On Wed, Jul 25, 2018 at 08:41:00PM +0200, Torsten Bögershausen wrote: > On Tue, Jul 24, 2018 at 06:51:39AM -0400, Jeff King wrote: > > When we initially added the strbuf_readlink() function in > > b11b7e13f4 (Add generic 'strbuf_readlink()' helper function, > > 2008-12-17), the point was that we generally have a _guess_ > > as to the correct size based on the stat information, but we > > can't necessarily trust it. > > > > Over the years, a few callers have grown up that simply pass > > in 0, even though they have the stat information. Let's have > > them pass in their hint for consistency (and in theory > > efficiency, since it may avoid an extra resize/syscall loop, > > but neither location is probably performance critical). > > > > Note that st.st_size is actually an off_t, so in theory we > > need xsize_t() here. But none of the other callsites use it, > > and since this is just a hint, it doesn't matter either way > > (if we wrap we'll simply start with a too-small hint and > > then eventually complain when we cannot allocate the > > memory). > > Thanks a lot for the series. > > For the last paragraph I would actually vote the other way around - > how about something like this ? > Note that st.st_size is actually an off_t, so we should use > xsize_t() here. In pratise we don't expect links to be large like that, > but let's give a good example in the source code and use xsize_t() > whenever an off_t is converted into size_t. > This will make live easier whenever someones diggs into 32/64 bit > "conversion safetyness" I actually don't mind using xsize_t(), but if we're going into I think we should do it consistently. I.e., as a patch on top with that explanation. -Peff
