// 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 (
"fmt"
"reflect"
"strings"
"sync"
"sync/atomic"
)
// Merge merges the src message into dst.
// This assumes that dst and src of the same type and are non-nil.
func (a *InternalMessageInfo) Merge(dst, src Message) {
mi := atomicLoadMergeInfo(&a.merge)
if mi == nil {
mi = getMergeInfo(reflect.TypeOf(dst).Elem())
atomicStoreMergeInfo(&a.merge, mi)
}
mi.merge(toPointer(&dst), toPointer(&src))
}
type mergeInfo struct {
typ reflect.Type
initialized int32 // 0: only typ is valid, 1: everything is valid
lock sync.Mutex
fields []mergeFieldInfo
unrecognized field // Offset of XXX_unrecognized
}
type mergeFieldInfo struct {
field field // Offset of field, guaranteed to be valid
// isPointer reports whether the value in the field is a pointer.
// This is true for the following situations:
// * Pointer to struct
// * Pointer to basic type (proto2 only)
// * Slice (first value in slice header is a pointer)
// * String (first value in string header is a pointer)
isPointer bool
// basicWidth reports the width of the field assuming that it is directly
// embedded in the struct (as is the case for basic types in proto3).
// The possible values are:
// 0: invalid
// 1: bool
// 4: int32, uint32, float32
// 8: int64, uint64, float64
basicWidth int
// Where dst and src are pointers to the types being merged.
merge func(dst, src pointer)
}
var (
mergeInfoMap = map[reflect.Type]*mergeInfo{}
mergeInfoLock sync.Mutex
)
func getMergeInfo(t reflect.Type) *mergeInfo {
mergeInfoLock.Lock()
defer mergeInfoLock.Unlock()
mi := mergeInfoMap[t]
if mi == nil {
mi = &mergeInfo{typ: t}
mergeInfoMap[t] = mi
}
return mi
}
// merge merges src into dst assuming they are both of type *mi.typ.
func (mi *mergeInfo) merge(dst, src pointer) {
if dst.isNil() {
panic("proto: nil destination")
}
if src.isNil() {
return // Nothing to do.
}
if atomic.LoadInt32(&mi.initialized) == 0 {
mi.computeMergeInfo()
}
for _, fi := range mi.fields {
sfp := src.offset(fi.field)
// As an optimization, we can avoid the merge function call cost
// if we know for sure that the source will have no effect
// by checking if it is the zero value.
if unsafeAllowed {
if fi.isPointer && sfp.getPointer().isNil() { // Could be slice or string
continue
}
if fi.basicWidth > 0 {
switch {
case fi.basicWidth == 1 && !*sfp.toBool():
continue
case fi.basicWidth == 4 && *sfp.toUint32() == 0:
continue
case fi.basicWidth == 8 && *sfp.toUint64() == 0:
continue
}
}
}
dfp := dst.offset(fi.field)
fi.merge(dfp, sfp)
}
// TODO: Make this faster?
out := dst.asPointerTo(mi.typ).Elem()
in := src.asPointerTo(mi.typ).Elem()
if emIn, err := extendable(in.Addr().Interface()); err == nil {
emOut, _ := extendable(out.Addr().Interface())
mIn, muIn := emIn.extensionsRead()
if mIn != nil {
mOut := emOut.extensionsWrite()
muIn.Lock()
mergeExtension(mOut, mIn)
muIn.Unlock()
}
}
if mi.unrecognized.IsValid() {
if b := *src.offset(mi.unrecognized).toBytes(); len(b) > 0 {
*dst.offset(mi.unrecognized).toBytes() = append([]byte(nil), b...)
}
}
}
func (mi *mergeInfo) computeMergeInfo() {
mi.lock.Lock()
defer mi.lock.Unlock()
if mi.initialized != 0 {
return
}
t := mi.typ
n := t.NumField()
props := GetProperties(t)
for i := 0; i < n; i++ {
f := t.Field(i)
if strings.HasPrefix(f.Name, "XXX_") {
continue
}
mfi := mergeFieldInfo{field: toField(&f)}
tf := f.Type
// As an optimization, we can avoid the merge function call cost
// if we know for sure that the source will have no effect
// by checking if it is the zero value.
if unsafeAllowed {
switch tf.Kind() {
case reflect.Ptr, reflect.Slice, reflect.String:
// As a special case, we assume slices and strings are pointers
// since we know that the first field in the SliceSlice or
// StringHeader is a data pointer.
mfi.isPointer = true
case reflect.Bool:
mfi.basicWidth = 1
case reflect.Int32, reflect.Uint32, reflect.Float32:
mfi.basicWidth = 4
case reflect.Int64, reflect.Uint64, reflect.Float64:
mfi.basicWidth = 8
}
}
// Unwrap tf to get at 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("both pointer and slice for basic type in " + tf.Name())
}
switch tf.Kind() {
case reflect.Int32:
switch {
case isSlice: // E.g., []int32
mfi.merge = func(dst, src pointer) {
// NOTE: toInt32Slice is not defined (see pointer_reflect.go).
/*
sfsp := src.toInt32Slice()
if *sfsp != nil {
dfsp := dst.toInt32Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []int64{}
}
}
*/
sfs := src.getInt32Slice()
if sfs != nil {
dfs := dst.getInt32Slice()
dfs = append(dfs, sfs...)
if dfs == nil {
dfs = []int32{}
}
dst.setInt32Slice(dfs)
}
}
case isPointer: // E.g., *int32
mfi.merge = func(dst, src pointer) {
// NOTE: toInt32Ptr is not defined (see pointer_reflect.go).
/*
sfpp := src.toInt32Ptr()
if *sfpp != nil {
dfpp := dst.toInt32Ptr()
if *dfpp == nil {
*dfpp = Int32(**sfpp)
} else {
**dfpp = **sfpp
}
}
*/
sfp := src.getInt32Ptr()
if sfp != nil {
dfp := dst.getInt32Ptr()
if dfp == nil {
dst.setInt32Ptr(*sfp)
} else {
*dfp = *sfp
}
}
}
default: // E.g., int32
mfi.merge = func(dst, src pointer) {
if v := *src.toInt32(); v != 0 {
*dst.toInt32() = v
}
}
}
case reflect.Int64:
switch {
case isSlice: // E.g., []int64
mfi.merge = func(dst, src pointer) {
sfsp := src.toInt64Slice()
if *sfsp != nil {
dfsp := dst.toInt64Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []int64{}
}
}
}
case isPointer: // E.g., *int64
mfi.merge = func(dst, src pointer) {
sfpp := src.toInt64Ptr()
if *sfpp != nil {
dfpp := dst.toInt64Ptr()
if *dfpp == nil {
*dfpp = Int64(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., int64
mfi.merge = func(dst, src pointer) {
if v := *src.toInt64(); v != 0 {
*dst.toInt64() = v
}
}
}
case reflect.Uint32:
switch {
case isSlice: // E.g., []uint32
mfi.merge = func(dst, src pointer) {
sfsp := src.toUint32Slice()
if *sfsp != nil {
dfsp := dst.toUint32Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []uint32{}
}
}
}
case isPointer: // E.g., *uint32
mfi.merge = func(dst, src pointer) {
sfpp := src.toUint32Ptr()
if *sfpp != nil {
dfpp := dst.toUint32Ptr()
if *dfpp == nil {
*dfpp = Uint32(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., uint32
mfi.merge = func(dst, src pointer) {
if v := *src.toUint32(); v != 0 {
*dst.toUint32() = v
}
}
}
case reflect.Uint64:
switch {
case isSlice: // E.g., []uint64
mfi.merge = func(dst, src pointer) {
sfsp := src.toUint64Slice()
if *sfsp != nil {
dfsp := dst.toUint64Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []uint64{}
}
}
}
case isPointer: // E.g., *uint64
mfi.merge = func(dst, src pointer) {
sfpp := src.toUint64Ptr()
if *sfpp != nil {
dfpp := dst.toUint64Ptr()
if *dfpp == nil {
*dfpp = Uint64(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., uint64
mfi.merge = func(dst, src pointer) {
if v := *src.toUint64(); v != 0 {
*dst.toUint64() = v
}
}
}
case reflect.Float32:
switch {
case isSlice: // E.g., []float32
mfi.merge = func(dst, src pointer) {
sfsp := src.toFloat32Slice()
if *sfsp != nil {
dfsp := dst.toFloat32Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []float32{}
}
}
}
case isPointer: // E.g., *float32
mfi.merge = func(dst, src pointer) {
sfpp := src.toFloat32Ptr()
if *sfpp != nil {
dfpp := dst.toFloat32Ptr()
if *dfpp == nil {
*dfpp = Float32(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., float32
mfi.merge = func(dst, src pointer) {
if v := *src.toFloat32(); v != 0 {
*dst.toFloat32() = v
}
}
}
case reflect.Float64:
switch {
case isSlice: // E.g., []float64
mfi.merge = func(dst, src pointer) {
sfsp := src.toFloat64Slice()
if *sfsp != nil {
dfsp := dst.toFloat64Slice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []float64{}
}
}
}
case isPointer: // E.g., *float64
mfi.merge = func(dst, src pointer) {
sfpp := src.toFloat64Ptr()
if *sfpp != nil {
dfpp := dst.toFloat64Ptr()
if *dfpp == nil {
*dfpp = Float64(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., float64
mfi.merge = func(dst, src pointer) {
if v := *src.toFloat64(); v != 0 {
*dst.toFloat64() = v
}
}
}
case reflect.Bool:
switch {
case isSlice: // E.g., []bool
mfi.merge = func(dst, src pointer) {
sfsp := src.toBoolSlice()
if *sfsp != nil {
dfsp := dst.toBoolSlice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []bool{}
}
}
}
case isPointer: // E.g., *bool
mfi.merge = func(dst, src pointer) {
sfpp := src.toBoolPtr()
if *sfpp != nil {
dfpp := dst.toBoolPtr()
if *dfpp == nil {
*dfpp = Bool(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., bool
mfi.merge = func(dst, src pointer) {
if v := *src.toBool(); v {
*dst.toBool() = v
}
}
}
case reflect.String:
switch {
case isSlice: // E.g., []string
mfi.merge = func(dst, src pointer) {
sfsp := src.toStringSlice()
if *sfsp != nil {
dfsp := dst.toStringSlice()
*dfsp = append(*dfsp, *sfsp...)
if *dfsp == nil {
*dfsp = []string{}
}
}
}
case isPointer: // E.g., *string
mfi.merge = func(dst, src pointer) {
sfpp := src.toStringPtr()
if *sfpp != nil {
dfpp := dst.toStringPtr()
if *dfpp == nil {
*dfpp = String(**sfpp)
} else {
**dfpp = **sfpp
}
}
}
default: // E.g., string
mfi.merge = func(dst, src pointer) {
if v := *src.toString(); v != "" {
*dst.toString() = v
}
}
}
case reflect.Slice:
isProto3 := props.Prop[i].proto3
switch {
case isPointer:
panic("bad pointer in byte slice case in " + tf.Name())
case tf.Elem().Kind() != reflect.Uint8:
panic("bad element kind in byte slice case in " + tf.Name())
case isSlice: // E.g., [][]byte
mfi.merge = func(dst, src pointer) {
sbsp := src.toBytesSlice()
if *sbsp != nil {
dbsp := dst.toBytesSlice()
for _, sb := range *sbsp {
if sb == nil {
*dbsp = append(*dbsp, nil)
} else {
*dbsp = append(*dbsp, append([]byte{}, sb...))
}
}
if *dbsp == nil {
*dbsp = [][]byte{}
}
}
}
default: // E.g., []byte
mfi.merge = func(dst, src pointer) {
sbp := src.toBytes()
if *sbp != nil {
dbp := dst.toBytes()
if !isProto3 || len(*sbp) > 0 {
*dbp = append([]byte{}, *sbp...)
}
}
}
}
case reflect.Struct:
switch {
case !isPointer:
panic(fmt.Sprintf("message field %s without pointer", tf))
case isSlice: // E.g., []*pb.T
mi := getMergeInfo(tf)
mfi.merge = func(dst, src pointer) {
sps := src.getPointerSlice()
if sps != nil {
dps := dst.getPointerSlice()
for _, sp := range sps {
var dp pointer
if !sp.isNil() {
dp = valToPointer(reflect.New(tf))
mi.merge(dp, sp)
}
dps = append(dps, dp)
}
if dps == nil {
dps = []pointer{}
}
dst.setPointerSlice(dps)
}
}
default: // E.g., *pb.T
mi := getMergeInfo(tf)
mfi.merge = func(dst, src pointer) {
sp := src.getPointer()
if !sp.isNil() {
dp := dst.getPointer()
if dp.isNil() {
dp = valToPointer(reflect.New(tf))
dst.setPointer(dp)
}
mi.merge(dp, sp)
}
}
}
case reflect.Map:
switch {
case isPointer || isSlice:
panic("bad pointer or slice in map case in " + tf.Name())
default: // E.g., map[K]V
mfi.merge = func(dst, src pointer) {
sm := src.asPointerTo(tf).Elem()
if sm.Len() == 0 {
return
}
dm := dst.asPointerTo(tf).Elem()
if dm.IsNil() {
dm.Set(reflect.MakeMap(tf))
}
switch tf.Elem().Kind() {
case reflect.Ptr: // Proto struct (e.g., *T)
for _, key := range sm.MapKeys() {
val := sm.MapIndex(key)
val = reflect.ValueOf(Clone(val.Interface().(Message)))
dm.SetMapIndex(key, val)
}
case reflect.Slice: // E.g. Bytes type (e.g., []byte)
for _, key := range sm.MapKeys() {
val := sm.MapIndex(key)
val = reflect.ValueOf(append([]byte{}, val.Bytes()...))
dm.SetMapIndex(key, val)
}
default: // Basic type (e.g., string)
for _, key := range sm.MapKeys() {
val := sm.MapIndex(key)
dm.SetMapIndex(key, val)
}
}
}
}
case reflect.Interface:
// Must be oneof field.
switch {
case isPointer || isSlice:
panic("bad pointer or slice in interface case in " + tf.Name())
default: // E.g., interface{}
// TODO: Make this faster?
mfi.merge = func(dst, src pointer) {
su := src.asPointerTo(tf).Elem()
if !su.IsNil() {
du := dst.asPointerTo(tf).Elem()
typ := su.Elem().Type()
if du.IsNil() || du.Elem().Type() != typ {
du.Set(reflect.New(typ.Elem())) // Initialize interface if empty
}
sv := su.Elem().Elem().Field(0)
if sv.Kind() == reflect.Ptr && sv.IsNil() {
return
}
dv := du.Elem().Elem().Field(0)
if dv.Kind() == reflect.Ptr && dv.IsNil() {
dv.Set(reflect.New(sv.Type().Elem())) // Initialize proto message if empty
}
switch sv.Type().Kind() {
case reflect.Ptr: // Proto struct (e.g., *T)
Merge(dv.Interface().(Message), sv.Interface().(Message))
case reflect.Slice: // E.g. Bytes type (e.g., []byte)
dv.Set(reflect.ValueOf(append([]byte{}, sv.Bytes()...)))
default: // Basic type (e.g., string)
dv.Set(sv)
}
}
}
}
default:
panic(fmt.Sprintf("merger not found for type:%s", tf))
}
mi.fields = append(mi.fields, mfi)
}
mi.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")
}
mi.unrecognized = toField(&f)
}
atomic.StoreInt32(&mi.initialized, 1)
}
