| // 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: MessageSet and RawMessage. |
| |
| package proto |
| |
| import ( |
| "log" |
| "reflect" |
| "strings" |
| ) |
| |
| // Clone returns a deep copy of a protocol buffer. |
| func Clone(pb Message) Message { |
| in := reflect.ValueOf(pb) |
| if in.IsNil() { |
| return pb |
| } |
| |
| out := reflect.New(in.Type().Elem()) |
| // out is empty so a merge is a deep copy. |
| mergeStruct(out.Elem(), in.Elem()) |
| return out.Interface().(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) { |
| in := reflect.ValueOf(src) |
| out := reflect.ValueOf(dst) |
| if out.IsNil() { |
| panic("proto: nil destination") |
| } |
| if in.Type() != out.Type() { |
| // Explicit test prior to mergeStruct so that mistyped nils will fail |
| panic("proto: type mismatch") |
| } |
| if in.IsNil() { |
| // Merging nil into non-nil is a quiet no-op |
| return |
| } |
| mergeStruct(out.Elem(), in.Elem()) |
| } |
| |
| func mergeStruct(out, in reflect.Value) { |
| 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)) |
| } |
| |
| if emIn, ok := in.Addr().Interface().(extendableProto); ok { |
| emOut := out.Addr().Interface().(extendableProto) |
| mergeExtension(emOut.ExtensionMap(), emIn.ExtensionMap()) |
| } |
| |
| 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...)) |
| } |
| } |
| |
| func mergeAny(out, in reflect.Value) { |
| 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: |
| out.Set(in) |
| 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)) |
| 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()) |
| case reflect.Slice: |
| if in.IsNil() { |
| return |
| } |
| if in.Type().Elem().Kind() == reflect.Uint8 { |
| // []byte is a scalar bytes field, not a repeated field. |
| // 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)) |
| 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)) |
| eOut.value = v.Interface() |
| } |
| if eIn.enc != nil { |
| eOut.enc = make([]byte, len(eIn.enc)) |
| copy(eOut.enc, eIn.enc) |
| } |
| |
| out[extNum] = eOut |
| } |
| } |