Upgrading a "large" site from eZ Publish 3.9.2 to eZ Publish 3.10

Warning:*this article explains some hacks I had to do to upgrade quickly to eZ Publish 3.10. These modifications can be dangerous for your data, use them at your own risk and don't forget to make backups !*

Waiting for a more stable version of eZ Publish 4, I've upgraded my site from eZ Publish 3.9.2 to eZ Publish 3.10.0. My last upgrade was quite long, but this one could have taken ages ! As I mentioned in the developper forum, the updateniceurls.php script started with this message :

$ php4 bin/php/updateniceurls.php -s plain_site_admin
Using siteaccess plain_site_admin for nice url update
Importing old url aliases
Importing 62638 standard urls
........................................................ 0.09% 45h 46m 8s
........................................................ 0.18% 86h 55m 44s
........................................................ 0.27% 106h 58m 2s
........................................................ 0.36% 155h 18m 55s

WOW 155 hours, and just for the first step ! In fact, I don't want to change my URIs (Cool URIs don't change !) so I put these lines in site.ini.append.php :

[URLTranslator]
TransformationGroup=urlalias_compat

But even with these settings, the script tries to regenerate all URL aliases. After some searches, I found that eZURLAliasML::storePath() takes most of the time by calling several times eZURLAliasML::convertToAlias() on strings that are in my case already URL aliases ! This behaviour can be avoided by setting the $cleanupElements parameters to false (its default value is true) in the code of updateniceurls.php. eZURLAliasML::storePath() also calls eZURLAliasML::strtolower() several times. This method uses eZCharTransform to do an advanced strtolower but in my case with my existing ASCII URL aliases, there's no need of it. I has just replaced this code with a simple PHP strtolower() (don't forget to remove this hack after upgrade !).

With those hacks, eZURLAliasML::storePath() takes about 0.02 second per URI where the original code took between 0.6 and 10 seconds !

By following the upgrade documentation, the rest of the upgrade was, as always, quite easy.