From e2347e0d4181a20464f939480925e210998b4c6b Mon Sep 17 00:00:00 2001
From: Sander Muller <github@scode.nl>
Date: Sun, 18 Oct 2026 12:40:43 +0200
Subject: [PATCH] [perf] Cache realpath() of skip patterns in FileInfoMatcher

PHP does not cache a failed realpath() lookup. A wildcard skip pattern like
"**/vendor/*" fails that lookup once for every file. The matcher now resolves
each pattern once per run, and keeps a false result too.
---
 src/Skipper/Matcher/FileInfoMatcher.php       |  9 ++++++++-
 tests/Skipper/Matcher/FileInfoMatcherTest.php | 16 ++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/Skipper/Matcher/FileInfoMatcher.php b/src/Skipper/Matcher/FileInfoMatcher.php
index 19eef3ee00d..5f384eb57a1 100644
--- a/src/Skipper/Matcher/FileInfoMatcher.php
+++ b/src/Skipper/Matcher/FileInfoMatcher.php
@@ -11,6 +11,13 @@
  */
 final class FileInfoMatcher
 {
+    /**
+     * PHP does not cache a failed realpath() lookup, and a wildcard pattern fails it for every file
+     *
+     * @var array<string, string|false>
+     */
+    private array $realpathByPattern = [];
+
     /**
      * Returns the original (un-normalized) pattern that matched, so callers can report the exact
      * configured path. Returns null when no pattern matches.
@@ -90,7 +97,7 @@ private function matchFnmatch(string $matchingPath, string $filePath): bool
 
     private function matchRealpath(string $matchingPath, string $filePath): bool
     {
-        $realPathMatchingPath = realpath($matchingPath);
+        $realPathMatchingPath = $this->realpathByPattern[$matchingPath] ??= realpath($matchingPath);
         if ($realPathMatchingPath === false) {
             return false;
         }
diff --git a/tests/Skipper/Matcher/FileInfoMatcherTest.php b/tests/Skipper/Matcher/FileInfoMatcherTest.php
index 72f92ee4dc7..97c3dd76d48 100644
--- a/tests/Skipper/Matcher/FileInfoMatcherTest.php
+++ b/tests/Skipper/Matcher/FileInfoMatcherTest.php
@@ -35,6 +35,22 @@ public function testMatchPatternReturnsNullWhenNoPatternMatches(): void
         $this->assertNull($matchedPattern);
     }
 
+    public function testRealPathOfEachPatternIsResolvedSeparatelyOnRepeatedCalls(): void
+    {
+        // the file paths are not real paths, so only the realpath() comparison can match them
+        $pathInPattern = __DIR__ . '/Fixture/path/in';
+        $inPattern = __DIR__ . '/Fixture/in';
+        $patterns = [$pathInPattern, $inPattern];
+
+        $pathInFile = __DIR__ . '/Fixture/path/with/../in/it/KeepThisFile.txt';
+        $inFile = __DIR__ . '/Fixture/path/../in/it/KeepThisFile.txt';
+
+        for ($i = 0; $i < 2; ++$i) {
+            $this->assertSame($pathInPattern, $this->fileInfoMatcher->matchPattern($pathInFile, $patterns));
+            $this->assertSame($inPattern, $this->fileInfoMatcher->matchPattern($inFile, $patterns));
+        }
+    }
+
     #[DataProvider('providePatterns')]
     public function testPatternNormalization(string $filePath, string $filePattern, bool $shouldMatch): void
     {