//! Bounded owner-scoped RAM filesystem guest probe.

use super::*;
use os_vfs_tmpfs::{Error, Tmpfs};

pub fn run(allocator: &mut memory::FrameAllocator) -> Result<(), &'static str> {
    let frames_before = allocator.remaining_pages();
    let mut fs = Tmpfs::new(7, 8).map_err(|_| "k1590-new")?;
    let first = fs.create(11, b"a").map_err(|_| "k1590-create-a")?;
    if fs.write_at(11, first, 0, b"abc") != Ok(3)
        || fs.write_at(11, first, 5, b"XY") != Ok(2)
        || fs.len(11, first) != Ok(7) {
        return Err("k1590-write-gap");
    }
    let mut output = [b'!'; 8];
    if fs.read_at(11, first, 0, &mut output) != Ok(7)
        || output != [b'a', b'b', b'c', 0, 0, b'X', b'Y', b'!'] {
        return Err("k1590-read-gap");
    }
    write_line("TURKOS/OS/K1590-TMPFS: ZERO-GAP=7");

    let second = fs.create(22, b"b").map_err(|_| "k1590-create-b")?;
    let before_quota = fs;
    if fs.write_at(22, second, 0, b"zz") != Err(Error::NoSpace)
        || fs != before_quota || fs.write_at(22, second, 0, b"z") != Ok(1)
        || fs.used() != 8 { return Err("k1590-quota"); }
    write_line("TURKOS/OS/K1590-TMPFS: QUOTA=REJECTED UNCHANGED");

    let before_owner = fs;
    let mut canary = [b'!'; 8];
    if fs.read_at(22, first, 0, &mut canary)
        != Err(Error::InvalidOwner)
        || canary != [b'!'; 8]
        || fs.write_at(22, first, 0, b"X")
            != Err(Error::InvalidOwner)
        || fs != before_owner {
        return Err("k1590-owner");
    }
    write_line("TURKOS/OS/K1590-TMPFS: OWNER=REJECTED");

    if fs.unlink(11, b"a") != Ok(()) || fs.used() != 1
        || fs.len(11, first) != Err(Error::NoEntry) {
        return Err("k1590-unlink");
    }
    write_line("TURKOS/OS/K1590-TMPFS: UNLINK=RECLAIMED");

    if fs.reset() != Ok(8) || fs.used() != 0
        || fs.len(22, second) != Err(Error::Stale)
        || allocator.remaining_pages() != frames_before {
        return Err("k1590-reset");
    }
    write_line("TURKOS/OS/K1590-TMPFS: RESET=STALE FRAMES=UNCHANGED");
    Ok(())
}