| // 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 ( |
| "fmt" |
| |
| "github.com/golang/protobuf/v2/internal/encoding/wire" |
| "github.com/golang/protobuf/v2/reflect/protoreflect" |
| ) |
| |
| // 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 { |
| if size, err := sizeMessageFast(m); err == nil { |
| return size |
| } |
| return sizeMessage(m.ProtoReflect()) |
| } |
| |
| func sizeMessageFast(m Message) (int, error) { |
| // TODO: Pass MarshalOptions to size to permit disabling fast path? |
| methods := protoMethods(m) |
| if methods == nil || methods.Size == nil { |
| return 0, errInternalNoFast |
| } |
| return methods.Size(m), nil |
| } |
| |
| func sizeMessage(m protoreflect.Message) (size int) { |
| fields := m.Type().Fields() |
| knownFields := m.KnownFields() |
| m.KnownFields().Range(func(num protoreflect.FieldNumber, value protoreflect.Value) bool { |
| field := fields.ByNumber(num) |
| if field == nil { |
| field = knownFields.ExtensionTypes().ByNumber(num) |
| if field == nil { |
| panic(fmt.Errorf("no descriptor for field %d in %q", num, m.Type().FullName())) |
| } |
| } |
| size += sizeField(field, value) |
| return true |
| }) |
| m.UnknownFields().Range(func(_ protoreflect.FieldNumber, raw protoreflect.RawFields) bool { |
| size += len(raw) |
| return true |
| }) |
| return size |
| } |
| |
| func sizeField(field protoreflect.FieldDescriptor, value protoreflect.Value) (size int) { |
| num := field.Number() |
| kind := field.Kind() |
| switch { |
| case field.Cardinality() != protoreflect.Repeated: |
| return wire.SizeTag(num) + sizeSingular(num, kind, value) |
| case field.IsMap(): |
| return sizeMap(num, kind, field.Message(), value.Map()) |
| case field.IsPacked(): |
| return sizePacked(num, kind, value.List()) |
| default: |
| return sizeList(num, kind, value.List()) |
| } |
| } |
| |
| func sizeMap(num wire.Number, kind protoreflect.Kind, mdesc protoreflect.MessageDescriptor, mapv protoreflect.Map) (size int) { |
| keyf := mdesc.Fields().ByNumber(1) |
| valf := mdesc.Fields().ByNumber(2) |
| mapv.Range(func(key protoreflect.MapKey, value protoreflect.Value) bool { |
| size += wire.SizeTag(num) |
| size += wire.SizeBytes(sizeField(keyf, key.Value()) + sizeField(valf, value)) |
| return true |
| }) |
| return size |
| } |
| |
| func sizePacked(num wire.Number, kind protoreflect.Kind, list protoreflect.List) (size int) { |
| content := 0 |
| for i, llen := 0, list.Len(); i < llen; i++ { |
| content += sizeSingular(num, kind, list.Get(i)) |
| } |
| return wire.SizeTag(num) + wire.SizeBytes(content) |
| } |
| |
| func sizeList(num wire.Number, kind protoreflect.Kind, list protoreflect.List) (size int) { |
| for i, llen := 0, list.Len(); i < llen; i++ { |
| size += wire.SizeTag(num) + sizeSingular(num, kind, list.Get(i)) |
| } |
| return size |
| } |