+++ /dev/null
-// 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)
- }
- }
- }
-}
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