Improve efficiency of retrieving log file entries

diff --git a/lib/log/owncloud.php b/lib/log/owncloud.php
index 0b7a231d3045aa76de1432c8446be0dba25d9cdb..5913d8b5b8360c1ea2491578fb5d3c1b4563d03d 100644 (file)
--- a/lib/log/owncloud.php
+++ b/lib/log/owncloud.php
@@ -62,23 +62,26 @@ class OC_Log_Owncloud {
        public static function getEntries($limit=50, $offset=0){
                self::init();
                $minLevel=OC_Config::getValue( "loglevel", OC_Log::WARN );
-               $entries=array();
-               if(!file_exists(self::$logFile)) {
-                       return array();
-               }
-               $contents=file(self::$logFile);
-               if(!$contents) {//error while reading log
-                       return array();
-               }
-               $end=max(count($contents)-$offset-1, 0);
-               $start=max($end-$limit,0);
-               $i=$end;
-               while($i>$start){
-                       $entry=json_decode($contents[$i]);
-                       if($entry->level>=$minLevel){
-                               $entries[]=$entry;
+               $entries = array();
+               $handle = fopen(self::$logFile, 'r');
+               if ($handle) {
+                       // Just a guess to set the file pointer to the right spot
+                       $maxLineLength = 150;
+                       fseek($handle, -($limit * $maxLineLength + $offset * $maxLineLength), SEEK_END);
+                       // Skip first line, because it is most likely a partial line
+                       fgets($handle);
+                       while (!feof($handle)) {
+                               $line = fgets($handle);
+                               if (!empty($line)) {
+                                       $entry = json_decode($line);
+                                       if ($entry->level >= $minLevel) {
+                                               $entries[] = $entry;
+                                       }
+                               }
                        }
-                       $i--;
+                       fclose($handle);
+                       // Extract the needed entries and reverse the order
+                       $entries = array_reverse(array_slice($entries, -($limit + $offset), $limit));
                }
                return $entries;
        }