vendor files

vendor/github.com/mailru/easyjson/gen/decoder.go

@@ -0,0 +1,489 @@
+package gen
+
+import (
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+	"unicode"
+
+	"github.com/mailru/easyjson"
+)
+
+// Target this byte size for initial slice allocation to reduce garbage collection.
+const minSliceBytes = 64
+
+func (g *Generator) getDecoderName(t reflect.Type) string {
+	return g.functionName("decode", t)
+}
+
+var primitiveDecoders = map[reflect.Kind]string{
+	reflect.String:  "in.String()",
+	reflect.Bool:    "in.Bool()",
+	reflect.Int:     "in.Int()",
+	reflect.Int8:    "in.Int8()",
+	reflect.Int16:   "in.Int16()",
+	reflect.Int32:   "in.Int32()",
+	reflect.Int64:   "in.Int64()",
+	reflect.Uint:    "in.Uint()",
+	reflect.Uint8:   "in.Uint8()",
+	reflect.Uint16:  "in.Uint16()",
+	reflect.Uint32:  "in.Uint32()",
+	reflect.Uint64:  "in.Uint64()",
+	reflect.Float32: "in.Float32()",
+	reflect.Float64: "in.Float64()",
+}
+
+var primitiveStringDecoders = map[reflect.Kind]string{
+	reflect.String:  "in.String()",
+	reflect.Int:     "in.IntStr()",
+	reflect.Int8:    "in.Int8Str()",
+	reflect.Int16:   "in.Int16Str()",
+	reflect.Int32:   "in.Int32Str()",
+	reflect.Int64:   "in.Int64Str()",
+	reflect.Uint:    "in.UintStr()",
+	reflect.Uint8:   "in.Uint8Str()",
+	reflect.Uint16:  "in.Uint16Str()",
+	reflect.Uint32:  "in.Uint32Str()",
+	reflect.Uint64:  "in.Uint64Str()",
+	reflect.Uintptr: "in.UintptrStr()",
+}
+
+var customDecoders = map[string]string{
+	"json.Number":    "in.JsonNumber()",
+}
+
+// genTypeDecoder generates decoding code for the type t, but uses unmarshaler interface if implemented by t.
+func (g *Generator) genTypeDecoder(t reflect.Type, out string, tags fieldTags, indent int) error {
+	ws := strings.Repeat("  ", indent)
+
+	unmarshalerIface := reflect.TypeOf((*easyjson.Unmarshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(unmarshalerIface) {
+		fmt.Fprintln(g.out, ws+"("+out+").UnmarshalEasyJSON(in)")
+		return nil
+	}
+
+	unmarshalerIface = reflect.TypeOf((*json.Unmarshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(unmarshalerIface) {
+		fmt.Fprintln(g.out, ws+"if data := in.Raw(); in.Ok() {")
+		fmt.Fprintln(g.out, ws+"  in.AddError( ("+out+").UnmarshalJSON(data) )")
+		fmt.Fprintln(g.out, ws+"}")
+		return nil
+	}
+
+	unmarshalerIface = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(unmarshalerIface) {
+		fmt.Fprintln(g.out, ws+"if data := in.UnsafeBytes(); in.Ok() {")
+		fmt.Fprintln(g.out, ws+"  in.AddError( ("+out+").UnmarshalText(data) )")
+		fmt.Fprintln(g.out, ws+"}")
+		return nil
+	}
+
+	err := g.genTypeDecoderNoCheck(t, out, tags, indent)
+	return err
+}
+
+// genTypeDecoderNoCheck generates decoding code for the type t.
+func (g *Generator) genTypeDecoderNoCheck(t reflect.Type, out string, tags fieldTags, indent int) error {
+	ws := strings.Repeat("  ", indent)
+	// Check whether type is primitive, needs to be done after interface check.
+	if dec := customDecoders[t.String()]; dec != ""  {
+		fmt.Fprintln(g.out, ws+out+" = "+dec)
+		return nil
+	} else if dec := primitiveStringDecoders[t.Kind()]; dec != "" && tags.asString {
+		fmt.Fprintln(g.out, ws+out+" = "+g.getType(t)+"("+dec+")")
+		return nil
+	} else if dec := primitiveDecoders[t.Kind()]; dec != "" {
+		fmt.Fprintln(g.out, ws+out+" = "+g.getType(t)+"("+dec+")")
+		return nil
+	}
+
+	switch t.Kind() {
+	case reflect.Slice:
+		tmpVar := g.uniqueVarName()
+		elem := t.Elem()
+
+		if elem.Kind() == reflect.Uint8 {
+			fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+			fmt.Fprintln(g.out, ws+"  in.Skip()")
+			fmt.Fprintln(g.out, ws+"  "+out+" = nil")
+			fmt.Fprintln(g.out, ws+"} else {")
+			fmt.Fprintln(g.out, ws+"  "+out+" = in.Bytes()")
+			fmt.Fprintln(g.out, ws+"}")
+
+		} else {
+
+			capacity := minSliceBytes / elem.Size()
+			if capacity == 0 {
+				capacity = 1
+			}
+
+			fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+			fmt.Fprintln(g.out, ws+"  in.Skip()")
+			fmt.Fprintln(g.out, ws+"  "+out+" = nil")
+			fmt.Fprintln(g.out, ws+"} else {")
+			fmt.Fprintln(g.out, ws+"  in.Delim('[')")
+			fmt.Fprintln(g.out, ws+"  if "+out+" == nil {")
+			fmt.Fprintln(g.out, ws+"    if !in.IsDelim(']') {")
+			fmt.Fprintln(g.out, ws+"      "+out+" = make("+g.getType(t)+", 0, "+fmt.Sprint(capacity)+")")
+			fmt.Fprintln(g.out, ws+"    } else {")
+			fmt.Fprintln(g.out, ws+"      "+out+" = "+g.getType(t)+"{}")
+			fmt.Fprintln(g.out, ws+"    }")
+			fmt.Fprintln(g.out, ws+"  } else { ")
+			fmt.Fprintln(g.out, ws+"    "+out+" = ("+out+")[:0]")
+			fmt.Fprintln(g.out, ws+"  }")
+			fmt.Fprintln(g.out, ws+"  for !in.IsDelim(']') {")
+			fmt.Fprintln(g.out, ws+"    var "+tmpVar+" "+g.getType(elem))
+
+			if err := g.genTypeDecoder(elem, tmpVar, tags, indent+2); err != nil {
+				return err
+			}
+
+			fmt.Fprintln(g.out, ws+"    "+out+" = append("+out+", "+tmpVar+")")
+			fmt.Fprintln(g.out, ws+"    in.WantComma()")
+			fmt.Fprintln(g.out, ws+"  }")
+			fmt.Fprintln(g.out, ws+"  in.Delim(']')")
+			fmt.Fprintln(g.out, ws+"}")
+		}
+
+	case reflect.Array:
+		iterVar := g.uniqueVarName()
+		elem := t.Elem()
+
+		if elem.Kind() == reflect.Uint8 {
+			fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+			fmt.Fprintln(g.out, ws+"  in.Skip()")
+			fmt.Fprintln(g.out, ws+"} else {")
+			fmt.Fprintln(g.out, ws+"  copy("+out+"[:], in.Bytes())")
+			fmt.Fprintln(g.out, ws+"}")
+
+		} else {
+
+			length := t.Len()
+
+			fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+			fmt.Fprintln(g.out, ws+"  in.Skip()")
+			fmt.Fprintln(g.out, ws+"} else {")
+			fmt.Fprintln(g.out, ws+"  in.Delim('[')")
+			fmt.Fprintln(g.out, ws+"  "+iterVar+" := 0")
+			fmt.Fprintln(g.out, ws+"  for !in.IsDelim(']') {")
+			fmt.Fprintln(g.out, ws+"    if "+iterVar+" < "+fmt.Sprint(length)+" {")
+
+			if err := g.genTypeDecoder(elem, out+"["+iterVar+"]", tags, indent+3); err != nil {
+				return err
+			}
+
+			fmt.Fprintln(g.out, ws+"      "+iterVar+"++")
+			fmt.Fprintln(g.out, ws+"    } else {")
+			fmt.Fprintln(g.out, ws+"      in.SkipRecursive()")
+			fmt.Fprintln(g.out, ws+"    }")
+			fmt.Fprintln(g.out, ws+"    in.WantComma()")
+			fmt.Fprintln(g.out, ws+"  }")
+			fmt.Fprintln(g.out, ws+"  in.Delim(']')")
+			fmt.Fprintln(g.out, ws+"}")
+		}
+
+	case reflect.Struct:
+		dec := g.getDecoderName(t)
+		g.addType(t)
+
+		fmt.Fprintln(g.out, ws+dec+"(in, &"+out+")")
+
+	case reflect.Ptr:
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"  "+out+" = nil")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  if "+out+" == nil {")
+		fmt.Fprintln(g.out, ws+"    "+out+" = new("+g.getType(t.Elem())+")")
+		fmt.Fprintln(g.out, ws+"  }")
+
+		if err := g.genTypeDecoder(t.Elem(), "*"+out, tags, indent+1); err != nil {
+			return err
+		}
+
+		fmt.Fprintln(g.out, ws+"}")
+
+	case reflect.Map:
+		key := t.Key()
+		keyDec, ok := primitiveStringDecoders[key.Kind()]
+		if !ok {
+			return fmt.Errorf("map type %v not supported: only string and integer keys are allowed", key)
+		}
+		elem := t.Elem()
+		tmpVar := g.uniqueVarName()
+
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  in.Delim('{')")
+		fmt.Fprintln(g.out, ws+"  if !in.IsDelim('}') {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = make("+g.getType(t)+")")
+		fmt.Fprintln(g.out, ws+"  } else {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = nil")
+		fmt.Fprintln(g.out, ws+"  }")
+
+		fmt.Fprintln(g.out, ws+"  for !in.IsDelim('}') {")
+		fmt.Fprintln(g.out, ws+"    key := "+g.getType(key)+"("+keyDec+")")
+		fmt.Fprintln(g.out, ws+"    in.WantColon()")
+		fmt.Fprintln(g.out, ws+"    var "+tmpVar+" "+g.getType(elem))
+
+		if err := g.genTypeDecoder(elem, tmpVar, tags, indent+2); err != nil {
+			return err
+		}
+
+		fmt.Fprintln(g.out, ws+"    ("+out+")[key] = "+tmpVar)
+		fmt.Fprintln(g.out, ws+"    in.WantComma()")
+		fmt.Fprintln(g.out, ws+"  }")
+		fmt.Fprintln(g.out, ws+"  in.Delim('}')")
+		fmt.Fprintln(g.out, ws+"}")
+
+	case reflect.Interface:
+		if t.NumMethod() != 0 {
+			return fmt.Errorf("interface type %v not supported: only interface{} is allowed", t)
+		}
+		fmt.Fprintln(g.out, ws+"if m, ok := "+out+".(easyjson.Unmarshaler); ok {")
+		fmt.Fprintln(g.out, ws+"m.UnmarshalEasyJSON(in)")
+		fmt.Fprintln(g.out, ws+"} else if m, ok := "+out+".(json.Unmarshaler); ok {")
+		fmt.Fprintln(g.out, ws+"_ = m.UnmarshalJSON(in.Raw())")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = in.Interface()")
+		fmt.Fprintln(g.out, ws+"}")
+	default:
+		return fmt.Errorf("don't know how to decode %v", t)
+	}
+	return nil
+
+}
+
+func (g *Generator) genStructFieldDecoder(t reflect.Type, f reflect.StructField) error {
+	jsonName := g.fieldNamer.GetJSONFieldName(t, f)
+	tags := parseFieldTags(f)
+
+	if tags.omit {
+		return nil
+	}
+
+	fmt.Fprintf(g.out, "    case %q:\n", jsonName)
+	if err := g.genTypeDecoder(f.Type, "out."+f.Name, tags, 3); err != nil {
+		return err
+	}
+
+	if tags.required {
+		fmt.Fprintf(g.out, "%sSet = true\n", f.Name)
+	}
+
+	return nil
+}
+
+func (g *Generator) genRequiredFieldSet(t reflect.Type, f reflect.StructField) {
+	tags := parseFieldTags(f)
+
+	if !tags.required {
+		return
+	}
+
+	fmt.Fprintf(g.out, "var %sSet bool\n", f.Name)
+}
+
+func (g *Generator) genRequiredFieldCheck(t reflect.Type, f reflect.StructField) {
+	jsonName := g.fieldNamer.GetJSONFieldName(t, f)
+	tags := parseFieldTags(f)
+
+	if !tags.required {
+		return
+	}
+
+	g.imports["fmt"] = "fmt"
+
+	fmt.Fprintf(g.out, "if !%sSet {\n", f.Name)
+	fmt.Fprintf(g.out, "    in.AddError(fmt.Errorf(\"key '%s' is required\"))\n", jsonName)
+	fmt.Fprintf(g.out, "}\n")
+}
+
+func mergeStructFields(fields1, fields2 []reflect.StructField) (fields []reflect.StructField) {
+	used := map[string]bool{}
+	for _, f := range fields2 {
+		used[f.Name] = true
+		fields = append(fields, f)
+	}
+
+	for _, f := range fields1 {
+		if !used[f.Name] {
+			fields = append(fields, f)
+		}
+	}
+	return
+}
+
+func getStructFields(t reflect.Type) ([]reflect.StructField, error) {
+	if t.Kind() != reflect.Struct {
+		return nil, fmt.Errorf("got %v; expected a struct", t)
+	}
+
+	var efields []reflect.StructField
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if !f.Anonymous {
+			continue
+		}
+
+		t1 := f.Type
+		if t1.Kind() == reflect.Ptr {
+			t1 = t1.Elem()
+		}
+
+		fs, err := getStructFields(t1)
+		if err != nil {
+			return nil, fmt.Errorf("error processing embedded field: %v", err)
+		}
+		efields = mergeStructFields(efields, fs)
+	}
+
+	var fields []reflect.StructField
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if f.Anonymous {
+			continue
+		}
+
+		c := []rune(f.Name)[0]
+		if unicode.IsUpper(c) {
+			fields = append(fields, f)
+		}
+	}
+	return mergeStructFields(efields, fields), nil
+}
+
+func (g *Generator) genDecoder(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+		return g.genSliceArrayDecoder(t)
+	default:
+		return g.genStructDecoder(t)
+	}
+}
+
+func (g *Generator) genSliceArrayDecoder(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice/array/map type", t)
+	}
+
+	fname := g.getDecoderName(t)
+	typ := g.getType(t)
+
+	fmt.Fprintln(g.out, "func "+fname+"(in *jlexer.Lexer, out *"+typ+") {")
+	fmt.Fprintln(g.out, " isTopLevel := in.IsStart()")
+	err := g.genTypeDecoderNoCheck(t, "*out", fieldTags{}, 1)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintln(g.out, "  if isTopLevel {")
+	fmt.Fprintln(g.out, "    in.Consumed()")
+	fmt.Fprintln(g.out, "  }")
+	fmt.Fprintln(g.out, "}")
+
+	return nil
+}
+
+func (g *Generator) genStructDecoder(t reflect.Type) error {
+	if t.Kind() != reflect.Struct {
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct type", t)
+	}
+
+	fname := g.getDecoderName(t)
+	typ := g.getType(t)
+
+	fmt.Fprintln(g.out, "func "+fname+"(in *jlexer.Lexer, out *"+typ+") {")
+	fmt.Fprintln(g.out, "  isTopLevel := in.IsStart()")
+	fmt.Fprintln(g.out, "  if in.IsNull() {")
+	fmt.Fprintln(g.out, "    if isTopLevel {")
+	fmt.Fprintln(g.out, "      in.Consumed()")
+	fmt.Fprintln(g.out, "    }")
+	fmt.Fprintln(g.out, "    in.Skip()")
+	fmt.Fprintln(g.out, "    return")
+	fmt.Fprintln(g.out, "  }")
+
+	// Init embedded pointer fields.
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if !f.Anonymous || f.Type.Kind() != reflect.Ptr {
+			continue
+		}
+		fmt.Fprintln(g.out, "  out."+f.Name+" = new("+g.getType(f.Type.Elem())+")")
+	}
+
+	fs, err := getStructFields(t)
+	if err != nil {
+		return fmt.Errorf("cannot generate decoder for %v: %v", t, err)
+	}
+
+	for _, f := range fs {
+		g.genRequiredFieldSet(t, f)
+	}
+
+	fmt.Fprintln(g.out, "  in.Delim('{')")
+	fmt.Fprintln(g.out, "  for !in.IsDelim('}') {")
+	fmt.Fprintln(g.out, "    key := in.UnsafeString()")
+	fmt.Fprintln(g.out, "    in.WantColon()")
+	fmt.Fprintln(g.out, "    if in.IsNull() {")
+	fmt.Fprintln(g.out, "       in.Skip()")
+	fmt.Fprintln(g.out, "       in.WantComma()")
+	fmt.Fprintln(g.out, "       continue")
+	fmt.Fprintln(g.out, "    }")
+
+	fmt.Fprintln(g.out, "    switch key {")
+	for _, f := range fs {
+		if err := g.genStructFieldDecoder(t, f); err != nil {
+			return err
+		}
+	}
+
+	fmt.Fprintln(g.out, "    default:")
+	fmt.Fprintln(g.out, "      in.SkipRecursive()")
+	fmt.Fprintln(g.out, "    }")
+	fmt.Fprintln(g.out, "    in.WantComma()")
+	fmt.Fprintln(g.out, "  }")
+	fmt.Fprintln(g.out, "  in.Delim('}')")
+	fmt.Fprintln(g.out, "  if isTopLevel {")
+	fmt.Fprintln(g.out, "    in.Consumed()")
+	fmt.Fprintln(g.out, "  }")
+
+	for _, f := range fs {
+		g.genRequiredFieldCheck(t, f)
+	}
+
+	fmt.Fprintln(g.out, "}")
+
+	return nil
+}
+
+func (g *Generator) genStructUnmarshaler(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map, reflect.Struct:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array/map type", t)
+	}
+
+	fname := g.getDecoderName(t)
+	typ := g.getType(t)
+
+	if !g.noStdMarshalers {
+		fmt.Fprintln(g.out, "// UnmarshalJSON supports json.Unmarshaler interface")
+		fmt.Fprintln(g.out, "func (v *"+typ+") UnmarshalJSON(data []byte) error {")
+		fmt.Fprintln(g.out, "  r := jlexer.Lexer{Data: data}")
+		fmt.Fprintln(g.out, "  "+fname+"(&r, v)")
+		fmt.Fprintln(g.out, "  return r.Error()")
+		fmt.Fprintln(g.out, "}")
+	}
+
+	fmt.Fprintln(g.out, "// UnmarshalEasyJSON supports easyjson.Unmarshaler interface")
+	fmt.Fprintln(g.out, "func (v *"+typ+") UnmarshalEasyJSON(l *jlexer.Lexer) {")
+	fmt.Fprintln(g.out, "  "+fname+"(l, v)")
+	fmt.Fprintln(g.out, "}")
+
+	return nil
+}

vendor/github.com/mailru/easyjson/gen/encoder.go

@@ -0,0 +1,382 @@
+package gen
+
+import (
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/mailru/easyjson"
+)
+
+func (g *Generator) getEncoderName(t reflect.Type) string {
+	return g.functionName("encode", t)
+}
+
+var primitiveEncoders = map[reflect.Kind]string{
+	reflect.String:  "out.String(string(%v))",
+	reflect.Bool:    "out.Bool(bool(%v))",
+	reflect.Int:     "out.Int(int(%v))",
+	reflect.Int8:    "out.Int8(int8(%v))",
+	reflect.Int16:   "out.Int16(int16(%v))",
+	reflect.Int32:   "out.Int32(int32(%v))",
+	reflect.Int64:   "out.Int64(int64(%v))",
+	reflect.Uint:    "out.Uint(uint(%v))",
+	reflect.Uint8:   "out.Uint8(uint8(%v))",
+	reflect.Uint16:  "out.Uint16(uint16(%v))",
+	reflect.Uint32:  "out.Uint32(uint32(%v))",
+	reflect.Uint64:  "out.Uint64(uint64(%v))",
+	reflect.Float32: "out.Float32(float32(%v))",
+	reflect.Float64: "out.Float64(float64(%v))",
+}
+
+var primitiveStringEncoders = map[reflect.Kind]string{
+	reflect.String:  "out.String(string(%v))",
+	reflect.Int:     "out.IntStr(int(%v))",
+	reflect.Int8:    "out.Int8Str(int8(%v))",
+	reflect.Int16:   "out.Int16Str(int16(%v))",
+	reflect.Int32:   "out.Int32Str(int32(%v))",
+	reflect.Int64:   "out.Int64Str(int64(%v))",
+	reflect.Uint:    "out.UintStr(uint(%v))",
+	reflect.Uint8:   "out.Uint8Str(uint8(%v))",
+	reflect.Uint16:  "out.Uint16Str(uint16(%v))",
+	reflect.Uint32:  "out.Uint32Str(uint32(%v))",
+	reflect.Uint64:  "out.Uint64Str(uint64(%v))",
+	reflect.Uintptr: "out.UintptrStr(uintptr(%v))",
+}
+
+// fieldTags contains parsed version of json struct field tags.
+type fieldTags struct {
+	name string
+
+	omit        bool
+	omitEmpty   bool
+	noOmitEmpty bool
+	asString    bool
+	required    bool
+}
+
+// parseFieldTags parses the json field tag into a structure.
+func parseFieldTags(f reflect.StructField) fieldTags {
+	var ret fieldTags
+
+	for i, s := range strings.Split(f.Tag.Get("json"), ",") {
+		switch {
+		case i == 0 && s == "-":
+			ret.omit = true
+		case i == 0:
+			ret.name = s
+		case s == "omitempty":
+			ret.omitEmpty = true
+		case s == "!omitempty":
+			ret.noOmitEmpty = true
+		case s == "string":
+			ret.asString = true
+		case s == "required":
+			ret.required = true
+		}
+	}
+
+	return ret
+}
+
+// genTypeEncoder generates code that encodes in of type t into the writer, but uses marshaler interface if implemented by t.
+func (g *Generator) genTypeEncoder(t reflect.Type, in string, tags fieldTags, indent int, assumeNonEmpty bool) error {
+	ws := strings.Repeat("  ", indent)
+
+	marshalerIface := reflect.TypeOf((*easyjson.Marshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(marshalerIface) {
+		fmt.Fprintln(g.out, ws+"("+in+").MarshalEasyJSON(out)")
+		return nil
+	}
+
+	marshalerIface = reflect.TypeOf((*json.Marshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(marshalerIface) {
+		fmt.Fprintln(g.out, ws+"out.Raw( ("+in+").MarshalJSON() )")
+		return nil
+	}
+
+	marshalerIface = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(marshalerIface) {
+		fmt.Fprintln(g.out, ws+"out.RawText( ("+in+").MarshalText() )")
+		return nil
+	}
+
+	err := g.genTypeEncoderNoCheck(t, in, tags, indent, assumeNonEmpty)
+	return err
+}
+
+// genTypeEncoderNoCheck generates code that encodes in of type t into the writer.
+func (g *Generator) genTypeEncoderNoCheck(t reflect.Type, in string, tags fieldTags, indent int, assumeNonEmpty bool) error {
+	ws := strings.Repeat("  ", indent)
+
+	// Check whether type is primitive, needs to be done after interface check.
+	if enc := primitiveStringEncoders[t.Kind()]; enc != "" && tags.asString {
+		fmt.Fprintf(g.out, ws+enc+"\n", in)
+		return nil
+	} else if enc := primitiveEncoders[t.Kind()]; enc != "" {
+		fmt.Fprintf(g.out, ws+enc+"\n", in)
+		return nil
+	}
+
+	switch t.Kind() {
+	case reflect.Slice:
+		elem := t.Elem()
+		iVar := g.uniqueVarName()
+		vVar := g.uniqueVarName()
+
+		if t.Elem().Kind() == reflect.Uint8 {
+			fmt.Fprintln(g.out, ws+"out.Base64Bytes("+in+")")
+		} else {
+			if !assumeNonEmpty {
+				fmt.Fprintln(g.out, ws+"if "+in+" == nil && (out.Flags & jwriter.NilSliceAsEmpty) == 0 {")
+				fmt.Fprintln(g.out, ws+`  out.RawString("null")`)
+				fmt.Fprintln(g.out, ws+"} else {")
+			} else {
+				fmt.Fprintln(g.out, ws+"{")
+			}
+			fmt.Fprintln(g.out, ws+"  out.RawByte('[')")
+			fmt.Fprintln(g.out, ws+"  for "+iVar+", "+vVar+" := range "+in+" {")
+			fmt.Fprintln(g.out, ws+"    if "+iVar+" > 0 {")
+			fmt.Fprintln(g.out, ws+"      out.RawByte(',')")
+			fmt.Fprintln(g.out, ws+"    }")
+
+			if err := g.genTypeEncoder(elem, vVar, tags, indent+2, false); err != nil {
+				return err
+			}
+
+			fmt.Fprintln(g.out, ws+"  }")
+			fmt.Fprintln(g.out, ws+"  out.RawByte(']')")
+			fmt.Fprintln(g.out, ws+"}")
+		}
+
+	case reflect.Array:
+		elem := t.Elem()
+		iVar := g.uniqueVarName()
+
+		if t.Elem().Kind() == reflect.Uint8 {
+			fmt.Fprintln(g.out, ws+"out.Base64Bytes("+in+"[:])")
+		} else {
+			fmt.Fprintln(g.out, ws+"out.RawByte('[')")
+			fmt.Fprintln(g.out, ws+"for "+iVar+" := range "+in+" {")
+			fmt.Fprintln(g.out, ws+"  if "+iVar+" > 0 {")
+			fmt.Fprintln(g.out, ws+"    out.RawByte(',')")
+			fmt.Fprintln(g.out, ws+"  }")
+
+			if err := g.genTypeEncoder(elem, in+"["+iVar+"]", tags, indent+1, false); err != nil {
+				return err
+			}
+
+			fmt.Fprintln(g.out, ws+"}")
+			fmt.Fprintln(g.out, ws+"out.RawByte(']')")
+		}
+
+	case reflect.Struct:
+		enc := g.getEncoderName(t)
+		g.addType(t)
+
+		fmt.Fprintln(g.out, ws+enc+"(out, "+in+")")
+
+	case reflect.Ptr:
+		if !assumeNonEmpty {
+			fmt.Fprintln(g.out, ws+"if "+in+" == nil {")
+			fmt.Fprintln(g.out, ws+`  out.RawString("null")`)
+			fmt.Fprintln(g.out, ws+"} else {")
+		}
+
+		if err := g.genTypeEncoder(t.Elem(), "*"+in, tags, indent+1, false); err != nil {
+			return err
+		}
+
+		if !assumeNonEmpty {
+			fmt.Fprintln(g.out, ws+"}")
+		}
+
+	case reflect.Map:
+		key := t.Key()
+		keyEnc, ok := primitiveStringEncoders[key.Kind()]
+		if !ok {
+			return fmt.Errorf("map key type %v not supported: only string and integer keys are allowed", key)
+		}
+		tmpVar := g.uniqueVarName()
+
+		if !assumeNonEmpty {
+			fmt.Fprintln(g.out, ws+"if "+in+" == nil && (out.Flags & jwriter.NilMapAsEmpty) == 0 {")
+			fmt.Fprintln(g.out, ws+"  out.RawString(`null`)")
+			fmt.Fprintln(g.out, ws+"} else {")
+		} else {
+			fmt.Fprintln(g.out, ws+"{")
+		}
+		fmt.Fprintln(g.out, ws+"  out.RawByte('{')")
+		fmt.Fprintln(g.out, ws+"  "+tmpVar+"First := true")
+		fmt.Fprintln(g.out, ws+"  for "+tmpVar+"Name, "+tmpVar+"Value := range "+in+" {")
+		fmt.Fprintln(g.out, ws+"    if "+tmpVar+"First { "+tmpVar+"First = false } else { out.RawByte(',') }")
+		fmt.Fprintln(g.out, ws+"    "+fmt.Sprintf(keyEnc, tmpVar+"Name"))
+		fmt.Fprintln(g.out, ws+"    out.RawByte(':')")
+
+		if err := g.genTypeEncoder(t.Elem(), tmpVar+"Value", tags, indent+2, false); err != nil {
+			return err
+		}
+
+		fmt.Fprintln(g.out, ws+"  }")
+		fmt.Fprintln(g.out, ws+"  out.RawByte('}')")
+		fmt.Fprintln(g.out, ws+"}")
+
+	case reflect.Interface:
+		if t.NumMethod() != 0 {
+			return fmt.Errorf("interface type %v not supported: only interface{} is allowed", t)
+		}
+		fmt.Fprintln(g.out, ws+"if m, ok := "+in+".(easyjson.Marshaler); ok {")
+		fmt.Fprintln(g.out, ws+"  m.MarshalEasyJSON(out)")
+		fmt.Fprintln(g.out, ws+"} else if m, ok := "+in+".(json.Marshaler); ok {")
+		fmt.Fprintln(g.out, ws+"  out.Raw(m.MarshalJSON())")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  out.Raw(json.Marshal("+in+"))")
+		fmt.Fprintln(g.out, ws+"}")
+
+	default:
+		return fmt.Errorf("don't know how to encode %v", t)
+	}
+	return nil
+}
+
+func (g *Generator) notEmptyCheck(t reflect.Type, v string) string {
+	optionalIface := reflect.TypeOf((*easyjson.Optional)(nil)).Elem()
+	if reflect.PtrTo(t).Implements(optionalIface) {
+		return "(" + v + ").IsDefined()"
+	}
+
+	switch t.Kind() {
+	case reflect.Slice, reflect.Map:
+		return "len(" + v + ") != 0"
+	case reflect.Interface, reflect.Ptr:
+		return v + " != nil"
+	case reflect.Bool:
+		return v
+	case reflect.String:
+		return v + ` != ""`
+	case reflect.Float32, reflect.Float64,
+		reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+
+		return v + " != 0"
+
+	default:
+		// note: Array types don't have a useful empty value
+		return "true"
+	}
+}
+
+func (g *Generator) genStructFieldEncoder(t reflect.Type, f reflect.StructField) error {
+	jsonName := g.fieldNamer.GetJSONFieldName(t, f)
+	tags := parseFieldTags(f)
+
+	if tags.omit {
+		return nil
+	}
+	noOmitEmpty := (!tags.omitEmpty && !g.omitEmpty) || tags.noOmitEmpty
+	if noOmitEmpty {
+		fmt.Fprintln(g.out, "  {")
+	} else {
+		fmt.Fprintln(g.out, "  if", g.notEmptyCheck(f.Type, "in."+f.Name), "{")
+	}
+	fmt.Fprintf(g.out, "    const prefix string = %q\n", ","+strconv.Quote(jsonName)+":")
+	fmt.Fprintln(g.out, "    if first {")
+	fmt.Fprintln(g.out, "      first = false")
+	fmt.Fprintln(g.out, "      out.RawString(prefix[1:])")
+	fmt.Fprintln(g.out, "    } else {")
+	fmt.Fprintln(g.out, "      out.RawString(prefix)")
+	fmt.Fprintln(g.out, "    }")
+
+	if err := g.genTypeEncoder(f.Type, "in."+f.Name, tags, 2, !noOmitEmpty); err != nil {
+		return err
+	}
+	fmt.Fprintln(g.out, "  }")
+	return nil
+}
+
+func (g *Generator) genEncoder(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+		return g.genSliceArrayMapEncoder(t)
+	default:
+		return g.genStructEncoder(t)
+	}
+}
+
+func (g *Generator) genSliceArrayMapEncoder(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice/array/map type", t)
+	}
+
+	fname := g.getEncoderName(t)
+	typ := g.getType(t)
+
+	fmt.Fprintln(g.out, "func "+fname+"(out *jwriter.Writer, in "+typ+") {")
+	err := g.genTypeEncoderNoCheck(t, "in", fieldTags{}, 1, false)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintln(g.out, "}")
+	return nil
+}
+
+func (g *Generator) genStructEncoder(t reflect.Type) error {
+	if t.Kind() != reflect.Struct {
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct type", t)
+	}
+
+	fname := g.getEncoderName(t)
+	typ := g.getType(t)
+
+	fmt.Fprintln(g.out, "func "+fname+"(out *jwriter.Writer, in "+typ+") {")
+	fmt.Fprintln(g.out, "  out.RawByte('{')")
+	fmt.Fprintln(g.out, "  first := true")
+	fmt.Fprintln(g.out, "  _ = first")
+
+	fs, err := getStructFields(t)
+	if err != nil {
+		return fmt.Errorf("cannot generate encoder for %v: %v", t, err)
+	}
+	for _, f := range fs {
+		if err := g.genStructFieldEncoder(t, f); err != nil {
+			return err
+		}
+	}
+
+	fmt.Fprintln(g.out, "  out.RawByte('}')")
+	fmt.Fprintln(g.out, "}")
+
+	return nil
+}
+
+func (g *Generator) genStructMarshaler(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map, reflect.Struct:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array/map type", t)
+	}
+
+	fname := g.getEncoderName(t)
+	typ := g.getType(t)
+
+	if !g.noStdMarshalers {
+		fmt.Fprintln(g.out, "// MarshalJSON supports json.Marshaler interface")
+		fmt.Fprintln(g.out, "func (v "+typ+") MarshalJSON() ([]byte, error) {")
+		fmt.Fprintln(g.out, "  w := jwriter.Writer{}")
+		fmt.Fprintln(g.out, "  "+fname+"(&w, v)")
+		fmt.Fprintln(g.out, "  return w.Buffer.BuildBytes(), w.Error")
+		fmt.Fprintln(g.out, "}")
+	}
+
+	fmt.Fprintln(g.out, "// MarshalEasyJSON supports easyjson.Marshaler interface")
+	fmt.Fprintln(g.out, "func (v "+typ+") MarshalEasyJSON(w *jwriter.Writer) {")
+	fmt.Fprintln(g.out, "  "+fname+"(w, v)")
+	fmt.Fprintln(g.out, "}")
+
+	return nil
+}

vendor/github.com/mailru/easyjson/gen/generator.go

@@ -0,0 +1,523 @@
+package gen
+
+import (
+	"bytes"
+	"fmt"
+	"hash/fnv"
+	"io"
+	"path"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+)
+
+const pkgWriter = "github.com/mailru/easyjson/jwriter"
+const pkgLexer = "github.com/mailru/easyjson/jlexer"
+const pkgEasyJSON = "github.com/mailru/easyjson"
+
+// FieldNamer defines a policy for generating names for struct fields.
+type FieldNamer interface {
+	GetJSONFieldName(t reflect.Type, f reflect.StructField) string
+}
+
+// Generator generates the requested marshaler/unmarshalers.
+type Generator struct {
+	out *bytes.Buffer
+
+	pkgName    string
+	pkgPath    string
+	buildTags  string
+	hashString string
+
+	varCounter int
+
+	noStdMarshalers bool
+	omitEmpty       bool
+	fieldNamer      FieldNamer
+
+	// package path to local alias map for tracking imports
+	imports map[string]string
+
+	// types that marshalers were requested for by user
+	marshalers map[reflect.Type]bool
+
+	// types that encoders were already generated for
+	typesSeen map[reflect.Type]bool
+
+	// types that encoders were requested for (e.g. by encoders of other types)
+	typesUnseen []reflect.Type
+
+	// function name to relevant type maps to track names of de-/encoders in
+	// case of a name clash or unnamed structs
+	functionNames map[string]reflect.Type
+}
+
+// NewGenerator initializes and returns a Generator.
+func NewGenerator(filename string) *Generator {
+	ret := &Generator{
+		imports: map[string]string{
+			pkgWriter:       "jwriter",
+			pkgLexer:        "jlexer",
+			pkgEasyJSON:     "easyjson",
+			"encoding/json": "json",
+		},
+		fieldNamer:    DefaultFieldNamer{},
+		marshalers:    make(map[reflect.Type]bool),
+		typesSeen:     make(map[reflect.Type]bool),
+		functionNames: make(map[string]reflect.Type),
+	}
+
+	// Use a file-unique prefix on all auxiliary funcs to avoid
+	// name clashes.
+	hash := fnv.New32()
+	hash.Write([]byte(filename))
+	ret.hashString = fmt.Sprintf("%x", hash.Sum32())
+
+	return ret
+}
+
+// SetPkg sets the name and path of output package.
+func (g *Generator) SetPkg(name, path string) {
+	g.pkgName = name
+	g.pkgPath = path
+}
+
+// SetBuildTags sets build tags for the output file.
+func (g *Generator) SetBuildTags(tags string) {
+	g.buildTags = tags
+}
+
+// SetFieldNamer sets field naming strategy.
+func (g *Generator) SetFieldNamer(n FieldNamer) {
+	g.fieldNamer = n
+}
+
+// UseSnakeCase sets snake_case field naming strategy.
+func (g *Generator) UseSnakeCase() {
+	g.fieldNamer = SnakeCaseFieldNamer{}
+}
+
+// UseLowerCamelCase sets lowerCamelCase field naming strategy.
+func (g *Generator) UseLowerCamelCase() {
+	g.fieldNamer = LowerCamelCaseFieldNamer{}
+}
+
+// NoStdMarshalers instructs not to generate standard MarshalJSON/UnmarshalJSON
+// methods (only the custom interface).
+func (g *Generator) NoStdMarshalers() {
+	g.noStdMarshalers = true
+}
+
+// OmitEmpty triggers `json=",omitempty"` behaviour by default.
+func (g *Generator) OmitEmpty() {
+	g.omitEmpty = true
+}
+
+// addTypes requests to generate encoding/decoding funcs for the given type.
+func (g *Generator) addType(t reflect.Type) {
+	if g.typesSeen[t] {
+		return
+	}
+	for _, t1 := range g.typesUnseen {
+		if t1 == t {
+			return
+		}
+	}
+	g.typesUnseen = append(g.typesUnseen, t)
+}
+
+// Add requests to generate marshaler/unmarshalers and encoding/decoding
+// funcs for the type of given object.
+func (g *Generator) Add(obj interface{}) {
+	t := reflect.TypeOf(obj)
+	if t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	g.addType(t)
+	g.marshalers[t] = true
+}
+
+// printHeader prints package declaration and imports.
+func (g *Generator) printHeader() {
+	if g.buildTags != "" {
+		fmt.Println("// +build ", g.buildTags)
+		fmt.Println()
+	}
+	fmt.Println("// Code generated by easyjson for marshaling/unmarshaling. DO NOT EDIT.")
+	fmt.Println()
+	fmt.Println("package ", g.pkgName)
+	fmt.Println()
+
+	byAlias := map[string]string{}
+	var aliases []string
+	for path, alias := range g.imports {
+		aliases = append(aliases, alias)
+		byAlias[alias] = path
+	}
+
+	sort.Strings(aliases)
+	fmt.Println("import (")
+	for _, alias := range aliases {
+		fmt.Printf("  %s %q\n", alias, byAlias[alias])
+	}
+
+	fmt.Println(")")
+	fmt.Println("")
+	fmt.Println("// suppress unused package warning")
+	fmt.Println("var (")
+	fmt.Println("   _ *json.RawMessage")
+	fmt.Println("   _ *jlexer.Lexer")
+	fmt.Println("   _ *jwriter.Writer")
+	fmt.Println("   _ easyjson.Marshaler")
+	fmt.Println(")")
+
+	fmt.Println()
+}
+
+// Run runs the generator and outputs generated code to out.
+func (g *Generator) Run(out io.Writer) error {
+	g.out = &bytes.Buffer{}
+
+	for len(g.typesUnseen) > 0 {
+		t := g.typesUnseen[len(g.typesUnseen)-1]
+		g.typesUnseen = g.typesUnseen[:len(g.typesUnseen)-1]
+		g.typesSeen[t] = true
+
+		if err := g.genDecoder(t); err != nil {
+			return err
+		}
+		if err := g.genEncoder(t); err != nil {
+			return err
+		}
+
+		if !g.marshalers[t] {
+			continue
+		}
+
+		if err := g.genStructMarshaler(t); err != nil {
+			return err
+		}
+		if err := g.genStructUnmarshaler(t); err != nil {
+			return err
+		}
+	}
+	g.printHeader()
+	_, err := out.Write(g.out.Bytes())
+	return err
+}
+
+// fixes vendored paths
+func fixPkgPathVendoring(pkgPath string) string {
+	const vendor = "/vendor/"
+	if i := strings.LastIndex(pkgPath, vendor); i != -1 {
+		return pkgPath[i+len(vendor):]
+	}
+	return pkgPath
+}
+
+func fixAliasName(alias string) string {
+	alias = strings.Replace(
+		strings.Replace(alias, ".", "_", -1),
+		"-",
+		"_",
+		-1,
+	)
+
+	if alias[0] == 'v' { // to void conflicting with var names, say v1
+		alias = "_" + alias
+	}
+	return alias
+}
+
+// pkgAlias creates and returns and import alias for a given package.
+func (g *Generator) pkgAlias(pkgPath string) string {
+	pkgPath = fixPkgPathVendoring(pkgPath)
+	if alias := g.imports[pkgPath]; alias != "" {
+		return alias
+	}
+
+	for i := 0; ; i++ {
+		alias := fixAliasName(path.Base(pkgPath))
+		if i > 0 {
+			alias += fmt.Sprint(i)
+		}
+
+		exists := false
+		for _, v := range g.imports {
+			if v == alias {
+				exists = true
+				break
+			}
+		}
+
+		if !exists {
+			g.imports[pkgPath] = alias
+			return alias
+		}
+	}
+}
+
+// getType return the textual type name of given type that can be used in generated code.
+func (g *Generator) getType(t reflect.Type) string {
+	if t.Name() == "" {
+		switch t.Kind() {
+		case reflect.Ptr:
+			return "*" + g.getType(t.Elem())
+		case reflect.Slice:
+			return "[]" + g.getType(t.Elem())
+		case reflect.Array:
+			return "[" + strconv.Itoa(t.Len()) + "]" + g.getType(t.Elem())
+		case reflect.Map:
+			return "map[" + g.getType(t.Key()) + "]" + g.getType(t.Elem())
+		}
+	}
+
+	if t.Name() == "" || t.PkgPath() == "" {
+		if t.Kind() == reflect.Struct {
+			// the fields of an anonymous struct can have named types,
+			// and t.String() will not be sufficient because it does not
+			// remove the package name when it matches g.pkgPath.
+			// so we convert by hand
+			nf := t.NumField()
+			lines := make([]string, 0, nf)
+			for i := 0; i < nf; i++ {
+				f := t.Field(i)
+				line := f.Name + " " + g.getType(f.Type)
+				t := f.Tag
+				if t != "" {
+					line += " " + escapeTag(t)
+				}
+				lines = append(lines, line)
+			}
+			return strings.Join([]string{"struct { ", strings.Join(lines, "; "), " }"}, "")
+		}
+		return t.String()
+	} else if t.PkgPath() == g.pkgPath {
+		return t.Name()
+	}
+	return g.pkgAlias(t.PkgPath()) + "." + t.Name()
+}
+
+// escape a struct field tag string back to source code
+func escapeTag(tag reflect.StructTag) string {
+	t := string(tag)
+	if strings.ContainsRune(t, '`') {
+		// there are ` in the string; we can't use ` to enclose the string
+		return strconv.Quote(t)
+	}
+	return "`" + t + "`"
+}
+
+// uniqueVarName returns a file-unique name that can be used for generated variables.
+func (g *Generator) uniqueVarName() string {
+	g.varCounter++
+	return fmt.Sprint("v", g.varCounter)
+}
+
+// safeName escapes unsafe characters in pkg/type name and returns a string that can be used
+// in encoder/decoder names for the type.
+func (g *Generator) safeName(t reflect.Type) string {
+	name := t.PkgPath()
+	if t.Name() == "" {
+		name += "anonymous"
+	} else {
+		name += "." + t.Name()
+	}
+
+	parts := []string{}
+	part := []rune{}
+	for _, c := range name {
+		if unicode.IsLetter(c) || unicode.IsDigit(c) {
+			part = append(part, c)
+		} else if len(part) > 0 {
+			parts = append(parts, string(part))
+			part = []rune{}
+		}
+	}
+	return joinFunctionNameParts(false, parts...)
+}
+
+// functionName returns a function name for a given type with a given prefix. If a function
+// with this prefix already exists for a type, it is returned.
+//
+// Method is used to track encoder/decoder names for the type.
+func (g *Generator) functionName(prefix string, t reflect.Type) string {
+	prefix = joinFunctionNameParts(true, "easyjson", g.hashString, prefix)
+	name := joinFunctionNameParts(true, prefix, g.safeName(t))
+
+	// Most of the names will be unique, try a shortcut first.
+	if e, ok := g.functionNames[name]; !ok || e == t {
+		g.functionNames[name] = t
+		return name
+	}
+
+	// Search if the function already exists.
+	for name1, t1 := range g.functionNames {
+		if t1 == t && strings.HasPrefix(name1, prefix) {
+			return name1
+		}
+	}
+
+	// Create a new name in the case of a clash.
+	for i := 1; ; i++ {
+		nm := fmt.Sprint(name, i)
+		if _, ok := g.functionNames[nm]; ok {
+			continue
+		}
+		g.functionNames[nm] = t
+		return nm
+	}
+}
+
+// DefaultFieldsNamer implements trivial naming policy equivalent to encoding/json.
+type DefaultFieldNamer struct{}
+
+func (DefaultFieldNamer) GetJSONFieldName(t reflect.Type, f reflect.StructField) string {
+	jsonName := strings.Split(f.Tag.Get("json"), ",")[0]
+	if jsonName != "" {
+		return jsonName
+	} else {
+		return f.Name
+	}
+}
+
+// LowerCamelCaseFieldNamer
+type LowerCamelCaseFieldNamer struct{}
+
+func isLower(b byte) bool {
+	return b <= 122 && b >= 97
+}
+
+func isUpper(b byte) bool {
+	return b >= 65 && b <= 90
+}
+
+// convert HTTPRestClient to httpRestClient
+func lowerFirst(s string) string {
+	if s == "" {
+		return ""
+	}
+
+	str := ""
+	strlen := len(s)
+
+	/**
+	  Loop each char
+	  If is uppercase:
+	    If is first char, LOWER it
+	    If the following char is lower, LEAVE it
+	    If the following char is upper OR numeric, LOWER it
+	    If is the end of string, LEAVE it
+	  Else lowercase
+	*/
+
+	foundLower := false
+	for i := range s {
+		ch := s[i]
+		if isUpper(ch) {
+			if i == 0 {
+				str += string(ch + 32)
+			} else if !foundLower { // Currently just a stream of capitals, eg JSONRESTS[erver]
+				if strlen > (i+1) && isLower(s[i+1]) {
+					// Next char is lower, keep this a capital
+					str += string(ch)
+				} else {
+					// Either at end of string or next char is capital
+					str += string(ch + 32)
+				}
+			} else {
+				str += string(ch)
+			}
+		} else {
+			foundLower = true
+			str += string(ch)
+		}
+	}
+
+	return str
+}
+
+func (LowerCamelCaseFieldNamer) GetJSONFieldName(t reflect.Type, f reflect.StructField) string {
+	jsonName := strings.Split(f.Tag.Get("json"), ",")[0]
+	if jsonName != "" {
+		return jsonName
+	} else {
+		return lowerFirst(f.Name)
+	}
+}
+
+// SnakeCaseFieldNamer implements CamelCase to snake_case conversion for fields names.
+type SnakeCaseFieldNamer struct{}
+
+func camelToSnake(name string) string {
+	var ret bytes.Buffer
+
+	multipleUpper := false
+	var lastUpper rune
+	var beforeUpper rune
+
+	for _, c := range name {
+		// Non-lowercase character after uppercase is considered to be uppercase too.
+		isUpper := (unicode.IsUpper(c) || (lastUpper != 0 && !unicode.IsLower(c)))
+
+		if lastUpper != 0 {
+			// Output a delimiter if last character was either the first uppercase character
+			// in a row, or the last one in a row (e.g. 'S' in "HTTPServer").
+			// Do not output a delimiter at the beginning of the name.
+
+			firstInRow := !multipleUpper
+			lastInRow := !isUpper
+
+			if ret.Len() > 0 && (firstInRow || lastInRow) && beforeUpper != '_' {
+				ret.WriteByte('_')
+			}
+			ret.WriteRune(unicode.ToLower(lastUpper))
+		}
+
+		// Buffer uppercase char, do not output it yet as a delimiter may be required if the
+		// next character is lowercase.
+		if isUpper {
+			multipleUpper = (lastUpper != 0)
+			lastUpper = c
+			continue
+		}
+
+		ret.WriteRune(c)
+		lastUpper = 0
+		beforeUpper = c
+		multipleUpper = false
+	}
+
+	if lastUpper != 0 {
+		ret.WriteRune(unicode.ToLower(lastUpper))
+	}
+	return string(ret.Bytes())
+}
+
+func (SnakeCaseFieldNamer) GetJSONFieldName(t reflect.Type, f reflect.StructField) string {
+	jsonName := strings.Split(f.Tag.Get("json"), ",")[0]
+	if jsonName != "" {
+		return jsonName
+	}
+
+	return camelToSnake(f.Name)
+}
+
+func joinFunctionNameParts(keepFirst bool, parts ...string) string {
+	buf := bytes.NewBufferString("")
+	for i, part := range parts {
+		if i == 0 && keepFirst {
+			buf.WriteString(part)
+		} else {
+			if len(part) > 0 {
+				buf.WriteString(strings.ToUpper(string(part[0])))
+			}
+			if len(part) > 1 {
+				buf.WriteString(part[1:])
+			}
+		}
+	}
+	return buf.String()
+}

vendor/github.com/mailru/easyjson/gen/generator_test.go

@@ -0,0 +1,87 @@
+package gen
+
+import (
+	"testing"
+)
+
+func TestCamelToSnake(t *testing.T) {
+	for i, test := range []struct {
+		In, Out string
+	}{
+		{"", ""},
+		{"A", "a"},
+		{"SimpleExample", "simple_example"},
+		{"internalField", "internal_field"},
+
+		{"SomeHTTPStuff", "some_http_stuff"},
+		{"WriteJSON", "write_json"},
+		{"HTTP2Server", "http2_server"},
+		{"Some_Mixed_Case", "some_mixed_case"},
+		{"do_nothing", "do_nothing"},
+
+		{"JSONHTTPRPCServer", "jsonhttprpc_server"}, // nothing can be done here without a dictionary
+	} {
+		got := camelToSnake(test.In)
+		if got != test.Out {
+			t.Errorf("[%d] camelToSnake(%s) = %s; want %s", i, test.In, got, test.Out)
+		}
+	}
+}
+
+func TestCamelToLowerCamel(t *testing.T) {
+	for i, test := range []struct {
+		In, Out string
+	}{
+		{"", ""},
+		{"A", "a"},
+		{"SimpleExample", "simpleExample"},
+		{"internalField", "internalField"},
+
+		{"SomeHTTPStuff", "someHTTPStuff"},
+		{"WriteJSON", "writeJSON"},
+		{"HTTP2Server", "http2Server"},
+
+		{"JSONHTTPRPCServer", "jsonhttprpcServer"}, // nothing can be done here without a dictionary
+	} {
+		got := lowerFirst(test.In)
+		if got != test.Out {
+			t.Errorf("[%d] lowerFirst(%s) = %s; want %s", i, test.In, got, test.Out)
+		}
+	}
+}
+
+func TestJoinFunctionNameParts(t *testing.T) {
+	for i, test := range []struct {
+		keepFirst bool
+		parts     []string
+		out       string
+	}{
+		{false, []string{}, ""},
+		{false, []string{"a"}, "A"},
+		{false, []string{"simple", "example"}, "SimpleExample"},
+		{true, []string{"first", "example"}, "firstExample"},
+		{false, []string{"some", "UPPER", "case"}, "SomeUPPERCase"},
+		{false, []string{"number", "123"}, "Number123"},
+	} {
+		got := joinFunctionNameParts(test.keepFirst, test.parts...)
+		if got != test.out {
+			t.Errorf("[%d] joinFunctionNameParts(%v) = %s; want %s", i, test.parts, got, test.out)
+		}
+	}
+}
+
+func TestFixVendorPath(t *testing.T) {
+	for i, test := range []struct {
+		In, Out string
+	}{
+		{"", ""},
+		{"time", "time"},
+		{"project/vendor/subpackage", "subpackage"},
+	} {
+		got := fixPkgPathVendoring(test.In)
+		if got != test.Out {
+			t.Errorf("[%d] fixPkgPathVendoring(%s) = %s; want %s", i, test.In, got, test.Out)
+		}
+	}
+
+}