.

t/neo/storage/fs1/cmd/fstail/xstrconv.go

@@ -3,7 +3,6 @@
 package main
 
 import (
-	"fmt"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -17,9 +16,12 @@ func pyQuote(s string) string {
 	return mem.String(out)
 }
 
+
+const hex = "0123456789abcdef"
+
 func pyQuoteBytes(b []byte) []byte {
 	s := mem.String(b)
-	buf := make([]byte, 0, len(s))
+	buf := make([]byte, 0, len(s) + 2/*quotes*/)
 
 	// smartquotes: choose ' or " as quoting character
 	// https://github.com/python/cpython/blob/v2.7.13-116-g1aa1803b3d/Objects/stringobject.c#L947
@@ -34,7 +36,7 @@ func pyQuoteBytes(b []byte) []byte {
 	for i, r := range s {
 		switch r {
 		case utf8.RuneError:
-			buf = append(buf, []byte(fmt.Sprintf("\\x%02x", s[i]))...)
+			buf = append(buf, '\\', 'x', hex[s[i]>>4], hex[s[i]&0xf])
 		case '\\', rune(quote):
 			buf = append(buf, '\\', byte(r))
 		case rune(noquote):
@@ -53,7 +55,7 @@ func pyQuoteBytes(b []byte) []byte {
 			switch {
 			case r < ' ':
 				// we already converted to \<letter> what python represents as such above
-				buf = append(buf, []byte(fmt.Sprintf("\\x%02x", s[i]))...)
+				buf = append(buf, '\\', 'x', hex[s[i]>>4], hex[s[i]&0xf])
 
 			default:
 				// we already handled ', " and (< ' ') above, so now it

t/neo/storage/fs1/cmd/fstail/xstrconv_test.go

@@ -15,9 +15,7 @@ func byterange(start, stop byte) []byte {
 	return b
 }
 
-func TestPyQuote(t *testing.T) {
-	// XXX -> global
-	testv := []struct {in, quoted string} {
+var pyQuoteTestv = []struct {in, quoted string} {
 	// empty
 	{``, `''`},
 
@@ -41,12 +39,21 @@ func TestPyQuote(t *testing.T) {
 
 	// invalid utf-8
 	{"\xd0a", `'\xd0a'`},
-	}
+}
 
-	for _, tt := range testv {
+func TestPyQuote(t *testing.T) {
+	for _, tt := range pyQuoteTestv {
 		quoted := pyQuote(tt.in)
 		if quoted != tt.quoted {
 			t.Errorf("pyQuote(%q) -> %s  ; want %s", tt.in, quoted, tt.quoted)
 		}
 	}
 }
+
+func BenchmarkPyQuote(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tt := range pyQuoteTestv {
+			pyQuote(tt.in)
+		}
+	}
+}