I wonder if Data might be a better tool for the job here since it is it’s own slice type and would avoid copying large amounts of data into temporary buffers.
> On May 8, 2017, at 16:47, Rick Mann via swift-users <swift-users@swift.org> > wrote: > > I have this C library that interacts with some hardware over the network that > produces a ton of data. It tells me up front the maximum size the data might > be so I can allocate a buffer for it, then does a bunch of network requests > downloading that data into the buffer, then tells me when it's done and what > the final, smaller size is. > > Thanks to previous discussions on the list, I settled on using a [UInt8] as > the buffer, because it let me avoid various .withUnsafePointer{} calls (I > need the unsafe buffer pointer to live outside the scope of the closures). > Unfortunately, When I go to shrink the buffer to its final size with: > > self.dataBuffer = Array(self.dataBuffer![0 ..< finalBufferSize]) > > This ends up taking over 2 minutes to complete (on an iPad Pro). > finalBufferSize is very large, 240 MB, but I think it's doing a very naive > copy. > > I've since worked around this problem, but is there any way to improve on > this? > > Thanks, > > -- > Rick Mann > rm...@latencyzero.com > > > _______________________________________________ > swift-users mailing list > swift-users@swift.org > https://lists.swift.org/mailman/listinfo/swift-users _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users