Windows Memory Mapped File IO (jeremyong.com)
Memory-mapping is my preferred way to do file I/O, on pretty much every platform I write code for (desktop and console). In this post, we’ll start by discussing some of the key advantages of this approach, as well as some disadvantages. Then, we’ll look at some Windows-specific undocumented user-mode functions which help mitigate some of those disadvantages. In particular, we’ll address an important perceived limitation of memory-mapped I/O, namely, file resizing.