go/internal/gcimporter: avoid setting unnecessary lines in fakeFileSet
As discussed in golang/go#46586, the gcimporter spends large portion of
time just validating fake lines.
Fix this by only setting the lines we need. Benchcmd results for
TestImportStdLib:
name old time/op new time/op delta
TestImportStdLib 1.11s ±40% 0.57s ±58% -48.17% (p=0.000 n=18+18)
name old user-time/op new user-time/op delta
TestImportStdLib 1.24s ±46% 0.71s ±61% -42.84% (p=0.000 n=18+18)
name old sys-time/op new sys-time/op delta
TestImportStdLib 249ms ±64% 139ms ±47% -44.19% (p=0.000 n=19+18)
name old peak-RSS-bytes new peak-RSS-bytes delta
TestImportStdLib 80.1MB ±24% 86.6MB ±13% +8.06% (p=0.001 n=20+20)
Fixes golang/go#46586
Change-Id: I5ef99ea9f242fc80d2d17750a8d9b28f7fc71245
Reviewed-on: https://go-review.googlesource.com/c/tools/+/357291
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
diff --git a/go/internal/gcimporter/iimport.go b/go/internal/gcimporter/iimport.go
index 58d4e2b..806030d 100644
--- a/go/internal/gcimporter/iimport.go
+++ b/go/internal/gcimporter/iimport.go
@@ -159,9 +159,10 @@
fake: fakeFileSet{
fset: fset,
- files: make(map[string]*token.File),
+ files: make(map[string]*fileInfo),
},
}
+ defer p.fake.setLines() // set lines for files in fset
for i, pt := range predeclared() {
p.typCache[uint64(i)] = pt
