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

use std::sync::{Arc, Mutex};
use std::io::{self, ErrorKind, Read, Seek, SeekFrom};
#[cfg(feature = "nightly")]
use std::io::{IoSliceMut, Initializer};
use std::fmt::{self, Formatter, Debug};

pub struct ArcMutexU8Reader<T: AsRef<[u8]> + ?Sized> {
    data: Arc<Mutex<T>>,
    pos: usize,
}

impl<T: AsRef<[u8]> + ?Sized> Debug for ArcMutexU8Reader<T> {
    #[inline]
    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
        impl_debug_for_struct!(ArcMutexU8Reader, f, self, let .data = self.data.as_ref().lock().unwrap().as_ref(), .pos);
    }
}

impl<T: AsRef<[u8]> + ?Sized> ArcMutexU8Reader<T> {
    #[inline]
    pub fn new(data: Arc<Mutex<T>>) -> ArcMutexU8Reader<T> {
        ArcMutexU8Reader {
            data,
            pos: 0,
        }
    }
}

impl<T: AsRef<[u8]> + ?Sized> Read for ArcMutexU8Reader<T> {
    fn read(&mut self, buf: &mut [u8]) -> Result<usize, io::Error> {
        let data = self.data.lock().unwrap();
        let data: &[u8] = &data.as_ref()[self.pos..];

        let data_len = data.len();
        let buf_len = buf.len();

        let len = if data_len > buf_len {
            let data = &data[..buf_len];

            buf.copy_from_slice(data);

            buf_len
        } else {
            buf[..data_len].copy_from_slice(data);

            data_len
        };

        self.pos += len;

        Ok(len)
    }

    #[cfg(feature = "nightly")]
    #[inline]
    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
        let mut nread = 0;
        for buf in bufs {
            let n = self.read(buf)?;
            nread += n;
            if n < buf.len() {
                break;
            }
        }
        Ok(nread)
    }

    #[cfg(feature = "nightly")]
    #[inline]
    unsafe fn initializer(&self) -> Initializer {
        Initializer::nop()
    }
}

impl<T: AsRef<[u8]> + ?Sized> Seek for ArcMutexU8Reader<T> {
    fn seek(&mut self, style: SeekFrom) -> Result<u64, io::Error> {
        let (base_pos, offset) = match style {
            SeekFrom::Start(n) => {
                let n = if n > usize::max_value() as u64 {
                    usize::max_value()
                } else {
                    n as usize
                };

                self.pos = n;

                return Ok(n as u64);
            }
            SeekFrom::End(n) => (
                {
                    let data = self.data.lock().unwrap();
                    let data: &[u8] = &data.as_ref()[self.pos..];

                    data.len()
                },
                n
            ),
            SeekFrom::Current(n) => (self.pos, n),
        };

        let offset = if offset > isize::max_value() as i64 {
            isize::max_value()
        } else if offset < isize::min_value() as i64 {
            isize::min_value()
        } else {
            offset as isize
        };

        let new_pos = if offset >= 0 {
            base_pos.checked_add(offset as usize)
        } else {
            base_pos.checked_sub((offset.wrapping_neg()) as usize)
        };

        match new_pos {
            Some(n) => {
                self.pos = n;

                Ok(self.pos as u64)
            }
            None => Err(io::Error::new(ErrorKind::InvalidInput, "invalid seek to a negative or overflowing position"))
        }
    }

    #[cfg(feature = "nightly")]
    #[inline]
    fn stream_len(&mut self) -> Result<u64, io::Error> {
        let data_len = {
            let data = self.data.lock().unwrap();
            let data: &[u8] = &data.as_ref()[self.pos..];

            data.len()
        };

        Ok(data_len as u64)
    }

    #[cfg(feature = "nightly")]
    #[inline]
    fn stream_position(&mut self) -> Result<u64, io::Error> {
        Ok(self.pos as u64)
    }
}