[FrameworkBundle] Fix perf issue in CacheClearCommand::warmup()

Author: nicolas-grekas

Command/CacheClearCommand.php

@@ -141,7 +141,7 @@ protected function warmup($warmupDir, $realCacheDir, $enableOptionalWarmers = tr
         $safeTempKernel = str_replace('\\', '\\\\', get_class($tempKernel));
         $realKernelFQN = get_class($realKernel);
 
-        foreach (Finder::create()->files()->name('*.meta')->in($warmupDir) as $file) {
+        foreach (Finder::create()->files()->depth('<3')->name('*.meta')->in($warmupDir) as $file) {
             file_put_contents($file, preg_replace(
                 '/(C\:\d+\:)"'.$safeTempKernel.'"/',
                 sprintf('$1"%s"', $realKernelFQN),
@@ -153,14 +153,16 @@ protected function warmup($warmupDir, $realCacheDir, $enableOptionalWarmers = tr
         $search = array($warmupDir, str_replace('\\', '\\\\', $warmupDir));
         $replace = str_replace('\\', '/', $realCacheDir);
         foreach (Finder::create()->files()->in($warmupDir) as $file) {
-            $content = str_replace($search, $replace, file_get_contents($file));
-            file_put_contents($file, $content);
+            $content = str_replace($search, $replace, file_get_contents($file), $count);
+            if ($count) {
+                file_put_contents($file, $content);
+            }
         }
 
         // fix references to container's class
         $tempContainerClass = get_class($tempKernel->getContainer());
         $realContainerClass = get_class($realKernel->getContainer());
-        foreach (Finder::create()->files()->name($tempContainerClass.'*')->in($warmupDir) as $file) {
+        foreach (Finder::create()->files()->depth('<2')->name($tempContainerClass.'*')->in($warmupDir) as $file) {
             $content = str_replace($tempContainerClass, $realContainerClass, file_get_contents($file));
             file_put_contents($file, $content);
             rename($file, str_replace(DIRECTORY_SEPARATOR.$tempContainerClass, DIRECTORY_SEPARATOR.$realContainerClass, $file));