diff --git a/.jules/bolt.md b/.jules/bolt.md index f1a8c1466..7d4c5edb0 100644 --- a/.jules/bolt.md +++ b/.jules/bolt.md @@ -77,3 +77,6 @@ Optimized metric route processing to O(N) by creating a mapping of routes direct ## 2024-07-13 - [Optimize Export Dictionary FK lookups] **Learning:** Found O(N * C * E) performance bottleneck in ERD export dictionaries due to repeated array searching with `edges.some()` inside a nested loop over nodes and columns. **Action:** Replace repeated linear array scans for edges by precomputing O(1) Set lookups of foreign key column handles per node before looping. +## 2024-06-03 - Prevent intermediate array allocations in React hot paths +**Learning:** Using `Array.from(string)` to iterate over strings allocates intermediate arrays and map functions, causing significant garbage collection pressure on hot paths like ERD handle generation. `for...of` natively iterates over Unicode code points without this overhead. +**Action:** Always prefer `for...of` loops over `Array.from` when iterating strings in performance-critical rendering paths (like graph nodes and handles) to minimize garbage collection pressure. diff --git a/frontend/src/erd/handleUtils.ts b/frontend/src/erd/handleUtils.ts index 054d5ab2a..a0b0fb536 100644 --- a/frontend/src/erd/handleUtils.ts +++ b/frontend/src/erd/handleUtils.ts @@ -1,8 +1,10 @@ export function sanitizeHandleId(columnName: string): string { - const encoded = Array.from(columnName, (char) => { - // Array.from only yields non-empty Unicode scalars, so codePointAt(0) is defined. - return char.codePointAt(0)!.toString(16).padStart(4, '0') - }).join('-') + const encodedChars = []; + for (const char of columnName) { + // for...of iterates over Unicode code points natively + encodedChars.push(char.codePointAt(0)!.toString(16).padStart(4, '0')); + } + const encoded = encodedChars.join('-'); return `c-${encoded || 'empty'}` }