ekuiper-new/xsql/functions.go

package xsql

import (
	"github.com/emqx/kuiper/common"
	"github.com/emqx/kuiper/plugins"
	"github.com/emqx/kuiper/xstream/api"
	"strings"
)

type FunctionValuer struct{}

func (*FunctionValuer) Value(key string) (interface{}, bool) {
	return nil, false
}

func (*FunctionValuer) Meta(key string) (interface{}, bool) {
	return nil, false
}

var aggFuncMap = map[string]string{"avg": "",
	"count": "",
	"max":   "", "min": "",
	"sum": "",
}

var mathFuncMap = map[string]string{"abs": "", "acos": "", "asin": "", "atan": "", "atan2": "",
	"bitand": "", "bitor": "", "bitxor": "", "bitnot": "",
	"ceil": "", "cos": "", "cosh": "",
	"exp": "",
	"ln":  "", "log": "",
	"mod":   "",
	"power": "",
	"rand":  "", "round": "",
	"sign": "", "sin": "", "sinh": "", "sqrt": "",
	"tan": "", "tanh": "",
}

var strFuncMap = map[string]string{"concat": "",
	"endswith":    "",
	"format_time": "",
	"indexof":     "",
	"length":      "", "lower": "", "lpad": "", "ltrim": "",
	"numbytes":       "",
	"regexp_matches": "", "regexp_replace": "", "regexp_substr": "", "rpad": "", "rtrim": "",
	"substring": "", "startswith": "", "split_value": "",
	"trim":  "",
	"upper": "",
}

var convFuncMap = map[string]string{"concat": "", "cast": "", "chr": "",
	"encode": "",
	"trunc":  "",
}

var hashFuncMap = map[string]string{"md5": "",
	"sha1": "", "sha256": "", "sha384": "", "sha512": "",
}

var otherFuncMap = map[string]string{"isnull": "",
	"newuuid": "", "timestamp": "", "mqtt": "", "meta": "",
}

func (*FunctionValuer) Call(name string, args []interface{}) (interface{}, bool) {
	lowerName := strings.ToLower(name)
	if _, ok := mathFuncMap[lowerName]; ok {
		return mathCall(name, args)
	} else if _, ok := strFuncMap[lowerName]; ok {
		return strCall(lowerName, args)
	} else if _, ok := convFuncMap[lowerName]; ok {
		return convCall(lowerName, args)
	} else if _, ok := hashFuncMap[lowerName]; ok {
		return hashCall(lowerName, args)
	} else if _, ok := otherFuncMap[lowerName]; ok {
		return otherCall(lowerName, args)
	} else if _, ok := aggFuncMap[lowerName]; ok {
		return nil, false
	} else {
		common.Log.Debugf("run func %s", name)
		if nf, err := plugins.GetPlugin(name, "functions"); err != nil {
			return err, false
		} else {
			f, ok := nf.(api.Function)
			if !ok {
				return nil, false
			}
			if f.IsAggregate() {
				return nil, false
			}
			result, ok := f.Exec(args)
			common.Log.Debugf("run custom function %s, get result %v", name, result)
			return result, ok
		}
	}
}