vortex_expr/
scope_vars.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::any::{Any, TypeId};
5use std::hash::{BuildHasherDefault, Hasher};
6
7use vortex_utils::aliases::hash_map::HashMap;
8
9/// A TypeMap based on `https://docs.rs/http/1.2.0/src/http/extensions.rs.html#41-266`.
10pub(crate) type ScopeVars = HashMap<TypeId, Box<dyn ScopeVar>, BuildHasherDefault<IdHasher>>;
11
12/// With TypeIds as keys, there's no need to hash them. They are already hashes
13/// themselves, coming from the compiler. The IdHasher just holds the u64 of
14/// the TypeId, and then returns it, instead of doing any bit fiddling.
15#[derive(Default)]
16pub(super) struct IdHasher(u64);
17
18impl Hasher for IdHasher {
19    #[inline]
20    fn finish(&self) -> u64 {
21        self.0
22    }
23
24    fn write(&mut self, _: &[u8]) {
25        unreachable!("TypeId calls write_u64");
26    }
27
28    #[inline]
29    fn write_u64(&mut self, id: u64) {
30        self.0 = id;
31    }
32}
33
34/// This traits defines variables that can be stored inside of an execution's [`Scope`](crate::Scope).
35pub trait ScopeVar: Any + Send + Sync {
36    fn as_any(&self) -> &dyn Any;
37    fn as_any_mut(&mut self) -> &mut dyn Any;
38    fn clone_box(&self) -> Box<dyn ScopeVar>;
39}
40
41impl Clone for Box<dyn ScopeVar> {
42    fn clone(&self) -> Self {
43        (**self).clone_box()
44    }
45}
46
47impl<T: Clone + Send + Sync + 'static> ScopeVar for T {
48    fn as_any(&self) -> &dyn Any {
49        self
50    }
51
52    fn as_any_mut(&mut self) -> &mut dyn Any {
53        self
54    }
55
56    fn clone_box(&self) -> Box<dyn ScopeVar> {
57        Box::new(self.clone())
58    }
59}
vortex_expr/scope_vars.rs

vortex_expr/
scope_vars.rs
