linux-musl-x86/1.74.1/lib/rustlib/src/rust/library/std/src/os/unix/fs/tests.rs

use super::*;

#[test]
fn read_vectored_at() {
    let msg = b"preadv is working!";
    let dir = crate::sys_common::io::test::tmpdir();

    let filename = dir.join("preadv.txt");
    {
        let mut file = fs::File::create(&filename).unwrap();
        file.write_all(msg).unwrap();
    }
    {
        let file = fs::File::open(&filename).unwrap();
        let mut buf0 = [0; 4];
        let mut buf1 = [0; 3];

        let mut iovec = [io::IoSliceMut::new(&mut buf0), io::IoSliceMut::new(&mut buf1)];

        let n = file.read_vectored_at(&mut iovec, 4).unwrap();

        assert!(n == 4 || n == 7);
        assert_eq!(&buf0, b"dv i");

        if n == 7 {
            assert_eq!(&buf1, b"s w");
        }
    }
}

#[test]
fn write_vectored_at() {
    let msg = b"pwritev is not working!";
    let dir = crate::sys_common::io::test::tmpdir();

    let filename = dir.join("preadv.txt");
    {
        let mut file = fs::File::create(&filename).unwrap();
        file.write_all(msg).unwrap();
    }
    let expected = {
        let file = fs::File::options().write(true).open(&filename).unwrap();
        let buf0 = b"    ";
        let buf1 = b"great  ";

        let iovec = [io::IoSlice::new(buf0), io::IoSlice::new(buf1)];

        let n = file.write_vectored_at(&iovec, 11).unwrap();

        assert!(n == 4 || n == 11);

        if n == 4 { b"pwritev is     working!" } else { b"pwritev is     great  !" }
    };

    let content = fs::read(&filename).unwrap();
    assert_eq!(&content, expected);
}