1

internal/api_to_rpc/copy.go

@@ -0,0 +1,235 @@
+package common
+
+import (
+	"fmt"
+	"google.golang.org/protobuf/types/known/wrapperspb"
+	"reflect"
+)
+
+func CopyAny(from, to interface{}) {
+	t := reflect.ValueOf(to).Elem()
+	if !t.CanSet() {
+		return
+	}
+	f := reflect.ValueOf(from)
+	if isBaseNil(f) {
+		return
+	}
+	copyAny(f, t)
+}
+
+func setBaseValue(from, to reflect.Value) {
+	if isBaseNil(from) {
+		return
+	}
+	var l int
+	t := to.Type()
+	for t.Kind() == reflect.Ptr {
+		l++
+		t = t.Elem()
+	}
+	v := baseValue(from)
+	for i := 0; i < l; i++ {
+		t := reflect.New(v.Type())
+		t.Elem().Set(v)
+		v = t
+	}
+	to.Set(v)
+}
+
+func copyAny(from, to reflect.Value) {
+	if !to.CanSet() {
+		return
+	}
+	if isBaseNil(from) {
+		return
+	}
+	btfrom := baseType(from.Type())
+	btto := baseType(to.Type())
+	if typeEq(btfrom, btto) {
+		setBaseValue(from, to)
+		return
+	}
+	if _, ok := wrapType[btto.String()]; ok { // string -> wrapperspb.StringValue
+		val := reflect.New(btto).Elem()
+		copyAny(from, val.FieldByName("Value"))
+		setBaseValue(val, to)
+		return
+	}
+	if _, ok := wrapType[btfrom.String()]; ok { // wrapperspb.StringValue -> string
+		copyAny(baseValue(from).FieldByName("Value"), to)
+		return
+	}
+	if btfrom.Kind() == reflect.Struct && btto.Kind() == reflect.Struct {
+		copyStruct(baseValue(from), baseValue(to))
+		return
+	}
+	if btfrom.Kind() == reflect.Slice && btto.Kind() == reflect.Slice {
+		copySlice(baseValue(from), baseValue(to))
+		return
+	}
+	if btto.Kind() == reflect.String {
+		if isBaseNil(to) {
+			to.Set(getBaseZeroValue(baseType(to.Type())))
+		}
+		setBaseValue(reflect.ValueOf(toString(from)), to)
+		return
+	}
+	if toNumber(from, to) {
+		return
+	}
+}
+
+func getBaseZeroValue(t reflect.Type) reflect.Value {
+	var l int
+	for t.Kind() == reflect.Ptr {
+		l++
+		t = t.Elem()
+	}
+	v := reflect.Zero(t)
+	for i := 0; i < l; i++ {
+		t := reflect.New(v.Type())
+		t.Elem().Set(v)
+		v = t
+	}
+	return v
+}
+
+func isBaseNil(v reflect.Value) bool {
+	for {
+		switch v.Kind() {
+		case reflect.Ptr:
+			v = v.Elem()
+		case reflect.Invalid:
+			return true
+		default:
+			return isNil(v)
+		}
+	}
+}
+
+func baseType(t reflect.Type) reflect.Type {
+	for t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	return t
+}
+
+func typeEq(t1, t2 reflect.Type) bool {
+	return t1.String() == t2.String()
+}
+
+func isNil(value reflect.Value) bool {
+	switch value.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Map, reflect.Pointer, reflect.UnsafePointer, reflect.Interface, reflect.Slice:
+		return value.IsNil()
+	}
+	return false
+}
+
+func baseValue(value reflect.Value) reflect.Value {
+	for value.Kind() == reflect.Ptr {
+		value = value.Elem()
+	}
+	return value
+}
+
+func copyStruct(from, to reflect.Value) {
+	toType := to.Type()
+	fromType := from.Type()
+	n := to.NumField()
+	for i := 0; i < n; i++ {
+		toFieldType := toType.Field(i)
+		if _, found := fromType.FieldByName(toFieldType.Name); !found {
+			continue
+		}
+		copyAny(from.FieldByName(toFieldType.Name), to.Field(i))
+	}
+}
+
+func copySlice(from, to reflect.Value) {
+	size := from.Len()
+	temp := reflect.MakeSlice(to.Type(), 0, size)
+	elemTo := to.Type().Elem()
+	for i := 0; i < size; i++ {
+		itemTo := getBaseZeroValue(elemTo)
+		copyAny(from.Index(i), itemTo)
+		temp = reflect.Append(temp, itemTo)
+	}
+	to.Set(temp)
+}
+
+func toString(value reflect.Value) string {
+	if value.Kind() == reflect.Slice {
+		switch value.Type().String() {
+		case "[]uint8":
+			return string(value.Interface().([]uint8))
+		case "[]int32":
+			return string(value.Interface().([]int32))
+		}
+	}
+	return fmt.Sprint(value.Interface())
+}
+
+func toNumber(from1, to1 reflect.Value) bool {
+	if isBaseNil(to1) {
+		to1.Set(getBaseZeroValue(to1.Type()))
+	}
+	from := baseValue(from1)
+	to := baseValue(to1)
+	switch from.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch to.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			to.SetInt(from.Int())
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			to.SetUint(uint64(from.Int()))
+			return true
+		case reflect.Float64, reflect.Float32:
+			to.SetFloat(float64(from.Int()))
+			return true
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		switch to.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			to.SetInt(int64(from.Uint()))
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			to.SetInt(int64(from.Uint()))
+			return true
+		case reflect.Float64, reflect.Float32:
+			to.SetFloat(float64(from.Uint()))
+			return true
+		}
+	case reflect.Float64, reflect.Float32:
+		switch to.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			to.SetInt(int64(from.Float()))
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			to.SetUint(uint64(from.Float()))
+			return true
+		case reflect.Float64, reflect.Float32:
+			to.SetFloat(from.Float())
+			return true
+		}
+	}
+	return false
+}
+
+func typeName(v interface{}) string {
+	return reflect.TypeOf(v).String()
+}
+
+var wrapType = map[string]struct{}{
+	typeName(wrapperspb.DoubleValue{}): {},
+	typeName(wrapperspb.FloatValue{}):  {},
+	typeName(wrapperspb.Int64Value{}):  {},
+	typeName(wrapperspb.UInt64Value{}): {},
+	typeName(wrapperspb.Int32Value{}):  {},
+	typeName(wrapperspb.UInt32Value{}): {},
+	typeName(wrapperspb.BoolValue{}):   {},
+	typeName(wrapperspb.StringValue{}): {},
+	typeName(wrapperspb.BytesValue{}):  {},
+}