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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

use std::io;
use std::future::Future;
use std::net::ToSocketAddrs;
use std::os::unix::io::RawFd;
use std::pin::Pin;
use std::task::{Context, Poll};

use futures_core::ready;
use futures_io::{AsyncRead, AsyncBufRead, AsyncWrite};

use crate::buf::Buffer;
use crate::drive::demo::DemoDriver;
use crate::{Drive, Ring};
use crate::event;
use crate::Submission;

use super::socket;

pub struct TcpStream<D: Drive = DemoDriver<'static>> {
    ring: Ring<D>,
    buf: Buffer,
    active: Op,
    fd: RawFd,
}

#[derive(Copy, Clone, Debug, Eq, PartialEq)]
enum Op {
    Read,
    Write,
    Close,
    Nothing,
}

impl TcpStream {
    pub fn connect<A: ToSocketAddrs>(addr: A) -> Connect {
        TcpStream::connect_on_driver(addr, DemoDriver::default())
    }
}

impl<D: Drive + Clone> TcpStream<D> {
    pub fn connect_on_driver<A: ToSocketAddrs>(addr: A, driver: D) -> Connect<D> {
        let (fd, addr) = match socket(addr) {
            Ok(fd)  => fd,
            Err(e)  => return Connect(Err(Some(e))),
        };
        Connect(Ok(Submission::new(event::Connect::new(fd, addr), driver)))
    }
}

impl<D: Drive> TcpStream<D> {
    pub(super) fn from_fd(fd: RawFd, ring: Ring<D>) -> TcpStream<D> {
        TcpStream {
            buf: Buffer::new(),
            active: Op::Nothing,
            fd, ring,
        }
    }

    fn guard_op(self: Pin<&mut Self>, op: Op) {
        let this = unsafe { Pin::get_unchecked_mut(self) };
        if this.active != Op::Nothing && this.active != op {
            this.cancel();
        }
        this.active = op;
    }

    fn cancel(&mut self) {
        self.active = Op::Nothing;
        self.ring.cancel(self.buf.cancellation());
    }

    #[inline(always)]
    fn ring(self: Pin<&mut Self>) -> Pin<&mut Ring<D>> {
        unsafe { Pin::map_unchecked_mut(self, |this| &mut this.ring) }
    }

    #[inline(always)]
    fn buf(self: Pin<&mut Self>) -> Pin<&mut Buffer> {
        unsafe { Pin::map_unchecked_mut(self, |this| &mut this.buf) }
    }

    #[inline(always)]
    fn split(self: Pin<&mut Self>) -> (Pin<&mut Ring<D>>, &mut Buffer) {
        unsafe {
            let this = Pin::get_unchecked_mut(self);
            (Pin::new_unchecked(&mut this.ring), &mut this.buf)
        }
    }
}

pub struct Connect<D: Drive = DemoDriver<'static>>(
    Result<Submission<event::Connect, D>, Option<io::Error>>
);

impl<D: Drive + Clone> Future for Connect<D> {
    type Output = io::Result<TcpStream<D>>;

    fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
        unsafe {
            match &mut Pin::get_unchecked_mut(self).0 {
                Ok(submission)  => {
                    let mut submission = Pin::new_unchecked(submission);
                    let (connect, result) = ready!(submission.as_mut().poll(ctx));
                    result?;
                    let driver = submission.driver().clone();
                    Poll::Ready(Ok(TcpStream::from_fd(connect.fd, Ring::new(driver))))
                }
                Err(err)        => {
                    let err = err.take().expect("polled Connect future after completion");
                    Poll::Ready(Err(err))
                }
            }
        }
    }
}

impl<D: Drive> AsyncRead for TcpStream<D> {
    fn poll_read(mut self: Pin<&mut Self>, ctx: &mut Context<'_>, buf: &mut [u8])
        -> Poll<io::Result<usize>>
    {
        let mut inner = ready!(self.as_mut().poll_fill_buf(ctx))?;
        let len = io::Read::read(&mut inner, buf)?;
        self.consume(len);
        Poll::Ready(Ok(len))
    }
}

impl<D: Drive> AsyncBufRead for TcpStream<D> {
    fn poll_fill_buf(mut self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
        self.as_mut().guard_op(Op::Read);
        let fd = self.fd;
        let (ring, buf) = self.split();
        buf.fill_buf(|buf| {
            let n = ready!(ring.poll(ctx, true, |sqe| unsafe { sqe.prep_read(fd, buf, 0) }))?;
            Poll::Ready(Ok(n as u32))
        })
    }

    fn consume(self: Pin<&mut Self>, amt: usize) {
        self.buf().consume(amt);
    }
}

impl<D: Drive> AsyncWrite for TcpStream<D> {
    fn poll_write(mut self: Pin<&mut Self>, ctx: &mut Context<'_>, slice: &[u8]) -> Poll<io::Result<usize>> {
        self.as_mut().guard_op(Op::Write);
        let fd = self.fd;
        let (ring, buf) = self.split();
        let data = ready!(buf.fill_buf(|mut buf| {
            Poll::Ready(Ok(io::Write::write(&mut buf, slice)? as u32))
        }))?;
        let n = ready!(ring.poll(ctx, true, |sqe| unsafe { sqe.prep_write(fd, data, 0) }))?;
        buf.clear();
        Poll::Ready(Ok(n))
    }

    fn poll_flush(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<io::Result<()>> {
        ready!(self.poll_write(ctx, &[]))?;
        Poll::Ready(Ok(()))
    }

    fn poll_close(mut self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<io::Result<()>> {
        self.as_mut().guard_op(Op::Close);
        let fd = self.fd;
        ready!(self.ring().poll(ctx, true, |sqe| unsafe {
            uring_sys::io_uring_prep_close(sqe.raw_mut(), fd)
        }))?;
        Poll::Ready(Ok(()))
    }
}