Roman Dementiev wrote:
Thorsten Ottosen wrote:
"Roman Dementiev" <dementiev@ira.uka.de> wrote in message
yes. One must rewrite only the lower layer of Stxxl using native file access methods and native multithreading.
is that because you need mem.mapped files? Otherwise, why don't you use boost filsystem and boost threads?
I do not necessarily need memory mapped files.
The Boost filesystem library is more about manipulating files and directories. But what I need is the file access itself: create/open/read/write/close file. I would have been using std::fstream as a portable file access method, but it lacks support of files larger than 2 GB. It is really big disadvantage in my case.
The boost iostreams library, which is in CVS now and will be part of the next boost release, contains a class file_descriptor for accessing files using OS or runtime library file descriptors. http://www.kangaroologic.com/iostreams/libs/iostreams/doc/?path=6.1.3 Currently, random access if performed using offsets of type std::streamoff, which is often implemented as a 32-bit unsigned long. However, I recently decided to relax this restriction and allow offsets to be specified using larger intergral type. On windows, seeking will be implemented using _lseek64 where available. On Posix, lseek will be used; it uses off_t, which is (I think) often 64 bits. Access via iostreams will still have to use std::streamoff, since that is out of my control; but you should be able to use an instance of file_descriptor directly. The new code should be available soon. Best Regards, Jonathan