Squid internals

The Storage Manager (src/store*.c)
Replacement Policies
There is a 'generic' API for replacement policies
Each storedir has a replacement policy object
There is a replacement policy object for memory caching
This allows the admin to choose the best replacement policies in a given situation
This also allows the storedir code to enforce its own replacement policy (think a cyclic filesystem..)
Currently there are two replacement policies avaliable
LRU (simple double-linked list)
Heap replacement