protobuf-go/proto/reset.go
Joe Tsai 705acadcc7 proto: reset message by default in Unmarshal
We change Unmarshal to reset a message by default.
* We add a Merge option to UnmarshalOptions for explicit merging.
* We speed up Reset by checking for the Reset method.
* Remove TODOs in prototext and protojson about reset behavior.

Fixes golang/protobuf#890

Change-Id: Ibd8963c741053f564acf061fbdb846699942109c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/195457
Reviewed-by: Damien Neil <dneil@google.com>
2019-09-17 21:13:42 +00:00

35 lines
821 B
Go

// 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/reflect/protoreflect"
// Reset clears every field in the message.
func Reset(m Message) {
// TODO: Document memory aliasing guarantees.
if mr, ok := m.(interface{ Reset() }); ok && hasProtoMethods {
mr.Reset()
return
}
resetMessage(m.ProtoReflect())
}
func resetMessage(m protoreflect.Message) {
// Clear all known fields.
fds := m.Descriptor().Fields()
for i := 0; i < fds.Len(); i++ {
m.Clear(fds.Get(i))
}
// Clear extension fields.
m.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
m.Clear(fd)
return true
})
// Clear unknown fields.
m.SetUnknown(nil)
}