1 //! Shims for ControlPlane when chaos mode is disabled. Enables
2 //! unconditional use of the type and its methods throughout cranelift.
3 
4 /// A shim for ControlPlane when chaos mode is disabled.
5 /// Please see the [crate-level documentation](crate).
6 #[derive(Debug, Clone, Default)]
7 pub struct ControlPlane {
8     /// prevent direct instantiation (use `default` instead)
9     _private: (),
10 }
11 
12 /// A shim for ControlPlane's `Arbitrary` implementation when chaos mode is
13 /// disabled. It doesn't consume any bytes and always returns a default
14 /// control plane.
15 impl arbitrary::Arbitrary<'_> for ControlPlane {
16     fn arbitrary(_u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Self> {
17         Ok(Self::default())
18     }
19 }
20 
21 impl ControlPlane {
22     /// Set the [fuel limit](crate#fuel-limit). This variant is used when
23     /// chaos mode is disabled. It doesn't do anything.
24     pub fn set_fuel(&mut self, _fuel: u8) {}
25 
26     /// Returns a pseudo-random boolean. This variant is used when chaos
27     /// mode is disabled. It always returns `false`.
28     #[inline]
29     pub fn get_decision(&mut self) -> bool {
30         false
31     }
32 
33     /// Returns an arbitrary value. This variant is used when chaos mode is
34     /// disabled. It always returns the default value.
35     #[inline]
36     pub fn get_arbitrary<T: for<'a> arbitrary::Arbitrary<'a> + Default>(&mut self) -> T {
37         T::default()
38     }
39 
40     /// Shuffles the items in the slice into a pseudo-random permutation.
41     /// This variant is used when chaos mode is disabled. It doesn't do
42     /// anything.
43     #[inline]
44     pub fn shuffle<T>(&mut self, _slice: &mut [T]) {}
45 
46     /// Returns a new iterator over the same items as the input iterator in
47     /// a pseudo-random order. This variant is used when chaos mode is
48     /// disabled. It always returns the same order.
49     #[inline]
50     pub fn shuffled<T>(&mut self, iter: impl Iterator<Item = T>) -> impl Iterator<Item = T> {
51         iter
52     }
53 }
54