From ffa293918ba16486e4a5e3846a01b66183d7b7e5 Mon Sep 17 00:00:00 2001
From: seonghobae <8172694+seonghobae@users.noreply.github.com>
Date: Fri, 10 Jul 2026 03:12:07 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20[performance=20improvement]?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

파일 시스템 접근을 최소화하기 위해 파일 제외 목록 확인을 Files.isDirectory 호출 이전으로 이동했습니다.
---
 .jules/bolt.md                    |  1 +
 src/main/kotlin/html4tree/main.kt | 19 +++++++++++--------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/.jules/bolt.md b/.jules/bolt.md
index a9253e7a..82fe47bb 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -12,3 +12,4 @@
 ## 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.
+## 2026-07-10 - Expensive OS stat calls before cheap in-memory checks\n**Learning:** In Kotlin/Java, checking file properties (like `isDirectory` or `isSymbolicLink`) via `java.nio.file.Files` requires allocating `Path` objects and performs expensive native OS stat calls. When processing file listings, always short-circuit filesystem checks by testing against exclusion lists (using cheap in-memory string operations) before calling methods that touch the filesystem.\n**Action:** Re-ordered conditionals to check `exclude` sets before invoking `Files.isDirectory` and `Files.isSymbolicLink`.
diff --git a/src/main/kotlin/html4tree/main.kt b/src/main/kotlin/html4tree/main.kt
index 1f1a5a2e..d8ad85dc 100644
--- a/src/main/kotlin/html4tree/main.kt
+++ b/src/main/kotlin/html4tree/main.kt
@@ -216,14 +216,17 @@ fun process_dir(curr_dir: File){
         val dir_files: MutableList<File> = curr_dir.listFiles()?.toMutableList() ?: mutableListOf()
         dir_files.sortWith(compareBy ({it.name}) )
         dir_files.forEach {
-           val isLinkedDirectory = Files.isDirectory(it.toPath(), LinkOption.NOFOLLOW_LINKS)
-           if((it.getName() !in exclude) && (isLinkedDirectory || !it.isDirectory()) && !Files.isSymbolicLink(it.toPath())) {
-              val fileName = it.getName()
-              val encodedHref = if (isLinkedDirectory) { "./${fileName.urlEncodePath()}/" } else { "./${fileName.urlEncodePath()}" }
-              val ariaLabel = "${fileName} ${if (isLinkedDirectory) { "디렉토리" } else { "파일" }}".escapeHtml()
-              val icon = if (isLinkedDirectory) { "&#128193;" } else { "&rtrif;" }
-              l.append("""          <li><a style="display:block; width:100%" href="${encodedHref}" aria-label="${ariaLabel}"><span aria-hidden="true">${icon}</span> ${fileName.escapeHtml()}</a></li>""")
-              l.append('\n')
+           val fileName = it.getName()
+           // ⚡ Bolt Performance Optimization: Short-circuit string match before expensive OS filesystem calls
+           if (fileName !in exclude) {
+               val isLinkedDirectory = Files.isDirectory(it.toPath(), LinkOption.NOFOLLOW_LINKS)
+               if ((isLinkedDirectory || !it.isDirectory()) && !Files.isSymbolicLink(it.toPath())) {
+                  val encodedHref = if (isLinkedDirectory) { "./${fileName.urlEncodePath()}/" } else { "./${fileName.urlEncodePath()}" }
+                  val ariaLabel = "${fileName} ${if (isLinkedDirectory) { "디렉토리" } else { "파일" }}".escapeHtml()
+                  val icon = if (isLinkedDirectory) { "&#128193;" } else { "&rtrif;" }
+                  l.append("""          <li><a style="display:block; width:100%" href="${encodedHref}" aria-label="${ariaLabel}"><span aria-hidden="true">${icon}</span> ${fileName.escapeHtml()}</a></li>""")
+                  l.append('\n')
+               }
            }
         }