schnutibox/vendor/github.com/jhump/protoreflect/codec/encode_fields.go

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package codec
import (
"fmt"
"math"
"reflect"
"sort"
"github.com/golang/protobuf/proto"
"github.com/golang/protobuf/protoc-gen-go/descriptor"
"github.com/jhump/protoreflect/desc"
)
// EncodeZigZag64 does zig-zag encoding to convert the given
// signed 64-bit integer into a form that can be expressed
// efficiently as a varint, even for negative values.
func EncodeZigZag64(v int64) uint64 {
return (uint64(v) << 1) ^ uint64(v>>63)
}
// EncodeZigZag32 does zig-zag encoding to convert the given
// signed 32-bit integer into a form that can be expressed
// efficiently as a varint, even for negative values.
func EncodeZigZag32(v int32) uint64 {
return uint64((uint32(v) << 1) ^ uint32((v >> 31)))
}
func (cb *Buffer) EncodeFieldValue(fd *desc.FieldDescriptor, val interface{}) error {
if fd.IsMap() {
mp := val.(map[interface{}]interface{})
entryType := fd.GetMessageType()
keyType := entryType.FindFieldByNumber(1)
valType := entryType.FindFieldByNumber(2)
var entryBuffer Buffer
if cb.IsDeterministic() {
entryBuffer.SetDeterministic(true)
keys := make([]interface{}, 0, len(mp))
for k := range mp {
keys = append(keys, k)
}
sort.Sort(sortable(keys))
for _, k := range keys {
v := mp[k]
entryBuffer.Reset()
if err := entryBuffer.encodeFieldElement(keyType, k); err != nil {
return err
}
rv := reflect.ValueOf(v)
if rv.Kind() != reflect.Ptr || !rv.IsNil() {
if err := entryBuffer.encodeFieldElement(valType, v); err != nil {
return err
}
}
if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
return err
}
if err := cb.EncodeRawBytes(entryBuffer.Bytes()); err != nil {
return err
}
}
} else {
for k, v := range mp {
entryBuffer.Reset()
if err := entryBuffer.encodeFieldElement(keyType, k); err != nil {
return err
}
rv := reflect.ValueOf(v)
if rv.Kind() != reflect.Ptr || !rv.IsNil() {
if err := entryBuffer.encodeFieldElement(valType, v); err != nil {
return err
}
}
if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
return err
}
if err := cb.EncodeRawBytes(entryBuffer.Bytes()); err != nil {
return err
}
}
}
return nil
} else if fd.IsRepeated() {
sl := val.([]interface{})
wt, err := getWireType(fd.GetType())
if err != nil {
return err
}
if isPacked(fd) && len(sl) > 0 &&
(wt == proto.WireVarint || wt == proto.WireFixed32 || wt == proto.WireFixed64) {
// packed repeated field
var packedBuffer Buffer
for _, v := range sl {
if err := packedBuffer.encodeFieldValue(fd, v); err != nil {
return err
}
}
if err := cb.EncodeTagAndWireType(fd.GetNumber(), proto.WireBytes); err != nil {
return err
}
return cb.EncodeRawBytes(packedBuffer.Bytes())
} else {
// non-packed repeated field
for _, v := range sl {
if err := cb.encodeFieldElement(fd, v); err != nil {
return err
}
}
return nil
}
} else {
return cb.encodeFieldElement(fd, val)
}
}
func isPacked(fd *desc.FieldDescriptor) bool {
opts := fd.AsFieldDescriptorProto().GetOptions()
// if set, use that value
if opts != nil && opts.Packed != nil {
return opts.GetPacked()
}
// if unset: proto2 defaults to false, proto3 to true
return fd.GetFile().IsProto3()
}
// sortable is used to sort map keys. Values will be integers (int32, int64, uint32, and uint64),
// bools, or strings.
type sortable []interface{}
func (s sortable) Len() int {
return len(s)
}
func (s sortable) Less(i, j int) bool {
vi := s[i]
vj := s[j]
switch reflect.TypeOf(vi).Kind() {
case reflect.Int32:
return vi.(int32) < vj.(int32)
case reflect.Int64:
return vi.(int64) < vj.(int64)
case reflect.Uint32:
return vi.(uint32) < vj.(uint32)
case reflect.Uint64:
return vi.(uint64) < vj.(uint64)
case reflect.String:
return vi.(string) < vj.(string)
case reflect.Bool:
return !vi.(bool) && vj.(bool)
default:
panic(fmt.Sprintf("cannot compare keys of type %v", reflect.TypeOf(vi)))
}
}
func (s sortable) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (b *Buffer) encodeFieldElement(fd *desc.FieldDescriptor, val interface{}) error {
wt, err := getWireType(fd.GetType())
if err != nil {
return err
}
if err := b.EncodeTagAndWireType(fd.GetNumber(), wt); err != nil {
return err
}
if err := b.encodeFieldValue(fd, val); err != nil {
return err
}
if wt == proto.WireStartGroup {
return b.EncodeTagAndWireType(fd.GetNumber(), proto.WireEndGroup)
}
return nil
}
func (b *Buffer) encodeFieldValue(fd *desc.FieldDescriptor, val interface{}) error {
switch fd.GetType() {
case descriptor.FieldDescriptorProto_TYPE_BOOL:
v := val.(bool)
if v {
return b.EncodeVarint(1)
}
return b.EncodeVarint(0)
case descriptor.FieldDescriptorProto_TYPE_ENUM,
descriptor.FieldDescriptorProto_TYPE_INT32:
v := val.(int32)
return b.EncodeVarint(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
v := val.(int32)
return b.EncodeFixed32(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_SINT32:
v := val.(int32)
return b.EncodeVarint(EncodeZigZag32(v))
case descriptor.FieldDescriptorProto_TYPE_UINT32:
v := val.(uint32)
return b.EncodeVarint(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_FIXED32:
v := val.(uint32)
return b.EncodeFixed32(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_INT64:
v := val.(int64)
return b.EncodeVarint(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
v := val.(int64)
return b.EncodeFixed64(uint64(v))
case descriptor.FieldDescriptorProto_TYPE_SINT64:
v := val.(int64)
return b.EncodeVarint(EncodeZigZag64(v))
case descriptor.FieldDescriptorProto_TYPE_UINT64:
v := val.(uint64)
return b.EncodeVarint(v)
case descriptor.FieldDescriptorProto_TYPE_FIXED64:
v := val.(uint64)
return b.EncodeFixed64(v)
case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
v := val.(float64)
return b.EncodeFixed64(math.Float64bits(v))
case descriptor.FieldDescriptorProto_TYPE_FLOAT:
v := val.(float32)
return b.EncodeFixed32(uint64(math.Float32bits(v)))
case descriptor.FieldDescriptorProto_TYPE_BYTES:
v := val.([]byte)
return b.EncodeRawBytes(v)
case descriptor.FieldDescriptorProto_TYPE_STRING:
v := val.(string)
return b.EncodeRawBytes(([]byte)(v))
case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
return b.EncodeDelimitedMessage(val.(proto.Message))
case descriptor.FieldDescriptorProto_TYPE_GROUP:
// just append the nested message to this buffer
return b.EncodeMessage(val.(proto.Message))
// whosoever writeth start-group tag (e.g. caller) is responsible for writing end-group tag
default:
return fmt.Errorf("unrecognized field type: %v", fd.GetType())
}
}
func getWireType(t descriptor.FieldDescriptorProto_Type) (int8, error) {
switch t {
case descriptor.FieldDescriptorProto_TYPE_ENUM,
descriptor.FieldDescriptorProto_TYPE_BOOL,
descriptor.FieldDescriptorProto_TYPE_INT32,
descriptor.FieldDescriptorProto_TYPE_SINT32,
descriptor.FieldDescriptorProto_TYPE_UINT32,
descriptor.FieldDescriptorProto_TYPE_INT64,
descriptor.FieldDescriptorProto_TYPE_SINT64,
descriptor.FieldDescriptorProto_TYPE_UINT64:
return proto.WireVarint, nil
case descriptor.FieldDescriptorProto_TYPE_FIXED32,
descriptor.FieldDescriptorProto_TYPE_SFIXED32,
descriptor.FieldDescriptorProto_TYPE_FLOAT:
return proto.WireFixed32, nil
case descriptor.FieldDescriptorProto_TYPE_FIXED64,
descriptor.FieldDescriptorProto_TYPE_SFIXED64,
descriptor.FieldDescriptorProto_TYPE_DOUBLE:
return proto.WireFixed64, nil
case descriptor.FieldDescriptorProto_TYPE_BYTES,
descriptor.FieldDescriptorProto_TYPE_STRING,
descriptor.FieldDescriptorProto_TYPE_MESSAGE:
return proto.WireBytes, nil
case descriptor.FieldDescriptorProto_TYPE_GROUP:
return proto.WireStartGroup, nil
default:
return 0, ErrBadWireType
}
}