source: code/trunk/vendor/google.golang.org/protobuf/proto/reset.go@ 822

// 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"

        "google.golang.org/protobuf/reflect/protoreflect"
)

// Reset clears every field in the message.
// The resulting message shares no observable memory with its previous state
// other than the memory for the message itself.
func Reset(m Message) {
        if mr, ok := m.(interface{ Reset() }); ok && hasProtoMethods {
                mr.Reset()
                return
        }
        resetMessage(m.ProtoReflect())
}

func resetMessage(m protoreflect.Message) {
        if !m.IsValid() {
                panic(fmt.Sprintf("cannot reset invalid %v message", m.Descriptor().FullName()))
        }

        // 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)
}