mmap() vs. reading blocks

Question

I\'m working on a program that will be processing files that could potentially be 100GB or more in size. The files contain sets of variable length records. I\'ve got a first

Answer 1

I remember mapping a huge file containing a tree structure into memory years ago. I was amazed by the speed compared to normal de-serialization which involves lot of work in memory, like allocating tree nodes and setting pointers. So in fact I was comparing a single call to mmap (or its counterpart on Windows) against many (MANY) calls to operator new and constructor calls. For such kind of task, mmap is unbeatable compared to de-serialization. Of course one should look into boosts relocatable pointer for this.