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
171
172
173
174
175
176

use anyhow::Error;
use std::any::Any;
use std::convert::TryInto;
use std::io::{self, Read, Write};
use system_interface::io::ReadReady;

use crate::preview2::{InputStream, OutputStream};
#[cfg(unix)]
use cap_std::io_lifetimes::{AsFd, BorrowedFd};
#[cfg(windows)]
use cap_std::io_lifetimes::{AsHandle, BorrowedHandle};
#[cfg(windows)]
use io_extras::os::windows::{AsHandleOrSocket, BorrowedHandleOrSocket};

pub struct Stdin(std::io::Stdin);

pub fn stdin() -> Stdin {
    Stdin(std::io::stdin())
}

#[async_trait::async_trait]
impl InputStream for Stdin {
    fn as_any(&self) -> &dyn Any {
        self
    }
    #[cfg(unix)]
    fn pollable_read(&self) -> Option<rustix::fd::BorrowedFd> {
        Some(self.0.as_fd())
    }

    #[cfg(windows)]
    fn pollable_read(&self) -> Option<io_extras::os::windows::BorrowedHandleOrSocket> {
        Some(self.0.as_handle_or_socket())
    }

    async fn read(&mut self, buf: &mut [u8]) -> Result<(u64, bool), Error> {
        match Read::read(&mut self.0, buf) {
            Ok(0) => Ok((0, true)),
            Ok(n) => Ok((n as u64, false)),
            Err(err) if err.kind() == io::ErrorKind::Interrupted => Ok((0, false)),
            Err(err) => Err(err.into()),
        }
    }
    async fn read_vectored<'a>(
        &mut self,
        bufs: &mut [io::IoSliceMut<'a>],
    ) -> Result<(u64, bool), Error> {
        match Read::read_vectored(&mut self.0, bufs) {
            Ok(0) => Ok((0, true)),
            Ok(n) => Ok((n as u64, false)),
            Err(err) if err.kind() == io::ErrorKind::Interrupted => Ok((0, false)),
            Err(err) => Err(err.into()),
        }
    }
    #[cfg(can_vector)]
    fn is_read_vectored(&self) {
        Read::is_read_vectored(&mut self.0)
    }

    async fn skip(&mut self, nelem: u64) -> Result<(u64, bool), Error> {
        let num = io::copy(&mut io::Read::take(&mut self.0, nelem), &mut io::sink())?;
        Ok((num, num < nelem))
    }

    async fn num_ready_bytes(&self) -> Result<u64, Error> {
        Ok(self.0.num_ready_bytes()?)
    }

    async fn readable(&self) -> Result<(), Error> {
        Err(anyhow::anyhow!("idk"))
    }
}
#[cfg(windows)]
impl AsHandle for Stdin {
    fn as_handle(&self) -> BorrowedHandle<'_> {
        self.0.as_handle()
    }
}
#[cfg(windows)]
impl AsHandleOrSocket for Stdin {
    #[inline]
    fn as_handle_or_socket(&self) -> BorrowedHandleOrSocket {
        self.0.as_handle_or_socket()
    }
}
#[cfg(unix)]
impl AsFd for Stdin {
    fn as_fd(&self) -> BorrowedFd<'_> {
        self.0.as_fd()
    }
}

macro_rules! wasi_output_stream_impl {
    ($ty:ty, $ident:ident) => {
        #[async_trait::async_trait]
        impl OutputStream for $ty {
            fn as_any(&self) -> &dyn Any {
                self
            }

            #[cfg(unix)]
            fn pollable_write(&self) -> Option<rustix::fd::BorrowedFd> {
                Some(self.0.as_fd())
            }
            #[cfg(windows)]
            fn pollable_write(&self) -> Option<io_extras::os::windows::BorrowedHandleOrSocket> {
                Some(self.0.as_handle_or_socket())
            }

            async fn write(&mut self, buf: &[u8]) -> Result<u64, Error> {
                let n = Write::write(&mut self.0, buf)?;
                Ok(n.try_into()?)
            }
            async fn write_vectored<'a>(&mut self, bufs: &[io::IoSlice<'a>]) -> Result<u64, Error> {
                let n = Write::write_vectored(&mut self.0, bufs)?;
                Ok(n.try_into()?)
            }
            #[cfg(can_vector)]
            fn is_write_vectored(&self) {
                Write::is_write_vectored(&mut self.0)
            }
            // TODO: Optimize for stdio streams.
            /*
            async fn splice(
                &mut self,
                src: &mut dyn InputStream,
                nelem: u64,
            ) -> Result<u64, Error> {
                todo!()
            }
            */

            async fn write_zeroes(&mut self, nelem: u64) -> Result<u64, Error> {
                let num = io::copy(&mut io::Read::take(io::repeat(0), nelem), &mut self.0)?;
                Ok(num)
            }

            async fn writable(&self) -> Result<(), Error> {
                Ok(())
            }
        }
        #[cfg(windows)]
        impl AsHandle for $ty {
            fn as_handle(&self) -> BorrowedHandle<'_> {
                self.0.as_handle()
            }
        }
        #[cfg(unix)]
        impl AsFd for $ty {
            fn as_fd(&self) -> BorrowedFd<'_> {
                self.0.as_fd()
            }
        }
        #[cfg(windows)]
        impl AsHandleOrSocket for $ty {
            #[inline]
            fn as_handle_or_socket(&self) -> BorrowedHandleOrSocket {
                self.0.as_handle_or_socket()
            }
        }
    };
}

pub struct Stdout(std::io::Stdout);

pub fn stdout() -> Stdout {
    Stdout(std::io::stdout())
}
wasi_output_stream_impl!(Stdout, Stdout);

pub struct Stderr(std::io::Stderr);

pub fn stderr() -> Stderr {
    Stderr(std::io::stderr())
}
wasi_output_stream_impl!(Stderr, Stderr);