mstak_util/
mmap.rs

1use crate::{read_file_size, validate};
2use core::{ffi::CStr, ptr::null_mut, slice};
3
4/// A mmap.
5pub struct Mmap {
6    ptr: *mut u8,
7    len: usize,
8}
9
10impl Mmap {
11    /// Creates a mmap opening a file at a path.
12    pub fn new(path: &CStr) -> Self {
13        let len = read_file_size(path);
14
15        Self {
16            ptr: unsafe {
17                libc::mmap(
18                    null_mut(),
19                    len,
20                    libc::PROT_READ,
21                    libc::MAP_PRIVATE,
22                    // spell-checker: disable-next-line
23                    libc::open(path.as_ptr(), libc::O_RDONLY),
24                    0,
25                )
26            } as _,
27            len,
28        }
29    }
30
31    /// Returns a slice of bytes.
32    pub fn as_slice(&self) -> &[u8] {
33        unsafe { slice::from_raw_parts(self.ptr, self.len) }
34    }
35}
36
37impl Drop for Mmap {
38    fn drop(&mut self) {
39        unsafe {
40            validate(libc::munmap(self.ptr as _, self.len));
41        }
42    }
43}
44
45#[cfg(test)]
46mod tests {
47    use super::*;
48
49    #[test]
50    fn read_file() {
51        Mmap::new(c"src/lib.rs");
52    }
53}
mstak_util/mmap.rs

mstak_util/
mmap.rs
