I remember we replaced the fseek() with an fseeko() because we ran into a bug where we were trying to seek to a large offset (in r.terracost).
No objection to removing the 2 includes, given that it still compiles w/o them on other platforms.
-Laura
On Oct 6, 2008, at 9:18 PM, grass-dev-request@lists.osgeo.org wrote:
Message: 4
Date: Tue, 7 Oct 2008 00:12:10 +0100 (BST)
From: Paul Kelly <paul-grass@stjohnspoint.co.uk>
Subject: Re: [GRASS-dev] fseeko() in libiostream
To: Andrew Danner <adanner@cs.swarthmore.edu>
Message-ID: <Pine.LNX.4.62.0810070005140.2785@vortex.ukshells.co.uk>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
On Mon, 6 Oct 2008, Andrew Danner wrote:
fseek is not the same as fseeko.
int fseek(FILE *stream, long offset, int whence);
int fseeko(FILE *stream, off_t offset, int whence);
If large file support is enabled, fseeko will convert off_t to a 64 bit type
even on a 32-bit OS. I’m not sure if long will be 64 bit on a 64-bit OS for
fseek.
r.in.xyz may work with large files using plain old fseek as long as r.in.xyz
doesn’t make long seeks. ami_stream.h could potentially make long seeks
(e.g., skip the first 8GB of a 30GB file), though in practice, I’m not sure
that code that uses ami_stream (r.terraflow) actually uses this kind of
fseek. Still the interface is designed to potentially use long seeks and I
would be reluctant to simply replace fseeko with fseek in ami_stream.h.
you may to add a #define to check the compiler type and use fseek only if
fseeko does not exist.
Right - I was vaguely aware of some configure checks for fseeko() but as
ami_stream.h was the only file in GRASS using fseeko() I wasn’t sure if it
had been made redundant by something else. But looking closely at
include/config.h, I see that we can conditionalise fseeko() on
#ifdef HAVE_LARGEFILES. After doing that, on Windows fseeko() is redefined
to fseeko64() and all then works well.
A couple of further Windows compile errors in lib/iostream though:
sh-2.04$ make
c++ -I/c/grass/grass7/dist.i686-pc-mingw32/include -I/c/grass/extra/include -O2 -s -I/c/grass/extra/include -D_FILE_OFFSET_BITS=64 -DPACKAGE="“grasslibs”" -I/c/grass/grass7/dist.i686-pc-mingw32/include -o OBJ.i686-pc-mingw32/mm_utils.o -c mm_utils.cc
mm_utils.cc:38:22: sys/mman.h: No such file or directory
make: *** [OBJ.i686-pc-mingw32/mm_utils.o] Error 1
sh-2.04$ make
c++ -I/c/grass/grass7/dist.i686-pc-mingw32/include -I/c/grass/extra/include -O2 -s -I/c/grass/extra/include -D_FILE_OFFSET_BITS=64 -DPACKAGE="“grasslibs”" -I/c/grass/grass7/dist.i686-pc-mingw32/include -o OBJ.i686-pc-mingw32/mm_utils.o -c mm_utils.cc
c++ -I/c/grass/grass7/dist.i686-pc-mingw32/include -I/c/grass/extra/include -O2 -s -I/c/grass/extra/include -D_FILE_OFFSET_BITS=64 -DPACKAGE="“grasslibs”" -I/c/grass/grass7/dist.i686-pc-mingw32/include -o OBJ.i686-pc-mingw32/rtimer.o -c rtimer.cc
rtimer.cc:38:26: sys/resource.h: No such file or directory
make: *** [OBJ.i686-pc-mingw32/rtimer.o] Error 1
In the two respective cases I commented out the #includes for sys/mman.h
and sys/resource.h and everything compiled fine. r.terraflow compiles fine
too. So I’ll simply remove those two #includes unless there’s any
objection?
Thanks for the feedback,
Paul