Add TODO notes

src/Packagist/WebBundle/Command/CompileStatsCommand.php

@@ -137,6 +137,7 @@ class CompileStatsCommand extends ContainerAwareCommand
         $redis->rename('downloads:absolute:new', 'downloads:absolute');
     }
 
+    // TODO could probably run faster with lua scripting
     protected function sumLastNDays($days, $id, \DateTime $yesterday)
     {
         $date = clone $yesterday;

src/Packagist/WebBundle/Package/SymlinkDumper.php

@@ -398,6 +398,7 @@ class SymlinkDumper
             $this->cleanOldFiles($buildDir, $oldBuildDir, $safeFiles);
         }
 
+        // TODO when a package is deleted, it should be removed from provider files, or marked for removal at least
         return true;
     }