ipc-channel 0.4.0

A multi-process implementation for multi-producer, single-consumer channels.
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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

// Copyright 2015 The Servo Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::collections::HashMap;
use std::sync::Mutex;
use std::sync::mpsc::{self, Receiver, Sender};
use std::thread;

use ipc::{self, IpcReceiver, IpcReceiverSet, IpcSelectionResult, IpcSender, OpaqueIpcMessage};
use ipc::{OpaqueIpcReceiver};
use serde::{Deserialize, Serialize};

lazy_static! {
    pub static ref ROUTER: RouterProxy = RouterProxy::new();
}

pub struct RouterProxy {
    comm: Mutex<RouterProxyComm>,
}

impl RouterProxy {
    pub fn new() -> RouterProxy {
        let (msg_sender, msg_receiver) = mpsc::channel();
        let (wakeup_sender, wakeup_receiver) = ipc::channel().unwrap();
        thread::spawn(move || Router::new(msg_receiver, wakeup_receiver).run());
        RouterProxy {
            comm: Mutex::new(RouterProxyComm {
                msg_sender: msg_sender,
                wakeup_sender: wakeup_sender,
            }),
        }
    }

    pub fn add_route(&self, receiver: OpaqueIpcReceiver, callback: RouterHandler) {
        let comm = self.comm.lock().unwrap();
        comm.msg_sender.send(RouterMsg::AddRoute(receiver, callback)).unwrap();
        comm.wakeup_sender.send(()).unwrap();
    }

    /// A convenience function to route an `IpcReceiver<T>` to an existing `Sender<T>`.
    pub fn route_ipc_receiver_to_mpsc_sender<T>(&self,
                                                ipc_receiver: IpcReceiver<T>,
                                                mpsc_sender: Sender<T>)
                                                where T: Deserialize +
                                                         Serialize +
                                                         Send +
                                                         'static {
        self.add_route(ipc_receiver.to_opaque(), Box::new(move |message| {
            drop(mpsc_sender.send(message.to::<T>().unwrap()))
        }))
    }

    /// A convenience function to route an `IpcReceiver<T>` to a `Receiver<T>`: the most common
    /// use of a `Router`.
    pub fn route_ipc_receiver_to_new_mpsc_receiver<T>(&self, ipc_receiver: IpcReceiver<T>)
                                                  -> Receiver<T>
                                                  where T: Deserialize +
                                                           Serialize +
                                                           Send +
                                                           'static {
        let (mpsc_sender, mpsc_receiver) = mpsc::channel();
        self.route_ipc_receiver_to_mpsc_sender(ipc_receiver, mpsc_sender);
        mpsc_receiver
    }
}

struct RouterProxyComm {
    msg_sender: Sender<RouterMsg>,
    wakeup_sender: IpcSender<()>,
}

struct Router {
    msg_receiver: Receiver<RouterMsg>,
    msg_wakeup_id: i64,
    ipc_receiver_set: IpcReceiverSet,
    handlers: HashMap<i64,RouterHandler>,
}

impl Router {
    fn new(msg_receiver: Receiver<RouterMsg>, wakeup_receiver: IpcReceiver<()>) -> Router {
        let mut ipc_receiver_set = IpcReceiverSet::new().unwrap();
        let msg_wakeup_id = ipc_receiver_set.add(wakeup_receiver).unwrap();
        Router {
            msg_receiver: msg_receiver,
            msg_wakeup_id: msg_wakeup_id,
            ipc_receiver_set: ipc_receiver_set,
            handlers: HashMap::new(),
        }
    }

    fn run(&mut self) {
        loop {
            let results = match self.ipc_receiver_set.select() {
                Ok(results) => results,
                Err(_) => break,
            };
            for result in results.into_iter() {
                match result {
                    IpcSelectionResult::MessageReceived(id, _) if id == self.msg_wakeup_id => {
                        match self.msg_receiver.recv().unwrap() {
                            RouterMsg::AddRoute(receiver, handler) => {
                                let new_receiver_id = self.ipc_receiver_set
                                                          .add_opaque(receiver)
                                                          .unwrap();
                                self.handlers.insert(new_receiver_id, handler);
                            }
                        }
                    }
                    IpcSelectionResult::MessageReceived(id, message) => {
                        self.handlers.get_mut(&id).unwrap()(message)
                    }
                    IpcSelectionResult::ChannelClosed(id) => {
                        self.handlers.remove(&id).unwrap();
                    }
                }
            }
        }
    }
}

enum RouterMsg {
    AddRoute(OpaqueIpcReceiver, RouterHandler),
}

pub type RouterHandler = Box<FnMut(OpaqueIpcMessage) + Send>;