+++ /dev/null
-// Go support for Protocol Buffers - Google's data interchange format
-//
-// Copyright 2011 The Go Authors. All rights reserved.
-// https://github.com/golang/protobuf
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Protocol buffer deep copy and merge.
-// TODO: RawMessage.
-
-package proto
-
-import (
- "fmt"
- "log"
- "reflect"
- "strings"
-)
-
-// Clone returns a deep copy of a protocol buffer.
-func Clone(src Message) Message {
- in := reflect.ValueOf(src)
- if in.IsNil() {
- return src
- }
- out := reflect.New(in.Type().Elem())
- dst := out.Interface().(Message)
- Merge(dst, src)
- return dst
-}
-
-// Merger is the interface representing objects that can merge messages of the same type.
-type Merger interface {
- // Merge merges src into this message.
- // Required and optional fields that are set in src will be set to that value in dst.
- // Elements of repeated fields will be appended.
- //
- // Merge may panic if called with a different argument type than the receiver.
- Merge(src Message)
-}
-
-// generatedMerger is the custom merge method that generated protos will have.
-// We must add this method since a generate Merge method will conflict with
-// many existing protos that have a Merge data field already defined.
-type generatedMerger interface {
- XXX_Merge(src Message)
-}
-
-// Merge merges src into dst.
-// Required and optional fields that are set in src will be set to that value in dst.
-// Elements of repeated fields will be appended.
-// Merge panics if src and dst are not the same type, or if dst is nil.
-func Merge(dst, src Message) {
- if m, ok := dst.(Merger); ok {
- m.Merge(src)
- return
- }
-
- in := reflect.ValueOf(src)
- out := reflect.ValueOf(dst)
- if out.IsNil() {
- panic("proto: nil destination")
- }
- if in.Type() != out.Type() {
- panic(fmt.Sprintf("proto.Merge(%T, %T) type mismatch", dst, src))
- }
- if in.IsNil() {
- return // Merge from nil src is a noop
- }
- if m, ok := dst.(generatedMerger); ok {
- m.XXX_Merge(src)
- return
- }
- mergeStruct(out.Elem(), in.Elem())
-}
-
-func mergeStruct(out, in reflect.Value) {
- sprop := GetProperties(in.Type())
- for i := 0; i < in.NumField(); i++ {
- f := in.Type().Field(i)
- if strings.HasPrefix(f.Name, "XXX_") {
- continue
- }
- mergeAny(out.Field(i), in.Field(i), false, sprop.Prop[i])
- }
-
- if emIn, ok := in.Addr().Interface().(extensionsBytes); ok {
- emOut := out.Addr().Interface().(extensionsBytes)
- bIn := emIn.GetExtensions()
- bOut := emOut.GetExtensions()
- *bOut = append(*bOut, *bIn...)
- } else if emIn, err := extendable(in.Addr().Interface()); err == nil {
- emOut, _ := extendable(out.Addr().Interface())
- mIn, muIn := emIn.extensionsRead()
- if mIn != nil {
- mOut := emOut.extensionsWrite()
- muIn.Lock()
- mergeExtension(mOut, mIn)
- muIn.Unlock()
- }
- }
-
- uf := in.FieldByName("XXX_unrecognized")
- if !uf.IsValid() {
- return
- }
- uin := uf.Bytes()
- if len(uin) > 0 {
- out.FieldByName("XXX_unrecognized").SetBytes(append([]byte(nil), uin...))
- }
-}
-
-// mergeAny performs a merge between two values of the same type.
-// viaPtr indicates whether the values were indirected through a pointer (implying proto2).
-// prop is set if this is a struct field (it may be nil).
-func mergeAny(out, in reflect.Value, viaPtr bool, prop *Properties) {
- if in.Type() == protoMessageType {
- if !in.IsNil() {
- if out.IsNil() {
- out.Set(reflect.ValueOf(Clone(in.Interface().(Message))))
- } else {
- Merge(out.Interface().(Message), in.Interface().(Message))
- }
- }
- return
- }
- switch in.Kind() {
- case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
- reflect.String, reflect.Uint32, reflect.Uint64:
- if !viaPtr && isProto3Zero(in) {
- return
- }
- out.Set(in)
- case reflect.Interface:
- // Probably a oneof field; copy non-nil values.
- if in.IsNil() {
- return
- }
- // Allocate destination if it is not set, or set to a different type.
- // Otherwise we will merge as normal.
- if out.IsNil() || out.Elem().Type() != in.Elem().Type() {
- out.Set(reflect.New(in.Elem().Elem().Type())) // interface -> *T -> T -> new(T)
- }
- mergeAny(out.Elem(), in.Elem(), false, nil)
- case reflect.Map:
- if in.Len() == 0 {
- return
- }
- if out.IsNil() {
- out.Set(reflect.MakeMap(in.Type()))
- }
- // For maps with value types of *T or []byte we need to deep copy each value.
- elemKind := in.Type().Elem().Kind()
- for _, key := range in.MapKeys() {
- var val reflect.Value
- switch elemKind {
- case reflect.Ptr:
- val = reflect.New(in.Type().Elem().Elem())
- mergeAny(val, in.MapIndex(key), false, nil)
- case reflect.Slice:
- val = in.MapIndex(key)
- val = reflect.ValueOf(append([]byte{}, val.Bytes()...))
- default:
- val = in.MapIndex(key)
- }
- out.SetMapIndex(key, val)
- }
- case reflect.Ptr:
- if in.IsNil() {
- return
- }
- if out.IsNil() {
- out.Set(reflect.New(in.Elem().Type()))
- }
- mergeAny(out.Elem(), in.Elem(), true, nil)
- case reflect.Slice:
- if in.IsNil() {
- return
- }
- if in.Type().Elem().Kind() == reflect.Uint8 {
- // []byte is a scalar bytes field, not a repeated field.
-
- // Edge case: if this is in a proto3 message, a zero length
- // bytes field is considered the zero value, and should not
- // be merged.
- if prop != nil && prop.proto3 && in.Len() == 0 {
- return
- }
-
- // Make a deep copy.
- // Append to []byte{} instead of []byte(nil) so that we never end up
- // with a nil result.
- out.SetBytes(append([]byte{}, in.Bytes()...))
- return
- }
- n := in.Len()
- if out.IsNil() {
- out.Set(reflect.MakeSlice(in.Type(), 0, n))
- }
- switch in.Type().Elem().Kind() {
- case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
- reflect.String, reflect.Uint32, reflect.Uint64:
- out.Set(reflect.AppendSlice(out, in))
- default:
- for i := 0; i < n; i++ {
- x := reflect.Indirect(reflect.New(in.Type().Elem()))
- mergeAny(x, in.Index(i), false, nil)
- out.Set(reflect.Append(out, x))
- }
- }
- case reflect.Struct:
- mergeStruct(out, in)
- default:
- // unknown type, so not a protocol buffer
- log.Printf("proto: don't know how to copy %v", in)
- }
-}
-
-func mergeExtension(out, in map[int32]Extension) {
- for extNum, eIn := range in {
- eOut := Extension{desc: eIn.desc}
- if eIn.value != nil {
- v := reflect.New(reflect.TypeOf(eIn.value)).Elem()
- mergeAny(v, reflect.ValueOf(eIn.value), false, nil)
- eOut.value = v.Interface()
- }
- if eIn.enc != nil {
- eOut.enc = make([]byte, len(eIn.enc))
- copy(eOut.enc, eIn.enc)
- }
-
- out[extNum] = eOut
- }
-}
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