From a7516a9dfa45ee44dd1d65e1923ae0837924f647 Mon Sep 17 00:00:00 2001 From: Lucas Bremgartner Date: Tue, 10 Sep 2019 18:52:02 +0000 Subject: [PATCH] encoding/json: fix and optimize marshal for quoted string MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since Go 1.2 every string can be marshaled to JSON without error even if it contains invalid UTF-8 byte sequences. Therefore there is no need to use Marshal again for the only reason of enclosing the string in double quotes. Not using Marshal here also removes the error check as there has not been a way for Marshal to fail anyway. name old time/op new time/op delta Issue34127-4 360ns ± 3% 200ns ± 3% -44.56% (p=0.008 n=5+5) name old alloc/op new alloc/op delta Issue34127-4 56.0B ± 0% 40.0B ± 0% -28.57% (p=0.008 n=5+5) name old allocs/op new allocs/op delta Issue34127-4 3.00 ± 0% 2.00 ± 0% -33.33% (p=0.008 n=5+5) Fixes #34154 Change-Id: Ib60dc11980f9b20d8bef2982de7168943d632263 GitHub-Last-Rev: 9b0ac1d4c5318b6bf9ed7930320f2bd755f9939c GitHub-Pull-Request: golang/go#34127 Reviewed-on: https://go-review.googlesource.com/c/go/+/193604 Reviewed-by: Daniel Martí Run-TryBot: Daniel Martí TryBot-Result: Gobot Gobot --- bench_test.go | 16 ++++++++++++++++ encode.go | 10 +++++----- stream_test.go | 10 ++++++++++ 3 files changed, 31 insertions(+), 5 deletions(-) diff --git a/bench_test.go b/bench_test.go index f2592e3..f92d39f 100644 --- a/bench_test.go +++ b/bench_test.go @@ -297,6 +297,22 @@ func BenchmarkIssue10335(b *testing.B) { }) } +func BenchmarkIssue34127(b *testing.B) { + b.ReportAllocs() + j := struct { + Bar string `json:"bar,string"` + }{ + Bar: `foobar`, + } + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + if _, err := Marshal(&j); err != nil { + b.Fatal(err) + } + } + }) +} + func BenchmarkUnmapped(b *testing.B) { b.ReportAllocs() j := []byte(`{"s": "hello", "y": 2, "o": {"x": 0}, "a": [1, 99, {"x": 1}]}`) diff --git a/encode.go b/encode.go index 2e1f56f..0758b2f 100644 --- a/encode.go +++ b/encode.go @@ -600,11 +600,11 @@ func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) { return } if opts.quoted { - sb, err := Marshal(v.String()) - if err != nil { - e.error(err) - } - e.string(string(sb), opts.escapeHTML) + b := make([]byte, 0, v.Len()+2) + b = append(b, '"') + b = append(b, []byte(v.String())...) + b = append(b, '"') + e.stringBytes(b, opts.escapeHTML) } else { e.string(v.String(), opts.escapeHTML) } diff --git a/stream_test.go b/stream_test.go index e3317dd..ebb4f23 100644 --- a/stream_test.go +++ b/stream_test.go @@ -118,6 +118,11 @@ func TestEncoderSetEscapeHTML(t *testing.T) { Ptr strPtrMarshaler }{`""`, `""`} + // https://golang.org/issue/34154 + stringOption := struct { + Bar string `json:"bar,string"` + }{`foobar`} + for _, tt := range []struct { name string v interface{} @@ -137,6 +142,11 @@ func TestEncoderSetEscapeHTML(t *testing.T) { `{"NonPtr":"\u003cstr\u003e","Ptr":"\u003cstr\u003e"}`, `{"NonPtr":"","Ptr":""}`, }, + { + "stringOption", stringOption, + `{"bar":"\"\u003chtml\u003efoobar\u003c/html\u003e\""}`, + `{"bar":"\"foobar\""}`, + }, } { var buf bytes.Buffer enc := NewEncoder(&buf)