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| author | Emmanuel T Odeke <emmanuel@orijtech.com> | 2022-09-09 09:59:21 -0700 |
|---|---|---|
| committer | Emmanuel Odeke <emmanuel@orijtech.com> | 2022-09-14 16:11:21 +0000 |
| commit | 4baa486983204fdff64f80809627f79a538d8d82 (patch) | |
| tree | f410368cd3fb61dcdd3ec725f06fef3aa2ef3496 /src/cmd/compile/internal/syntax | |
| parent | a7e9a379e970f0c48aae47da1778213f646b5f45 (diff) | |
| download | go-4baa486983204fdff64f80809627f79a538d8d82.tar.xz | |
all: remove unnecessary allocations from w.WriteString(fmt.Sprint*(...)) by fmt.Fprint*(w, ...)
Noticed in a manual audit from a customer codebase that the pattern
w.WriteString(fmt.Sprint*(args...))
was less efficient and in most cases we can just invoke:
fmt.Fprint*(w, args...)
and from the simple benchmarks we can see quick wins in all dimensions:
$ benchstat before.txt after.txt
name old time/op new time/op delta
DetailString-8 5.48µs ±23% 4.40µs ±11% -19.79% (p=0.000 n=20+17)
name old alloc/op new alloc/op delta
DetailString-8 2.63kB ± 0% 2.11kB ± 0% -19.76% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
DetailString-8 63.0 ± 0% 50.0 ± 0% -20.63% (p=0.000 n=20+20)
Change-Id: I47a2827cd34d6b92644900b1bd5f4c0a3287bdb1
Reviewed-on: https://go-review.googlesource.com/c/go/+/429861
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: hopehook <hopehook@golangcn.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Diffstat (limited to 'src/cmd/compile/internal/syntax')
| -rw-r--r-- | src/cmd/compile/internal/syntax/scanner_test.go | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/cmd/compile/internal/syntax/scanner_test.go b/src/cmd/compile/internal/syntax/scanner_test.go index 2deb3bbf84..450ec1ff8a 100644 --- a/src/cmd/compile/internal/syntax/scanner_test.go +++ b/src/cmd/compile/internal/syntax/scanner_test.go @@ -88,10 +88,10 @@ func TestEmbeddedTokens(t *testing.T) { // make source var buf bytes.Buffer for i, s := range sampleTokens { - buf.WriteString("\t\t\t\t"[:i&3]) // leading indentation - buf.WriteString(s.src) // token - buf.WriteString(" "[:i&7]) // trailing spaces - buf.WriteString(fmt.Sprintf("/*line foo:%d */ // bar\n", i)) // comments + newline (don't crash w/o directive handler) + buf.WriteString("\t\t\t\t"[:i&3]) // leading indentation + buf.WriteString(s.src) // token + buf.WriteString(" "[:i&7]) // trailing spaces + fmt.Fprintf(&buf, "/*line foo:%d */ // bar\n", i) // comments + newline (don't crash w/o directive handler) } // scan source |