ekuiper-new/internal/topo/transform/func.go

// Copyright 2022 EMQ Technologies Co., Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build template || !core
// +build template !core

package transform

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"reflect"
	"strconv"

	"github.com/Masterminds/sprig/v3"

	"github.com/lf-edge/ekuiper/internal/conf"
)

func RegisterAdditionalFuncs() {
	conf.FuncMap = sprig.FuncMap()
	conf.FuncMap["json"] = conf.FuncMap["toJson"]
	conf.FuncMap["base64"] = Base64Encode
}

func Base64Encode(para interface{}) (string, error) {
	v := reflect.ValueOf(para)
	if !v.IsValid() {
		return "", fmt.Errorf("based64 error for nil")
	}
	switch v.Kind() {
	case reflect.Bool:
		bv := strconv.FormatBool(v.Bool())
		return base64.StdEncoding.EncodeToString([]byte(bv)), nil
	case reflect.Int, reflect.Int64:
		iv := strconv.FormatInt(v.Int(), 10)
		return base64.StdEncoding.EncodeToString([]byte(iv)), nil
	case reflect.Uint64:
		iv := strconv.FormatUint(v.Uint(), 10)
		return base64.StdEncoding.EncodeToString([]byte(iv)), nil
	case reflect.Float32:
		fv := strconv.FormatFloat(v.Float(), 'f', -1, 32)
		return base64.StdEncoding.EncodeToString([]byte(fv)), nil
	case reflect.Float64:
		fv := strconv.FormatFloat(v.Float(), 'f', -1, 64)
		return base64.StdEncoding.EncodeToString([]byte(fv)), nil
	case reflect.String:
		return base64.StdEncoding.EncodeToString([]byte(v.String())), nil
	case reflect.Map:
		if a, err := json.Marshal(para); err != nil {
			return "", err
		} else {
			en := base64.StdEncoding.EncodeToString(a)
			return en, nil
		}
	default:
		return "", fmt.Errorf("Unsupported data type %s for base64 function.", v.Kind())
	}
}