Mitigate dependency upon ConfigCache

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.3.0
+-----
+
+ * added the dumpFile() method to atomically write files
+
 2.2.0
 -----
 

Filesystem.php

@@ -430,4 +430,32 @@ private function toIterator($files)
 
         return $files;
     }
+
+    /**
+     * Atomically dumps content into a file.
+     *
+     * @param  string  $filename The file to be written to.
+     * @param  string  $content  The data to write into the file.
+     * @param  integer $mode     The file mode (octal).
+     * @throws IOException       If the file cannot be written to.
+     */
+    public function dumpFile($filename, $content, $mode = 0666)
+    {
+        $dir = dirname($filename);
+
+        if (!is_dir($dir)) {
+            $this->mkdir($dir);
+        } elseif (!is_writable($dir)) {
+            throw new IOException(sprintf('Unable to write in the %s directory\n', $dir));
+        }
+
+        $tmpFile = tempnam($dir, basename($filename));
+
+        if (false === @file_put_contents($tmpFile, $content)) {
+            throw new IOException(sprintf('Failed to write file "%s".', $filename));
+        }
+
+        $this->rename($tmpFile, $filename);
+        $this->chmod($filename, $mode);
+    }
 }