Merge commit 'ddf105b646' into sync-from-ra

crates/salsa/tests/incremental/constants.rs

@@ -0,0 +1,145 @@
+use crate::implementation::{TestContext, TestContextImpl};
+use salsa::debug::DebugQueryTable;
+use salsa::Durability;
+
+#[salsa::query_group(Constants)]
+pub(crate) trait ConstantsDatabase: TestContext {
+    #[salsa::input]
+    fn input(&self, key: char) -> usize;
+
+    fn add(&self, key1: char, key2: char) -> usize;
+
+    fn add3(&self, key1: char, key2: char, key3: char) -> usize;
+}
+
+fn add(db: &dyn ConstantsDatabase, key1: char, key2: char) -> usize {
+    db.log().add(format!("add({}, {})", key1, key2));
+    db.input(key1) + db.input(key2)
+}
+
+fn add3(db: &dyn ConstantsDatabase, key1: char, key2: char, key3: char) -> usize {
+    db.log().add(format!("add3({}, {}, {})", key1, key2, key3));
+    db.add(key1, key2) + db.input(key3)
+}
+
+// Test we can assign a constant and things will be correctly
+// recomputed afterwards.
+#[test]
+fn invalidate_constant() {
+    let db = &mut TestContextImpl::default();
+    db.set_input_with_durability('a', 44, Durability::HIGH);
+    db.set_input_with_durability('b', 22, Durability::HIGH);
+    assert_eq!(db.add('a', 'b'), 66);
+
+    db.set_input_with_durability('a', 66, Durability::HIGH);
+    assert_eq!(db.add('a', 'b'), 88);
+}
+
+#[test]
+fn invalidate_constant_1() {
+    let db = &mut TestContextImpl::default();
+
+    // Not constant:
+    db.set_input('a', 44);
+    assert_eq!(db.add('a', 'a'), 88);
+
+    // Becomes constant:
+    db.set_input_with_durability('a', 44, Durability::HIGH);
+    assert_eq!(db.add('a', 'a'), 88);
+
+    // Invalidates:
+    db.set_input_with_durability('a', 33, Durability::HIGH);
+    assert_eq!(db.add('a', 'a'), 66);
+}
+
+// Test cases where we assign same value to 'a' after declaring it a
+// constant.
+#[test]
+fn set_after_constant_same_value() {
+    let db = &mut TestContextImpl::default();
+    db.set_input_with_durability('a', 44, Durability::HIGH);
+    db.set_input_with_durability('a', 44, Durability::HIGH);
+    db.set_input('a', 44);
+}
+
+#[test]
+fn not_constant() {
+    let mut db = TestContextImpl::default();
+
+    db.set_input('a', 22);
+    db.set_input('b', 44);
+    assert_eq!(db.add('a', 'b'), 66);
+    assert_eq!(Durability::LOW, AddQuery.in_db(&db).durability(('a', 'b')));
+}
+
+#[test]
+fn durability() {
+    let mut db = TestContextImpl::default();
+
+    db.set_input_with_durability('a', 22, Durability::HIGH);
+    db.set_input_with_durability('b', 44, Durability::HIGH);
+    assert_eq!(db.add('a', 'b'), 66);
+    assert_eq!(Durability::HIGH, AddQuery.in_db(&db).durability(('a', 'b')));
+}
+
+#[test]
+fn mixed_constant() {
+    let mut db = TestContextImpl::default();
+
+    db.set_input_with_durability('a', 22, Durability::HIGH);
+    db.set_input('b', 44);
+    assert_eq!(db.add('a', 'b'), 66);
+    assert_eq!(Durability::LOW, AddQuery.in_db(&db).durability(('a', 'b')));
+}
+
+#[test]
+fn becomes_constant_with_change() {
+    let mut db = TestContextImpl::default();
+
+    db.set_input('a', 22);
+    db.set_input('b', 44);
+    assert_eq!(db.add('a', 'b'), 66);
+    assert_eq!(Durability::LOW, AddQuery.in_db(&db).durability(('a', 'b')));
+
+    db.set_input_with_durability('a', 23, Durability::HIGH);
+    assert_eq!(db.add('a', 'b'), 67);
+    assert_eq!(Durability::LOW, AddQuery.in_db(&db).durability(('a', 'b')));
+
+    db.set_input_with_durability('b', 45, Durability::HIGH);
+    assert_eq!(db.add('a', 'b'), 68);
+    assert_eq!(Durability::HIGH, AddQuery.in_db(&db).durability(('a', 'b')));
+
+    db.set_input_with_durability('b', 45, Durability::MEDIUM);
+    assert_eq!(db.add('a', 'b'), 68);
+    assert_eq!(Durability::MEDIUM, AddQuery.in_db(&db).durability(('a', 'b')));
+}
+
+// Test a subtle case in which an input changes from constant to
+// non-constant, but its value doesn't change. If we're not careful,
+// this can cause us to incorrectly consider derived values as still
+// being constant.
+#[test]
+fn constant_to_non_constant() {
+    let mut db = TestContextImpl::default();
+
+    db.set_input_with_durability('a', 11, Durability::HIGH);
+    db.set_input_with_durability('b', 22, Durability::HIGH);
+    db.set_input_with_durability('c', 33, Durability::HIGH);
+
+    // Here, `add3` invokes `add`, which yields 33. Both calls are
+    // constant.
+    assert_eq!(db.add3('a', 'b', 'c'), 66);
+
+    db.set_input('a', 11);
+
+    // Here, `add3` invokes `add`, which *still* yields 33, but which
+    // is no longer constant. Since value didn't change, we might
+    // preserve `add3` unchanged, not noticing that it is no longer
+    // constant.
+    assert_eq!(db.add3('a', 'b', 'c'), 66);
+
+    // In that case, we would not get the correct result here, when
+    // 'a' changes *again*.
+    db.set_input('a', 22);
+    assert_eq!(db.add3('a', 'b', 'c'), 77);
+}