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

use std::io::{self, ErrorKind, Write};
use std::ops::DerefMut;
use std::sync::{Arc, Mutex};

pub struct SynchronizedOptionWriter<W: Write> {
    inner: Arc<Mutex<Option<W>>>,
}

impl<W: Write> SynchronizedOptionWriter<W> {
    #[inline]
    pub fn new(writer: Arc<Mutex<Option<W>>>) -> SynchronizedOptionWriter<W> {
        SynchronizedOptionWriter {
            inner: writer,
        }
    }
}

impl<W: Write> Write for SynchronizedOptionWriter<W> {
    #[inline]
    fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
        match self
            .inner
            .lock()
            .map_err(|err| io::Error::new(ErrorKind::WouldBlock, err.to_string()))?
            .deref_mut()
        {
            Some(writer) => writer.write(buf),
            None => Err(io::Error::new(ErrorKind::BrokenPipe, "the writer has been removed out")),
        }
    }

    #[inline]
    fn flush(&mut self) -> Result<(), io::Error> {
        match self
            .inner
            .lock()
            .map_err(|err| io::Error::new(ErrorKind::WouldBlock, err.to_string()))?
            .deref_mut()
        {
            Some(writer) => writer.flush(),
            None => Err(io::Error::new(ErrorKind::BrokenPipe, "the writer has been removed out")),
        }
    }
}