When we implemented the git portion of Sublime Merge, we chose to use mmap for reading git object files. This turned out to be considerably more difficult than we had first thought. Using mmap in desktop applications has some serious caveats, and here’s why… - Sublime HQ - [HN]

• Speeding up file I/O: mmap() vs. read()
• Shared Memory or mmap - Linux C/C++ IPC