Squid internals

The Storage Manager (src/store*.c)
Requesting memory for incoming object data - storeGetMemSpace()
storeGetMemSpace() is responsible for finding memory to allocate to a part of an object as it comes in from the network
It checks to see whether memory is avaliable and if not it invokes the memory replacement policy to find objects to "clean"
Only the in-memory pages of an object are cleaned, not the object itself