rust/crates/salsa/tests/incremental/memoized_volatile.rs

78 lines
2.3 KiB
Rust

use crate::implementation::{TestContext, TestContextImpl};
use salsa::{Database, Durability};
#[salsa::query_group(MemoizedVolatile)]
pub(crate) trait MemoizedVolatileContext: TestContext {
// Queries for testing a "volatile" value wrapped by
// memoization.
fn memoized2(&self) -> usize;
fn memoized1(&self) -> usize;
fn volatile(&self) -> usize;
}
fn memoized2(db: &dyn MemoizedVolatileContext) -> usize {
db.log().add("Memoized2 invoked");
db.memoized1()
}
fn memoized1(db: &dyn MemoizedVolatileContext) -> usize {
db.log().add("Memoized1 invoked");
let v = db.volatile();
v / 2
}
fn volatile(db: &dyn MemoizedVolatileContext) -> usize {
db.log().add("Volatile invoked");
db.salsa_runtime().report_untracked_read();
db.clock().increment()
}
#[test]
fn volatile_x2() {
let query = TestContextImpl::default();
// Invoking volatile twice doesn't execute twice, because volatile
// queries are memoized by default.
query.volatile();
query.volatile();
query.assert_log(&["Volatile invoked"]);
}
/// Test that:
///
/// - On the first run of R0, we recompute everything.
/// - On the second run of R1, we recompute nothing.
/// - On the first run of R1, we recompute Memoized1 but not Memoized2 (since Memoized1 result
/// did not change).
/// - On the second run of R1, we recompute nothing.
/// - On the first run of R2, we recompute everything (since Memoized1 result *did* change).
#[test]
fn revalidate() {
let mut query = TestContextImpl::default();
query.memoized2();
query.assert_log(&["Memoized2 invoked", "Memoized1 invoked", "Volatile invoked"]);
query.memoized2();
query.assert_log(&[]);
// Second generation: volatile will change (to 1) but memoized1
// will not (still 0, as 1/2 = 0)
query.synthetic_write(Durability::LOW);
query.memoized2();
query.assert_log(&["Volatile invoked", "Memoized1 invoked"]);
query.memoized2();
query.assert_log(&[]);
// Third generation: volatile will change (to 2) and memoized1
// will too (to 1). Therefore, after validating that Memoized1
// changed, we now invoke Memoized2.
query.synthetic_write(Durability::LOW);
query.memoized2();
query.assert_log(&["Volatile invoked", "Memoized1 invoked", "Memoized2 invoked"]);
query.memoized2();
query.assert_log(&[]);
}