blob: 554b9c6c09a1fae51c688bef6c7a88123fd4c338 [file] [log] [blame]
// 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 proto
import (
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/internal/encoding/messageset"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/runtime/protoiface"
)
// Size returns the size in bytes of the wire-format encoding of m.
func Size(m Message) int {
return MarshalOptions{}.Size(m)
}
// Size returns the size in bytes of the wire-format encoding of m.
func (o MarshalOptions) Size(m Message) int {
// Treat a nil message interface as an empty message; nothing to output.
if m == nil {
return 0
}
return o.size(m.ProtoReflect())
}
// size is a centralized function that all size operations go through.
// For profiling purposes, avoid changing the name of this function or
// introducing other code paths for size that do not go through this.
func (o MarshalOptions) size(m protoreflect.Message) (size int) {
methods := protoMethods(m)
if methods != nil && methods.Size != nil {
out := methods.Size(protoiface.SizeInput{
Message: m,
})
return out.Size
}
if methods != nil && methods.Marshal != nil {
// This is not efficient, but we don't have any choice.
// This case is mainly used for legacy types with a Marshal method.
out, _ := methods.Marshal(protoiface.MarshalInput{
Message: m,
})
return len(out.Buf)
}
return o.sizeMessageSlow(m)
}
func (o MarshalOptions) sizeMessageSlow(m protoreflect.Message) (size int) {
if messageset.IsMessageSet(m.Descriptor()) {
return o.sizeMessageSet(m)
}
m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
size += o.sizeField(fd, v)
return true
})
size += len(m.GetUnknown())
return size
}
func (o MarshalOptions) sizeField(fd protoreflect.FieldDescriptor, value protoreflect.Value) (size int) {
num := fd.Number()
switch {
case fd.IsList():
return o.sizeList(num, fd, value.List())
case fd.IsMap():
return o.sizeMap(num, fd, value.Map())
default:
return protowire.SizeTag(num) + o.sizeSingular(num, fd.Kind(), value)
}
}
func (o MarshalOptions) sizeList(num protowire.Number, fd protoreflect.FieldDescriptor, list protoreflect.List) (size int) {
if fd.IsPacked() && list.Len() > 0 {
content := 0
for i, llen := 0, list.Len(); i < llen; i++ {
content += o.sizeSingular(num, fd.Kind(), list.Get(i))
}
return protowire.SizeTag(num) + protowire.SizeBytes(content)
}
for i, llen := 0, list.Len(); i < llen; i++ {
size += protowire.SizeTag(num) + o.sizeSingular(num, fd.Kind(), list.Get(i))
}
return size
}
func (o MarshalOptions) sizeMap(num protowire.Number, fd protoreflect.FieldDescriptor, mapv protoreflect.Map) (size int) {
mapv.Range(func(key protoreflect.MapKey, value protoreflect.Value) bool {
size += protowire.SizeTag(num)
size += protowire.SizeBytes(o.sizeField(fd.MapKey(), key.Value()) + o.sizeField(fd.MapValue(), value))
return true
})
return size
}