dispatch/vendor/google.golang.org/protobuf/internal/impl/codec_map.go

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2020-04-22 23:06:36 +00:00
// Copyright 2019 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 impl
import (
"errors"
"reflect"
"sort"
"google.golang.org/protobuf/encoding/protowire"
pref "google.golang.org/protobuf/reflect/protoreflect"
)
type mapInfo struct {
goType reflect.Type
keyWiretag uint64
valWiretag uint64
keyFuncs valueCoderFuncs
valFuncs valueCoderFuncs
keyZero pref.Value
keyKind pref.Kind
conv *mapConverter
}
func encoderFuncsForMap(fd pref.FieldDescriptor, ft reflect.Type) (valueMessage *MessageInfo, funcs pointerCoderFuncs) {
// TODO: Consider generating specialized map coders.
keyField := fd.MapKey()
valField := fd.MapValue()
keyWiretag := protowire.EncodeTag(1, wireTypes[keyField.Kind()])
valWiretag := protowire.EncodeTag(2, wireTypes[valField.Kind()])
keyFuncs := encoderFuncsForValue(keyField)
valFuncs := encoderFuncsForValue(valField)
conv := newMapConverter(ft, fd)
mapi := &mapInfo{
goType: ft,
keyWiretag: keyWiretag,
valWiretag: valWiretag,
keyFuncs: keyFuncs,
valFuncs: valFuncs,
keyZero: keyField.Default(),
keyKind: keyField.Kind(),
conv: conv,
}
if valField.Kind() == pref.MessageKind {
valueMessage = getMessageInfo(ft.Elem())
}
funcs = pointerCoderFuncs{
size: func(p pointer, f *coderFieldInfo, opts marshalOptions) int {
return sizeMap(p.AsValueOf(ft).Elem(), mapi, f, opts)
},
marshal: func(b []byte, p pointer, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
return appendMap(b, p.AsValueOf(ft).Elem(), mapi, f, opts)
},
unmarshal: func(b []byte, p pointer, wtyp protowire.Type, f *coderFieldInfo, opts unmarshalOptions) (unmarshalOutput, error) {
mp := p.AsValueOf(ft)
if mp.Elem().IsNil() {
mp.Elem().Set(reflect.MakeMap(mapi.goType))
}
if f.mi == nil {
return consumeMap(b, mp.Elem(), wtyp, mapi, f, opts)
} else {
return consumeMapOfMessage(b, mp.Elem(), wtyp, mapi, f, opts)
}
},
}
switch valField.Kind() {
case pref.MessageKind:
funcs.merge = mergeMapOfMessage
case pref.BytesKind:
funcs.merge = mergeMapOfBytes
default:
funcs.merge = mergeMap
}
if valFuncs.isInit != nil {
funcs.isInit = func(p pointer, f *coderFieldInfo) error {
return isInitMap(p.AsValueOf(ft).Elem(), mapi, f)
}
}
return valueMessage, funcs
}
const (
mapKeyTagSize = 1 // field 1, tag size 1.
mapValTagSize = 1 // field 2, tag size 2.
)
func sizeMap(mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) int {
if mapv.Len() == 0 {
return 0
}
n := 0
iter := mapRange(mapv)
for iter.Next() {
key := mapi.conv.keyConv.PBValueOf(iter.Key()).MapKey()
keySize := mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
var valSize int
value := mapi.conv.valConv.PBValueOf(iter.Value())
if f.mi == nil {
valSize = mapi.valFuncs.size(value, mapValTagSize, opts)
} else {
p := pointerOfValue(iter.Value())
valSize += mapValTagSize
valSize += protowire.SizeBytes(f.mi.sizePointer(p, opts))
}
n += f.tagsize + protowire.SizeBytes(keySize+valSize)
}
return n
}
func consumeMap(b []byte, mapv reflect.Value, wtyp protowire.Type, mapi *mapInfo, f *coderFieldInfo, opts unmarshalOptions) (out unmarshalOutput, err error) {
if wtyp != protowire.BytesType {
return out, errUnknown
}
b, n := protowire.ConsumeBytes(b)
if n < 0 {
return out, protowire.ParseError(n)
}
var (
key = mapi.keyZero
val = mapi.conv.valConv.New()
)
for len(b) > 0 {
num, wtyp, n := protowire.ConsumeTag(b)
if n < 0 {
return out, protowire.ParseError(n)
}
if num > protowire.MaxValidNumber {
return out, errors.New("invalid field number")
}
b = b[n:]
err := errUnknown
switch num {
case 1:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.keyFuncs.unmarshal(b, key, num, wtyp, opts)
if err != nil {
break
}
key = v
n = o.n
case 2:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.valFuncs.unmarshal(b, val, num, wtyp, opts)
if err != nil {
break
}
val = v
n = o.n
}
if err == errUnknown {
n = protowire.ConsumeFieldValue(num, wtyp, b)
if n < 0 {
return out, protowire.ParseError(n)
}
} else if err != nil {
return out, err
}
b = b[n:]
}
mapv.SetMapIndex(mapi.conv.keyConv.GoValueOf(key), mapi.conv.valConv.GoValueOf(val))
out.n = n
return out, nil
}
func consumeMapOfMessage(b []byte, mapv reflect.Value, wtyp protowire.Type, mapi *mapInfo, f *coderFieldInfo, opts unmarshalOptions) (out unmarshalOutput, err error) {
if wtyp != protowire.BytesType {
return out, errUnknown
}
b, n := protowire.ConsumeBytes(b)
if n < 0 {
return out, protowire.ParseError(n)
}
var (
key = mapi.keyZero
val = reflect.New(f.mi.GoReflectType.Elem())
)
for len(b) > 0 {
num, wtyp, n := protowire.ConsumeTag(b)
if n < 0 {
return out, protowire.ParseError(n)
}
if num > protowire.MaxValidNumber {
return out, errors.New("invalid field number")
}
b = b[n:]
err := errUnknown
switch num {
case 1:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.keyFuncs.unmarshal(b, key, num, wtyp, opts)
if err != nil {
break
}
key = v
n = o.n
case 2:
if wtyp != protowire.BytesType {
break
}
var v []byte
v, n = protowire.ConsumeBytes(b)
if n < 0 {
return out, protowire.ParseError(n)
}
var o unmarshalOutput
o, err = f.mi.unmarshalPointer(v, pointerOfValue(val), 0, opts)
if o.initialized {
// Consider this map item initialized so long as we see
// an initialized value.
out.initialized = true
}
}
if err == errUnknown {
n = protowire.ConsumeFieldValue(num, wtyp, b)
if n < 0 {
return out, protowire.ParseError(n)
}
} else if err != nil {
return out, err
}
b = b[n:]
}
mapv.SetMapIndex(mapi.conv.keyConv.GoValueOf(key), val)
out.n = n
return out, nil
}
func appendMapItem(b []byte, keyrv, valrv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
if f.mi == nil {
key := mapi.conv.keyConv.PBValueOf(keyrv).MapKey()
val := mapi.conv.valConv.PBValueOf(valrv)
size := 0
size += mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
size += mapi.valFuncs.size(val, mapValTagSize, opts)
b = protowire.AppendVarint(b, uint64(size))
b, err := mapi.keyFuncs.marshal(b, key.Value(), mapi.keyWiretag, opts)
if err != nil {
return nil, err
}
return mapi.valFuncs.marshal(b, val, mapi.valWiretag, opts)
} else {
key := mapi.conv.keyConv.PBValueOf(keyrv).MapKey()
val := pointerOfValue(valrv)
valSize := f.mi.sizePointer(val, opts)
size := 0
size += mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
size += mapValTagSize + protowire.SizeBytes(valSize)
b = protowire.AppendVarint(b, uint64(size))
b, err := mapi.keyFuncs.marshal(b, key.Value(), mapi.keyWiretag, opts)
if err != nil {
return nil, err
}
b = protowire.AppendVarint(b, mapi.valWiretag)
b = protowire.AppendVarint(b, uint64(valSize))
return f.mi.marshalAppendPointer(b, val, opts)
}
}
func appendMap(b []byte, mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
if mapv.Len() == 0 {
return b, nil
}
if opts.Deterministic() {
return appendMapDeterministic(b, mapv, mapi, f, opts)
}
iter := mapRange(mapv)
for iter.Next() {
var err error
b = protowire.AppendVarint(b, f.wiretag)
b, err = appendMapItem(b, iter.Key(), iter.Value(), mapi, f, opts)
if err != nil {
return b, err
}
}
return b, nil
}
func appendMapDeterministic(b []byte, mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
keys := mapv.MapKeys()
sort.Slice(keys, func(i, j int) bool {
switch keys[i].Kind() {
case reflect.Bool:
return !keys[i].Bool() && keys[j].Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return keys[i].Int() < keys[j].Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return keys[i].Uint() < keys[j].Uint()
case reflect.Float32, reflect.Float64:
return keys[i].Float() < keys[j].Float()
case reflect.String:
return keys[i].String() < keys[j].String()
default:
panic("invalid kind: " + keys[i].Kind().String())
}
})
for _, key := range keys {
var err error
b = protowire.AppendVarint(b, f.wiretag)
b, err = appendMapItem(b, key, mapv.MapIndex(key), mapi, f, opts)
if err != nil {
return b, err
}
}
return b, nil
}
func isInitMap(mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo) error {
if mi := f.mi; mi != nil {
mi.init()
if !mi.needsInitCheck {
return nil
}
iter := mapRange(mapv)
for iter.Next() {
val := pointerOfValue(iter.Value())
if err := mi.checkInitializedPointer(val); err != nil {
return err
}
}
} else {
iter := mapRange(mapv)
for iter.Next() {
val := mapi.conv.valConv.PBValueOf(iter.Value())
if err := mapi.valFuncs.isInit(val); err != nil {
return err
}
}
}
return nil
}
func mergeMap(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
dstm.SetMapIndex(iter.Key(), iter.Value())
}
}
func mergeMapOfBytes(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
dstm.SetMapIndex(iter.Key(), reflect.ValueOf(append(emptyBuf[:], iter.Value().Bytes()...)))
}
}
func mergeMapOfMessage(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
val := reflect.New(f.ft.Elem().Elem())
if f.mi != nil {
f.mi.mergePointer(pointerOfValue(val), pointerOfValue(iter.Value()), opts)
} else {
opts.Merge(asMessage(val), asMessage(iter.Value()))
}
dstm.SetMapIndex(iter.Key(), val)
}
}