I tracked this down (at least it was the source of a slow goimports for me) and put up a CL at https://go-review.googlesource.com/c/tools/+/132598/ .The issue was that it's eventually exec'ing the go command for every import in the presence of modules, which adds up quickly and also doesn't easily show up in profiling.
- Todd On Saturday, November 10, 2018 at 2:46:42 AM UTC-6, rog wrote: > > I will add that I regularly see goimports with modules take many seconds > to run. I'm using acmego and I sometimes end up needing to switch that off > because it corrupts text seconds after a save. > > On Fri, 9 Nov 2018, 3:26 pm Joseph Lorenzini <jal...@gmail.com > <javascript:> wrote: > >> Hi Ian/Russ, >> >> I should have clarified that I was doing goimports -l on a directory of >> go packages. I know that's atypical. Its definitely not 30 seconds on a >> single file. It is however slower on a single file. >> >> Here are the numbers for a single file using the official goimports tool: >> >> goimports with go.mod: 101 milliseconds >> goimports without a go.mod: 19 milliseconds >> >> And Ian, here's the numbers for module aware go imports >> >> goimports (module aware) with a go.mod: 306 milliseconds >> goimports(module aware) without a go.mod: 73 milliseconds >> >> Russ in regards to reproducing the problem, here's my go.mod file: >> https://gist.github.com/jaloren/6a5908507794e2fec28c403af506855f. As for >> the input file, it doesn't matter what the go file is as long as the >> imports in the file are out of order. The slow down happens when goimports >> need to rearrange the imports so standard packages are on top and third >> party packages are on the bottom. >> >> Hope that helps. >> >> Joe >> >> >> >> >> >> On Thu, Nov 8, 2018 at 2:36 PM Russ Cox <r...@golang.org <javascript:>> >> wrote: >> >>> On Wed, Nov 7, 2018 at 7:43 PM Joseph Lorenzini <jal...@gmail.com >>> <javascript:>> wrote: >>> >>>> If have a go.mod, goimports takes 30 seconds to run. If I remove the >>>> go.mod, then goimports takes half a second to run. Is this expected? Is >>>> goimports trying to do something with the packages found in go.mod? Is >>>> there a way to configure goimports so it ignores go.mod? >>>> >>> >>> That's not supposed to happen. It's hard to say what's going on with so >>> little detail. >>> Can you give us a concrete go.mod and input.go file that causes >>> 'goimports input.go' to take 30 seconds? >>> >>> It looks like we dropped the ball and did not commit >>> https://go-review.googlesource.com/c/tools/+/128362/2/imports/fix.go, >>> which we should probably do. But that was about better results, not >>> speed. >>> >>> Thanks. >>> Russ >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
