On Mon, Apr 2, 2018 at 2:48 PM, Michael Banck <michael.ba...@credativ.de> wrote:
> Hi! > > On Sun, Apr 01, 2018 at 05:27:21PM +0200, Magnus Hagander wrote: > > It might be a micro-optimisation, but ISTM that we shouldn't do the > > basename(palloc(fn)) in is_heap_file() unless we actually need it -- so > not > > at the top of the function. (And surely "." and ".." should not occur > here? > > I think that's a result of copy/paste from the online checksum patch? > > > > We also do exactly the same basename(palloc(fn)) in sendFile(). Can we > > find a way to reuse that duplication? Perhaps we want to split it into > the > > two pieces already out in sendFile() and pass it in as separate > parameters? > > I've done the latter now, although it looks a bit weird that the second > argument data is a subset of the first. I couldn't find another way to > not have it done twice, though. > I agree, but I think it's still cleaner. On further look, there is actually no need to pstrdup() at all -- we never used the modified part of the string anyway, because we don't care about the oid (unlike pg_verify_checksums). So I adjusted the patch by that. > If not then this second one should at least only be done inside the if > > (verify_checksums). > > We can't have both, as we need to call the is_heap_file() function in > order to determine whether we should verify the checksums. > Right. I realize that -- thus the "if not". But I guess I was not clear in what I meant -- see attached file for it. > There is a bigger problem next to that though -- I believe basename() > does > > not exist on Win32. I haven't tested it, but there is zero documentation > of > > it existing, which usually indicates it doesn't. That's the part that > > definitely needs to get fixed. > > > > I think you need to look into the functionality in port/path.c, in > > particular last_dir_separator()? > > Thanks for the pointer, I've used that now; I mentioned before that > basename() might be a portability hazard, but couldn't find a good > substitute myself. > Yeah, I have a recollection somewhere of running into this before, but I couldn't find any references. But the complete lack of docs about it on msdn.microsoft.com is a clear red flag :) > > V6 of the patch is attached. > > Excellent. I've done some mangling on it: * Changed the is_heap_file to is_checksummed_file (and the associtaed struct name), because this is really what it's about (we for example verify checksums on indexes, which are clearly not heaps) * Moved the list of files to the top of the file next to the other lists of files/directories * Added missing function prototype at the top, and changed the parameter names to be a bit more clear * Added some comments * Changed the logic around the checksum-check to avoid the pstrdup() and to not call the path functions unless necessary (per comment above) * "filen" -> "file" in message * xlog.h does not need to be included * pgindent Remaining question: The check for (cnt % BLCKSZ != 0) currently does "continue", which means that this block of data isn't actually sent to the client at all, which seems completely wrong. We only want to prevent checksum validations. I have moved the check up a bit, and refactored it so it continues to do the actual transmission of the file if this path is hit. I have pushed an updated patch with those changes. Please review the result and let me know I broke something :) Thanks!! -- Magnus Hagander Me: https://www.hagander.net/ <http://www.hagander.net/> Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>
