Memcache route collections

[RobinMcCorkell]

Only works for serializable objects, which do not contain closures (anonymous functions). Kill actionInclude() and anonymous functions in route files!

Confirmed working for:

• ocs
• files_external
• user_ldap

Doesn't work for:

• root (core)
• files
• files_sharing
• files_versions

cc @DeepDiver1975 @Raydiation @MorrisJobke

[LukasReschke]

I'd vote for #13227 before adding this

[scrutinizer-notifier]

The inspection completed: 6 new issues, 3 updated code elements

[ghost]

Refer to this link for build results (access rights to CI server needed):
https://ci.owncloud.org//job/pull-request-analyser-ng-simple/6540/
👍 Test PASSed. 👍

[RobinMcCorkell]

Test code:

<?php
session_write_close();
require_once('./lib/base.php');

$cache = new \OC\Memcache\APCu('router');
//$cache = new \OC\Memcache\Null('router');

$router = new \OC\Route\CachingRouter($cache);
for ($i = 0; $i < 1000; ++$i) {
    $router->loadedApps = array();
    $router->collections = array();
    $router->loadCollection('ocs', 'ocs/routes.php');
}

Change the Memcache backend as necessary for different metrics. I had to gut the Router class a bit to allow access to protected and private members and functions, and to overrride an include_once. Below, 1 is using the Null backend, 2 is using the APCu backend:

[RobinMcCorkell]

Hmm, this approach doesn't work. Calls to OC_API::register register things in the API handler, not just create routes, so not loading ocs/routes.php means that OCS API calls break. It seems that the only way it's going to work is by caching the individual routes as they are created in the router, since those bits appear to be static.