nautalid 0.1.0

Scratch container substrate — TLS 1.3 HTTP/2+3 kernel, LID/AetherDB, optional filter bus (GPL-3.0-or-later).
use crate::zeromq::codec::{Message, ZmqFramedRead};
use crate::zeromq::endpoint::Endpoint;
use crate::zeromq::error::{ZmqError, ZmqResult};
use crate::zeromq::fair_queue::FairQueue;
use crate::zeromq::message::ZmqMessage;
use crate::zeromq::sub::{SubBackendMsgType, SubSocketBackend};
use crate::zeromq::transport::AcceptStopHandle;
use crate::zeromq::util::PeerIdentity;
use crate::zeromq::{
    MultiPeerBackend, Socket, SocketBackend, SocketEvent, SocketOptions, SocketRecv, SocketSend,
    SocketType,
};

use async_trait::async_trait;
use futures_channel::mpsc;
use futures_util::{SinkExt, StreamExt};

use std::collections::HashMap;
use std::sync::Arc;

pub struct XSubSocket {
    backend: Arc<SubSocketBackend>,
    fair_queue: FairQueue<ZmqFramedRead, PeerIdentity>,
    binds: HashMap<Endpoint, AcceptStopHandle>,
}

impl Drop for XSubSocket {
    fn drop(&mut self) {
        self.backend.shutdown();
    }
}

impl XSubSocket {
    pub async fn subscribe(&mut self, subscription: &str) -> ZmqResult<()> {
        self.backend.subs.lock().insert(subscription.to_string());
        let message =
            SubSocketBackend::create_subs_message(subscription, SubBackendMsgType::SUBSCRIBE);
        for mut peer in self.backend.peers.iter_mut() {
            peer.send_queue
                .send(Message::Message(message.clone()))
                .await?;
        }
        Ok(())
    }

    pub async fn unsubscribe(&mut self, subscription: &str) -> ZmqResult<()> {
        self.backend.subs.lock().remove(subscription);
        let message =
            SubSocketBackend::create_subs_message(subscription, SubBackendMsgType::UNSUBSCRIBE);
        for mut peer in self.backend.peers.iter_mut() {
            peer.send_queue
                .send(Message::Message(message.clone()))
                .await?;
        }
        Ok(())
    }

    fn apply_subscription_send(&self, message: &ZmqMessage) -> bool {
        let Some(first) = message.get(0) else {
            return false;
        };
        if first.is_empty() {
            return false;
        }
        match first[0] {
            1 => {
                if let Ok(sub) = std::str::from_utf8(&first[1..]) {
                    self.backend.subs.lock().insert(sub.to_string());
                }
                true
            }
            0 => {
                if let Ok(sub) = std::str::from_utf8(&first[1..]) {
                    self.backend.subs.lock().remove(sub);
                }
                true
            }
            _ => false,
        }
    }
}

#[async_trait]
impl Socket for XSubSocket {
    fn with_options(options: SocketOptions) -> Self {
        let fair_queue = FairQueue::new(true);
        Self {
            backend: Arc::new(SubSocketBackend::with_options(
                Some(fair_queue.inner()),
                SocketType::XSUB,
                options,
            )),
            fair_queue,
            binds: HashMap::new(),
        }
    }

    fn backend(&self) -> Arc<dyn MultiPeerBackend> {
        self.backend.clone()
    }

    fn binds(&mut self) -> &mut HashMap<Endpoint, AcceptStopHandle> {
        &mut self.binds
    }

    fn monitor(&mut self) -> mpsc::Receiver<SocketEvent> {
        let (sender, receiver) = mpsc::channel(1024);
        self.backend.socket_monitor.lock().replace(sender);
        receiver
    }
}

#[async_trait]
impl SocketRecv for XSubSocket {
    async fn recv(&mut self) -> ZmqResult<ZmqMessage> {
        loop {
            match self.fair_queue.next().await {
                Some((_peer_id, Ok(Message::Message(message)))) => return Ok(message),
                Some((_peer_id, Ok(_))) => {}
                Some((peer_id, Err(_))) => {
                    self.backend.peer_disconnected(&peer_id);
                }
                None => return Err(ZmqError::NoMessage),
            }
        }
    }
}

#[async_trait]
impl SocketSend for XSubSocket {
    async fn send(&mut self, message: ZmqMessage) -> ZmqResult<()> {
        if !self.apply_subscription_send(&message) {
            return Err(ZmqError::Other(
                "XSUB send accepts subscription frames (0x01/0x00 prefix) only",
            ));
        }
        for mut peer in self.backend.peers.iter_mut() {
            peer.send_queue
                .send(Message::Message(message.clone()))
                .await?;
        }
        Ok(())
    }
}