⚡ Bolt: [성능 최적화] ignore 파일 정규식 매칭 최적화

.jules/bolt.md

@@ -12,3 +12,6 @@
 ## 2024-07-08 - URL Encoding String Allocation Bottleneck
 **Learning:** `byte.toString(16).padStart(2, '0').toUpperCase()` inside a loop allocating up to 3 strings per reserved byte in a hot path causes significant GC pressure. This is a common but dangerous anti-pattern in Kotlin when processing large strings or numerous files in directory crawlers.
 **Action:** Replace chained string operations with direct character mapping and bitwise operations (`ushr`, `and`) when building formatted hex output, which avoids intermediate string creation entirely. Ensure 100% branch coverage with test inputs spanning both < 10 and > 9 hex values.
+## 2024-08-01 - Avoid List Sorting and Re-Iteration For Matching
+**Learning:** In Kotlin, using `.sorted().forEach()` and an inner `.forEach()` over regexes to find matching files is inefficient. It allocates a new list, sorts it (O(N log N)), and evaluates every regex even after a match is found.
+**Action:** Remove `.sorted()` when order doesn't matter for the operation (like adding to a Set). Use `.any()` on the regex list to short-circuit evaluation as soon as the first match is found, saving CPU cycles on N * M comparisons.

src/main/kotlin/html4tree/main.kt

@@ -139,13 +139,13 @@ fun process_ignore_file(curr_dir: File): Set<String> {
            }
        }
 
-       curr_dir.list()?.sorted()?.forEach {
-           val current = it
-           ignored_regexes.forEach { regex ->
-              if(regex.matches(current)){
-                 files_to_exclude.add(current)
-              }
-         }
+       // ⚡ Bolt Performance Optimization: Skip unnecessary sorting and use short-circuiting
+       // Removing .sorted() avoids creating a new list and sorting it when we only need to check for matches.
+       // Using .any() short-circuits the regex checks as soon as a match is found.
+       curr_dir.list()?.forEach { current ->
+           if (ignored_regexes.any { it.matches(current) }) {
+               files_to_exclude.add(current)
+           }
        }
     }