From 95a11c7381e01fdaaf34e25b82db0632081ab74e Mon Sep 17 00:00:00 2001 From: Ian Davis Date: Mon, 10 Sep 2018 12:13:09 +0100 Subject: [PATCH] net/url: remove an allocation for short strings in escape MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use a 64 byte array to avoid an allocation on the assumption that most url escaping is performed on short strings. Also adds a fast path for escaping strings whose only replacements are spaces which is common in query components. Adds benchmarks for QueryEscape, PathEscape, QueryUnescape and PathUnescape but no optimizations are include for the unescape functions so I don't include those benchmark results here. Reduces allocations by 10% in the existing String benchmark with a modest performance increase. name old time/op new time/op delta QueryEscape/#00-8 64.6ns ± 1% 43.8ns ± 0% -32.14% (p=0.000 n=9+9) QueryEscape/#01-8 276ns ± 3% 249ns ± 0% -9.62% (p=0.000 n=10+7) QueryEscape/#02-8 176ns ± 2% 155ns ± 3% -12.21% (p=0.000 n=10+10) QueryEscape/#03-8 388ns ± 1% 362ns ± 0% -6.55% (p=0.000 n=10+8) QueryEscape/#04-8 2.32µs ± 2% 2.27µs ± 2% -2.26% (p=0.001 n=10+10) PathEscape/#00-8 78.0ns ± 3% 63.4ns ± 1% -18.69% (p=0.000 n=10+10) PathEscape/#01-8 276ns ± 2% 260ns ± 0% -6.01% (p=0.000 n=10+10) PathEscape/#02-8 175ns ± 0% 153ns ± 0% -12.53% (p=0.000 n=8+10) PathEscape/#03-8 389ns ± 2% 361ns ± 0% -7.21% (p=0.000 n=10+9) PathEscape/#04-8 2.30µs ± 2% 2.27µs ± 1% -1.33% (p=0.001 n=9+10) String-8 3.56µs ± 4% 3.42µs ± 7% -4.00% (p=0.003 n=10+10) name old alloc/op new alloc/op delta QueryEscape/#00-8 16.0B ± 0% 8.0B ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#01-8 128B ± 0% 64B ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#02-8 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#03-8 128B ± 0% 64B ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#04-8 832B ± 0% 832B ± 0% ~ (all equal) PathEscape/#00-8 32.0B ± 0% 16.0B ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#01-8 128B ± 0% 64B ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#02-8 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#03-8 128B ± 0% 64B ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#04-8 704B ± 0% 704B ± 0% ~ (all equal) String-8 1.84kB ± 0% 1.66kB ± 0% -9.57% (p=0.000 n=10+10) name old allocs/op new allocs/op delta QueryEscape/#00-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#01-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#02-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#03-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) QueryEscape/#04-8 2.00 ± 0% 2.00 ± 0% ~ (all equal) PathEscape/#00-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#01-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#02-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#03-8 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.000 n=10+10) PathEscape/#04-8 2.00 ± 0% 2.00 ± 0% ~ (all equal) String-8 69.0 ± 0% 61.0 ± 0% -11.59% (p=0.000 n=10+10) Updates #17860 Change-Id: I45c5e9d40b242f874c61f6ccc73bf94c494bb868 Reviewed-on: https://go-review.googlesource.com/134296 Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick --- src/net/url/url.go | 21 +++++++- src/net/url/url_test.go | 103 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 123 insertions(+), 1 deletion(-) diff --git a/src/net/url/url.go b/src/net/url/url.go index 4943ea6d67..b678b82352 100644 --- a/src/net/url/url.go +++ b/src/net/url/url.go @@ -304,7 +304,26 @@ func escape(s string, mode encoding) string { return s } - t := make([]byte, len(s)+2*hexCount) + var buf [64]byte + var t []byte + + required := len(s) + 2*hexCount + if required <= len(buf) { + t = buf[:required] + } else { + t = make([]byte, required) + } + + if hexCount == 0 { + copy(t, s) + for i := 0; i < len(s); i++ { + if s[i] == ' ' { + t[i] = '+' + } + } + return string(t) + } + j := 0 for i := 0; i < len(s); i++ { switch c := s[i]; { diff --git a/src/net/url/url_test.go b/src/net/url/url_test.go index 19d4d636d6..231340a9eb 100644 --- a/src/net/url/url_test.go +++ b/src/net/url/url_test.go @@ -1754,3 +1754,106 @@ func TestInvalidUserPassword(t *testing.T) { t.Errorf("error = %q; want substring %q", got, wantsub) } } + +var escapeBenchmarks = []struct { + unescaped string + query string + path string +}{ + { + unescaped: "one two", + query: "one+two", + path: "one%20two", + }, + { + unescaped: "Фотки собак", + query: "%D0%A4%D0%BE%D1%82%D0%BA%D0%B8+%D1%81%D0%BE%D0%B1%D0%B0%D0%BA", + path: "%D0%A4%D0%BE%D1%82%D0%BA%D0%B8%20%D1%81%D0%BE%D0%B1%D0%B0%D0%BA", + }, + + { + unescaped: "shortrun(break)shortrun", + query: "shortrun%28break%29shortrun", + path: "shortrun%28break%29shortrun", + }, + + { + unescaped: "longerrunofcharacters(break)anotherlongerrunofcharacters", + query: "longerrunofcharacters%28break%29anotherlongerrunofcharacters", + path: "longerrunofcharacters%28break%29anotherlongerrunofcharacters", + }, + + { + unescaped: strings.Repeat("padded/with+various%characters?that=need$some@escaping+paddedsowebreak/256bytes", 4), + query: strings.Repeat("padded%2Fwith%2Bvarious%25characters%3Fthat%3Dneed%24some%40escaping%2Bpaddedsowebreak%2F256bytes", 4), + path: strings.Repeat("padded%2Fwith+various%25characters%3Fthat=need$some@escaping+paddedsowebreak%2F256bytes", 4), + }, +} + +func BenchmarkQueryEscape(b *testing.B) { + for _, tc := range escapeBenchmarks { + b.Run("", func(b *testing.B) { + b.ReportAllocs() + var g string + for i := 0; i < b.N; i++ { + g = QueryEscape(tc.unescaped) + } + b.StopTimer() + if g != tc.query { + b.Errorf("QueryEscape(%q) == %q, want %q", tc.unescaped, g, tc.query) + } + + }) + } +} + +func BenchmarkPathEscape(b *testing.B) { + for _, tc := range escapeBenchmarks { + b.Run("", func(b *testing.B) { + b.ReportAllocs() + var g string + for i := 0; i < b.N; i++ { + g = PathEscape(tc.unescaped) + } + b.StopTimer() + if g != tc.path { + b.Errorf("PathEscape(%q) == %q, want %q", tc.unescaped, g, tc.path) + } + + }) + } +} + +func BenchmarkQueryUnescape(b *testing.B) { + for _, tc := range escapeBenchmarks { + b.Run("", func(b *testing.B) { + b.ReportAllocs() + var g string + for i := 0; i < b.N; i++ { + g, _ = QueryUnescape(tc.query) + } + b.StopTimer() + if g != tc.unescaped { + b.Errorf("QueryUnescape(%q) == %q, want %q", tc.query, g, tc.unescaped) + } + + }) + } +} + +func BenchmarkPathUnescape(b *testing.B) { + for _, tc := range escapeBenchmarks { + b.Run("", func(b *testing.B) { + b.ReportAllocs() + var g string + for i := 0; i < b.N; i++ { + g, _ = PathUnescape(tc.path) + } + b.StopTimer() + if g != tc.unescaped { + b.Errorf("PathUnescape(%q) == %q, want %q", tc.path, g, tc.unescaped) + } + + }) + } +} -- 2.48.1