2016.07.03 17:27 "Re: [Tiff] No memcpy() in TIFFRead/WriteEncodedStrip/Tile in uncompressed case", by Even Rouault
Le dimanche 03 juillet 2016 19:20:13, Tom Lane a écrit:
When profiling I/O in the uncompressed case, I noticed that TIFFRead/WriteEncodedStrip/Tile used memcpy() to copy the data between the user provided buffer and the tif_rawdata intermediate buffer. I've committed an improvement to avoid that: https://trac.osgeo.org/gdal/changeset/34533 It works fine in my testing, but I'm not sure if I may have forgotten corner cases in the use of the API that would need additional checks and you may be aware of.
Seems like in the write case, you've added a new assumption that it's okay for the library to clobber the user-supplied buffer contents. I'm dubious about that, the more so since it only happens in some cases.
Actually, the clobbering already happened (and is indeed a pain to deal with on the application side). The
/* swab if needed - note that source buffer will be altered */
tif->tif_postdecode( tif, (uint8*) data, cc );
was already done in the general case: https://github.com/vadz/libtiff/blob/Release-v4-0-6/libtiff/tif_write.c#L265 and
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