2008.08.23 16:46 "Re: [Tiff] creating sparse files......", by Bob Friesenhahn

Probably "tif_unix.c" should really be called "tif_posix.c". It does actually work under Windows using Window's underscore-prefixed POSIX

Well if it claims Posix compatibility, and then doesn't conform to the posix specifications, then I'd claim "it doesn't work".

I am not able to fix Microsoft Windows.

Which means that apparently the "ftruncate" call needs to be translated into chsize() by the library that pretends to provide posix compatibility on windows.

File truncation is not currently used.

If my suggestion doesn't work on windows, then I'm ok with #ifndef WINDOWS around my code. You (or someone else) was suggesting putting

Besides natively working on Windows, I am worried about cases such as when files are accessed over a network on a Windows-based file server or when files are written to a Windows FAT filesystem (such as a digital camera flash card). Insertion of 'holes' or null bytes is filesystem dependent and the OS instance performing the requests may not be the one which owns the filesystem doing the writing. For example, a Linux system may use CIFS to access a Windows system which updates a FAT filesystem.

Various special cases like this need to be demonstrated to work before the special optimization could be incorporated in libtiff. It also needs to be demonstrated that the special optimization does not cause any negative impact on write performance or later update performance.

Oh. You mentioned: "if it's YOUR application that becomes slower". Indeed, I'd feel bad about it. However, I'm used to this happening all the time. Every time I upgrade, things are becoming more bloated and slower. This doesn't only happen in "windows-land".

There are people on this list who depend on correct function of libtiff for their income. It is not a matter of feelings.

Bob
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Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/