Improve interface caching when we have many interfaces
In interfaces.inc there's a caching system to avoid too many calls to pfSense_interface_listget().
This cache is invalidated a lot, also many times where we don't need to. It is for example invalidated several times for each VLAN during boot, which leads to slow boot times when we have more than a few hundred VLANs.
The list of interfaces can only change when we create or destroy interfaces. Therefore a rewrite of the cache-system to only invalidate on create/destroy, along with deferring invalidation to outside of loops (eg. we loop through each VLAN twice during boot), will drastically reduce boot times.
I will send a pull request soon to implement the changes.
Along with issue #10589, this change will improve boot times from timing out (max PHP execution time) to booting in a few minutes for 1000 or 1500 VLANs.
This is the case for 2.4.5 and 2.4.5-p1. I believe its also the case for 2.5.0.