cds 0.10.0

Collection of Optimized Data Structures
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80

use crate::{
    len::LengthType,
    mem::{alloc::dealloc_buffer, SpareMemoryPolicy},
    smallvec::SmallVec,
};
use core::mem;

impl<T, const C: usize, L, SM> Drop for SmallVec<T, C, L, SM>
where
    L: LengthType,
    SM: SpareMemoryPolicy<T>,
{
    fn drop(&mut self) {
        self.truncate(0);

        let cap = self.capacity.as_usize();
        if mem::size_of::<T>() != 0 && cap > C {
            // SAFETY: cap > C means reserve_impl has succeeded at least once.
            // Hence, array_size cannot overflow because reserve_impl uses the safe function
            // to calculate new_layout.
            dealloc_buffer(self.buf.heap_mut_ptr(), cap);
        }
    }
}

#[cfg(test)]
mod testing {
    use crate as cds;
    use cds::{
        len::U8,
        mem::Pattern,
        smallvec::SmallVec,
        testing::dropped::{Dropped, Track},
    };

    unsafe fn check_spare_mem(mut s: *const u8, e: *const u8, p: u8) {
        while s < e {
            assert_eq!(s.read(), p);
            s = s.add(1);
        }
    }

    #[test]
    fn test_drop_truncate_local() {
        const PATTERN: u8 = 0xDC;
        type SV<'a> = SmallVec<Dropped<'a, 16>, 16, U8, Pattern<PATTERN>>;
        let t = Track::<16>::new();

        let mut v = SV::from_iter(t.take(5));
        assert_eq!(t.n_allocated(), 5);
        assert!(t.dropped_range(0..0)); // empty range
        assert!(v.is_local());

        v.truncate(0);
        let p = v.as_ptr();
        unsafe { check_spare_mem(p.cast(), p.add(v.capacity()).cast(), PATTERN) };

        drop(v);
        assert!(t.dropped_range(0..5));
    }

    #[test]
    fn test_drop_truncate_heap() {
        const PATTERN: u8 = 0xED;
        type SV<'a> = SmallVec<Dropped<'a, 16>, 1, U8, Pattern<PATTERN>>;
        let t = Track::<16>::new();

        let mut v = SV::from_iter(t.take(5));
        assert_eq!(t.n_allocated(), 5);
        assert!(t.dropped_range(0..0)); // empty range
        assert!(v.is_heap());

        v.truncate(0);
        let p = v.as_ptr();
        unsafe { check_spare_mem(p.cast(), p.add(v.capacity()).cast(), PATTERN) };

        drop(v);
        assert!(t.dropped_range(0..5));
    }
}