vendor/github.com/gogo/protobuf/proto/discard.go - voltha-openolt-adapter - Gitiles

 // Go support for Protocol Buffers - Google's data interchange format
 //
 // Copyright 2017 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.

 package proto

 import (
 	"fmt"
 	"reflect"
 	"strings"
 	"sync"
 	"sync/atomic"
 )

 type generatedDiscarder interface {
 	XXX_DiscardUnknown()
 }

 // DiscardUnknown recursively discards all unknown fields from this message
 // and all embedded messages.
 //
 // When unmarshaling a message with unrecognized fields, the tags and values
 // of such fields are preserved in the Message. This allows a later call to
 // marshal to be able to produce a message that continues to have those
 // unrecognized fields. To avoid this, DiscardUnknown is used to
 // explicitly clear the unknown fields after unmarshaling.
 //
 // For proto2 messages, the unknown fields of message extensions are only
 // discarded from messages that have been accessed via GetExtension.
 func DiscardUnknown(m Message) {
 	if m, ok := m.(generatedDiscarder); ok {
 		m.XXX_DiscardUnknown()
 		return
 	}
 	// TODO: Dynamically populate a InternalMessageInfo for legacy messages,
 	// but the master branch has no implementation for InternalMessageInfo,
 	// so it would be more work to replicate that approach.
 	discardLegacy(m)
 }

 // DiscardUnknown recursively discards all unknown fields.
 func (a *InternalMessageInfo) DiscardUnknown(m Message) {
 	di := atomicLoadDiscardInfo(&a.discard)
 	if di == nil {
 		di = getDiscardInfo(reflect.TypeOf(m).Elem())
 		atomicStoreDiscardInfo(&a.discard, di)
 	}
 	di.discard(toPointer(&m))
 }

 type discardInfo struct {
 	typ reflect.Type

 	initialized int32 // 0: only typ is valid, 1: everything is valid
 	lock        sync.Mutex

 	fields       []discardFieldInfo
 	unrecognized field
 }

 type discardFieldInfo struct {
 	field   field // Offset of field, guaranteed to be valid
 	discard func(src pointer)
 }

 var (
 	discardInfoMap  = map[reflect.Type]*discardInfo{}
 	discardInfoLock sync.Mutex
 )

 func getDiscardInfo(t reflect.Type) *discardInfo {
 	discardInfoLock.Lock()
 	defer discardInfoLock.Unlock()
 	di := discardInfoMap[t]
 	if di == nil {
 		di = &discardInfo{typ: t}
 		discardInfoMap[t] = di
 	}
 	return di
 }

 func (di *discardInfo) discard(src pointer) {
 	if src.isNil() {
 		return // Nothing to do.
 	}

 	if atomic.LoadInt32(&di.initialized) == 0 {
 		di.computeDiscardInfo()
 	}

 	for _, fi := range di.fields {
 		sfp := src.offset(fi.field)
 		fi.discard(sfp)
 	}

 	// For proto2 messages, only discard unknown fields in message extensions
 	// that have been accessed via GetExtension.
 	if em, err := extendable(src.asPointerTo(di.typ).Interface()); err == nil {
 		// Ignore lock since DiscardUnknown is not concurrency safe.
 		emm, _ := em.extensionsRead()
 		for _, mx := range emm {
 			if m, ok := mx.value.(Message); ok {
 				DiscardUnknown(m)
 			}
 		}
 	}

 	if di.unrecognized.IsValid() {
 		*src.offset(di.unrecognized).toBytes() = nil
 	}
 }

 func (di *discardInfo) computeDiscardInfo() {
 	di.lock.Lock()
 	defer di.lock.Unlock()
 	if di.initialized != 0 {
 		return
 	}
 	t := di.typ
 	n := t.NumField()

 	for i := 0; i < n; i++ {
 		f := t.Field(i)
 		if strings.HasPrefix(f.Name, "XXX_") {
 			continue
 		}

 		dfi := discardFieldInfo{field: toField(&f)}
 		tf := f.Type

 		// Unwrap tf to get its most basic type.
 		var isPointer, isSlice bool
 		if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
 			isSlice = true
 			tf = tf.Elem()
 		}
 		if tf.Kind() == reflect.Ptr {
 			isPointer = true
 			tf = tf.Elem()
 		}
 		if isPointer && isSlice && tf.Kind() != reflect.Struct {
 			panic(fmt.Sprintf("%v.%s cannot be a slice of pointers to primitive types", t, f.Name))
 		}

 		switch tf.Kind() {
 		case reflect.Struct:
 			switch {
 			case !isPointer:
 				panic(fmt.Sprintf("%v.%s cannot be a direct struct value", t, f.Name))
 			case isSlice: // E.g., []*pb.T
 				discardInfo := getDiscardInfo(tf)
 				dfi.discard = func(src pointer) {
 					sps := src.getPointerSlice()
 					for _, sp := range sps {
 						if !sp.isNil() {
 							discardInfo.discard(sp)
 						}
 					}
 				}
 			default: // E.g., *pb.T
 				discardInfo := getDiscardInfo(tf)
 				dfi.discard = func(src pointer) {
 					sp := src.getPointer()
 					if !sp.isNil() {
 						discardInfo.discard(sp)
 					}
 				}
 			}
 		case reflect.Map:
 			switch {
 			case isPointer || isSlice:
 				panic(fmt.Sprintf("%v.%s cannot be a pointer to a map or a slice of map values", t, f.Name))
 			default: // E.g., map[K]V
 				if tf.Elem().Kind() == reflect.Ptr { // Proto struct (e.g., *T)
 					dfi.discard = func(src pointer) {
 						sm := src.asPointerTo(tf).Elem()
 						if sm.Len() == 0 {
 							return
 						}
 						for _, key := range sm.MapKeys() {
 							val := sm.MapIndex(key)
 							DiscardUnknown(val.Interface().(Message))
 						}
 					}
 				} else {
 					dfi.discard = func(pointer) {} // Noop
 				}
 			}
 		case reflect.Interface:
 			// Must be oneof field.
 			switch {
 			case isPointer || isSlice:
 				panic(fmt.Sprintf("%v.%s cannot be a pointer to a interface or a slice of interface values", t, f.Name))
 			default: // E.g., interface{}
 				// TODO: Make this faster?
 				dfi.discard = func(src pointer) {
 					su := src.asPointerTo(tf).Elem()
 					if !su.IsNil() {
 						sv := su.Elem().Elem().Field(0)
 						if sv.Kind() == reflect.Ptr && sv.IsNil() {
 							return
 						}
 						switch sv.Type().Kind() {
 						case reflect.Ptr: // Proto struct (e.g., *T)
 							DiscardUnknown(sv.Interface().(Message))
 						}
 					}
 				}
 			}
 		default:
 			continue
 		}
 		di.fields = append(di.fields, dfi)
 	}

 	di.unrecognized = invalidField
 	if f, ok := t.FieldByName("XXX_unrecognized"); ok {
 		if f.Type != reflect.TypeOf([]byte{}) {
 			panic("expected XXX_unrecognized to be of type []byte")
 		}
 		di.unrecognized = toField(&f)
 	}

 	atomic.StoreInt32(&di.initialized, 1)
 }

 func discardLegacy(m Message) {
 	v := reflect.ValueOf(m)
 	if v.Kind() != reflect.Ptr || v.IsNil() {
 		return
 	}
 	v = v.Elem()
 	if v.Kind() != reflect.Struct {
 		return
 	}
 	t := v.Type()

 	for i := 0; i < v.NumField(); i++ {
 		f := t.Field(i)
 		if strings.HasPrefix(f.Name, "XXX_") {
 			continue
 		}
 		vf := v.Field(i)
 		tf := f.Type

 		// Unwrap tf to get its most basic type.
 		var isPointer, isSlice bool
 		if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
 			isSlice = true
 			tf = tf.Elem()
 		}
 		if tf.Kind() == reflect.Ptr {
 			isPointer = true
 			tf = tf.Elem()
 		}
 		if isPointer && isSlice && tf.Kind() != reflect.Struct {
 			panic(fmt.Sprintf("%T.%s cannot be a slice of pointers to primitive types", m, f.Name))
 		}

 		switch tf.Kind() {
 		case reflect.Struct:
 			switch {
 			case !isPointer:
 				panic(fmt.Sprintf("%T.%s cannot be a direct struct value", m, f.Name))
 			case isSlice: // E.g., []*pb.T
 				for j := 0; j < vf.Len(); j++ {
 					discardLegacy(vf.Index(j).Interface().(Message))
 				}
 			default: // E.g., *pb.T
 				discardLegacy(vf.Interface().(Message))
 			}
 		case reflect.Map:
 			switch {
 			case isPointer || isSlice:
 				panic(fmt.Sprintf("%T.%s cannot be a pointer to a map or a slice of map values", m, f.Name))
 			default: // E.g., map[K]V
 				tv := vf.Type().Elem()
 				if tv.Kind() == reflect.Ptr && tv.Implements(protoMessageType) { // Proto struct (e.g., *T)
 					for _, key := range vf.MapKeys() {
 						val := vf.MapIndex(key)
 						discardLegacy(val.Interface().(Message))
 					}
 				}
 			}
 		case reflect.Interface:
 			// Must be oneof field.
 			switch {
 			case isPointer || isSlice:
 				panic(fmt.Sprintf("%T.%s cannot be a pointer to a interface or a slice of interface values", m, f.Name))
 			default: // E.g., test_proto.isCommunique_Union interface
 				if !vf.IsNil() && f.Tag.Get("protobuf_oneof") != "" {
 					vf = vf.Elem() // E.g., *test_proto.Communique_Msg
 					if !vf.IsNil() {
 						vf = vf.Elem()   // E.g., test_proto.Communique_Msg
 						vf = vf.Field(0) // E.g., Proto struct (e.g., *T) or primitive value
 						if vf.Kind() == reflect.Ptr {
 							discardLegacy(vf.Interface().(Message))
 						}
 					}
 				}
 			}
 		}
 	}

 	if vf := v.FieldByName("XXX_unrecognized"); vf.IsValid() {
 		if vf.Type() != reflect.TypeOf([]byte{}) {
 			panic("expected XXX_unrecognized to be of type []byte")
 		}
 		vf.Set(reflect.ValueOf([]byte(nil)))
 	}

 	// For proto2 messages, only discard unknown fields in message extensions
 	// that have been accessed via GetExtension.
 	if em, err := extendable(m); err == nil {
 		// Ignore lock since discardLegacy is not concurrency safe.
 		emm, _ := em.extensionsRead()
 		for _, mx := range emm {
 			if m, ok := mx.value.(Message); ok {
 				discardLegacy(m)
 			}
 		}
 	}
 }
	// Go support for Protocol Buffers - Google's data interchange format
	//
	// Copyright 2017 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.

	package proto

	import (
	"fmt"
	"reflect"
	"strings"
	"sync"
	"sync/atomic"
	)

	type generatedDiscarder interface {
	XXX_DiscardUnknown()
	}

	// DiscardUnknown recursively discards all unknown fields from this message
	// and all embedded messages.
	//
	// When unmarshaling a message with unrecognized fields, the tags and values
	// of such fields are preserved in the Message. This allows a later call to
	// marshal to be able to produce a message that continues to have those
	// unrecognized fields. To avoid this, DiscardUnknown is used to
	// explicitly clear the unknown fields after unmarshaling.
	//
	// For proto2 messages, the unknown fields of message extensions are only
	// discarded from messages that have been accessed via GetExtension.
	func DiscardUnknown(m Message) {
	if m, ok := m.(generatedDiscarder); ok {
	m.XXX_DiscardUnknown()
	return
	}
	// TODO: Dynamically populate a InternalMessageInfo for legacy messages,
	// but the master branch has no implementation for InternalMessageInfo,
	// so it would be more work to replicate that approach.
	discardLegacy(m)
	}

	// DiscardUnknown recursively discards all unknown fields.
	func (a *InternalMessageInfo) DiscardUnknown(m Message) {
	di := atomicLoadDiscardInfo(&a.discard)
	if di == nil {
	di = getDiscardInfo(reflect.TypeOf(m).Elem())
	atomicStoreDiscardInfo(&a.discard, di)
	}
	di.discard(toPointer(&m))
	}

	type discardInfo struct {
	typ reflect.Type

	initialized int32 // 0: only typ is valid, 1: everything is valid
	lock sync.Mutex

	fields []discardFieldInfo
	unrecognized field
	}

	type discardFieldInfo struct {
	field field // Offset of field, guaranteed to be valid
	discard func(src pointer)
	}

	var (
	discardInfoMap = map[reflect.Type]*discardInfo{}
	discardInfoLock sync.Mutex
	)

	func getDiscardInfo(t reflect.Type) *discardInfo {
	discardInfoLock.Lock()
	defer discardInfoLock.Unlock()
	di := discardInfoMap[t]
	if di == nil {
	di = &discardInfo{typ: t}
	discardInfoMap[t] = di
	}
	return di
	}

	func (di *discardInfo) discard(src pointer) {
	if src.isNil() {
	return // Nothing to do.
	}

	if atomic.LoadInt32(&di.initialized) == 0 {
	di.computeDiscardInfo()
	}

	for _, fi := range di.fields {
	sfp := src.offset(fi.field)
	fi.discard(sfp)
	}

	// For proto2 messages, only discard unknown fields in message extensions
	// that have been accessed via GetExtension.
	if em, err := extendable(src.asPointerTo(di.typ).Interface()); err == nil {
	// Ignore lock since DiscardUnknown is not concurrency safe.
	emm, _ := em.extensionsRead()
	for _, mx := range emm {
	if m, ok := mx.value.(Message); ok {
	DiscardUnknown(m)
	}
	}
	}

	if di.unrecognized.IsValid() {
	*src.offset(di.unrecognized).toBytes() = nil
	}
	}

	func (di *discardInfo) computeDiscardInfo() {
	di.lock.Lock()
	defer di.lock.Unlock()
	if di.initialized != 0 {
	return
	}
	t := di.typ
	n := t.NumField()

	for i := 0; i < n; i++ {
	f := t.Field(i)
	if strings.HasPrefix(f.Name, "XXX_") {
	continue
	}

	dfi := discardFieldInfo{field: toField(&f)}
	tf := f.Type

	// Unwrap tf to get its most basic type.
	var isPointer, isSlice bool
	if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
	isSlice = true
	tf = tf.Elem()
	}
	if tf.Kind() == reflect.Ptr {
	isPointer = true
	tf = tf.Elem()
	}
	if isPointer && isSlice && tf.Kind() != reflect.Struct {
	panic(fmt.Sprintf("%v.%s cannot be a slice of pointers to primitive types", t, f.Name))
	}

	switch tf.Kind() {
	case reflect.Struct:
	switch {
	case !isPointer:
	panic(fmt.Sprintf("%v.%s cannot be a direct struct value", t, f.Name))
	case isSlice: // E.g., []*pb.T
	discardInfo := getDiscardInfo(tf)
	dfi.discard = func(src pointer) {
	sps := src.getPointerSlice()
	for _, sp := range sps {
	if !sp.isNil() {
	discardInfo.discard(sp)
	}
	}
	}
	default: // E.g., *pb.T
	discardInfo := getDiscardInfo(tf)
	dfi.discard = func(src pointer) {
	sp := src.getPointer()
	if !sp.isNil() {
	discardInfo.discard(sp)
	}
	}
	}
	case reflect.Map:
	switch {
	case isPointer \|\| isSlice:
	panic(fmt.Sprintf("%v.%s cannot be a pointer to a map or a slice of map values", t, f.Name))
	default: // E.g., map[K]V
	if tf.Elem().Kind() == reflect.Ptr { // Proto struct (e.g., *T)
	dfi.discard = func(src pointer) {
	sm := src.asPointerTo(tf).Elem()
	if sm.Len() == 0 {
	return
	}
	for _, key := range sm.MapKeys() {
	val := sm.MapIndex(key)
	DiscardUnknown(val.Interface().(Message))
	}
	}
	} else {
	dfi.discard = func(pointer) {} // Noop
	}
	}
	case reflect.Interface:
	// Must be oneof field.
	switch {
	case isPointer \|\| isSlice:
	panic(fmt.Sprintf("%v.%s cannot be a pointer to a interface or a slice of interface values", t, f.Name))
	default: // E.g., interface{}
	// TODO: Make this faster?
	dfi.discard = func(src pointer) {
	su := src.asPointerTo(tf).Elem()
	if !su.IsNil() {
	sv := su.Elem().Elem().Field(0)
	if sv.Kind() == reflect.Ptr && sv.IsNil() {
	return
	}
	switch sv.Type().Kind() {
	case reflect.Ptr: // Proto struct (e.g., *T)
	DiscardUnknown(sv.Interface().(Message))
	}
	}
	}
	}
	default:
	continue
	}
	di.fields = append(di.fields, dfi)
	}

	di.unrecognized = invalidField
	if f, ok := t.FieldByName("XXX_unrecognized"); ok {
	if f.Type != reflect.TypeOf([]byte{}) {
	panic("expected XXX_unrecognized to be of type []byte")
	}
	di.unrecognized = toField(&f)
	}

	atomic.StoreInt32(&di.initialized, 1)
	}

	func discardLegacy(m Message) {
	v := reflect.ValueOf(m)
	if v.Kind() != reflect.Ptr \|\| v.IsNil() {
	return
	}
	v = v.Elem()
	if v.Kind() != reflect.Struct {
	return
	}
	t := v.Type()

	for i := 0; i < v.NumField(); i++ {
	f := t.Field(i)
	if strings.HasPrefix(f.Name, "XXX_") {
	continue
	}
	vf := v.Field(i)
	tf := f.Type

	// Unwrap tf to get its most basic type.
	var isPointer, isSlice bool
	if tf.Kind() == reflect.Slice && tf.Elem().Kind() != reflect.Uint8 {
	isSlice = true
	tf = tf.Elem()
	}
	if tf.Kind() == reflect.Ptr {
	isPointer = true
	tf = tf.Elem()
	}
	if isPointer && isSlice && tf.Kind() != reflect.Struct {
	panic(fmt.Sprintf("%T.%s cannot be a slice of pointers to primitive types", m, f.Name))
	}

	switch tf.Kind() {
	case reflect.Struct:
	switch {
	case !isPointer:
	panic(fmt.Sprintf("%T.%s cannot be a direct struct value", m, f.Name))
	case isSlice: // E.g., []*pb.T
	for j := 0; j < vf.Len(); j++ {
	discardLegacy(vf.Index(j).Interface().(Message))
	}
	default: // E.g., *pb.T
	discardLegacy(vf.Interface().(Message))
	}
	case reflect.Map:
	switch {
	case isPointer \|\| isSlice:
	panic(fmt.Sprintf("%T.%s cannot be a pointer to a map or a slice of map values", m, f.Name))
	default: // E.g., map[K]V
	tv := vf.Type().Elem()
	if tv.Kind() == reflect.Ptr && tv.Implements(protoMessageType) { // Proto struct (e.g., *T)
	for _, key := range vf.MapKeys() {
	val := vf.MapIndex(key)
	discardLegacy(val.Interface().(Message))
	}
	}
	}
	case reflect.Interface:
	// Must be oneof field.
	switch {
	case isPointer \|\| isSlice:
	panic(fmt.Sprintf("%T.%s cannot be a pointer to a interface or a slice of interface values", m, f.Name))
	default: // E.g., test_proto.isCommunique_Union interface
	if !vf.IsNil() && f.Tag.Get("protobuf_oneof") != "" {
	vf = vf.Elem() // E.g., *test_proto.Communique_Msg
	if !vf.IsNil() {
	vf = vf.Elem() // E.g., test_proto.Communique_Msg
	vf = vf.Field(0) // E.g., Proto struct (e.g., *T) or primitive value
	if vf.Kind() == reflect.Ptr {
	discardLegacy(vf.Interface().(Message))
	}
	}
	}
	}
	}
	}

	if vf := v.FieldByName("XXX_unrecognized"); vf.IsValid() {
	if vf.Type() != reflect.TypeOf([]byte{}) {
	panic("expected XXX_unrecognized to be of type []byte")
	}
	vf.Set(reflect.ValueOf([]byte(nil)))
	}

	// For proto2 messages, only discard unknown fields in message extensions
	// that have been accessed via GetExtension.
	if em, err := extendable(m); err == nil {
	// Ignore lock since discardLegacy is not concurrency safe.
	emm, _ := em.extensionsRead()
	for _, mx := range emm {
	if m, ok := mx.value.(Message); ok {
	discardLegacy(m)
	}
	}
	}
	}