnectorParam> {
send: ConnectorSend<TParam>,
receive: ConnectorReceive,
peer_addr: SocketAddr,
}
#[derive(Debug)]
struct MissingId {
pub id: NonZeroU64,
pub last_request_time: f64,
}
#[derive(Debug)]
struct CachedPacket<TSend> {
pub packet: Packet<TSend>,
pub last_emit_time: f64,
}
#[derive(Debug, Eq, PartialEq)]
pub enum NetworkState {
Connected,
Disconnected,
Connecting,
}
impl MissingId {
pub fn new(id: NonZeroU64) -> MissingId {
MissingId {
id,
last_request_time: 0.,
}
}
}
pub trait Socket {
fn recv_from(&mut self, buffer: &mut [u8]) -> std::io::Result<(usize, SocketAddr)>;
fn local_addr(&self) -> SocketAddr;
fn send_to(&mut self, buffer: &[u8], target: SocketAddr) -> Result<()>;
}
impl Socket for UdpSocket {
fn recv_from(&mut self, buffer: &mut [u8]) -> std::io::Result<(usize, SocketAddr)> {
UdpSocket::recv_from(self, buffer)
}
fn local_addr(&self) -> SocketAddr {
UdpSocket::local_addr(self).unwrap()
}
fn send_to(&mut self, buffer: &[u8], target: SocketAddr) -> Result<()> {
UdpSocket::send_to(self, buffer, target)?;
Ok(())
}
}
impl<TParam: ConnectorParam> Connector<TParam> {
pub fn bound_to(peer_addr: SocketAddr) -> Self {
Connector {
send: Default::default(),
receive: Default::default(),
peer_addr,
}
}
pub fn bound_addr(&self) -> SocketAddr {
self.peer_addr
}
pub fn connect(&mut self, socket: &mut Socket) -> Result<()> {
self.send = Default::default();
self.receive = Default::default();
self.send_ping(socket)
}
pub fn state(&self) -> NetworkState {
if self.receive.last_ping_time + TParam::RECEIVE_PING_TIMEOUT_S < time::precise_time_s() {
if self.send.last_ping_time + TParam::SEND_PING_TIMEOUT_S > time::precise_time_s() {
NetworkState::Connecting
} else {
NetworkState::Disconnected
}
} else {
NetworkState::Connected
}
}
pub fn receive_from(&mut self, socket: &mut Socket) -> Result<Vec<TParam::TReceive>> {
let mut buffer = [0u8; 1024];
let mut result = Vec::new();
let mut had_message = false;
loop {
let receive_result = socket.recv_from(&mut buffer);
let count = match receive_result {
Ok((_, addr)) if addr != self.peer_addr => continue, Ok((count, _)) if count == 0 => {
if !had_message {
return Err(std::io::Error::from(ErrorKind::BrokenPipe).into());
} else {
return Ok(result);
}
}
Ok((count, _)) => count,
Err(ref e) if e.kind() == ErrorKind::WouldBlock => return Ok(result),
Err(e) => return Err(e.into()),
};
had_message = true;
if let Some(msg) = self.handle_incoming_data(socket, &buffer[..count])? {
result.push(msg);
}
}
}
pub fn update_and_receive(&mut self, socket: &mut Socket) -> Result<Vec<TParam::TReceive>> {
self.update(socket)?;
self.receive_from(socket)
}
pub fn update(&mut self, socket: &mut Socket) -> Result<()> {
if NetworkState::Disconnected == self.state() {
return Ok(());
}
if self.send.last_ping_time + TParam::PING_INTERVAL_S < time::precise_time_s() {
self.send_ping(socket)?;
}
for missing_packet in &mut self.receive.missing_message_id_list {
if missing_packet.last_request_time + TParam::REQUEST_MISSING_PACKET_INTERVAL_S
< time::precise_time_s()
{
send_packet_to::<TParam::TSend>(
self.peer_addr,
socket,
&Packet::RequestPacket {
id: missing_packet.id,
},
)?;
missing_packet.last_request_time = time::precise_time_s();
}
}
for unconfirmed_packet in self.send.unconfirmed_message_cache.values_mut() {
if unconfirmed_packet.last_emit_time + TParam::EMIT_UNCONFIRMED_PACKET_INTERVAL_S
< time::precise_time_s()
{
unconfirmed_packet.last_emit_time = time::precise_time_s();
send_packet_to(self.peer_addr, socket, &unconfirmed_packet.packet)?;
}
}
Ok(())
}
pub fn handle_incoming_data(
&mut self,
socket: &mut Socket,
data: &[u8],
) -> Result<Option<TParam::TReceive>> {
let packet: Packet<_> = bincode::deserialize(data)?;
println!("Received {:?}", packet);
Ok(match packet {
Packet::Ping {
last_send_message_id,
} => {
if let Some(last_send_message_id) = last_send_message_id {
self.request_message_up_to(last_send_message_id.get());
}
self.receive.last_ping_time = time::precise_time_s();
send_packet_to::<TParam::TSend>(
self.peer_addr,
socket,
&Packet::Pong {
last_send_message_id: self.send.next_message_id,
},
)?;
None
}
Packet::RequestPacket { id } => {
if let Some(packet) = self.send.unconfirmed_message_cache.get_mut(&id) {
packet.last_emit_time = time::precise_time_s();
send_packet_to(self.peer_addr, socket, &packet.packet)?;
} else {
send_packet_to::<TParam::TSend>(
self.peer_addr,
socket,
&Packet::PacketNotFound { id },
)?;
}
None
}
Packet::ConfirmPacket { id } => {
self.send.unconfirmed_message_cache.remove(&id);
None
}
Packet::PacketNotFound { id } => {
self.receive.missing_message_id_list.retain(|i| i.id != id);
None
}
Packet::Pong {
last_send_message_id,
} => {
if let Some(last_send_message_id) = last_send_message_id {
self.request_message_up_to(last_send_message_id.get());
}
self.receive.last_ping_time = time::precise_time_s();
None
}
Packet::Data { message_id, data } => {
if let Some(message_id) = message_id {
self.request_message_up_to(message_id.get() - 1);
send_packet_to::<TParam::TSend>(
self.peer_addr,
socket,
&Packet::ConfirmPacket { id: message_id },
)?;
}
self.receive.last_message_id = message_id;
Some(data)
}
})
}
fn send_ping(&mut self, socket: &mut Socket) -> Result<()> {
self.send.last_ping_time = time::precise_time_s();
send_packet_to::<TParam::TSend>(
self.peer_addr,
socket,
&Packet::Ping {
last_send_message_id: self
.send
.next_message_id
.map(|id| unsafe { NonZeroU64::new_unchecked(id.get() - 1) }),
},
)
}
fn request_message_up_to(&mut self, id: u64) {
let mut start = if let Some(id) = self.receive.last_message_id {
id
} else {
unsafe { NonZeroU64::new_unchecked(1) }
};
while start.get() <= id {
if self
.receive
.missing_message_id_list
.iter()
.find(|id| id.id == start)
.is_none()
{
self.receive
.missing_message_id_list
.push(MissingId::new(start));
}
start = unsafe { NonZeroU64::new_unchecked(start.get() + 1) };
}
self.receive.last_message_id = NonZeroU64::new(id);
}
pub fn send_unconfirmed(&mut self, socket: &mut Socket, msg: TParam::TSend) -> Result<()> {
send_packet_to(
self.peer_addr,
socket,
&Packet::Data {
data: msg,
message_id: None,
},
)?;
Ok(())
}
pub fn send_confirmed(&mut self, socket: &mut Socket, msg: TParam::TSend) -> Result<()> {
let sending_id = if let Some(id) = self.send.next_message_id {
id
} else {
unsafe { NonZeroU64::new_unchecked(1) }
};
let data = Packet::Data {
data: msg,
message_id: Some(sending_id),
};
send_packet_to(self.peer_addr, socket, &data)?;
self.send.unconfirmed_message_cache.insert(
sending_id,
CachedPacket {
packet: data,
last_emit_time: time::precise_time_s(),
},
);
self.send.next_message_id = NonZeroU64::new(sending_id.get() + 1);
Ok(())
}
}
fn send_packet_to<TSend: serde::Serialize>(
peer_addr: SocketAddr,
socket: &mut Socket,
packet: &Packet<TSend>,
) -> Result<()> {
let bytes = bincode::serialize(packet)?;
println!(
"Sending {:?} from {:?} to {:?}",
bytes,
socket.local_addr(),
peer_addr
);
socket.send_to(&bytes, peer_addr)?;
Ok(())
}