using mmap on large (> 2 Gig) files

Fredrik Lundh fredrik at
Tue Oct 24 08:00:44 CEST 2006

sturlamolden wrote:

> Looking at Python's source (mmapmodule.c), it seems that "mmap.mmap"
> always sets the offset argument in Windows' MapViewOfFile and UNIX'
> mmap to 0. This means that it is always mapping from the beginning of
> the file. Thus, Python's mmap module is useless for large files. This
> is really bad coding. The one that wrote mmapmodule.c didn't consider
> the possibility that a 64 bit file system like NTFS can harbour files
> to large to fit in a 32 address space. Thus, mmapmodule.c needs to be
> fixed before it can be used for large files.

if you've gotten that far, maybe you could come up with a patch, instead 
of stating that someone else "needs to fix it" ?


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