They're used more than it looks like they are. One of the largest ways they're used in the Store namespace is *to create FileStream objects*...which is such a waste of an allocation. A small test program I wrote created ~1000 FileInfo objects every minute, most of that thanks to merging. Considering the other object allocations in the library, though, it's unlikely removing them *alone* will do anything measurable to performance. But I disagree that it shouldn't be a concern. That kind of attitude will kill our performance if applied to other areas of the code.
Thanks, Christopher On Thu, Jun 14, 2012 at 2:23 PM, Troy Howard <thowar...@gmail.com> wrote: > +1 on the string vs DirectoryInfo overload, Iatmar > > Re: Comments and JVM, I'd suggest editing the .NET comments to remove > Java specific recommendations/concerns. We're not running on the JVM, > so consumes of our code don't need that info. > > Re: GC pressure on the File/DirectoryInfo objects.. There's so few of > them it really doesn't make a difference. That aspect of their usage > should not be a concern. A greater concern is that they don't really > support the full range of Win32API file access (eg long paths, etc). > > Thanks, > Troy > > > On Thu, Jun 14, 2012 at 9:39 AM, Christopher Currens > <currens.ch...@gmail.com> wrote: > > That comment is correct. We don't have support for NIOFSDirectory in > .NET > > (and the JVM support for it in windows has a major bug). We also don't > > support MMapDirectory, because we haven't bothered to support it yet. I > > think digy ported it once, but it didn't add any speed benefits, and was > > actually fairly slower than the FSDirectory classes. > > > > It wasn't that long ago that we had the string constructors for Directory > > classes. I think they were in the java code and then replace with File > > (DirectoryInfo for .NET). I've always hated passing in DirectoryInfo, > and > > I don't really understand why it's in the code. It doesn't seem to give > > much added benefit, if any. You can pass a string that is a path to an > > existing file and it will still create the DirectoryInfo object. I would > > think (but don't know) it would be better for performance to *not* use > the > > File and Directory classes (I'm actually not sure how deep the usages of > > these classes go, so I'm not sure what difference it would make), since > it > > results in added pressure on the GC with the extra object creations. > > > > +1 to this. > > > > On Thu, Jun 14, 2012 at 5:25 AM, Itamar Syn-Hershko <ita...@code972.com > >wrote: > > > >> I'd assume so, at least partially > >> > >> I just copy-pasted from one method below > >> > >> On Thu, Jun 14, 2012 at 2:52 PM, Stefan Bodewig <bode...@apache.org> > >> wrote: > >> > >> > On 2012-06-14, <synhers...@apache.org> wrote: > >> > > >> > >> /// <p/>Currently this returns <see > >> > cref="SimpleFSDirectory" /> as > >> > >> /// NIOFSDirectory is currently not supported. > >> > >> /// > >> > >> /// <p/><b>NOTE</b>: this method may suddenly change > >> which > >> > >> /// implementation is returned from release to > release, > >> in > >> > >> /// the event that higher performance defaults become > >> > >> /// possible; if the precise implementation is > important > >> to > >> > >> /// your application, please instantiate it directly, > >> > >> /// instead. On 64 bit systems, it may also good to > >> > >> /// return <see cref="MMapDirectory" />, but this is > >> > disabled > >> > >> /// because of officially missing unmap support in > Java. > >> > >> /// For optimal performance you should consider using > >> > >> /// this implementation on 64 bit JVMs. > >> > > >> > Does this apply to the .NET code? > >> > > >> > Stefan > >> > > >> > > >> >
