diff --git a/.jules/bolt.md b/.jules/bolt.md index fb3e8f1..5e9dfb7 100644 --- a/.jules/bolt.md +++ b/.jules/bolt.md @@ -2,3 +2,6 @@ ## 2026-04-08 - [Performance: Defer Allocation during Traversal] **Learning:** During DAG traversals, creating owned variants of identifiers (like `file.to_path_buf()`) *before* checking `visited` HashSets results in heap allocations (O(E)) for every edge instead of every visited node (O(V)). By moving the `&PathBuf` allocation strictly *after* all HashSet `contains` checks using the borrowed reference (`&Path`), we drastically reduce memory churn. **Action:** Always check `HashSet::contains` with a borrowed reference *before* creating the owned version required by `HashSet::insert`, especially in performance-critical graph traversal paths. +## 2026-04-14 - [Performance: Avoid redundant `to_path_buf` in Hash lookups] +**Learning:** In highly recursive functions like Tarjan's SCC DFS algorithm (`tarjan_dfs`), calling `.to_path_buf()` on `&Path` just to satisfy `.get()` or `.contains()` calls on HashMaps/Sets causes significant unnecessary heap allocation overhead (O(E) instead of O(V)). +**Action:** When working with standard or custom hashing collections (like `RapidMap`, `RapidSet`, `std::collections::HashMap`), pass borrowed types (e.g., `&Path`) for lookups instead of allocating owned types (`PathBuf`). Only create the owned form when actually inserting into the collection, and create it exactly once per node visit. diff --git a/crates/flow/src/incremental/invalidation.rs b/crates/flow/src/incremental/invalidation.rs index da9ac9c..821d6f9 100644 --- a/crates/flow/src/incremental/invalidation.rs +++ b/crates/flow/src/incremental/invalidation.rs @@ -342,11 +342,12 @@ impl InvalidationDetector { fn tarjan_dfs(&self, v: &Path, state: &mut TarjanState, sccs: &mut Vec>) { // Initialize node let index = state.index_counter; - state.indices.insert(v.to_path_buf(), index); - state.lowlinks.insert(v.to_path_buf(), index); + let v_buf = v.to_path_buf(); + state.indices.insert(v_buf.clone(), index); + state.lowlinks.insert(v_buf.clone(), index); state.index_counter += 1; - state.stack.push(v.to_path_buf()); - state.on_stack.insert(v.to_path_buf()); + state.stack.push(v_buf.clone()); + state.on_stack.insert(v_buf); // Visit all successors (dependencies) let dependencies = self.graph.get_dependencies(v); @@ -358,19 +359,19 @@ impl InvalidationDetector { // Update lowlink let w_lowlink = *state.lowlinks.get(dep).unwrap(); - let v_lowlink = state.lowlinks.get_mut(&v.to_path_buf()).unwrap(); + let v_lowlink = state.lowlinks.get_mut(v).unwrap(); *v_lowlink = (*v_lowlink).min(w_lowlink); } else if state.on_stack.contains(dep) { // Successor is on stack (part of current SCC) let w_index = *state.indices.get(dep).unwrap(); - let v_lowlink = state.lowlinks.get_mut(&v.to_path_buf()).unwrap(); + let v_lowlink = state.lowlinks.get_mut(v).unwrap(); *v_lowlink = (*v_lowlink).min(w_index); } } // If v is a root node, pop the stack to create an SCC - let v_index = *state.indices.get(&v.to_path_buf()).unwrap(); - let v_lowlink = *state.lowlinks.get(&v.to_path_buf()).unwrap(); + let v_index = *state.indices.get(v).unwrap(); + let v_lowlink = *state.lowlinks.get(v).unwrap(); if v_lowlink == v_index { let mut scc = Vec::new();