#[path = "../../../os-vfs-ro-cache/src/lib.rs"]
mod cache;

fn key(inode: u64, block: u64, mount_generation: u64) -> cache::Key {
    cache::Key {volume: 1, mount_generation, media_generation: 3,
        inode, block}
}

#[test]
fn os_vfs_ro_cache_positive() {
    let mut blocks = cache::Cache::new();
    let first = key(2, 0, 7);
    let second = key(2, 1, 7);
    let third = key(3, 0, 7);
    let fourth = key(4, 0, 7);
    assert_eq!(blocks.insert(first, [b'A'; 16]), Ok(None));
    assert_eq!(blocks.insert(second, [b'B'; 16]), Ok(None));
    assert_eq!(blocks.entries().iter().flatten().count(), 2);
    assert_eq!(blocks.get(first), Ok(Some([b'A'; 16])));
    assert_eq!(blocks.insert(third, [b'C'; 16]), Ok(Some(second)));
    assert_eq!(blocks.get(second), Ok(None));
    assert_eq!(blocks.get(first), Ok(Some([b'A'; 16])));
    assert_eq!(blocks.pin(first), Ok(()));
    assert_eq!(blocks.pin(third), Ok(()));
    let before_full = blocks;
    assert_eq!(blocks.insert(fourth, [b'D'; 16]), Err(cache::Error::Busy));
    assert_eq!(blocks, before_full);
    assert_eq!(blocks.unpin(third), Ok(()));
    assert_eq!(blocks.insert(fourth, [b'D'; 16]), Ok(Some(third)));
    assert_eq!(blocks.get(first), Ok(Some([b'A'; 16])));
    assert_eq!(blocks.get(fourth), Ok(Some([b'D'; 16])));
    assert_eq!(blocks.unpin(first), Ok(()));
    assert_eq!(blocks.invalidate_mount(1, 7), Ok(2));
    assert_eq!(blocks.get(first), Ok(None));
    assert_eq!(blocks.get(fourth), Ok(None));
}

#[test]
fn os_vfs_ro_cache_negative() {
    let mut blocks = cache::Cache::new();
    let original = key(2, 0, 7);
    assert_eq!(blocks.insert(original, [b'A'; 16]), Ok(None));
    let stale_mount = key(2, 0, 8);
    let changed_media = cache::Key {media_generation: 4, ..original};
    assert_eq!(blocks.get(stale_mount), Ok(None));
    assert_eq!(blocks.get(changed_media), Ok(None));
    assert_eq!(blocks.get(cache::Key {volume: 0, ..original}),
        Err(cache::Error::InvalidKey));
    assert_eq!(blocks.pin(original), Ok(()));
    let before_pinned = blocks;
    assert_eq!(blocks.invalidate_mount(1, 7), Err(cache::Error::Busy));
    assert_eq!(blocks, before_pinned);
    assert_eq!(blocks.insert(original, [b'X'; 16]), Err(cache::Error::Busy));
    assert_eq!(blocks, before_pinned);
    assert_eq!(blocks.unpin(original), Ok(()));
    assert_eq!(blocks.unpin(original), Err(cache::Error::NotFound));
    assert_eq!(blocks.get(original), Ok(Some([b'A'; 16])));
}