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

use std::ffi::CString;
use std::io;
use std::path::Path;
use std::marker::PhantomData;
use libc::{c_int, size_t, c_char};
use libc::c_void;
use crate::get_error;
use std::mem::transmute;

use crate::sys;

/// A structure that provides an abstract interface to stream I/O.
pub struct RWops<'a> {
    raw: *mut sys::SDL_RWops,
    _marker: PhantomData<&'a ()>
}

impl<'a> RWops<'a> {
    pub unsafe fn raw(&self) -> *mut sys::SDL_RWops { self.raw }

    pub unsafe fn from_ll<'b>(raw: *mut sys::SDL_RWops) -> RWops<'b> {
        RWops {
            raw,
            _marker: PhantomData
        }
    }

    /// Creates an SDL file stream.
    pub fn from_file<P: AsRef<Path>>(path: P, mode: &str) -> Result<RWops <'static>, String> {
        let raw = unsafe {
            let path_c = CString::new(path.as_ref().to_str().unwrap()).unwrap();
            let mode_c = CString::new(mode).unwrap();
            sys::SDL_RWFromFile(path_c.as_ptr() as *const c_char, mode_c.as_ptr() as *const c_char)
        };

        if raw.is_null() {
            Err(get_error())
        } else {
            Ok(RWops {
                raw,
                _marker: PhantomData
            })
        }
    }

    /// Prepares a read-only memory buffer for use with `RWops`.
    ///
    /// This method can only fail if the buffer size is zero.
    pub fn from_bytes(buf: &'a [u8]) -> Result<RWops <'a>, String> {
        let raw = unsafe {
            sys::SDL_RWFromConstMem(buf.as_ptr() as *const c_void, buf.len() as c_int)
        };

        if raw.is_null() {
            Err(get_error())
        } else {
            Ok(RWops {
                raw,
                _marker: PhantomData
            })
        }
    }

    /// Reads a `Read` object into a buffer and then passes it to `RWops.from_bytes`.
    ///
    /// The buffer must be provided to this function and must live as long as the
    /// `RWops`, but the `RWops` does not take ownership of it.
    pub fn from_read<T>(r: &mut T, buffer: &'a mut Vec<u8>) -> Result<RWops<'a>, String>
        where T: io::Read + Sized {
        match r.read_to_end(buffer) {
            Ok(_size) => RWops::from_bytes(buffer),
            Err(ioerror) => {
                let msg = format!("IO error: {}", ioerror);
                Err(msg)
            }
        }
    }

    /// Prepares a read-write memory buffer for use with `RWops`.
    ///
    /// This method can only fail if the buffer size is zero.
    pub fn from_bytes_mut(buf: &'a mut [u8]) -> Result<RWops <'a>, String> {
        let raw = unsafe {
            sys::SDL_RWFromMem(buf.as_ptr() as *mut c_void, buf.len() as c_int)
        };

        if raw.is_null() {
            Err(get_error())
        } else {
            Ok(RWops {
                raw,
                _marker: PhantomData
            })
        }
    }

    /// Gets the stream's total size in bytes.
    ///
    /// Returns `None` if the stream size can't be determined
    /// (either because it doesn't make sense for the stream type, or there was an error).
    pub fn len(&self) -> Option<usize> {
        let result = unsafe { ((*self.raw).size.unwrap())(self.raw) };

        match result {
            -1 => None,
            v => Some(v as usize)
        }
    }

    // Tells if the stream is empty
    pub fn is_empty(&self) -> bool {
        match self.len() {
            Some(s) => s == 0,
            None => true,
        }
    }
}

impl<'a> Drop for RWops<'a> {
    fn drop(&mut self) {
        let ret = unsafe { ((*self.raw).close.unwrap())(self.raw) };
        if ret != 0 {
            panic!(get_error());
        }
    }
}

impl<'a> io::Read for RWops<'a> {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        let out_len = buf.len() as size_t;
        // FIXME: it's better to use as_mut_ptr().
        // number of objects read, or 0 at error or end of file.
        let ret = unsafe {
            ((*self.raw).read.unwrap())(self.raw, buf.as_ptr() as *mut c_void, 1, out_len as sys::size_t)
        };
        Ok(ret as usize)
    }
}

impl<'a> io::Write for RWops<'a> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        let in_len = buf.len() as size_t;
        let ret = unsafe {
            ((*self.raw).write.unwrap())(self.raw, buf.as_ptr() as *const c_void, 1, in_len as sys::size_t)
        };
        Ok(ret as usize)
    }

    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}

impl<'a> io::Seek for RWops<'a> {
    fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
        // whence code is different from SeekStyle
        let (whence, offset) = match pos {
            io::SeekFrom::Start(pos) => (sys::RW_SEEK_SET, pos as i64),
            io::SeekFrom::End(pos) => (sys::RW_SEEK_END, pos),
            io::SeekFrom::Current(pos) => (sys::RW_SEEK_CUR, pos)
        };
        let ret = unsafe {
            ((*self.raw).seek.unwrap())(self.raw, offset, transmute(whence))
        };
        if ret == -1 {
            Err(io::Error::last_os_error())
        } else {
            Ok(ret as u64)
        }
    }
}