net-mux 0.2.4

A Net Stream Multiplexing Library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104

use std::collections::HashMap;

use parking_lot::Mutex;
use tokio::sync::{mpsc, oneshot};

use crate::{
    alloc::StreamId,
    error::Error,
    frame::{Cmd, Frame},
};

// Internal stream manager that maintains active stream registry channel
pub(crate) struct StreamManager {
    streams: Mutex<HashMap<StreamId, StreamHandle>>,
    stream_creation_tx: mpsc::UnboundedSender<StreamId>,
}

pub(crate) struct StreamHandle {
    frame_tx: mpsc::Sender<Frame>,
    remote_fin_tx: Option<oneshot::Sender<()>>,
    remote_ack_tx: Option<oneshot::Sender<()>>,
}

impl StreamManager {
    pub fn new(stream_creation_tx: mpsc::UnboundedSender<StreamId>) -> Self {
        Self {
            streams: Mutex::new(HashMap::new()),
            stream_creation_tx,
        }
    }

    pub fn add_stream(
        &self,
        stream_id: StreamId,
        frame_tx: mpsc::Sender<Frame>,
        remote_fin_tx: oneshot::Sender<()>,
        remote_ack_tx: Option<oneshot::Sender<()>>,
    ) -> Result<(), Error> {
        let stream_handle = StreamHandle {
            frame_tx,
            remote_fin_tx: Some(remote_fin_tx),
            remote_ack_tx,
        };

        let mut streams_guard = self.streams.lock();
        if streams_guard.contains_key(&stream_id) {
            return Err(Error::DuplicateStream(stream_id));
        }

        streams_guard.insert(stream_id, stream_handle);
        Ok(())
    }

    pub fn remove_stream(&self, stream_id: StreamId) -> Result<(), Error> {
        let mut streams_guard = self.streams.lock();
        if !streams_guard.contains_key(&stream_id) {
            return Err(Error::StreamNotFound(stream_id));
        }
        streams_guard.remove(&stream_id);
        Ok(())
    }

    pub async fn dispatch_frame_to_stream(&self, frame: Frame) -> Result<(), Error> {
        let stream_id = frame.header.stream_id;
        match frame.header.cmd {
            Cmd::Syn => self
                .stream_creation_tx
                .send(stream_id)
                .map_err(|_| Error::SendFrameFailed(stream_id)),
            Cmd::Ack => self
                .streams
                .lock()
                .get_mut(&stream_id)
                .ok_or(Error::StreamNotFound(stream_id))?
                .remote_ack_tx
                .take()
                .ok_or(Error::Internal("remote ack tx not found".to_string()))?
                .send(())
                .map_err(|_| Error::SendFrameFailed(stream_id)),
            Cmd::Fin => self
                .streams
                .lock()
                .get_mut(&stream_id)
                .ok_or(Error::StreamNotFound(stream_id))?
                .remote_fin_tx
                .take()
                .ok_or(Error::Internal("remote fin tx not found".to_string()))?
                .send(())
                .map_err(|_| Error::SendFrameFailed(stream_id)),
            Cmd::Psh => {
                let frame_tx = self
                    .streams
                    .lock()
                    .get(&stream_id)
                    .map(|s| s.frame_tx.clone())
                    .ok_or(Error::StreamNotFound(stream_id))?;
                frame_tx
                    .send(frame)
                    .await
                    .map_err(|_| Error::SendFrameFailed(stream_id))
            }
        }
    }
}