--- /dev/null
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 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
+
+/*
+ * Types and routines for supporting protocol buffer extensions.
+ */
+
+import (
+ "errors"
+ "fmt"
+ "io"
+ "reflect"
+ "strconv"
+ "sync"
+)
+
+// ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message.
+var ErrMissingExtension = errors.New("proto: missing extension")
+
+// ExtensionRange represents a range of message extensions for a protocol buffer.
+// Used in code generated by the protocol compiler.
+type ExtensionRange struct {
+ Start, End int32 // both inclusive
+}
+
+// extendableProto is an interface implemented by any protocol buffer generated by the current
+// proto compiler that may be extended.
+type extendableProto interface {
+ Message
+ ExtensionRangeArray() []ExtensionRange
+ extensionsWrite() map[int32]Extension
+ extensionsRead() (map[int32]Extension, sync.Locker)
+}
+
+// extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous
+// version of the proto compiler that may be extended.
+type extendableProtoV1 interface {
+ Message
+ ExtensionRangeArray() []ExtensionRange
+ ExtensionMap() map[int32]Extension
+}
+
+// extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto.
+type extensionAdapter struct {
+ extendableProtoV1
+}
+
+func (e extensionAdapter) extensionsWrite() map[int32]Extension {
+ return e.ExtensionMap()
+}
+
+func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
+ return e.ExtensionMap(), notLocker{}
+}
+
+// notLocker is a sync.Locker whose Lock and Unlock methods are nops.
+type notLocker struct{}
+
+func (n notLocker) Lock() {}
+func (n notLocker) Unlock() {}
+
+// extendable returns the extendableProto interface for the given generated proto message.
+// If the proto message has the old extension format, it returns a wrapper that implements
+// the extendableProto interface.
+func extendable(p interface{}) (extendableProto, error) {
+ switch p := p.(type) {
+ case extendableProto:
+ if isNilPtr(p) {
+ return nil, fmt.Errorf("proto: nil %T is not extendable", p)
+ }
+ return p, nil
+ case extendableProtoV1:
+ if isNilPtr(p) {
+ return nil, fmt.Errorf("proto: nil %T is not extendable", p)
+ }
+ return extensionAdapter{p}, nil
+ case extensionsBytes:
+ return slowExtensionAdapter{p}, nil
+ }
+ // Don't allocate a specific error containing %T:
+ // this is the hot path for Clone and MarshalText.
+ return nil, errNotExtendable
+}
+
+var errNotExtendable = errors.New("proto: not an extendable proto.Message")
+
+func isNilPtr(x interface{}) bool {
+ v := reflect.ValueOf(x)
+ return v.Kind() == reflect.Ptr && v.IsNil()
+}
+
+// XXX_InternalExtensions is an internal representation of proto extensions.
+//
+// Each generated message struct type embeds an anonymous XXX_InternalExtensions field,
+// thus gaining the unexported 'extensions' method, which can be called only from the proto package.
+//
+// The methods of XXX_InternalExtensions are not concurrency safe in general,
+// but calls to logically read-only methods such as has and get may be executed concurrently.
+type XXX_InternalExtensions struct {
+ // The struct must be indirect so that if a user inadvertently copies a
+ // generated message and its embedded XXX_InternalExtensions, they
+ // avoid the mayhem of a copied mutex.
+ //
+ // The mutex serializes all logically read-only operations to p.extensionMap.
+ // It is up to the client to ensure that write operations to p.extensionMap are
+ // mutually exclusive with other accesses.
+ p *struct {
+ mu sync.Mutex
+ extensionMap map[int32]Extension
+ }
+}
+
+// extensionsWrite returns the extension map, creating it on first use.
+func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension {
+ if e.p == nil {
+ e.p = new(struct {
+ mu sync.Mutex
+ extensionMap map[int32]Extension
+ })
+ e.p.extensionMap = make(map[int32]Extension)
+ }
+ return e.p.extensionMap
+}
+
+// extensionsRead returns the extensions map for read-only use. It may be nil.
+// The caller must hold the returned mutex's lock when accessing Elements within the map.
+func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) {
+ if e.p == nil {
+ return nil, nil
+ }
+ return e.p.extensionMap, &e.p.mu
+}
+
+// ExtensionDesc represents an extension specification.
+// Used in generated code from the protocol compiler.
+type ExtensionDesc struct {
+ ExtendedType Message // nil pointer to the type that is being extended
+ ExtensionType interface{} // nil pointer to the extension type
+ Field int32 // field number
+ Name string // fully-qualified name of extension, for text formatting
+ Tag string // protobuf tag style
+ Filename string // name of the file in which the extension is defined
+}
+
+func (ed *ExtensionDesc) repeated() bool {
+ t := reflect.TypeOf(ed.ExtensionType)
+ return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
+}
+
+// Extension represents an extension in a message.
+type Extension struct {
+ // When an extension is stored in a message using SetExtension
+ // only desc and value are set. When the message is marshaled
+ // enc will be set to the encoded form of the message.
+ //
+ // When a message is unmarshaled and contains extensions, each
+ // extension will have only enc set. When such an extension is
+ // accessed using GetExtension (or GetExtensions) desc and value
+ // will be set.
+ desc *ExtensionDesc
+ value interface{}
+ enc []byte
+}
+
+// SetRawExtension is for testing only.
+func SetRawExtension(base Message, id int32, b []byte) {
+ if ebase, ok := base.(extensionsBytes); ok {
+ clearExtension(base, id)
+ ext := ebase.GetExtensions()
+ *ext = append(*ext, b...)
+ return
+ }
+ epb, err := extendable(base)
+ if err != nil {
+ return
+ }
+ extmap := epb.extensionsWrite()
+ extmap[id] = Extension{enc: b}
+}
+
+// isExtensionField returns true iff the given field number is in an extension range.
+func isExtensionField(pb extendableProto, field int32) bool {
+ for _, er := range pb.ExtensionRangeArray() {
+ if er.Start <= field && field <= er.End {
+ return true
+ }
+ }
+ return false
+}
+
+// checkExtensionTypes checks that the given extension is valid for pb.
+func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error {
+ var pbi interface{} = pb
+ // Check the extended type.
+ if ea, ok := pbi.(extensionAdapter); ok {
+ pbi = ea.extendableProtoV1
+ }
+ if ea, ok := pbi.(slowExtensionAdapter); ok {
+ pbi = ea.extensionsBytes
+ }
+ if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b {
+ return fmt.Errorf("proto: bad extended type; %v does not extend %v", b, a)
+ }
+ // Check the range.
+ if !isExtensionField(pb, extension.Field) {
+ return errors.New("proto: bad extension number; not in declared ranges")
+ }
+ return nil
+}
+
+// extPropKey is sufficient to uniquely identify an extension.
+type extPropKey struct {
+ base reflect.Type
+ field int32
+}
+
+var extProp = struct {
+ sync.RWMutex
+ m map[extPropKey]*Properties
+}{
+ m: make(map[extPropKey]*Properties),
+}
+
+func extensionProperties(ed *ExtensionDesc) *Properties {
+ key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field}
+
+ extProp.RLock()
+ if prop, ok := extProp.m[key]; ok {
+ extProp.RUnlock()
+ return prop
+ }
+ extProp.RUnlock()
+
+ extProp.Lock()
+ defer extProp.Unlock()
+ // Check again.
+ if prop, ok := extProp.m[key]; ok {
+ return prop
+ }
+
+ prop := new(Properties)
+ prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil)
+ extProp.m[key] = prop
+ return prop
+}
+
+// HasExtension returns whether the given extension is present in pb.
+func HasExtension(pb Message, extension *ExtensionDesc) bool {
+ if epb, doki := pb.(extensionsBytes); doki {
+ ext := epb.GetExtensions()
+ buf := *ext
+ o := 0
+ for o < len(buf) {
+ tag, n := DecodeVarint(buf[o:])
+ fieldNum := int32(tag >> 3)
+ if int32(fieldNum) == extension.Field {
+ return true
+ }
+ wireType := int(tag & 0x7)
+ o += n
+ l, err := size(buf[o:], wireType)
+ if err != nil {
+ return false
+ }
+ o += l
+ }
+ return false
+ }
+ // TODO: Check types, field numbers, etc.?
+ epb, err := extendable(pb)
+ if err != nil {
+ return false
+ }
+ extmap, mu := epb.extensionsRead()
+ if extmap == nil {
+ return false
+ }
+ mu.Lock()
+ _, ok := extmap[extension.Field]
+ mu.Unlock()
+ return ok
+}
+
+// ClearExtension removes the given extension from pb.
+func ClearExtension(pb Message, extension *ExtensionDesc) {
+ clearExtension(pb, extension.Field)
+}
+
+func clearExtension(pb Message, fieldNum int32) {
+ if epb, ok := pb.(extensionsBytes); ok {
+ offset := 0
+ for offset != -1 {
+ offset = deleteExtension(epb, fieldNum, offset)
+ }
+ return
+ }
+ epb, err := extendable(pb)
+ if err != nil {
+ return
+ }
+ // TODO: Check types, field numbers, etc.?
+ extmap := epb.extensionsWrite()
+ delete(extmap, fieldNum)
+}
+
+// GetExtension retrieves a proto2 extended field from pb.
+//
+// If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
+// then GetExtension parses the encoded field and returns a Go value of the specified type.
+// If the field is not present, then the default value is returned (if one is specified),
+// otherwise ErrMissingExtension is reported.
+//
+// If the descriptor is not type complete (i.e., ExtensionDesc.ExtensionType is nil),
+// then GetExtension returns the raw encoded bytes of the field extension.
+func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) {
+ if epb, doki := pb.(extensionsBytes); doki {
+ ext := epb.GetExtensions()
+ return decodeExtensionFromBytes(extension, *ext)
+ }
+
+ epb, err := extendable(pb)
+ if err != nil {
+ return nil, err
+ }
+
+ if extension.ExtendedType != nil {
+ // can only check type if this is a complete descriptor
+ if cerr := checkExtensionTypes(epb, extension); cerr != nil {
+ return nil, cerr
+ }
+ }
+
+ emap, mu := epb.extensionsRead()
+ if emap == nil {
+ return defaultExtensionValue(extension)
+ }
+ mu.Lock()
+ defer mu.Unlock()
+ e, ok := emap[extension.Field]
+ if !ok {
+ // defaultExtensionValue returns the default value or
+ // ErrMissingExtension if there is no default.
+ return defaultExtensionValue(extension)
+ }
+
+ if e.value != nil {
+ // Already decoded. Check the descriptor, though.
+ if e.desc != extension {
+ // This shouldn't happen. If it does, it means that
+ // GetExtension was called twice with two different
+ // descriptors with the same field number.
+ return nil, errors.New("proto: descriptor conflict")
+ }
+ return e.value, nil
+ }
+
+ if extension.ExtensionType == nil {
+ // incomplete descriptor
+ return e.enc, nil
+ }
+
+ v, err := decodeExtension(e.enc, extension)
+ if err != nil {
+ return nil, err
+ }
+
+ // Remember the decoded version and drop the encoded version.
+ // That way it is safe to mutate what we return.
+ e.value = v
+ e.desc = extension
+ e.enc = nil
+ emap[extension.Field] = e
+ return e.value, nil
+}
+
+// defaultExtensionValue returns the default value for extension.
+// If no default for an extension is defined ErrMissingExtension is returned.
+func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) {
+ if extension.ExtensionType == nil {
+ // incomplete descriptor, so no default
+ return nil, ErrMissingExtension
+ }
+
+ t := reflect.TypeOf(extension.ExtensionType)
+ props := extensionProperties(extension)
+
+ sf, _, err := fieldDefault(t, props)
+ if err != nil {
+ return nil, err
+ }
+
+ if sf == nil || sf.value == nil {
+ // There is no default value.
+ return nil, ErrMissingExtension
+ }
+
+ if t.Kind() != reflect.Ptr {
+ // We do not need to return a Ptr, we can directly return sf.value.
+ return sf.value, nil
+ }
+
+ // We need to return an interface{} that is a pointer to sf.value.
+ value := reflect.New(t).Elem()
+ value.Set(reflect.New(value.Type().Elem()))
+ if sf.kind == reflect.Int32 {
+ // We may have an int32 or an enum, but the underlying data is int32.
+ // Since we can't set an int32 into a non int32 reflect.value directly
+ // set it as a int32.
+ value.Elem().SetInt(int64(sf.value.(int32)))
+ } else {
+ value.Elem().Set(reflect.ValueOf(sf.value))
+ }
+ return value.Interface(), nil
+}
+
+// decodeExtension decodes an extension encoded in b.
+func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) {
+ t := reflect.TypeOf(extension.ExtensionType)
+ unmarshal := typeUnmarshaler(t, extension.Tag)
+
+ // t is a pointer to a struct, pointer to basic type or a slice.
+ // Allocate space to store the pointer/slice.
+ value := reflect.New(t).Elem()
+
+ var err error
+ for {
+ x, n := decodeVarint(b)
+ if n == 0 {
+ return nil, io.ErrUnexpectedEOF
+ }
+ b = b[n:]
+ wire := int(x) & 7
+
+ b, err = unmarshal(b, valToPointer(value.Addr()), wire)
+ if err != nil {
+ return nil, err
+ }
+
+ if len(b) == 0 {
+ break
+ }
+ }
+ return value.Interface(), nil
+}
+
+// GetExtensions returns a slice of the extensions present in pb that are also listed in es.
+// The returned slice has the same length as es; missing extensions will appear as nil elements.
+func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) {
+ epb, err := extendable(pb)
+ if err != nil {
+ return nil, err
+ }
+ extensions = make([]interface{}, len(es))
+ for i, e := range es {
+ extensions[i], err = GetExtension(epb, e)
+ if err == ErrMissingExtension {
+ err = nil
+ }
+ if err != nil {
+ return
+ }
+ }
+ return
+}
+
+// ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order.
+// For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing
+// just the Field field, which defines the extension's field number.
+func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) {
+ epb, err := extendable(pb)
+ if err != nil {
+ return nil, err
+ }
+ registeredExtensions := RegisteredExtensions(pb)
+
+ emap, mu := epb.extensionsRead()
+ if emap == nil {
+ return nil, nil
+ }
+ mu.Lock()
+ defer mu.Unlock()
+ extensions := make([]*ExtensionDesc, 0, len(emap))
+ for extid, e := range emap {
+ desc := e.desc
+ if desc == nil {
+ desc = registeredExtensions[extid]
+ if desc == nil {
+ desc = &ExtensionDesc{Field: extid}
+ }
+ }
+
+ extensions = append(extensions, desc)
+ }
+ return extensions, nil
+}
+
+// SetExtension sets the specified extension of pb to the specified value.
+func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error {
+ if epb, ok := pb.(extensionsBytes); ok {
+ newb, err := encodeExtension(extension, value)
+ if err != nil {
+ return err
+ }
+ bb := epb.GetExtensions()
+ *bb = append(*bb, newb...)
+ return nil
+ }
+ epb, err := extendable(pb)
+ if err != nil {
+ return err
+ }
+ if err := checkExtensionTypes(epb, extension); err != nil {
+ return err
+ }
+ typ := reflect.TypeOf(extension.ExtensionType)
+ if typ != reflect.TypeOf(value) {
+ return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", value, extension.ExtensionType)
+ }
+ // nil extension values need to be caught early, because the
+ // encoder can't distinguish an ErrNil due to a nil extension
+ // from an ErrNil due to a missing field. Extensions are
+ // always optional, so the encoder would just swallow the error
+ // and drop all the extensions from the encoded message.
+ if reflect.ValueOf(value).IsNil() {
+ return fmt.Errorf("proto: SetExtension called with nil value of type %T", value)
+ }
+
+ extmap := epb.extensionsWrite()
+ extmap[extension.Field] = Extension{desc: extension, value: value}
+ return nil
+}
+
+// ClearAllExtensions clears all extensions from pb.
+func ClearAllExtensions(pb Message) {
+ if epb, doki := pb.(extensionsBytes); doki {
+ ext := epb.GetExtensions()
+ *ext = []byte{}
+ return
+ }
+ epb, err := extendable(pb)
+ if err != nil {
+ return
+ }
+ m := epb.extensionsWrite()
+ for k := range m {
+ delete(m, k)
+ }
+}
+
+// A global registry of extensions.
+// The generated code will register the generated descriptors by calling RegisterExtension.
+
+var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc)
+
+// RegisterExtension is called from the generated code.
+func RegisterExtension(desc *ExtensionDesc) {
+ st := reflect.TypeOf(desc.ExtendedType).Elem()
+ m := extensionMaps[st]
+ if m == nil {
+ m = make(map[int32]*ExtensionDesc)
+ extensionMaps[st] = m
+ }
+ if _, ok := m[desc.Field]; ok {
+ panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field)))
+ }
+ m[desc.Field] = desc
+}
+
+// RegisteredExtensions returns a map of the registered extensions of a
+// protocol buffer struct, indexed by the extension number.
+// The argument pb should be a nil pointer to the struct type.
+func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc {
+ return extensionMaps[reflect.TypeOf(pb).Elem()]
+}
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