salsa/tests/incremental/memoized_inputs.rs
Niko Matsakis fad97eeb6a remove the DB parameter
This had two unexpected consequences, one unfortunate, one "medium":

* All `salsa::Database` must be `'static`. This falls out from
`Q::DynDb` not having access to any lifetimes, but also the defaulting
rules for `dyn QueryGroup` that make it `dyn QueryGroup + 'static`. We
don't really support generic databases anyway yet so this isn't a big
deal, and we can add workarounds later (ideally via GATs).

* It is now statically impossible to invoke `snapshot` from a query,
and so we don't need to test that it panics. This is because the
signature of `snapshot` returns a `Snapshot<Self>` and that is not
accessible to a `dyn QueryGroup` type. Similarly, invoking
`Runtime::snapshot` directly is not possible becaues it is
crate-private. So I removed the test. This seems ok, but eventually I
would like to expose ways for queries to do parallel
execution (matklad and I had talked about a "speculation" primitive
for enabling that).

* This commit is 99% boilerplate I did with search-and-replace. I also
rolled in a few other changes I might have preferred to factor out,
most notably removing the `GetQueryTable` plumbing trait in favor of
free-methods, but it was awkward to factor them out and get all the
generics right (so much simpler in this version).
2020-07-04 14:17:11 +00:00

77 lines
1.6 KiB
Rust

use crate::implementation::{TestContext, TestContextImpl};
#[salsa::query_group(MemoizedInputs)]
pub(crate) trait MemoizedInputsContext: TestContext {
fn max(&self) -> usize;
#[salsa::input]
fn input1(&self) -> usize;
#[salsa::input]
fn input2(&self) -> usize;
}
fn max(db: &dyn MemoizedInputsContext) -> usize {
db.log().add("Max invoked");
std::cmp::max(db.input1(), db.input2())
}
#[test]
fn revalidate() {
let db = &mut TestContextImpl::default();
db.set_input1(0);
db.set_input2(0);
let v = db.max();
assert_eq!(v, 0);
db.assert_log(&["Max invoked"]);
let v = db.max();
assert_eq!(v, 0);
db.assert_log(&[]);
db.set_input1(44);
db.assert_log(&[]);
let v = db.max();
assert_eq!(v, 44);
db.assert_log(&["Max invoked"]);
let v = db.max();
assert_eq!(v, 44);
db.assert_log(&[]);
db.set_input1(44);
db.assert_log(&[]);
db.set_input2(66);
db.assert_log(&[]);
db.set_input1(64);
db.assert_log(&[]);
let v = db.max();
assert_eq!(v, 66);
db.assert_log(&["Max invoked"]);
let v = db.max();
assert_eq!(v, 66);
db.assert_log(&[]);
}
/// Test that invoking `set` on an input with the same value still
/// triggers a new revision.
#[test]
fn set_after_no_change() {
let db = &mut TestContextImpl::default();
db.set_input2(0);
db.set_input1(44);
let v = db.max();
assert_eq!(v, 44);
db.assert_log(&["Max invoked"]);
db.set_input1(44);
let v = db.max();
assert_eq!(v, 44);
db.assert_log(&["Max invoked"]);
}