regex over files

[Robin Becker]

Skip Montanaro wrote:
...
> If I mmap() a file, it's not slurped into main memory immediately, though as
> you pointed out, it's charged to my process's virtual memory.  As I access
> bits of the file's contents, it will page in only what's necessary.  If I
> mmap() a huge file, then print out a few bytes from the middle, only the
> page containing the interesting bytes is actually copied into physical
> memory.
....
my simple rather stupid experiment indicates that windows mmap at least 
will reserve 25Mb of paged file for a linear scan through a 25Mb file. I 
probably only need 4096b to scan. That's a lot less than even the page 
table requirement. This isn't rocket science just an old style observation.
-- 
Robin Becker