use super::{inspect, CanonicalInput, QueryResult};
use crate::ty::TyCtxt;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::sync::Lock;
use rustc_query_system::cache::WithDepNode;
use rustc_query_system::dep_graph::DepNodeIndex;
use rustc_session::Limit;
#[derive(Default)]
pub struct EvaluationCache<'tcx> {
map: Lock<FxHashMap<CanonicalInput<'tcx>, CacheEntry<'tcx>>>,
}
#[derive(Debug, PartialEq, Eq)]
pub struct CacheData<'tcx> {
pub result: QueryResult<'tcx>,
pub proof_tree: Option<&'tcx inspect::CanonicalGoalEvaluationStep<TyCtxt<'tcx>>>,
pub additional_depth: usize,
pub encountered_overflow: bool,
}
impl<'tcx> EvaluationCache<'tcx> {
pub fn insert(
&self,
tcx: TyCtxt<'tcx>,
key: CanonicalInput<'tcx>,
proof_tree: Option<&'tcx inspect::CanonicalGoalEvaluationStep<TyCtxt<'tcx>>>,
additional_depth: usize,
encountered_overflow: bool,
cycle_participants: FxHashSet<CanonicalInput<'tcx>>,
dep_node: DepNodeIndex,
result: QueryResult<'tcx>,
) {
let mut map = self.map.borrow_mut();
let entry = map.entry(key).or_default();
let data = WithDepNode::new(dep_node, QueryData { result, proof_tree });
entry.cycle_participants.extend(cycle_participants);
if encountered_overflow {
entry.with_overflow.insert(additional_depth, data);
} else {
entry.success = Some(Success { data, additional_depth });
}
if cfg!(debug_assertions) {
drop(map);
let expected = CacheData { result, proof_tree, additional_depth, encountered_overflow };
let actual = self.get(tcx, key, [], Limit(additional_depth));
if !actual.as_ref().is_some_and(|actual| expected == *actual) {
bug!("failed to lookup inserted element for {key:?}: {expected:?} != {actual:?}");
}
}
}
pub fn get(
&self,
tcx: TyCtxt<'tcx>,
key: CanonicalInput<'tcx>,
stack_entries: impl IntoIterator<Item = CanonicalInput<'tcx>>,
available_depth: Limit,
) -> Option<CacheData<'tcx>> {
let map = self.map.borrow();
let entry = map.get(&key)?;
for stack_entry in stack_entries {
if entry.cycle_participants.contains(&stack_entry) {
return None;
}
}
if let Some(ref success) = entry.success {
if available_depth.value_within_limit(success.additional_depth) {
let QueryData { result, proof_tree } = success.data.get(tcx);
return Some(CacheData {
result,
proof_tree,
additional_depth: success.additional_depth,
encountered_overflow: false,
});
}
}
entry.with_overflow.get(&available_depth.0).map(|e| {
let QueryData { result, proof_tree } = e.get(tcx);
CacheData {
result,
proof_tree,
additional_depth: available_depth.0,
encountered_overflow: true,
}
})
}
}
struct Success<'tcx> {
data: WithDepNode<QueryData<'tcx>>,
additional_depth: usize,
}
#[derive(Clone, Copy)]
pub struct QueryData<'tcx> {
pub result: QueryResult<'tcx>,
pub proof_tree: Option<&'tcx inspect::CanonicalGoalEvaluationStep<TyCtxt<'tcx>>>,
}
#[derive(Default)]
struct CacheEntry<'tcx> {
success: Option<Success<'tcx>>,
cycle_participants: FxHashSet<CanonicalInput<'tcx>>,
with_overflow: FxHashMap<usize, WithDepNode<QueryData<'tcx>>>,
}