On 06/22/2012 08:09 PM, Paul Eggert wrote: >>From a filesystem point of view, would it be > more efficient to invoke ftruncate at the end of > writing, rather than at the beginning? That way, > if the file already exists and is of the right size, > it won't need to be reallocated. We're not trying > to write any holes, so this optimization should be > valid. > > Please don't let this comment slow you down, as your > patch is fine as-is. I'm mainly asking because I was > wondering about the issue in general.
Hmm, I suppose at the writing stage, truncating after writing could be more efficient. Though if we're updating a split set, and the new set had some new files, then the new split set could be more likely be on separate parts of the disk, hence slowing future processing of the split set? You could also argue that you should free up as much place as possible and let the file system decide where best to allocate stuff, which can change over time. I'd err on the side of simplicity here. cheers, Pádraig.
