Merge pull request #20 from bet365/escape

added ,escape option which fixes #17

README.md

@@ -100,7 +100,8 @@ There are a couple of subtle ways you can configure the encoders.
 * It supports the same `json:"tag,options"` syntax as the stdlib, but not the same options. Currently the options you have are
     - `,stringer`, which instead of the standard serialization method for a given type, nominates that its `.String()` function is invoked instead to provide the serialization value.
     - `,raw`, which allows byteslice-like items (like `[]byte` and `string`) to be written to the buffer directly with no conversion, quoting or otherwise. `nil` or empty fields annotated as `raw` will output `null`. 
-    - `.encoder` which instead of the standard serialization method for a given type, nominates that its `.JSONEncode(*jingo.Buffer)` function is invoked instead. From there you can manually write to the buffer for that particular field. The interface you need to comply with is exported as `jingo.JSONEncoder`. 
+    - `,encoder` which instead of the standard serialization method for a given type, nominates that its `.JSONEncode(*jingo.Buffer)` function is invoked instead. From there you can manually write to the buffer for that particular field. The interface you need to comply with is exported as `jingo.JSONEncoder`. 
+    - `,escape`, which safely escapes `"` and `\` characters to valid JSON whilst writing. To get the same functionality when using `SliceEncoder` on its own, use `jingo.EscapeString` to initialize the encoder - e.g `NewSliceEncoder([]jingo.EscapeString)` - instead of `string` directly. There is obviously a performance impact on the write speed using this option, the benchmarks show it takes twice the time of a standard string write, so whilst it is still faster than using the stdlib, to get the best performance it is recommended to only be used when needed and only then when the escaping work can't be done up-front.
 
 ## How does it work
 

buffer.go

@@ -25,9 +25,15 @@ func (b *Buffer) Write(v []byte) (int, error) {
 	return len(v), nil
 }
 
+// WriteString writes a string to the buffer
+func (b *Buffer) WriteString(v string) {
+	b.Bytes = append(b.Bytes, v...)
+}
+
 // WriteByte writes a single byte into the output buffer
-func (b *Buffer) WriteByte(v byte) {
+func (b *Buffer) WriteByte(v byte) error {
 	b.Bytes = append(b.Bytes, v)
+	return nil
 }
 
 // Reset allows this to be reused by emptying

jingo_test.go

@@ -25,8 +25,9 @@ type all struct {
 	PropFloat64 float64 `json:"propFloat64,stringer"`
 	PropString  string  `json:"propString"`
 	PropStruct  struct {
-		PropNames []string  `json:"propName"`
-		PropPs    []*string `json:"ps"`
+		PropNames        []string  `json:"propName"`
+		PropPs           []*string `json:"ps"`
+		PropNamesEscaped []string  `json:"propNameEscaped,escape"`
 	} `json:"propStruct"`
 	PropEncode     encode0  `json:"propEncode,encoder"`
 	PropEncodeP    *encode0 `json:"propEncodeP,encoder"`
@@ -53,7 +54,7 @@ func (e *encode1) JSONEncode(w *Buffer) {
 	}
 }
 
-func ExampleJsonAll() {
+func Example() {
 
 	enc := NewStructEncoder(all{})
 	b := NewBufferFromPool()
@@ -75,11 +76,13 @@ func ExampleJsonAll() {
 		PropFloat64: 2799999999888.28293031999999,
 		PropString:  "thirty two thirty four",
 		PropStruct: struct {
-			PropNames []string  `json:"propName"`
-			PropPs    []*string `json:"ps"`
+			PropNames        []string  `json:"propName"`
+			PropPs           []*string `json:"ps"`
+			PropNamesEscaped []string  `json:"propNameEscaped,escape"`
 		}{
-			PropNames: []string{"a name", "another name", "another"},
-			PropPs:    []*string{&s, nil, &s},
+			PropNames:        []string{"a name", "another name", "another"},
+			PropPs:           []*string{&s, nil, &s},
+			PropNamesEscaped: []string{"one\\two\\,three\"", "\"four\\five\\,six\""},
 		},
 		PropEncode:  encode0{'1'},
 		PropEncodeP: &encode0{'2'},
@@ -89,10 +92,10 @@ func ExampleJsonAll() {
 	fmt.Println(b.String())
 
 	// Output:
-	// {"propBool":false,"propInt":1234567878910111212,"propInt8":123,"propInt16":12349,"propInt32":1234567891,"propInt64":1234567878910111213,"propUint":12345678789101112138,"propUint8":255,"propUint16":12345,"propUint32":1234567891,"propUint64":12345678789101112139,"propFloat32":21.232426,"propFloat64":2799999999888.2827,"propString":"thirty two thirty four","propStruct":{"propName":["a name","another name","another"],"ps":["test pointer string",null,"test pointer string"]},"propEncode":1,"propEncodeP":2,"propEncodenilP":null,"propEncodeS":134}
+	// {"propBool":false,"propInt":1234567878910111212,"propInt8":123,"propInt16":12349,"propInt32":1234567891,"propInt64":1234567878910111213,"propUint":12345678789101112138,"propUint8":255,"propUint16":12345,"propUint32":1234567891,"propUint64":12345678789101112139,"propFloat32":21.232426,"propFloat64":2799999999888.2827,"propString":"thirty two thirty four","propStruct":{"propName":["a name","another name","another"],"ps":["test pointer string",null,"test pointer string"],"propNameEscaped":["one\\two\\,three\"","\"four\\five\\,six\""]},"propEncode":1,"propEncodeP":2,"propEncodenilP":null,"propEncodeS":134}
 }
 
-func ExampleRaw() {
+func Example_testStruct2() {
 
 	type testStruct2 struct {
 		Raw  []byte `json:"raw,raw"`
@@ -138,6 +141,35 @@ func Test_NilStruct(t *testing.T) {
 	}
 }
 
+type StructWithEscapes struct {
+	String      string   `json:"str,escape"`
+	StringArray []string `json:"str-array,escape"`
+}
+
+func Test_StructWithEscapes(t *testing.T) {
+	es := StructWithEscapes{
+		String:      "one\\two\\,three\"",
+		StringArray: []string{"one\\two", "three\\,four"},
+	}
+
+	wantJSON := `{"str":"one\\two\\,three\"","str-array":["one\\two","three\\,four"]}`
+
+	var enc = NewStructEncoder(StructWithEscapes{})
+	buf := NewBufferFromPool()
+	enc.Marshal(&es, buf)
+	resultJSON := buf.String()
+
+	// Ensure JSON is valid.
+	if !json.Valid([]byte(resultJSON)) {
+		t.Errorf("Not valid JSON:" + resultJSON)
+	}
+
+	// Compare result
+	if resultJSON != wantJSON {
+		t.Errorf("Test_StructWithScapes Failed: want JSON:" + wantJSON + " got JSON:" + resultJSON)
+	}
+}
+
 type UnicodeObject struct {
 	Chinese string `json:"chinese"`
 	Emoji   string `json:"emoji"`
@@ -343,6 +375,26 @@ func BenchmarkSlice(b *testing.B) {
 	}
 }
 
+func BenchmarkSliceEscape(b *testing.B) {
+
+	ss := []string{
+		"a name",
+		"another name",
+		"another",
+		"and one more",
+		"last one, promise",
+	}
+
+	var enc = NewSliceEncoder([]EscapeString{})
+
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		buf := NewBufferFromPool()
+		enc.Marshal(&ss, buf)
+		buf.ReturnToPool()
+	}
+}
+
 func BenchmarkSliceStdLib(b *testing.B) {
 	ss := []string{
 		"a name",
@@ -384,11 +436,13 @@ var fake = &all{
 	PropFloat64: 2799999999888.28293031999999,
 	PropString:  "thirty two thirty four",
 	PropStruct: struct {
-		PropNames []string  `json:"propName"`
-		PropPs    []*string `json:"ps"`
+		PropNames        []string  `json:"propName"`
+		PropPs           []*string `json:"ps"`
+		PropNamesEscaped []string  `json:"propNameEscaped,escape"`
 	}{
-		PropNames: []string{"a name", "another name", "another"},
-		PropPs:    []*string{&s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s},
+		PropNames:        []string{"a name", "another name", "another"},
+		PropPs:           []*string{&s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s, nil, &s},
+		PropNamesEscaped: []string{"one\\two\\,three\"", "\"four\\five\\,six\""},
 	},
 }
 
@@ -443,6 +497,51 @@ func NewSmallPayload() *SmallPayload {
 	return s
 }
 
+var smallPayload = NewSmallPayload()
+
+func BenchmarkSmallPayload(b *testing.B) {
+
+	e := NewStructEncoder(SmallPayload{})
+
+	buf := NewBufferFromPool()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		e.Marshal(smallPayload, buf)
+		buf.Reset()
+	}
+}
+
+func BenchmarkSmallPayloadStdLib(b *testing.B) {
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		json.Marshal(smallPayload)
+	}
+}
+
+var largePayload = NewLargePayload()
+
+func BenchmarkLargePayload(b *testing.B) {
+
+	e := NewStructEncoder(LargePayload{})
+	buf := NewBufferFromPool()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		e.Marshal(largePayload, buf)
+		buf.Reset()
+	}
+}
+
+func BenchmarkLargePayloadStdLib(b *testing.B) {
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		json.Marshal(largePayload)
+	}
+}
+
 //
 //
 //

ptrconvert.go

@@ -95,3 +95,25 @@ func ptrStringToBuf(v unsafe.Pointer, b *Buffer) {
 func ptrTimeToBuf(v unsafe.Pointer, b *Buffer) {
 	b.Bytes = (*time.Time)(v).AppendFormat(b.Bytes, time.RFC3339Nano)
 }
+
+func ptrEscapeStringToBuf(v unsafe.Pointer, w *Buffer) {
+	bs := *(*string)(v)
+
+	pos := 0
+	for i := 0; i < len(bs); i++ {
+		switch bs[i] {
+		case '\\', '"':
+			if pos < i {
+				w.WriteString(bs[pos:i])
+			}
+			pos = i + 1
+
+			w.WriteByte('\\')
+			w.WriteByte(bs[i])
+		}
+	}
+
+	if pos < len(bs) {
+		w.WriteString(bs[pos:])
+	}
+}