cotoxy 0.1.0

A TCP proxy using Consul for service discovery
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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150

use std::io::{self, Read, Write};
use slog::Logger;
use fibers::net::TcpStream;
use futures::{Async, Future, Poll};

use {Error, Result};

#[derive(Debug)]
struct Buffer {
    inner: Vec<u8>,
    write_start: usize,
    read_start: usize,
}
impl Buffer {
    fn new(capacity: usize) -> Self {
        Buffer {
            inner: vec![0; capacity],
            write_start: 0,
            read_start: 0,
        }
    }
    fn read_from<R: Read + ::std::fmt::Debug>(
        &mut self,
        reader: &mut R,
    ) -> Result<Async<Option<usize>>> {
        if self.read_start == self.inner.len() {
            return Ok(Async::NotReady);
        }
        match reader.read(&mut self.inner[self.read_start..]) {
            Err(e) => {
                if e.kind() == io::ErrorKind::WouldBlock {
                    Ok(Async::NotReady)
                } else {
                    Err(track!(Error::from(e)))
                }
            }
            Ok(0) => Ok(Async::Ready(None)),
            Ok(size) => {
                self.read_start += size;
                Ok(Async::Ready(Some(size)))
            }
        }
    }
    fn write_to<W: Write + ::std::fmt::Debug>(
        &mut self,
        writer: &mut W,
    ) -> Result<Async<Option<usize>>> {
        if self.write_start == self.read_start {
            return Ok(Async::NotReady);
        }
        match writer.write(&self.inner[self.write_start..self.read_start]) {
            Err(e) => {
                if e.kind() == io::ErrorKind::WouldBlock {
                    Ok(Async::NotReady)
                } else {
                    Err(track!(Error::from(e)))
                }
            }
            Ok(0) => Ok(Async::Ready(None)),
            Ok(size) => {
                self.write_start += size;
                if self.write_start == self.read_start {
                    self.write_start = 0;
                    self.read_start = 0;
                }
                Ok(Async::Ready(Some(size)))
            }
        }
    }
}

#[derive(Debug)]
pub struct ProxyChannel {
    logger: Logger,
    client: TcpStream,
    client_buf: Buffer,
    server: TcpStream,
    server_buf: Buffer,
}
impl ProxyChannel {
    pub const DEFAULT_BUFFER_SIZE: usize = 8 * 1024;

    pub fn new(logger: Logger, client: TcpStream, server: TcpStream) -> Self {
        unsafe {
            let _ = client.with_inner(|socket| socket.set_nodelay(true));
            let _ = server.with_inner(|socket| socket.set_nodelay(true));
        }
        ProxyChannel {
            logger,
            client,
            client_buf: Buffer::new(Self::DEFAULT_BUFFER_SIZE),
            server,
            server_buf: Buffer::new(Self::DEFAULT_BUFFER_SIZE),
        }
    }
}
impl Future for ProxyChannel {
    type Item = ();
    type Error = Error;
    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
        loop {
            match track!(self.client_buf.read_from(&mut self.client))? {
                Async::NotReady => {}
                Async::Ready(None) => {
                    info!(self.logger, "Connection closed by client while reading");
                    return Ok(Async::Ready(()));
                }
                Async::Ready(Some(size)) => {
                    debug!(self.logger, "Received {} bytes from client", size);
                    continue;
                }
            }
            match track!(self.client_buf.write_to(&mut self.server))? {
                Async::NotReady => {}
                Async::Ready(None) => {
                    info!(self.logger, "Connection closed by server while writing");
                    return Ok(Async::Ready(()));
                }
                Async::Ready(Some(size)) => {
                    debug!(self.logger, "Sent {} bytes to server", size);
                    continue;
                }
            }
            match track!(self.server_buf.read_from(&mut self.server))? {
                Async::NotReady => {}
                Async::Ready(None) => {
                    info!(self.logger, "Connection closed by server while reading");
                    return Ok(Async::Ready(()));
                }
                Async::Ready(Some(size)) => {
                    debug!(self.logger, "Received {} bytes from server", size);
                    continue;
                }
            }
            match track!(self.server_buf.write_to(&mut self.client))? {
                Async::NotReady => {}
                Async::Ready(None) => {
                    info!(self.logger, "Connection closed by client while writing");
                    return Ok(Async::Ready(()));
                }
                Async::Ready(Some(size)) => {
                    debug!(self.logger, "Sent {} bytes to client", size);
                    continue;
                }
            }
            break;
        }
        Ok(Async::NotReady)
    }
}