// Go support for Protocol Buffers - Google's data interchange format // // Copyright 2016 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 ( "errors" "fmt" "io" "math" "reflect" "strconv" "strings" "sync" "sync/atomic" "unicode/utf8" ) // Unmarshal is the entry point from the generated .pb.go files. // This function is not intended to be used by non-generated code. // This function is not subject to any compatibility guarantee. // msg contains a pointer to a protocol buffer struct. // b is the data to be unmarshaled into the protocol buffer. // a is a pointer to a place to store cached unmarshal information. func (a *InternalMessageInfo) Unmarshal(msg Message, b []byte) error { // Load the unmarshal information for this message type. // The atomic load ensures memory consistency. u := atomicLoadUnmarshalInfo(&a.unmarshal) if u == nil { // Slow path: find unmarshal info for msg, update a with it. u = getUnmarshalInfo(reflect.TypeOf(msg).Elem()) atomicStoreUnmarshalInfo(&a.unmarshal, u) } // Then do the unmarshaling. err := u.unmarshal(toPointer(&msg), b) return err } type unmarshalInfo struct { typ reflect.Type // type of the protobuf struct // 0 = only typ field is initialized // 1 = completely initialized initialized int32 lock sync.Mutex // prevents double initialization dense []unmarshalFieldInfo // fields indexed by tag # sparse map[uint64]unmarshalFieldInfo // fields indexed by tag # reqFields []string // names of required fields reqMask uint64 // 1< 0 { // Read tag and wire type. // Special case 1 and 2 byte varints. var x uint64 if b[0] < 128 { x = uint64(b[0]) b = b[1:] } else if len(b) >= 2 && b[1] < 128 { x = uint64(b[0]&0x7f) + uint64(b[1])<<7 b = b[2:] } else { var n int x, n = decodeVarint(b) if n == 0 { return io.ErrUnexpectedEOF } b = b[n:] } tag := x >> 3 wire := int(x) & 7 // Dispatch on the tag to one of the unmarshal* functions below. var f unmarshalFieldInfo if tag < uint64(len(u.dense)) { f = u.dense[tag] } else { f = u.sparse[tag] } if fn := f.unmarshal; fn != nil { var err error b, err = fn(b, m.offset(f.field), wire) if err == nil { reqMask |= f.reqMask continue } if r, ok := err.(*RequiredNotSetError); ok { // Remember this error, but keep parsing. We need to produce // a full parse even if a required field is missing. if errLater == nil { errLater = r } reqMask |= f.reqMask continue } if err != errInternalBadWireType { if err == errInvalidUTF8 { if errLater == nil { fullName := revProtoTypes[reflect.PtrTo(u.typ)] + "." + f.name errLater = &invalidUTF8Error{fullName} } continue } return err } // Fragments with bad wire type are treated as unknown fields. } // Unknown tag. if !u.unrecognized.IsValid() { // Don't keep unrecognized data; just skip it. var err error b, err = skipField(b, wire) if err != nil { return err } continue } // Keep unrecognized data around. // maybe in extensions, maybe in the unrecognized field. z := m.offset(u.unrecognized).toBytes() var emap map[int32]Extension var e Extension for _, r := range u.extensionRanges { if uint64(r.Start) <= tag && tag <= uint64(r.End) { if u.extensions.IsValid() { mp := m.offset(u.extensions).toExtensions() emap = mp.extensionsWrite() e = emap[int32(tag)] z = &e.enc break } if u.oldExtensions.IsValid() { p := m.offset(u.oldExtensions).toOldExtensions() emap = *p if emap == nil { emap = map[int32]Extension{} *p = emap } e = emap[int32(tag)] z = &e.enc break } panic("no extensions field available") } } // Use wire type to skip data. var err error b0 := b b, err = skipField(b, wire) if err != nil { return err } *z = encodeVarint(*z, tag<<3|uint64(wire)) *z = append(*z, b0[:len(b0)-len(b)]...) if emap != nil { emap[int32(tag)] = e } } if reqMask != u.reqMask && errLater == nil { // A required field of this message is missing. for _, n := range u.reqFields { if reqMask&1 == 0 { errLater = &RequiredNotSetError{n} } reqMask >>= 1 } } return errLater } // computeUnmarshalInfo fills in u with information for use // in unmarshaling protocol buffers of type u.typ. func (u *unmarshalInfo) computeUnmarshalInfo() { u.lock.Lock() defer u.lock.Unlock() if u.initialized != 0 { return } t := u.typ n := t.NumField() // Set up the "not found" value for the unrecognized byte buffer. // This is the default for proto3. u.unrecognized = invalidField u.extensions = invalidField u.oldExtensions = invalidField // List of the generated type and offset for each oneof field. type oneofField struct { ityp reflect.Type // interface type of oneof field field field // offset in containing message } var oneofFields []oneofField for i := 0; i < n; i++ { f := t.Field(i) if f.Name == "XXX_unrecognized" { // The byte slice used to hold unrecognized input is special. if f.Type != reflect.TypeOf(([]byte)(nil)) { panic("bad type for XXX_unrecognized field: " + f.Type.Name()) } u.unrecognized = toField(&f) continue } if f.Name == "XXX_InternalExtensions" { // Ditto here. if f.Type != reflect.TypeOf(XXX_InternalExtensions{}) { panic("bad type for XXX_InternalExtensions field: " + f.Type.Name()) } u.extensions = toField(&f) if f.Tag.Get("protobuf_messageset") == "1" { u.isMessageSet = true } continue } if f.Name == "XXX_extensions" { // An older form of the extensions field. if f.Type != reflect.TypeOf((map[int32]Extension)(nil)) { panic("bad type for XXX_extensions field: " + f.Type.Name()) } u.oldExtensions = toField(&f) continue } if f.Name == "XXX_NoUnkeyedLiteral" || f.Name == "XXX_sizecache" { continue } oneof := f.Tag.Get("protobuf_oneof") if oneof != "" { oneofFields = append(oneofFields, oneofField{f.Type, toField(&f)}) // The rest of oneof processing happens below. continue } tags := f.Tag.Get("protobuf") tagArray := strings.Split(tags, ",") if len(tagArray) < 2 { panic("protobuf tag not enough fields in " + t.Name() + "." + f.Name + ": " + tags) } tag, err := strconv.Atoi(tagArray[1]) if err != nil { panic("protobuf tag field not an integer: " + tagArray[1]) } name := "" for _, tag := range tagArray[3:] { if strings.HasPrefix(tag, "name=") { name = tag[5:] } } // Extract unmarshaling function from the field (its type and tags). unmarshal := fieldUnmarshaler(&f) // Required field? var reqMask uint64 if tagArray[2] == "req" { bit := len(u.reqFields) u.reqFields = append(u.reqFields, name) reqMask = uint64(1) << uint(bit) // TODO: if we have more than 64 required fields, we end up // not verifying that all required fields are present. // Fix this, perhaps using a count of required fields? } // Store the info in the correct slot in the message. u.setTag(tag, toField(&f), unmarshal, reqMask, name) } // Find any types associated with oneof fields. // TODO: XXX_OneofFuncs returns more info than we need. Get rid of some of it? fn := reflect.Zero(reflect.PtrTo(t)).MethodByName("XXX_OneofFuncs") if fn.IsValid() { res := fn.Call(nil)[3] // last return value from XXX_OneofFuncs: []interface{} for i := res.Len() - 1; i >= 0; i-- { v := res.Index(i) // interface{} tptr := reflect.ValueOf(v.Interface()).Type() // *Msg_X typ := tptr.Elem() // Msg_X f := typ.Field(0) // oneof implementers have one field baseUnmarshal := fieldUnmarshaler(&f) tags := strings.Split(f.Tag.Get("protobuf"), ",") fieldNum, err := strconv.Atoi(tags[1]) if err != nil { panic("protobuf tag field not an integer: " + tags[1]) } var name string for _, tag := range tags { if strings.HasPrefix(tag, "name=") { name = strings.TrimPrefix(tag, "name=") break } } // Find the oneof field that this struct implements. // Might take O(n^2) to process all of the oneofs, but who cares. for _, of := range oneofFields { if tptr.Implements(of.ityp) { // We have found the corresponding interface for this struct. // That lets us know where this struct should be stored // when we encounter it during unmarshaling. unmarshal := makeUnmarshalOneof(typ, of.ityp, baseUnmarshal) u.setTag(fieldNum, of.field, unmarshal, 0, name) } } } } // Get extension ranges, if any. fn = reflect.Zero(reflect.PtrTo(t)).MethodByName("ExtensionRangeArray") if fn.IsValid() { if !u.extensions.IsValid() && !u.oldExtensions.IsValid() { panic("a message with extensions, but no extensions field in " + t.Name()) } u.extensionRanges = fn.Call(nil)[0].Interface().([]ExtensionRange) } // Explicitly disallow tag 0. This will ensure we flag an error // when decoding a buffer of all zeros. Without this code, we // would decode and skip an all-zero buffer of even length. // [0 0] is [tag=0/wiretype=varint varint-encoded-0]. u.setTag(0, zeroField, func(b []byte, f pointer, w int) ([]byte, error) { return nil, fmt.Errorf("proto: %s: illegal tag 0 (wire type %d)", t, w) }, 0, "") // Set mask for required field check. u.reqMask = uint64(1)<= 0 && (tag < 16 || tag < 2*n) { // TODO: what are the right numbers here? for len(u.dense) <= tag { u.dense = append(u.dense, unmarshalFieldInfo{}) } u.dense[tag] = i return } if u.sparse == nil { u.sparse = map[uint64]unmarshalFieldInfo{} } u.sparse[uint64(tag)] = i } // fieldUnmarshaler returns an unmarshaler for the given field. func fieldUnmarshaler(f *reflect.StructField) unmarshaler { if f.Type.Kind() == reflect.Map { return makeUnmarshalMap(f) } return typeUnmarshaler(f.Type, f.Tag.Get("protobuf")) } // typeUnmarshaler returns an unmarshaler for the given field type / field tag pair. func typeUnmarshaler(t reflect.Type, tags string) unmarshaler { tagArray := strings.Split(tags, ",") encoding := tagArray[0] name := "unknown" proto3 := false validateUTF8 := true for _, tag := range tagArray[3:] { if strings.HasPrefix(tag, "name=") { name = tag[5:] } if tag == "proto3" { proto3 = true } } validateUTF8 = validateUTF8 && proto3 // Figure out packaging (pointer, slice, or both) slice := false pointer := false if t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8 { slice = true t = t.Elem() } if t.Kind() == reflect.Ptr { pointer = true t = t.Elem() } // We'll never have both pointer and slice for basic types. if pointer && slice && t.Kind() != reflect.Struct { panic("both pointer and slice for basic type in " + t.Name()) } switch t.Kind() { case reflect.Bool: if pointer { return unmarshalBoolPtr } if slice { return unmarshalBoolSlice } return unmarshalBoolValue case reflect.Int32: switch encoding { case "fixed32": if pointer { return unmarshalFixedS32Ptr } if slice { return unmarshalFixedS32Slice } return unmarshalFixedS32Value case "varint": // this could be int32 or enum if pointer { return unmarshalInt32Ptr } if slice { return unmarshalInt32Slice } return unmarshalInt32Value case "zigzag32": if pointer { return unmarshalSint32Ptr } if slice { return unmarshalSint32Slice } return unmarshalSint32Value } case reflect.Int64: switch encoding { case "fixed64": if pointer { return unmarshalFixedS64Ptr } if slice { return unmarshalFixedS64Slice } return unmarshalFixedS64Value case "varint": if pointer { return unmarshalInt64Ptr } if slice { return unmarshalInt64Slice } return unmarshalInt64Value case "zigzag64": if pointer { return unmarshalSint64Ptr } if slice { return unmarshalSint64Slice } return unmarshalSint64Value } case reflect.Uint32: switch encoding { case "fixed32": if pointer { return unmarshalFixed32Ptr } if slice { return unmarshalFixed32Slice } return unmarshalFixed32Value case "varint": if pointer { return unmarshalUint32Ptr } if slice { return unmarshalUint32Slice } return unmarshalUint32Value } case reflect.Uint64: switch encoding { case "fixed64": if pointer { return unmarshalFixed64Ptr } if slice { return unmarshalFixed64Slice } return unmarshalFixed64Value case "varint": if pointer { return unmarshalUint64Ptr } if slice { return unmarshalUint64Slice } return unmarshalUint64Value } case reflect.Float32: if pointer { return unmarshalFloat32Ptr } if slice { return unmarshalFloat32Slice } return unmarshalFloat32Value case reflect.Float64: if pointer { return unmarshalFloat64Ptr } if slice { return unmarshalFloat64Slice } return unmarshalFloat64Value case reflect.Map: panic("map type in typeUnmarshaler in " + t.Name()) case reflect.Slice: if pointer { panic("bad pointer in slice case in " + t.Name()) } if slice { return unmarshalBytesSlice } return unmarshalBytesValue case reflect.String: if validateUTF8 { if pointer { return unmarshalUTF8StringPtr } if slice { return unmarshalUTF8StringSlice } return unmarshalUTF8StringValue } if pointer { return unmarshalStringPtr } if slice { return unmarshalStringSlice } return unmarshalStringValue case reflect.Struct: // message or group field if !pointer { panic(fmt.Sprintf("message/group field %s:%s without pointer", t, encoding)) } switch encoding { case "bytes": if slice { return makeUnmarshalMessageSlicePtr(getUnmarshalInfo(t), name) } return makeUnmarshalMessagePtr(getUnmarshalInfo(t), name) case "group": if slice { return makeUnmarshalGroupSlicePtr(getUnmarshalInfo(t), name) } return makeUnmarshalGroupPtr(getUnmarshalInfo(t), name) } } panic(fmt.Sprintf("unmarshaler not found type:%s encoding:%s", t, encoding)) } // Below are all the unmarshalers for individual fields of various types. func unmarshalInt64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x) *f.toInt64() = v return b, nil } func unmarshalInt64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x) *f.toInt64Ptr() = &v return b, nil } func unmarshalInt64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x) s := f.toInt64Slice() *s = append(*s, v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x) s := f.toInt64Slice() *s = append(*s, v) return b, nil } func unmarshalSint64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x>>1) ^ int64(x)<<63>>63 *f.toInt64() = v return b, nil } func unmarshalSint64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x>>1) ^ int64(x)<<63>>63 *f.toInt64Ptr() = &v return b, nil } func unmarshalSint64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x>>1) ^ int64(x)<<63>>63 s := f.toInt64Slice() *s = append(*s, v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int64(x>>1) ^ int64(x)<<63>>63 s := f.toInt64Slice() *s = append(*s, v) return b, nil } func unmarshalUint64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint64(x) *f.toUint64() = v return b, nil } func unmarshalUint64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint64(x) *f.toUint64Ptr() = &v return b, nil } func unmarshalUint64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint64(x) s := f.toUint64Slice() *s = append(*s, v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint64(x) s := f.toUint64Slice() *s = append(*s, v) return b, nil } func unmarshalInt32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x) *f.toInt32() = v return b, nil } func unmarshalInt32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x) f.setInt32Ptr(v) return b, nil } func unmarshalInt32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x) f.appendInt32Slice(v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x) f.appendInt32Slice(v) return b, nil } func unmarshalSint32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x>>1) ^ int32(x)<<31>>31 *f.toInt32() = v return b, nil } func unmarshalSint32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x>>1) ^ int32(x)<<31>>31 f.setInt32Ptr(v) return b, nil } func unmarshalSint32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x>>1) ^ int32(x)<<31>>31 f.appendInt32Slice(v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := int32(x>>1) ^ int32(x)<<31>>31 f.appendInt32Slice(v) return b, nil } func unmarshalUint32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint32(x) *f.toUint32() = v return b, nil } func unmarshalUint32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint32(x) *f.toUint32Ptr() = &v return b, nil } func unmarshalUint32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint32(x) s := f.toUint32Slice() *s = append(*s, v) } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] v := uint32(x) s := f.toUint32Slice() *s = append(*s, v) return b, nil } func unmarshalFixed64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 *f.toUint64() = v return b[8:], nil } func unmarshalFixed64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 *f.toUint64Ptr() = &v return b[8:], nil } func unmarshalFixed64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 s := f.toUint64Slice() *s = append(*s, v) b = b[8:] } return res, nil } if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 s := f.toUint64Slice() *s = append(*s, v) return b[8:], nil } func unmarshalFixedS64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56 *f.toInt64() = v return b[8:], nil } func unmarshalFixedS64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56 *f.toInt64Ptr() = &v return b[8:], nil } func unmarshalFixedS64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56 s := f.toInt64Slice() *s = append(*s, v) b = b[8:] } return res, nil } if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := int64(b[0]) | int64(b[1])<<8 | int64(b[2])<<16 | int64(b[3])<<24 | int64(b[4])<<32 | int64(b[5])<<40 | int64(b[6])<<48 | int64(b[7])<<56 s := f.toInt64Slice() *s = append(*s, v) return b[8:], nil } func unmarshalFixed32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 *f.toUint32() = v return b[4:], nil } func unmarshalFixed32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 *f.toUint32Ptr() = &v return b[4:], nil } func unmarshalFixed32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 s := f.toUint32Slice() *s = append(*s, v) b = b[4:] } return res, nil } if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 s := f.toUint32Slice() *s = append(*s, v) return b[4:], nil } func unmarshalFixedS32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24 *f.toInt32() = v return b[4:], nil } func unmarshalFixedS32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24 f.setInt32Ptr(v) return b[4:], nil } func unmarshalFixedS32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24 f.appendInt32Slice(v) b = b[4:] } return res, nil } if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := int32(b[0]) | int32(b[1])<<8 | int32(b[2])<<16 | int32(b[3])<<24 f.appendInt32Slice(v) return b[4:], nil } func unmarshalBoolValue(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } // Note: any length varint is allowed, even though any sane // encoder will use one byte. // See https://github.com/golang/protobuf/issues/76 x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } // TODO: check if x>1? Tests seem to indicate no. v := x != 0 *f.toBool() = v return b[n:], nil } func unmarshalBoolPtr(b []byte, f pointer, w int) ([]byte, error) { if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } v := x != 0 *f.toBoolPtr() = &v return b[n:], nil } func unmarshalBoolSlice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { x, n = decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } v := x != 0 s := f.toBoolSlice() *s = append(*s, v) b = b[n:] } return res, nil } if w != WireVarint { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } v := x != 0 s := f.toBoolSlice() *s = append(*s, v) return b[n:], nil } func unmarshalFloat64Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56) *f.toFloat64() = v return b[8:], nil } func unmarshalFloat64Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56) *f.toFloat64Ptr() = &v return b[8:], nil } func unmarshalFloat64Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56) s := f.toFloat64Slice() *s = append(*s, v) b = b[8:] } return res, nil } if w != WireFixed64 { return b, errInternalBadWireType } if len(b) < 8 { return nil, io.ErrUnexpectedEOF } v := math.Float64frombits(uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56) s := f.toFloat64Slice() *s = append(*s, v) return b[8:], nil } func unmarshalFloat32Value(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24) *f.toFloat32() = v return b[4:], nil } func unmarshalFloat32Ptr(b []byte, f pointer, w int) ([]byte, error) { if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24) *f.toFloat32Ptr() = &v return b[4:], nil } func unmarshalFloat32Slice(b []byte, f pointer, w int) ([]byte, error) { if w == WireBytes { // packed x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } res := b[x:] b = b[:x] for len(b) > 0 { if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24) s := f.toFloat32Slice() *s = append(*s, v) b = b[4:] } return res, nil } if w != WireFixed32 { return b, errInternalBadWireType } if len(b) < 4 { return nil, io.ErrUnexpectedEOF } v := math.Float32frombits(uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24) s := f.toFloat32Slice() *s = append(*s, v) return b[4:], nil } func unmarshalStringValue(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) *f.toString() = v return b[x:], nil } func unmarshalStringPtr(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) *f.toStringPtr() = &v return b[x:], nil } func unmarshalStringSlice(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) s := f.toStringSlice() *s = append(*s, v) return b[x:], nil } func unmarshalUTF8StringValue(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) *f.toString() = v if !utf8.ValidString(v) { return b[x:], errInvalidUTF8 } return b[x:], nil } func unmarshalUTF8StringPtr(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) *f.toStringPtr() = &v if !utf8.ValidString(v) { return b[x:], errInvalidUTF8 } return b[x:], nil } func unmarshalUTF8StringSlice(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := string(b[:x]) s := f.toStringSlice() *s = append(*s, v) if !utf8.ValidString(v) { return b[x:], errInvalidUTF8 } return b[x:], nil } var emptyBuf [0]byte func unmarshalBytesValue(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } // The use of append here is a trick which avoids the zeroing // that would be required if we used a make/copy pair. // We append to emptyBuf instead of nil because we want // a non-nil result even when the length is 0. v := append(emptyBuf[:], b[:x]...) *f.toBytes() = v return b[x:], nil } func unmarshalBytesSlice(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := append(emptyBuf[:], b[:x]...) s := f.toBytesSlice() *s = append(*s, v) return b[x:], nil } func makeUnmarshalMessagePtr(sub *unmarshalInfo, name string) unmarshaler { return func(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } // First read the message field to see if something is there. // The semantics of multiple submessages are weird. Instead of // the last one winning (as it is for all other fields), multiple // submessages are merged. v := f.getPointer() if v.isNil() { v = valToPointer(reflect.New(sub.typ)) f.setPointer(v) } err := sub.unmarshal(v, b[:x]) if err != nil { if r, ok := err.(*RequiredNotSetError); ok { r.field = name + "." + r.field } else { return nil, err } } return b[x:], err } } func makeUnmarshalMessageSlicePtr(sub *unmarshalInfo, name string) unmarshaler { return func(b []byte, f pointer, w int) ([]byte, error) { if w != WireBytes { return b, errInternalBadWireType } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } v := valToPointer(reflect.New(sub.typ)) err := sub.unmarshal(v, b[:x]) if err != nil { if r, ok := err.(*RequiredNotSetError); ok { r.field = name + "." + r.field } else { return nil, err } } f.appendPointer(v) return b[x:], err } } func makeUnmarshalGroupPtr(sub *unmarshalInfo, name string) unmarshaler { return func(b []byte, f pointer, w int) ([]byte, error) { if w != WireStartGroup { return b, errInternalBadWireType } x, y := findEndGroup(b) if x < 0 { return nil, io.ErrUnexpectedEOF } v := f.getPointer() if v.isNil() { v = valToPointer(reflect.New(sub.typ)) f.setPointer(v) } err := sub.unmarshal(v, b[:x]) if err != nil { if r, ok := err.(*RequiredNotSetError); ok { r.field = name + "." + r.field } else { return nil, err } } return b[y:], err } } func makeUnmarshalGroupSlicePtr(sub *unmarshalInfo, name string) unmarshaler { return func(b []byte, f pointer, w int) ([]byte, error) { if w != WireStartGroup { return b, errInternalBadWireType } x, y := findEndGroup(b) if x < 0 { return nil, io.ErrUnexpectedEOF } v := valToPointer(reflect.New(sub.typ)) err := sub.unmarshal(v, b[:x]) if err != nil { if r, ok := err.(*RequiredNotSetError); ok { r.field = name + "." + r.field } else { return nil, err } } f.appendPointer(v) return b[y:], err } } func makeUnmarshalMap(f *reflect.StructField) unmarshaler { t := f.Type kt := t.Key() vt := t.Elem() unmarshalKey := typeUnmarshaler(kt, f.Tag.Get("protobuf_key")) unmarshalVal := typeUnmarshaler(vt, f.Tag.Get("protobuf_val")) return func(b []byte, f pointer, w int) ([]byte, error) { // The map entry is a submessage. Figure out how big it is. if w != WireBytes { return nil, fmt.Errorf("proto: bad wiretype for map field: got %d want %d", w, WireBytes) } x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } b = b[n:] if x > uint64(len(b)) { return nil, io.ErrUnexpectedEOF } r := b[x:] // unused data to return b = b[:x] // data for map entry // Note: we could use #keys * #values ~= 200 functions // to do map decoding without reflection. Probably not worth it. // Maps will be somewhat slow. Oh well. // Read key and value from data. var nerr nonFatal k := reflect.New(kt) v := reflect.New(vt) for len(b) > 0 { x, n := decodeVarint(b) if n == 0 { return nil, io.ErrUnexpectedEOF } wire := int(x) & 7 b = b[n:] var err error switch x >> 3 { case 1: b, err = unmarshalKey(b, valToPointer(k), wire) case 2: b, err = unmarshalVal(b, valToPointer(v), wire) default: err = errInternalBadWireType // skip unknown tag } if nerr.Merge(err) { continue } if err != errInternalBadWireType { return nil, err } // Skip past unknown fields. b, err = skipField(b, wire) if err != nil { return nil, err } } // Get map, allocate if needed. m := f.asPointerTo(t).Elem() // an addressable map[K]T if m.IsNil() { m.Set(reflect.MakeMap(t)) } // Insert into map. m.SetMapIndex(k.Elem(), v.Elem()) return r, nerr.E } } // makeUnmarshalOneof makes an unmarshaler for oneof fields. // for: // message Msg { // oneof F { // int64 X = 1; // float64 Y = 2; // } // } // typ is the type of the concrete entry for a oneof case (e.g. Msg_X). // ityp is the interface type of the oneof field (e.g. isMsg_F). // unmarshal is the unmarshaler for the base type of the oneof case (e.g. int64). // Note that this function will be called once for each case in the oneof. func makeUnmarshalOneof(typ, ityp reflect.Type, unmarshal unmarshaler) unmarshaler { sf := typ.Field(0) field0 := toField(&sf) return func(b []byte, f pointer, w int) ([]byte, error) { // Allocate holder for value. v := reflect.New(typ) // Unmarshal data into holder. // We unmarshal into the first field of the holder object. var err error var nerr nonFatal b, err = unmarshal(b, valToPointer(v).offset(field0), w) if !nerr.Merge(err) { return nil, err } // Write pointer to holder into target field. f.asPointerTo(ityp).Elem().Set(v) return b, nerr.E } } // Error used by decode internally. var errInternalBadWireType = errors.New("proto: internal error: bad wiretype") // skipField skips past a field of type wire and returns the remaining bytes. func skipField(b []byte, wire int) ([]byte, error) { switch wire { case WireVarint: _, k := decodeVarint(b) if k == 0 { return b, io.ErrUnexpectedEOF } b = b[k:] case WireFixed32: if len(b) < 4 { return b, io.ErrUnexpectedEOF } b = b[4:] case WireFixed64: if len(b) < 8 { return b, io.ErrUnexpectedEOF } b = b[8:] case WireBytes: m, k := decodeVarint(b) if k == 0 || uint64(len(b)-k) < m { return b, io.ErrUnexpectedEOF } b = b[uint64(k)+m:] case WireStartGroup: _, i := findEndGroup(b) if i == -1 { return b, io.ErrUnexpectedEOF } b = b[i:] default: return b, fmt.Errorf("proto: can't skip unknown wire type %d", wire) } return b, nil } // findEndGroup finds the index of the next EndGroup tag. // Groups may be nested, so the "next" EndGroup tag is the first // unpaired EndGroup. // findEndGroup returns the indexes of the start and end of the EndGroup tag. // Returns (-1,-1) if it can't find one. func findEndGroup(b []byte) (int, int) { depth := 1 i := 0 for { x, n := decodeVarint(b[i:]) if n == 0 { return -1, -1 } j := i i += n switch x & 7 { case WireVarint: _, k := decodeVarint(b[i:]) if k == 0 { return -1, -1 } i += k case WireFixed32: if len(b)-4 < i { return -1, -1 } i += 4 case WireFixed64: if len(b)-8 < i { return -1, -1 } i += 8 case WireBytes: m, k := decodeVarint(b[i:]) if k == 0 { return -1, -1 } i += k if uint64(len(b)-i) < m { return -1, -1 } i += int(m) case WireStartGroup: depth++ case WireEndGroup: depth-- if depth == 0 { return j, i } default: return -1, -1 } } } // encodeVarint appends a varint-encoded integer to b and returns the result. func encodeVarint(b []byte, x uint64) []byte { for x >= 1<<7 { b = append(b, byte(x&0x7f|0x80)) x >>= 7 } return append(b, byte(x)) } // decodeVarint reads a varint-encoded integer from b. // Returns the decoded integer and the number of bytes read. // If there is an error, it returns 0,0. func decodeVarint(b []byte) (uint64, int) { var x, y uint64 if len(b) <= 0 { goto bad } x = uint64(b[0]) if x < 0x80 { return x, 1 } x -= 0x80 if len(b) <= 1 { goto bad } y = uint64(b[1]) x += y << 7 if y < 0x80 { return x, 2 } x -= 0x80 << 7 if len(b) <= 2 { goto bad } y = uint64(b[2]) x += y << 14 if y < 0x80 { return x, 3 } x -= 0x80 << 14 if len(b) <= 3 { goto bad } y = uint64(b[3]) x += y << 21 if y < 0x80 { return x, 4 } x -= 0x80 << 21 if len(b) <= 4 { goto bad } y = uint64(b[4]) x += y << 28 if y < 0x80 { return x, 5 } x -= 0x80 << 28 if len(b) <= 5 { goto bad } y = uint64(b[5]) x += y << 35 if y < 0x80 { return x, 6 } x -= 0x80 << 35 if len(b) <= 6 { goto bad } y = uint64(b[6]) x += y << 42 if y < 0x80 { return x, 7 } x -= 0x80 << 42 if len(b) <= 7 { goto bad } y = uint64(b[7]) x += y << 49 if y < 0x80 { return x, 8 } x -= 0x80 << 49 if len(b) <= 8 { goto bad } y = uint64(b[8]) x += y << 56 if y < 0x80 { return x, 9 } x -= 0x80 << 56 if len(b) <= 9 { goto bad } y = uint64(b[9]) x += y << 63 if y < 2 { return x, 10 } bad: return 0, 0 }