为大型文件和小型文件创建NSFileHandle之间有性能差异吗？

Question

This question strikes me as almost silly, but I just want to sanity check myself. For a variety of reasons, I'm welding together a bunch of files into a single megafile before packing this as a resource in my iOS app. I'm then using NSFileHandle to open the file, seek to the right place, and read out just the bytes I want.

Is there any performance difference between doing it this way and reading loose files? Or, supposing I could choose to use just one monolithic megafile, versus, say, 10 medium-sized (but still joined) files, is there any performance difference between "opening" the large versus a smaller file?

Since I know exactly where to seek to, and I'm reading just the bytes I want, I don't see how there could be a difference. But, hey -- Stranger things have proved to be. Thanks in advance!

Answer 1

There could be a difference if it was an extremely large number of files. Every open file uses up resources in memory (file handles, and the like), and on some storage devices, a file will take up an entire block even if it doesn't fill it. That can lead to wasted space in extreme cases. But in practice, it probably won't be a problem. To know for sure, you can profile your code and see if it's faster one way vs. the other, and see what sort of space it takes up on a typical device.