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Diffstat (limited to 'vendor/github.com/golang/protobuf/proto/clone.go')
-rw-r--r-- | vendor/github.com/golang/protobuf/proto/clone.go | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/vendor/github.com/golang/protobuf/proto/clone.go b/vendor/github.com/golang/protobuf/proto/clone.go new file mode 100644 index 00000000..e392575b --- /dev/null +++ b/vendor/github.com/golang/protobuf/proto/clone.go @@ -0,0 +1,229 @@ +// 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 ( + "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) { + 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 := extendable(in.Addr().Interface()); ok { + 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 + } +} |