On Tue, Jul 29, 2008 at 8:04 AM, Alexander Sychev <[EMAIL PROTECTED]>wrote:
> On Tue, 29 Jul 2008 12:52:14 +0400, Enrico Weigelt <[EMAIL PROTECTED]> > wrote: > > Hi! > > an full mmap() is a really nice thing. It can make a lot things >> easier if you just map the whole file into the process' memory and >> let the kernel handle the actual IO. >> > > Yes, it is comfortable. But just think a bit - what will you do in the mmap > implementation when you had mapped a remote file (in Plan9 you can't be sure > some file is local or it is really just a file), and the connection has just > been broken? Surprise! > > For example, in Windows you will have an "access violation". It is very > funny to rewrite a code for using the good old file i/o instead of mmap. > In Linux you can't map a non-regular file. > > Yes, you can read entire the file into the memory, but a size of the file > can be very big and you will destroy the main advantage of mmap - the > reading of only needed pieces of the file, not entire. > And if you read it in in pieces, how can you be sure the file isn't changing on the system it's hosted on while you're looking at it? > > I beleive, mmap is not for distributed systems. > > -- > Best regards, > santucco > >
