source: code/trunk/vendor/google.golang.org/protobuf/proto/checkinit.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 (
        "google.golang.org/protobuf/internal/errors"
        "google.golang.org/protobuf/reflect/protoreflect"
        "google.golang.org/protobuf/runtime/protoiface"
)

// CheckInitialized returns an error if any required fields in m are not set.
func CheckInitialized(m Message) error {
        // Treat a nil message interface as an "untyped" empty message,
        // which we assume to have no required fields.
        if m == nil {
                return nil
        }

        return checkInitialized(m.ProtoReflect())
}

// CheckInitialized returns an error if any required fields in m are not set.
func checkInitialized(m protoreflect.Message) error {
        if methods := protoMethods(m); methods != nil && methods.CheckInitialized != nil {
                _, err := methods.CheckInitialized(protoiface.CheckInitializedInput{
                        Message: m,
                })
                return err
        }
        return checkInitializedSlow(m)
}

func checkInitializedSlow(m protoreflect.Message) error {
        md := m.Descriptor()
        fds := md.Fields()
        for i, nums := 0, md.RequiredNumbers(); i < nums.Len(); i++ {
                fd := fds.ByNumber(nums.Get(i))
                if !m.Has(fd) {
                        return errors.RequiredNotSet(string(fd.FullName()))
                }
        }
        var err error
        m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
                switch {
                case fd.IsList():
                        if fd.Message() == nil {
                                return true
                        }
                        for i, list := 0, v.List(); i < list.Len() && err == nil; i++ {
                                err = checkInitialized(list.Get(i).Message())
                        }
                case fd.IsMap():
                        if fd.MapValue().Message() == nil {
                                return true
                        }
                        v.Map().Range(func(key protoreflect.MapKey, v protoreflect.Value) bool {
                                err = checkInitialized(v.Message())
                                return err == nil
                        })
                default:
                        if fd.Message() == nil {
                                return true
                        }
                        err = checkInitialized(v.Message())
                }
                return err == nil
        })
        return err
}