Function evicts_when_full

block/src/qcow/vec_cache.rs:172–209

()

    #[test]
    fn evicts_when_full() {
        let mut cache = CacheMap::<NumCache>::new(3);
        let mut evicted = None;
        cache
            .insert(0, NumCache(()), |index, _| {
                evicted = Some(index);
                Ok(())
            })
            .unwrap();
        assert_eq!(evicted, None);
        cache
            .insert(1, NumCache(()), |index, _| {
                evicted = Some(index);
                Ok(())
            })
            .unwrap();
        assert_eq!(evicted, None);
        cache
            .insert(2, NumCache(()), |index, _| {
                evicted = Some(index);
                Ok(())
            })
            .unwrap();
        assert_eq!(evicted, None);
        cache
            .insert(3, NumCache(()), |index, _| {
                evicted = Some(index);
                Ok(())
            })
            .unwrap();
        assert!(evicted.is_some());

        // Check that three of the four items inserted are still there and that the most recently
        // inserted is one of them.
        let num_items = (0..=3).filter(|k| cache.contains_key(*k)).count();
        assert_eq!(num_items, 3);
        assert!(cache.contains_key(3));
    }
}