add description

diff --git a/src/Core/Config/Util/ConfigFileManager.php b/src/Core/Config/Util/ConfigFileManager.php
index e4b84d158744603aa8b336bd8bd65f83a7916e7e..eb20317cb4815c09522f9ea16834e35dbcb65bbf 100644 (file)
--- a/src/Core/Config/Util/ConfigFileManager.php
+++ b/src/Core/Config/Util/ConfigFileManager.php
@@ -179,8 +179,15 @@ class ConfigFileManager
 
                if (file_exists($filename)) {
 
+                       // The fallback empty return content
                        $content = '<?php return [];';
 
+                       /**
+                        * This code-block creates a readonly node.config.php content stream (fopen() with "r")
+                        * The stream is locked shared (LOCK_SH), so not exclusively, but the OS knows that there's a lock
+                        *
+                        * Any exclusive locking (LOCK_EX) would need to wait until all LOCK_SHs are unlocked
+                        */
                        $configStream = fopen($filename, 'r');
                        try {
                                if (flock($configStream, LOCK_SH)) {
@@ -190,10 +197,18 @@ class ConfigFileManager
                                        }
                                }
                        } finally {
+                               // unlock and close the stream for every circumstances
                                flock($configStream, LOCK_UN);
                                fclose($configStream);
                        }
 
+                       /**
+                        * Evaluate the fetched content
+                        *
+                        * @note
+                        * Because `eval()` directly evaluates PHP content, we need to "close" the expected PHP content again with
+                        * the prefixed "?>". Now we're in plain HTML again and can evaluate any PHP file :-)
+                        */
                        $dataArray = eval('?>' . $content);
 
                        if (is_array($dataArray)) {
@@ -229,7 +244,7 @@ class ConfigFileManager
                                        $content = fread($configStream, filesize($filename));
                                        rewind($configStream);
                                        if (!$content) {
-                                               throw new ConfigFileException(sprintf('Couldn\'t read file %s', $filename));
+                                               throw new ConfigFileException(sprintf('Cannot read file %s', $filename));
                                        }
 
                                        $dataArray = eval('?>' . $content);