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use crate::message;
use crate::stream;
use log::{error, info, trace};
use std::io::ErrorKind;
use tokio::{
io::{AsyncReadExt, AsyncWriteExt},
net::TcpStream,
net::UnixStream,
};
/// Simple pub sub Client for Tcp connection
#[derive(Debug, Clone)]
pub struct PubSubTcpClient {
pub server: String,
pub port: u16,
}
/// Simple pub sub Client for Unix connection
#[derive(Debug, Clone)]
pub struct PubSubUnixClient {
pub path: String,
}
/// Simple pub sub Client
#[derive(Debug, Clone)]
pub enum PubSubClient {
Tcp(PubSubTcpClient),
Unix(PubSubUnixClient),
}
/// Stream for Tcp and Unix connection
#[derive(Debug)]
pub enum StreamType {
Tcp(TcpStream),
Unix(UnixStream),
}
/// on_message callback function
type Callback = fn(String, Vec<u8>);
/// Simple pub sub Client
#[derive(Debug)]
pub struct Client {
pub client_type: PubSubClient,
stream: Option<StreamType>,
callback: Option<Callback>,
}
/// default implementation for callback function
pub fn on_message(topic: String, message: Vec<u8>) {
match String::from_utf8(message.clone()) {
Ok(msg_str) => {
info!("topic: {} message: {}", topic, msg_str);
}
Err(_) => {
info!("topic: {} message: {:?}", topic, message);
}
};
}
impl Client {
/// Creates a new instance of `Client`
pub fn new(client_type: PubSubClient) -> Client {
Client {
client_type,
stream: None,
callback: None,
}
}
/// Sets the on_message callback function
pub fn on_message(&mut self, callback: Callback) {
self.callback = Some(callback)
}
/// Connects to the server
pub async fn connect(&mut self) -> Result<(), tokio::io::Error> {
match self.client_type.clone() {
PubSubClient::Tcp(tcp_client) => {
let server_url: String = format!("{}:{}", tcp_client.server, tcp_client.port);
let stream = TcpStream::connect(server_url).await?;
self.stream = Some(StreamType::Tcp(stream));
}
PubSubClient::Unix(unix_stream) => {
let path = unix_stream.path;
let stream = UnixStream::connect(path).await?;
self.stream = Some(StreamType::Unix(stream));
}
}
Ok(())
}
/// Sends the message to the given server and returns the ack
/// the server could be either a tcp or unix server
pub async fn post(self, msg: message::Msg) -> Result<Vec<u8>, tokio::io::Error> {
match self.stream {
Some(s) => {
match s {
StreamType::Tcp(mut tcp_stream) => {
match tcp_stream.write_all(&msg.bytes()).await {
Ok(_) => {}
Err(e) => {
error!("could not send the data to the server: {}", e.to_string());
return Err(e);
}
}
let mut buf: Vec<u8>;
buf = vec![0; 8];
trace!("reading the ack:");
let _ = match tcp_stream.read(&mut buf).await {
Ok(n) => n,
Err(e) => {
error!("could not retrive ack for published packet");
return Err(e);
}
};
return Ok(buf);
}
StreamType::Unix(mut unix_stream) => {
match unix_stream.write_all(&msg.bytes()).await {
Ok(_) => {}
Err(e) => {
error!("could not send the data to the server: {}", e.to_string());
return Err(e);
}
}
let mut buf: Vec<u8>;
buf = vec![0; 8];
trace!("reading the ack:");
let _ = match unix_stream.read(&mut buf).await {
Ok(n) => n,
Err(e) => {
error!("could not retrive ack for published packet");
return Err(e);
}
};
return Ok(buf);
}
};
}
None => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
"client not connected yet.",
)),
}
}
/// Publishes the message to the given topic
pub async fn publish(self, topic: String, message: Vec<u8>) -> Result<(), tokio::io::Error> {
let msg: message::Msg = message::Msg::new(message::PktType::PUBLISH, topic, Some(message));
trace!("msg: {:?}", msg);
let buf = match self.post(msg).await {
Ok(resp) => resp,
Err(e) => return Err(e),
};
trace!("the raw buffer is: {:?}", buf);
let resp_: message::Header = match message::Header::from_vec(buf) {
Ok(resp) => resp,
Err(e) => {
return Err(tokio::io::Error::new(ErrorKind::Other, format!("{:?}", e)));
}
};
trace!("{:?}", resp_);
Ok(())
}
/// Sends the query message to the server
pub async fn query(self, topic: String) -> Result<String, tokio::io::Error> {
let msg: message::Msg = message::Msg::new(
message::PktType::QUERY,
topic,
Some("a".to_string().as_bytes().to_vec()),
);
trace!("msg: {:?}", msg);
match self.stream {
Some(s) => match s {
StreamType::Tcp(mut tcp_stream) => match tcp_stream.write_all(&msg.bytes()).await {
Ok(_) => match stream::read_message(&mut tcp_stream).await {
Ok(msg) => match String::from_utf8(msg.message.clone()) {
Ok(msg_str) => Ok(msg_str),
Err(e) => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
)),
},
Err(e) => Err(e),
},
Err(e) => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
)),
},
StreamType::Unix(mut unix_stream) => {
match unix_stream.write_all(&msg.bytes()).await {
Ok(_) => match stream::read_message(&mut unix_stream).await {
Ok(msg) => match String::from_utf8(msg.message.clone()) {
Ok(msg_str) => Ok(msg_str),
Err(e) => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
)),
},
Err(e) => Err(e),
},
Err(e) => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
)),
}
}
},
None => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
"client not connected yet.".to_string(),
)),
}
}
/// subscribes to the given topic
pub async fn subscribe(self, topic: String) -> Result<(), tokio::io::Error> {
match self.stream {
Some(s) => {
let msg: message::Msg = message::Msg::new(message::PktType::SUBSCRIBE, topic, None);
trace!("msg: {:?}", msg);
match s {
StreamType::Tcp(mut tcp_stream) => {
match tcp_stream.write_all(&msg.bytes()).await {
Ok(_) => {}
Err(e) => {
error!("could not send the data to the server: {}", e.to_string());
return Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
));
}
};
loop {
match stream::read_message(&mut tcp_stream).await {
Ok(m) => match self.callback {
Some(fn_) => {
fn_(m.topic, m.message);
}
None => on_message(m.topic, m.message),
},
Err(e) => {
error!("could not read message: {}", e.to_string());
break;
}
};
}
}
StreamType::Unix(mut unix_stream) => {
match unix_stream.write_all(&msg.bytes()).await {
Ok(_) => {}
Err(e) => {
error!("could not send the data to the server: {}", e.to_string());
return Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
e.to_string(),
));
}
};
loop {
match stream::read_message(&mut unix_stream).await {
Ok(m) => match self.callback {
Some(fn_) => {
fn_(m.topic, m.message);
}
None => on_message(m.topic, m.message),
},
Err(e) => {
error!("could not read message: {}", e.to_string());
break;
}
};
}
}
};
Ok(())
}
None => Err(tokio::io::Error::new(
tokio::io::ErrorKind::Other,
"client not connected yet.".to_string(),
)),
}
}
}