gitroast/vendor/github.com/golang/protobuf/proto/decode.go

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// 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
/*
* Routines for decoding protocol buffer data to construct in-memory representations.
*/
import (
"errors"
"fmt"
"io"
"os"
"reflect"
)
// errOverflow is returned when an integer is too large to be represented.
var errOverflow = errors.New("proto: integer overflow")
// ErrInternalBadWireType is returned by generated code when an incorrect
// wire type is encountered. It does not get returned to user code.
var ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof")
// The fundamental decoders that interpret bytes on the wire.
// Those that take integer types all return uint64 and are
// therefore of type valueDecoder.
// DecodeVarint reads a varint-encoded integer from the slice.
// It returns the integer and the number of bytes consumed, or
// zero if there is not enough.
// This is the format for the
// int32, int64, uint32, uint64, bool, and enum
// protocol buffer types.
func DecodeVarint(buf []byte) (x uint64, n int) {
// x, n already 0
for shift := uint(0); shift < 64; shift += 7 {
if n >= len(buf) {
return 0, 0
}
b := uint64(buf[n])
n++
x |= (b & 0x7F) << shift
if (b & 0x80) == 0 {
return x, n
}
}
// The number is too large to represent in a 64-bit value.
return 0, 0
}
// DecodeVarint reads a varint-encoded integer from the Buffer.
// This is the format for the
// int32, int64, uint32, uint64, bool, and enum
// protocol buffer types.
func (p *Buffer) DecodeVarint() (x uint64, err error) {
// x, err already 0
i := p.index
l := len(p.buf)
for shift := uint(0); shift < 64; shift += 7 {
if i >= l {
err = io.ErrUnexpectedEOF
return
}
b := p.buf[i]
i++
x |= (uint64(b) & 0x7F) << shift
if b < 0x80 {
p.index = i
return
}
}
// The number is too large to represent in a 64-bit value.
err = errOverflow
return
}
// DecodeFixed64 reads a 64-bit integer from the Buffer.
// This is the format for the
// fixed64, sfixed64, and double protocol buffer types.
func (p *Buffer) DecodeFixed64() (x uint64, err error) {
// x, err already 0
i := p.index + 8
if i < 0 || i > len(p.buf) {
err = io.ErrUnexpectedEOF
return
}
p.index = i
x = uint64(p.buf[i-8])
x |= uint64(p.buf[i-7]) << 8
x |= uint64(p.buf[i-6]) << 16
x |= uint64(p.buf[i-5]) << 24
x |= uint64(p.buf[i-4]) << 32
x |= uint64(p.buf[i-3]) << 40
x |= uint64(p.buf[i-2]) << 48
x |= uint64(p.buf[i-1]) << 56
return
}
// DecodeFixed32 reads a 32-bit integer from the Buffer.
// This is the format for the
// fixed32, sfixed32, and float protocol buffer types.
func (p *Buffer) DecodeFixed32() (x uint64, err error) {
// x, err already 0
i := p.index + 4
if i < 0 || i > len(p.buf) {
err = io.ErrUnexpectedEOF
return
}
p.index = i
x = uint64(p.buf[i-4])
x |= uint64(p.buf[i-3]) << 8
x |= uint64(p.buf[i-2]) << 16
x |= uint64(p.buf[i-1]) << 24
return
}
// DecodeZigzag64 reads a zigzag-encoded 64-bit integer
// from the Buffer.
// This is the format used for the sint64 protocol buffer type.
func (p *Buffer) DecodeZigzag64() (x uint64, err error) {
x, err = p.DecodeVarint()
if err != nil {
return
}
x = (x >> 1) ^ uint64((int64(x&1)<<63)>>63)
return
}
// DecodeZigzag32 reads a zigzag-encoded 32-bit integer
// from the Buffer.
// This is the format used for the sint32 protocol buffer type.
func (p *Buffer) DecodeZigzag32() (x uint64, err error) {
x, err = p.DecodeVarint()
if err != nil {
return
}
x = uint64((uint32(x) >> 1) ^ uint32((int32(x&1)<<31)>>31))
return
}
// These are not ValueDecoders: they produce an array of bytes or a string.
// bytes, embedded messages
// DecodeRawBytes reads a count-delimited byte buffer from the Buffer.
// This is the format used for the bytes protocol buffer
// type and for embedded messages.
func (p *Buffer) DecodeRawBytes(alloc bool) (buf []byte, err error) {
n, err := p.DecodeVarint()
if err != nil {
return nil, err
}
nb := int(n)
if nb < 0 {
return nil, fmt.Errorf("proto: bad byte length %d", nb)
}
end := p.index + nb
if end < p.index || end > len(p.buf) {
return nil, io.ErrUnexpectedEOF
}
if !alloc {
// todo: check if can get more uses of alloc=false
buf = p.buf[p.index:end]
p.index += nb
return
}
buf = make([]byte, nb)
copy(buf, p.buf[p.index:])
p.index += nb
return
}
// DecodeStringBytes reads an encoded string from the Buffer.
// This is the format used for the proto2 string type.
func (p *Buffer) DecodeStringBytes() (s string, err error) {
buf, err := p.DecodeRawBytes(false)
if err != nil {
return
}
return string(buf), nil
}
// Skip the next item in the buffer. Its wire type is decoded and presented as an argument.
// If the protocol buffer has extensions, and the field matches, add it as an extension.
// Otherwise, if the XXX_unrecognized field exists, append the skipped data there.
func (o *Buffer) skipAndSave(t reflect.Type, tag, wire int, base structPointer, unrecField field) error {
oi := o.index
err := o.skip(t, tag, wire)
if err != nil {
return err
}
if !unrecField.IsValid() {
return nil
}
ptr := structPointer_Bytes(base, unrecField)
// Add the skipped field to struct field
obuf := o.buf
o.buf = *ptr
o.EncodeVarint(uint64(tag<<3 | wire))
*ptr = append(o.buf, obuf[oi:o.index]...)
o.buf = obuf
return nil
}
// Skip the next item in the buffer. Its wire type is decoded and presented as an argument.
func (o *Buffer) skip(t reflect.Type, tag, wire int) error {
var u uint64
var err error
switch wire {
case WireVarint:
_, err = o.DecodeVarint()
case WireFixed64:
_, err = o.DecodeFixed64()
case WireBytes:
_, err = o.DecodeRawBytes(false)
case WireFixed32:
_, err = o.DecodeFixed32()
case WireStartGroup:
for {
u, err = o.DecodeVarint()
if err != nil {
break
}
fwire := int(u & 0x7)
if fwire == WireEndGroup {
break
}
ftag := int(u >> 3)
err = o.skip(t, ftag, fwire)
if err != nil {
break
}
}
default:
err = fmt.Errorf("proto: can't skip unknown wire type %d for %s", wire, t)
}
return err
}
// Unmarshaler is the interface representing objects that can
// unmarshal themselves. The method should reset the receiver before
// decoding starts. The argument points to data that may be
// overwritten, so implementations should not keep references to the
// buffer.
type Unmarshaler interface {
Unmarshal([]byte) error
}
// Unmarshal parses the protocol buffer representation in buf and places the
// decoded result in pb. If the struct underlying pb does not match
// the data in buf, the results can be unpredictable.
//
// Unmarshal resets pb before starting to unmarshal, so any
// existing data in pb is always removed. Use UnmarshalMerge
// to preserve and append to existing data.
func Unmarshal(buf []byte, pb Message) error {
pb.Reset()
return UnmarshalMerge(buf, pb)
}
// UnmarshalMerge parses the protocol buffer representation in buf and
// writes the decoded result to pb. If the struct underlying pb does not match
// the data in buf, the results can be unpredictable.
//
// UnmarshalMerge merges into existing data in pb.
// Most code should use Unmarshal instead.
func UnmarshalMerge(buf []byte, pb Message) error {
// If the object can unmarshal itself, let it.
if u, ok := pb.(Unmarshaler); ok {
return u.Unmarshal(buf)
}
return NewBuffer(buf).Unmarshal(pb)
}
// DecodeMessage reads a count-delimited message from the Buffer.
func (p *Buffer) DecodeMessage(pb Message) error {
enc, err := p.DecodeRawBytes(false)
if err != nil {
return err
}
return NewBuffer(enc).Unmarshal(pb)
}
// DecodeGroup reads a tag-delimited group from the Buffer.
func (p *Buffer) DecodeGroup(pb Message) error {
typ, base, err := getbase(pb)
if err != nil {
return err
}
return p.unmarshalType(typ.Elem(), GetProperties(typ.Elem()), true, base)
}
// Unmarshal parses the protocol buffer representation in the
// Buffer and places the decoded result in pb. If the struct
// underlying pb does not match the data in the buffer, the results can be
// unpredictable.
func (p *Buffer) Unmarshal(pb Message) error {
// If the object can unmarshal itself, let it.
if u, ok := pb.(Unmarshaler); ok {
err := u.Unmarshal(p.buf[p.index:])
p.index = len(p.buf)
return err
}
typ, base, err := getbase(pb)
if err != nil {
return err
}
err = p.unmarshalType(typ.Elem(), GetProperties(typ.Elem()), false, base)
if collectStats {
stats.Decode++
}
return err
}
// unmarshalType does the work of unmarshaling a structure.
func (o *Buffer) unmarshalType(st reflect.Type, prop *StructProperties, is_group bool, base structPointer) error {
var state errorState
required, reqFields := prop.reqCount, uint64(0)
var err error
for err == nil && o.index < len(o.buf) {
oi := o.index
var u uint64
u, err = o.DecodeVarint()
if err != nil {
break
}
wire := int(u & 0x7)
if wire == WireEndGroup {
if is_group {
return nil // input is satisfied
}
return fmt.Errorf("proto: %s: wiretype end group for non-group", st)
}
tag := int(u >> 3)
if tag <= 0 {
return fmt.Errorf("proto: %s: illegal tag %d (wire type %d)", st, tag, wire)
}
fieldnum, ok := prop.decoderTags.get(tag)
if !ok {
// Maybe it's an extension?
if prop.extendable {
if e := structPointer_Interface(base, st).(extendableProto); isExtensionField(e, int32(tag)) {
if err = o.skip(st, tag, wire); err == nil {
ext := e.ExtensionMap()[int32(tag)] // may be missing
ext.enc = append(ext.enc, o.buf[oi:o.index]...)
e.ExtensionMap()[int32(tag)] = ext
}
continue
}
}
// Maybe it's a oneof?
if prop.oneofUnmarshaler != nil {
m := structPointer_Interface(base, st).(Message)
// First return value indicates whether tag is a oneof field.
ok, err = prop.oneofUnmarshaler(m, tag, wire, o)
if err == ErrInternalBadWireType {
// Map the error to something more descriptive.
// Do the formatting here to save generated code space.
err = fmt.Errorf("bad wiretype for oneof field in %T", m)
}
if ok {
continue
}
}
err = o.skipAndSave(st, tag, wire, base, prop.unrecField)
continue
}
p := prop.Prop[fieldnum]
if p.dec == nil {
fmt.Fprintf(os.Stderr, "proto: no protobuf decoder for %s.%s\n", st, st.Field(fieldnum).Name)
continue
}
dec := p.dec
if wire != WireStartGroup && wire != p.WireType {
if wire == WireBytes && p.packedDec != nil {
// a packable field
dec = p.packedDec
} else {
err = fmt.Errorf("proto: bad wiretype for field %s.%s: got wiretype %d, want %d", st, st.Field(fieldnum).Name, wire, p.WireType)
continue
}
}
decErr := dec(o, p, base)
if decErr != nil && !state.shouldContinue(decErr, p) {
err = decErr
}
if err == nil && p.Required {
// Successfully decoded a required field.
if tag <= 64 {
// use bitmap for fields 1-64 to catch field reuse.
var mask uint64 = 1 << uint64(tag-1)
if reqFields&mask == 0 {
// new required field
reqFields |= mask
required--
}
} else {
// This is imprecise. It can be fooled by a required field
// with a tag > 64 that is encoded twice; that's very rare.
// A fully correct implementation would require allocating
// a data structure, which we would like to avoid.
required--
}
}
}
if err == nil {
if is_group {
return io.ErrUnexpectedEOF
}
if state.err != nil {
return state.err
}
if required > 0 {
// Not enough information to determine the exact field. If we use extra
// CPU, we could determine the field only if the missing required field
// has a tag <= 64 and we check reqFields.
return &RequiredNotSetError{"{Unknown}"}
}
}
return err
}
// Individual type decoders
// For each,
// u is the decoded value,
// v is a pointer to the field (pointer) in the struct
// Sizes of the pools to allocate inside the Buffer.
// The goal is modest amortization and allocation
// on at least 16-byte boundaries.
const (
boolPoolSize = 16
uint32PoolSize = 8
uint64PoolSize = 4
)
// Decode a bool.
func (o *Buffer) dec_bool(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
if len(o.bools) == 0 {
o.bools = make([]bool, boolPoolSize)
}
o.bools[0] = u != 0
*structPointer_Bool(base, p.field) = &o.bools[0]
o.bools = o.bools[1:]
return nil
}
func (o *Buffer) dec_proto3_bool(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
*structPointer_BoolVal(base, p.field) = u != 0
return nil
}
// Decode an int32.
func (o *Buffer) dec_int32(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
word32_Set(structPointer_Word32(base, p.field), o, uint32(u))
return nil
}
func (o *Buffer) dec_proto3_int32(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
word32Val_Set(structPointer_Word32Val(base, p.field), uint32(u))
return nil
}
// Decode an int64.
func (o *Buffer) dec_int64(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
word64_Set(structPointer_Word64(base, p.field), o, u)
return nil
}
func (o *Buffer) dec_proto3_int64(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
word64Val_Set(structPointer_Word64Val(base, p.field), o, u)
return nil
}
// Decode a string.
func (o *Buffer) dec_string(p *Properties, base structPointer) error {
s, err := o.DecodeStringBytes()
if err != nil {
return err
}
*structPointer_String(base, p.field) = &s
return nil
}
func (o *Buffer) dec_proto3_string(p *Properties, base structPointer) error {
s, err := o.DecodeStringBytes()
if err != nil {
return err
}
*structPointer_StringVal(base, p.field) = s
return nil
}
// Decode a slice of bytes ([]byte).
func (o *Buffer) dec_slice_byte(p *Properties, base structPointer) error {
b, err := o.DecodeRawBytes(true)
if err != nil {
return err
}
*structPointer_Bytes(base, p.field) = b
return nil
}
// Decode a slice of bools ([]bool).
func (o *Buffer) dec_slice_bool(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
v := structPointer_BoolSlice(base, p.field)
*v = append(*v, u != 0)
return nil
}
// Decode a slice of bools ([]bool) in packed format.
func (o *Buffer) dec_slice_packed_bool(p *Properties, base structPointer) error {
v := structPointer_BoolSlice(base, p.field)
nn, err := o.DecodeVarint()
if err != nil {
return err
}
nb := int(nn) // number of bytes of encoded bools
fin := o.index + nb
if fin < o.index {
return errOverflow
}
y := *v
for o.index < fin {
u, err := p.valDec(o)
if err != nil {
return err
}
y = append(y, u != 0)
}
*v = y
return nil
}
// Decode a slice of int32s ([]int32).
func (o *Buffer) dec_slice_int32(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
structPointer_Word32Slice(base, p.field).Append(uint32(u))
return nil
}
// Decode a slice of int32s ([]int32) in packed format.
func (o *Buffer) dec_slice_packed_int32(p *Properties, base structPointer) error {
v := structPointer_Word32Slice(base, p.field)
nn, err := o.DecodeVarint()
if err != nil {
return err
}
nb := int(nn) // number of bytes of encoded int32s
fin := o.index + nb
if fin < o.index {
return errOverflow
}
for o.index < fin {
u, err := p.valDec(o)
if err != nil {
return err
}
v.Append(uint32(u))
}
return nil
}
// Decode a slice of int64s ([]int64).
func (o *Buffer) dec_slice_int64(p *Properties, base structPointer) error {
u, err := p.valDec(o)
if err != nil {
return err
}
structPointer_Word64Slice(base, p.field).Append(u)
return nil
}
// Decode a slice of int64s ([]int64) in packed format.
func (o *Buffer) dec_slice_packed_int64(p *Properties, base structPointer) error {
v := structPointer_Word64Slice(base, p.field)
nn, err := o.DecodeVarint()
if err != nil {
return err
}
nb := int(nn) // number of bytes of encoded int64s
fin := o.index + nb
if fin < o.index {
return errOverflow
}
for o.index < fin {
u, err := p.valDec(o)
if err != nil {
return err
}
v.Append(u)
}
return nil
}
// Decode a slice of strings ([]string).
func (o *Buffer) dec_slice_string(p *Properties, base structPointer) error {
s, err := o.DecodeStringBytes()
if err != nil {
return err
}
v := structPointer_StringSlice(base, p.field)
*v = append(*v, s)
return nil
}
// Decode a slice of slice of bytes ([][]byte).
func (o *Buffer) dec_slice_slice_byte(p *Properties, base structPointer) error {
b, err := o.DecodeRawBytes(true)
if err != nil {
return err
}
v := structPointer_BytesSlice(base, p.field)
*v = append(*v, b)
return nil
}
// Decode a map field.
func (o *Buffer) dec_new_map(p *Properties, base structPointer) error {
raw, err := o.DecodeRawBytes(false)
if err != nil {
return err
}
oi := o.index // index at the end of this map entry
o.index -= len(raw) // move buffer back to start of map entry
mptr := structPointer_NewAt(base, p.field, p.mtype) // *map[K]V
if mptr.Elem().IsNil() {
mptr.Elem().Set(reflect.MakeMap(mptr.Type().Elem()))
}
v := mptr.Elem() // map[K]V
// Prepare addressable doubly-indirect placeholders for the key and value types.
// See enc_new_map for why.
keyptr := reflect.New(reflect.PtrTo(p.mtype.Key())).Elem() // addressable *K
keybase := toStructPointer(keyptr.Addr()) // **K
var valbase structPointer
var valptr reflect.Value
switch p.mtype.Elem().Kind() {
case reflect.Slice:
// []byte
var dummy []byte
valptr = reflect.ValueOf(&dummy) // *[]byte
valbase = toStructPointer(valptr) // *[]byte
case reflect.Ptr:
// message; valptr is **Msg; need to allocate the intermediate pointer
valptr = reflect.New(reflect.PtrTo(p.mtype.Elem())).Elem() // addressable *V
valptr.Set(reflect.New(valptr.Type().Elem()))
valbase = toStructPointer(valptr)
default:
// everything else
valptr = reflect.New(reflect.PtrTo(p.mtype.Elem())).Elem() // addressable *V
valbase = toStructPointer(valptr.Addr()) // **V
}
// Decode.
// This parses a restricted wire format, namely the encoding of a message
// with two fields. See enc_new_map for the format.
for o.index < oi {
// tagcode for key and value properties are always a single byte
// because they have tags 1 and 2.
tagcode := o.buf[o.index]
o.index++
switch tagcode {
case p.mkeyprop.tagcode[0]:
if err := p.mkeyprop.dec(o, p.mkeyprop, keybase); err != nil {
return err
}
case p.mvalprop.tagcode[0]:
if err := p.mvalprop.dec(o, p.mvalprop, valbase); err != nil {
return err
}
default:
// TODO: Should we silently skip this instead?
return fmt.Errorf("proto: bad map data tag %d", raw[0])
}
}
keyelem, valelem := keyptr.Elem(), valptr.Elem()
if !keyelem.IsValid() {
keyelem = reflect.Zero(p.mtype.Key())
}
if !valelem.IsValid() {
valelem = reflect.Zero(p.mtype.Elem())
}
v.SetMapIndex(keyelem, valelem)
return nil
}
// Decode a group.
func (o *Buffer) dec_struct_group(p *Properties, base structPointer) error {
bas := structPointer_GetStructPointer(base, p.field)
if structPointer_IsNil(bas) {
// allocate new nested message
bas = toStructPointer(reflect.New(p.stype))
structPointer_SetStructPointer(base, p.field, bas)
}
return o.unmarshalType(p.stype, p.sprop, true, bas)
}
// Decode an embedded message.
func (o *Buffer) dec_struct_message(p *Properties, base structPointer) (err error) {
raw, e := o.DecodeRawBytes(false)
if e != nil {
return e
}
bas := structPointer_GetStructPointer(base, p.field)
if structPointer_IsNil(bas) {
// allocate new nested message
bas = toStructPointer(reflect.New(p.stype))
structPointer_SetStructPointer(base, p.field, bas)
}
// If the object can unmarshal itself, let it.
if p.isUnmarshaler {
iv := structPointer_Interface(bas, p.stype)
return iv.(Unmarshaler).Unmarshal(raw)
}
obuf := o.buf
oi := o.index
o.buf = raw
o.index = 0
err = o.unmarshalType(p.stype, p.sprop, false, bas)
o.buf = obuf
o.index = oi
return err
}
// Decode a slice of embedded messages.
func (o *Buffer) dec_slice_struct_message(p *Properties, base structPointer) error {
return o.dec_slice_struct(p, false, base)
}
// Decode a slice of embedded groups.
func (o *Buffer) dec_slice_struct_group(p *Properties, base structPointer) error {
return o.dec_slice_struct(p, true, base)
}
// Decode a slice of structs ([]*struct).
func (o *Buffer) dec_slice_struct(p *Properties, is_group bool, base structPointer) error {
v := reflect.New(p.stype)
bas := toStructPointer(v)
structPointer_StructPointerSlice(base, p.field).Append(bas)
if is_group {
err := o.unmarshalType(p.stype, p.sprop, is_group, bas)
return err
}
raw, err := o.DecodeRawBytes(false)
if err != nil {
return err
}
// If the object can unmarshal itself, let it.
if p.isUnmarshaler {
iv := v.Interface()
return iv.(Unmarshaler).Unmarshal(raw)
}
obuf := o.buf
oi := o.index
o.buf = raw
o.index = 0
err = o.unmarshalType(p.stype, p.sprop, is_group, bas)
o.buf = obuf
o.index = oi
return err
}