vendor.google.golang.org.protobuf.internal.impl.extension.go Maven / Gradle / Ivy
// 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 impl
import (
"reflect"
"sync"
"sync/atomic"
pref "google.golang.org/protobuf/reflect/protoreflect"
piface "google.golang.org/protobuf/runtime/protoiface"
)
// ExtensionInfo implements ExtensionType.
//
// This type contains a number of exported fields for legacy compatibility.
// The only non-deprecated use of this type is through the methods of the
// ExtensionType interface.
type ExtensionInfo struct {
// An ExtensionInfo may exist in several stages of initialization.
//
// extensionInfoUninitialized: Some or all of the legacy exported
// fields may be set, but none of the unexported fields have been
// initialized. This is the starting state for an ExtensionInfo
// in legacy generated code.
//
// extensionInfoDescInit: The desc field is set, but other unexported fields
// may not be initialized. Legacy exported fields may or may not be set.
// This is the starting state for an ExtensionInfo in newly generated code.
//
// extensionInfoFullInit: The ExtensionInfo is fully initialized.
// This state is only entered after lazy initialization is complete.
init uint32
mu sync.Mutex
goType reflect.Type
desc extensionTypeDescriptor
conv Converter
info *extensionFieldInfo // for fast-path method implementations
// ExtendedType is a typed nil-pointer to the parent message type that
// is being extended. It is possible for this to be unpopulated in v2
// since the message may no longer implement the MessageV1 interface.
//
// Deprecated: Use the ExtendedType method instead.
ExtendedType piface.MessageV1
// ExtensionType is the zero value of the extension type.
//
// For historical reasons, reflect.TypeOf(ExtensionType) and the
// type returned by InterfaceOf may not be identical.
//
// Deprecated: Use InterfaceOf(xt.Zero()) instead.
ExtensionType interface{}
// Field is the field number of the extension.
//
// Deprecated: Use the Descriptor().Number method instead.
Field int32
// Name is the fully qualified name of extension.
//
// Deprecated: Use the Descriptor().FullName method instead.
Name string
// Tag is the protobuf struct tag used in the v1 API.
//
// Deprecated: Do not use.
Tag string
// Filename is the proto filename in which the extension is defined.
//
// Deprecated: Use Descriptor().ParentFile().Path() instead.
Filename string
}
// Stages of initialization: See the ExtensionInfo.init field.
const (
extensionInfoUninitialized = 0
extensionInfoDescInit = 1
extensionInfoFullInit = 2
)
func InitExtensionInfo(xi *ExtensionInfo, xd pref.ExtensionDescriptor, goType reflect.Type) {
xi.goType = goType
xi.desc = extensionTypeDescriptor{xd, xi}
xi.init = extensionInfoDescInit
}
func (xi *ExtensionInfo) New() pref.Value {
return xi.lazyInit().New()
}
func (xi *ExtensionInfo) Zero() pref.Value {
return xi.lazyInit().Zero()
}
func (xi *ExtensionInfo) ValueOf(v interface{}) pref.Value {
return xi.lazyInit().PBValueOf(reflect.ValueOf(v))
}
func (xi *ExtensionInfo) InterfaceOf(v pref.Value) interface{} {
return xi.lazyInit().GoValueOf(v).Interface()
}
func (xi *ExtensionInfo) IsValidValue(v pref.Value) bool {
return xi.lazyInit().IsValidPB(v)
}
func (xi *ExtensionInfo) IsValidInterface(v interface{}) bool {
return xi.lazyInit().IsValidGo(reflect.ValueOf(v))
}
func (xi *ExtensionInfo) TypeDescriptor() pref.ExtensionTypeDescriptor {
if atomic.LoadUint32(&xi.init) < extensionInfoDescInit {
xi.lazyInitSlow()
}
return &xi.desc
}
func (xi *ExtensionInfo) lazyInit() Converter {
if atomic.LoadUint32(&xi.init) < extensionInfoFullInit {
xi.lazyInitSlow()
}
return xi.conv
}
func (xi *ExtensionInfo) lazyInitSlow() {
xi.mu.Lock()
defer xi.mu.Unlock()
if xi.init == extensionInfoFullInit {
return
}
defer atomic.StoreUint32(&xi.init, extensionInfoFullInit)
if xi.desc.ExtensionDescriptor == nil {
xi.initFromLegacy()
}
if !xi.desc.ExtensionDescriptor.IsPlaceholder() {
if xi.ExtensionType == nil {
xi.initToLegacy()
}
xi.conv = NewConverter(xi.goType, xi.desc.ExtensionDescriptor)
xi.info = makeExtensionFieldInfo(xi.desc.ExtensionDescriptor)
xi.info.validation = newValidationInfo(xi.desc.ExtensionDescriptor, xi.goType)
}
}
type extensionTypeDescriptor struct {
pref.ExtensionDescriptor
xi *ExtensionInfo
}
func (xtd *extensionTypeDescriptor) Type() pref.ExtensionType {
return xtd.xi
}
func (xtd *extensionTypeDescriptor) Descriptor() pref.ExtensionDescriptor {
return xtd.ExtensionDescriptor
}