log rotation

Lib/Logger.php

@@ -79,6 +79,37 @@ class Logger {
             if(! file_exists($file)) {
                 mkdir(dirname($file), 0777, true);
                 touch($file);
+            } else {
+                $mtime = filemtime($file);
+                // start of the current day
+                $start = strtotime("midnight");
+
+                // log rotate if the last entry in the log is from yesterday
+                if($mtime < $start) {
+                    $files = glob($file.'.?');
+                    natsort($files);
+                    $files = array_reverse($files);
+                    $files[] = $file;
+
+                    // we count before adding the next file
+                    $len = count($files);
+
+                    $next = intval(substr($files[0], -1)) + 1;
+                    $next = $next == 1 ? "$file.1" : substr($files[0], 0, -1).$next;
+
+                    array_unshift($files, $next);
+                    for($i = 0; $i < $len; ++$i) {
+                        // move all the log files to the next name
+                        rename($files[$i + 1], $files[$i]);
+                    }
+
+                    // delete all files with a number bigger than 9
+                    $files = glob($file.'.??');
+                    array_map('unlink', $files);
+
+                    // recreate the new log file
+                    touch($file);
+                }
             }
             file_put_contents($file, $msg, FILE_APPEND | LOCK_EX);
         }