[VOL-4292] OpenOLT Adapter changes for gRPC migration

Change-Id: I5af2125f2c2f53ffc78c474a94314bba408f8bae
diff --git a/vendor/github.com/golang/protobuf/jsonpb/encode.go b/vendor/github.com/golang/protobuf/jsonpb/encode.go
new file mode 100644
index 0000000..685c80a
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/jsonpb/encode.go
@@ -0,0 +1,559 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package jsonpb
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/encoding/protojson"
+	protoV2 "google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+)
+
+const wrapJSONMarshalV2 = false
+
+// Marshaler is a configurable object for marshaling protocol buffer messages
+// to the specified JSON representation.
+type Marshaler struct {
+	// OrigName specifies whether to use the original protobuf name for fields.
+	OrigName bool
+
+	// EnumsAsInts specifies whether to render enum values as integers,
+	// as opposed to string values.
+	EnumsAsInts bool
+
+	// EmitDefaults specifies whether to render fields with zero values.
+	EmitDefaults bool
+
+	// Indent controls whether the output is compact or not.
+	// If empty, the output is compact JSON. Otherwise, every JSON object
+	// entry and JSON array value will be on its own line.
+	// Each line will be preceded by repeated copies of Indent, where the
+	// number of copies is the current indentation depth.
+	Indent string
+
+	// AnyResolver is used to resolve the google.protobuf.Any well-known type.
+	// If unset, the global registry is used by default.
+	AnyResolver AnyResolver
+}
+
+// JSONPBMarshaler is implemented by protobuf messages that customize the
+// way they are marshaled to JSON. Messages that implement this should also
+// implement JSONPBUnmarshaler so that the custom format can be parsed.
+//
+// The JSON marshaling must follow the proto to JSON specification:
+//	https://developers.google.com/protocol-buffers/docs/proto3#json
+//
+// Deprecated: Custom types should implement protobuf reflection instead.
+type JSONPBMarshaler interface {
+	MarshalJSONPB(*Marshaler) ([]byte, error)
+}
+
+// Marshal serializes a protobuf message as JSON into w.
+func (jm *Marshaler) Marshal(w io.Writer, m proto.Message) error {
+	b, err := jm.marshal(m)
+	if len(b) > 0 {
+		if _, err := w.Write(b); err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+// MarshalToString serializes a protobuf message as JSON in string form.
+func (jm *Marshaler) MarshalToString(m proto.Message) (string, error) {
+	b, err := jm.marshal(m)
+	if err != nil {
+		return "", err
+	}
+	return string(b), nil
+}
+
+func (jm *Marshaler) marshal(m proto.Message) ([]byte, error) {
+	v := reflect.ValueOf(m)
+	if m == nil || (v.Kind() == reflect.Ptr && v.IsNil()) {
+		return nil, errors.New("Marshal called with nil")
+	}
+
+	// Check for custom marshalers first since they may not properly
+	// implement protobuf reflection that the logic below relies on.
+	if jsm, ok := m.(JSONPBMarshaler); ok {
+		return jsm.MarshalJSONPB(jm)
+	}
+
+	if wrapJSONMarshalV2 {
+		opts := protojson.MarshalOptions{
+			UseProtoNames:   jm.OrigName,
+			UseEnumNumbers:  jm.EnumsAsInts,
+			EmitUnpopulated: jm.EmitDefaults,
+			Indent:          jm.Indent,
+		}
+		if jm.AnyResolver != nil {
+			opts.Resolver = anyResolver{jm.AnyResolver}
+		}
+		return opts.Marshal(proto.MessageReflect(m).Interface())
+	} else {
+		// Check for unpopulated required fields first.
+		m2 := proto.MessageReflect(m)
+		if err := protoV2.CheckInitialized(m2.Interface()); err != nil {
+			return nil, err
+		}
+
+		w := jsonWriter{Marshaler: jm}
+		err := w.marshalMessage(m2, "", "")
+		return w.buf, err
+	}
+}
+
+type jsonWriter struct {
+	*Marshaler
+	buf []byte
+}
+
+func (w *jsonWriter) write(s string) {
+	w.buf = append(w.buf, s...)
+}
+
+func (w *jsonWriter) marshalMessage(m protoreflect.Message, indent, typeURL string) error {
+	if jsm, ok := proto.MessageV1(m.Interface()).(JSONPBMarshaler); ok {
+		b, err := jsm.MarshalJSONPB(w.Marshaler)
+		if err != nil {
+			return err
+		}
+		if typeURL != "" {
+			// we are marshaling this object to an Any type
+			var js map[string]*json.RawMessage
+			if err = json.Unmarshal(b, &js); err != nil {
+				return fmt.Errorf("type %T produced invalid JSON: %v", m.Interface(), err)
+			}
+			turl, err := json.Marshal(typeURL)
+			if err != nil {
+				return fmt.Errorf("failed to marshal type URL %q to JSON: %v", typeURL, err)
+			}
+			js["@type"] = (*json.RawMessage)(&turl)
+			if b, err = json.Marshal(js); err != nil {
+				return err
+			}
+		}
+		w.write(string(b))
+		return nil
+	}
+
+	md := m.Descriptor()
+	fds := md.Fields()
+
+	// Handle well-known types.
+	const secondInNanos = int64(time.Second / time.Nanosecond)
+	switch wellKnownType(md.FullName()) {
+	case "Any":
+		return w.marshalAny(m, indent)
+	case "BoolValue", "BytesValue", "StringValue",
+		"Int32Value", "UInt32Value", "FloatValue",
+		"Int64Value", "UInt64Value", "DoubleValue":
+		fd := fds.ByNumber(1)
+		return w.marshalValue(fd, m.Get(fd), indent)
+	case "Duration":
+		const maxSecondsInDuration = 315576000000
+		// "Generated output always contains 0, 3, 6, or 9 fractional digits,
+		//  depending on required precision."
+		s := m.Get(fds.ByNumber(1)).Int()
+		ns := m.Get(fds.ByNumber(2)).Int()
+		if s < -maxSecondsInDuration || s > maxSecondsInDuration {
+			return fmt.Errorf("seconds out of range %v", s)
+		}
+		if ns <= -secondInNanos || ns >= secondInNanos {
+			return fmt.Errorf("ns out of range (%v, %v)", -secondInNanos, secondInNanos)
+		}
+		if (s > 0 && ns < 0) || (s < 0 && ns > 0) {
+			return errors.New("signs of seconds and nanos do not match")
+		}
+		var sign string
+		if s < 0 || ns < 0 {
+			sign, s, ns = "-", -1*s, -1*ns
+		}
+		x := fmt.Sprintf("%s%d.%09d", sign, s, ns)
+		x = strings.TrimSuffix(x, "000")
+		x = strings.TrimSuffix(x, "000")
+		x = strings.TrimSuffix(x, ".000")
+		w.write(fmt.Sprintf(`"%vs"`, x))
+		return nil
+	case "Timestamp":
+		// "RFC 3339, where generated output will always be Z-normalized
+		//  and uses 0, 3, 6 or 9 fractional digits."
+		s := m.Get(fds.ByNumber(1)).Int()
+		ns := m.Get(fds.ByNumber(2)).Int()
+		if ns < 0 || ns >= secondInNanos {
+			return fmt.Errorf("ns out of range [0, %v)", secondInNanos)
+		}
+		t := time.Unix(s, ns).UTC()
+		// time.RFC3339Nano isn't exactly right (we need to get 3/6/9 fractional digits).
+		x := t.Format("2006-01-02T15:04:05.000000000")
+		x = strings.TrimSuffix(x, "000")
+		x = strings.TrimSuffix(x, "000")
+		x = strings.TrimSuffix(x, ".000")
+		w.write(fmt.Sprintf(`"%vZ"`, x))
+		return nil
+	case "Value":
+		// JSON value; which is a null, number, string, bool, object, or array.
+		od := md.Oneofs().Get(0)
+		fd := m.WhichOneof(od)
+		if fd == nil {
+			return errors.New("nil Value")
+		}
+		return w.marshalValue(fd, m.Get(fd), indent)
+	case "Struct", "ListValue":
+		// JSON object or array.
+		fd := fds.ByNumber(1)
+		return w.marshalValue(fd, m.Get(fd), indent)
+	}
+
+	w.write("{")
+	if w.Indent != "" {
+		w.write("\n")
+	}
+
+	firstField := true
+	if typeURL != "" {
+		if err := w.marshalTypeURL(indent, typeURL); err != nil {
+			return err
+		}
+		firstField = false
+	}
+
+	for i := 0; i < fds.Len(); {
+		fd := fds.Get(i)
+		if od := fd.ContainingOneof(); od != nil {
+			fd = m.WhichOneof(od)
+			i += od.Fields().Len()
+			if fd == nil {
+				continue
+			}
+		} else {
+			i++
+		}
+
+		v := m.Get(fd)
+
+		if !m.Has(fd) {
+			if !w.EmitDefaults || fd.ContainingOneof() != nil {
+				continue
+			}
+			if fd.Cardinality() != protoreflect.Repeated && (fd.Message() != nil || fd.Syntax() == protoreflect.Proto2) {
+				v = protoreflect.Value{} // use "null" for singular messages or proto2 scalars
+			}
+		}
+
+		if !firstField {
+			w.writeComma()
+		}
+		if err := w.marshalField(fd, v, indent); err != nil {
+			return err
+		}
+		firstField = false
+	}
+
+	// Handle proto2 extensions.
+	if md.ExtensionRanges().Len() > 0 {
+		// Collect a sorted list of all extension descriptor and values.
+		type ext struct {
+			desc protoreflect.FieldDescriptor
+			val  protoreflect.Value
+		}
+		var exts []ext
+		m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+			if fd.IsExtension() {
+				exts = append(exts, ext{fd, v})
+			}
+			return true
+		})
+		sort.Slice(exts, func(i, j int) bool {
+			return exts[i].desc.Number() < exts[j].desc.Number()
+		})
+
+		for _, ext := range exts {
+			if !firstField {
+				w.writeComma()
+			}
+			if err := w.marshalField(ext.desc, ext.val, indent); err != nil {
+				return err
+			}
+			firstField = false
+		}
+	}
+
+	if w.Indent != "" {
+		w.write("\n")
+		w.write(indent)
+	}
+	w.write("}")
+	return nil
+}
+
+func (w *jsonWriter) writeComma() {
+	if w.Indent != "" {
+		w.write(",\n")
+	} else {
+		w.write(",")
+	}
+}
+
+func (w *jsonWriter) marshalAny(m protoreflect.Message, indent string) error {
+	// "If the Any contains a value that has a special JSON mapping,
+	//  it will be converted as follows: {"@type": xxx, "value": yyy}.
+	//  Otherwise, the value will be converted into a JSON object,
+	//  and the "@type" field will be inserted to indicate the actual data type."
+	md := m.Descriptor()
+	typeURL := m.Get(md.Fields().ByNumber(1)).String()
+	rawVal := m.Get(md.Fields().ByNumber(2)).Bytes()
+
+	var m2 protoreflect.Message
+	if w.AnyResolver != nil {
+		mi, err := w.AnyResolver.Resolve(typeURL)
+		if err != nil {
+			return err
+		}
+		m2 = proto.MessageReflect(mi)
+	} else {
+		mt, err := protoregistry.GlobalTypes.FindMessageByURL(typeURL)
+		if err != nil {
+			return err
+		}
+		m2 = mt.New()
+	}
+
+	if err := protoV2.Unmarshal(rawVal, m2.Interface()); err != nil {
+		return err
+	}
+
+	if wellKnownType(m2.Descriptor().FullName()) == "" {
+		return w.marshalMessage(m2, indent, typeURL)
+	}
+
+	w.write("{")
+	if w.Indent != "" {
+		w.write("\n")
+	}
+	if err := w.marshalTypeURL(indent, typeURL); err != nil {
+		return err
+	}
+	w.writeComma()
+	if w.Indent != "" {
+		w.write(indent)
+		w.write(w.Indent)
+		w.write(`"value": `)
+	} else {
+		w.write(`"value":`)
+	}
+	if err := w.marshalMessage(m2, indent+w.Indent, ""); err != nil {
+		return err
+	}
+	if w.Indent != "" {
+		w.write("\n")
+		w.write(indent)
+	}
+	w.write("}")
+	return nil
+}
+
+func (w *jsonWriter) marshalTypeURL(indent, typeURL string) error {
+	if w.Indent != "" {
+		w.write(indent)
+		w.write(w.Indent)
+	}
+	w.write(`"@type":`)
+	if w.Indent != "" {
+		w.write(" ")
+	}
+	b, err := json.Marshal(typeURL)
+	if err != nil {
+		return err
+	}
+	w.write(string(b))
+	return nil
+}
+
+// marshalField writes field description and value to the Writer.
+func (w *jsonWriter) marshalField(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
+	if w.Indent != "" {
+		w.write(indent)
+		w.write(w.Indent)
+	}
+	w.write(`"`)
+	switch {
+	case fd.IsExtension():
+		// For message set, use the fname of the message as the extension name.
+		name := string(fd.FullName())
+		if isMessageSet(fd.ContainingMessage()) {
+			name = strings.TrimSuffix(name, ".message_set_extension")
+		}
+
+		w.write("[" + name + "]")
+	case w.OrigName:
+		name := string(fd.Name())
+		if fd.Kind() == protoreflect.GroupKind {
+			name = string(fd.Message().Name())
+		}
+		w.write(name)
+	default:
+		w.write(string(fd.JSONName()))
+	}
+	w.write(`":`)
+	if w.Indent != "" {
+		w.write(" ")
+	}
+	return w.marshalValue(fd, v, indent)
+}
+
+func (w *jsonWriter) marshalValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
+	switch {
+	case fd.IsList():
+		w.write("[")
+		comma := ""
+		lv := v.List()
+		for i := 0; i < lv.Len(); i++ {
+			w.write(comma)
+			if w.Indent != "" {
+				w.write("\n")
+				w.write(indent)
+				w.write(w.Indent)
+				w.write(w.Indent)
+			}
+			if err := w.marshalSingularValue(fd, lv.Get(i), indent+w.Indent); err != nil {
+				return err
+			}
+			comma = ","
+		}
+		if w.Indent != "" {
+			w.write("\n")
+			w.write(indent)
+			w.write(w.Indent)
+		}
+		w.write("]")
+		return nil
+	case fd.IsMap():
+		kfd := fd.MapKey()
+		vfd := fd.MapValue()
+		mv := v.Map()
+
+		// Collect a sorted list of all map keys and values.
+		type entry struct{ key, val protoreflect.Value }
+		var entries []entry
+		mv.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool {
+			entries = append(entries, entry{k.Value(), v})
+			return true
+		})
+		sort.Slice(entries, func(i, j int) bool {
+			switch kfd.Kind() {
+			case protoreflect.BoolKind:
+				return !entries[i].key.Bool() && entries[j].key.Bool()
+			case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind, protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
+				return entries[i].key.Int() < entries[j].key.Int()
+			case protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
+				return entries[i].key.Uint() < entries[j].key.Uint()
+			case protoreflect.StringKind:
+				return entries[i].key.String() < entries[j].key.String()
+			default:
+				panic("invalid kind")
+			}
+		})
+
+		w.write(`{`)
+		comma := ""
+		for _, entry := range entries {
+			w.write(comma)
+			if w.Indent != "" {
+				w.write("\n")
+				w.write(indent)
+				w.write(w.Indent)
+				w.write(w.Indent)
+			}
+
+			s := fmt.Sprint(entry.key.Interface())
+			b, err := json.Marshal(s)
+			if err != nil {
+				return err
+			}
+			w.write(string(b))
+
+			w.write(`:`)
+			if w.Indent != "" {
+				w.write(` `)
+			}
+
+			if err := w.marshalSingularValue(vfd, entry.val, indent+w.Indent); err != nil {
+				return err
+			}
+			comma = ","
+		}
+		if w.Indent != "" {
+			w.write("\n")
+			w.write(indent)
+			w.write(w.Indent)
+		}
+		w.write(`}`)
+		return nil
+	default:
+		return w.marshalSingularValue(fd, v, indent)
+	}
+}
+
+func (w *jsonWriter) marshalSingularValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
+	switch {
+	case !v.IsValid():
+		w.write("null")
+		return nil
+	case fd.Message() != nil:
+		return w.marshalMessage(v.Message(), indent+w.Indent, "")
+	case fd.Enum() != nil:
+		if fd.Enum().FullName() == "google.protobuf.NullValue" {
+			w.write("null")
+			return nil
+		}
+
+		vd := fd.Enum().Values().ByNumber(v.Enum())
+		if vd == nil || w.EnumsAsInts {
+			w.write(strconv.Itoa(int(v.Enum())))
+		} else {
+			w.write(`"` + string(vd.Name()) + `"`)
+		}
+		return nil
+	default:
+		switch v.Interface().(type) {
+		case float32, float64:
+			switch {
+			case math.IsInf(v.Float(), +1):
+				w.write(`"Infinity"`)
+				return nil
+			case math.IsInf(v.Float(), -1):
+				w.write(`"-Infinity"`)
+				return nil
+			case math.IsNaN(v.Float()):
+				w.write(`"NaN"`)
+				return nil
+			}
+		case int64, uint64:
+			w.write(fmt.Sprintf(`"%d"`, v.Interface()))
+			return nil
+		}
+
+		b, err := json.Marshal(v.Interface())
+		if err != nil {
+			return err
+		}
+		w.write(string(b))
+		return nil
+	}
+}