阶段性提交

pkg/serverconfigs/vars/var_func.go

@@ -0,0 +1,249 @@
+package vars
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"github.com/TeaOSLab/EdgeCommon/pkg/serverconfigs/shared"
+	"github.com/iwind/TeaGo/types"
+	"math"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+// func列表，code => type
+var funcMap = map[string]reflect.Value{
+	"float":  reflect.ValueOf(FuncFloat),
+	"round":  reflect.ValueOf(FuncRound),
+	"ceil":   reflect.ValueOf(FuncCeil),
+	"floor":  reflect.ValueOf(FuncFloor),
+	"format": reflect.ValueOf(FuncFormat),
+	"append": reflect.ValueOf(FuncAppend),
+}
+
+// FuncFloat 浮点数处理
+// float | float('%.2f')
+func FuncFloat(args ...interface{}) interface{} {
+	if len(args) == 0 {
+		return 0
+	}
+	if len(args) == 1 {
+		return types.Float64(args[0])
+	}
+	args[0] = types.Float64(args[0])
+	return FuncFormat(args...)
+}
+
+// FuncRound 对数字四舍五入
+// round | round(2)
+func FuncRound(args ...interface{}) interface{} {
+	if len(args) == 0 {
+		return 0
+	}
+	if len(args) == 1 {
+		return int64(math.Round(types.Float64(args[0])))
+	}
+
+	precision := types.Int64(args[1])
+	if precision <= 0 {
+		return int64(math.Round(types.Float64(args[0])))
+	}
+	return fmt.Sprintf("%."+strconv.FormatInt(precision, 10)+"f", types.Float64(args[0]))
+}
+
+// FuncCeil 对数字进行取不小于它的整数
+// ceil
+func FuncCeil(args ...interface{}) interface{} {
+	if len(args) == 0 {
+		return 0
+	}
+	return int64(math.Ceil(types.Float64(args[0])))
+}
+
+// FuncFloor 对数字进行取不大于它的整数
+// floor
+func FuncFloor(args ...interface{}) interface{} {
+	if len(args) == 0 {
+		return 0
+	}
+	return int64(math.Floor(types.Float64(args[0])))
+}
+
+// FuncFormat 格式化
+// format('%.2f')
+func FuncFormat(args ...interface{}) interface{} {
+	if len(args) == 0 {
+		return ""
+	}
+	if len(args) == 1 {
+		return types.String(args[0])
+	}
+	format := types.String(args[1])
+	if len(args) == 2 {
+		return fmt.Sprintf(format, args[0])
+	} else {
+		return fmt.Sprintf(format, append([]interface{}{args[0]}, args[2:]...)...)
+	}
+}
+
+// FuncAppend 附加字符串
+// append('a', 'b')
+func FuncAppend(args ...interface{}) interface{} {
+	s := strings.Builder{}
+	for _, arg := range args {
+		s.WriteString(types.String(arg))
+	}
+	return s.String()
+}
+
+// RunFuncExpr 执行函数表达式
+func RunFuncExpr(value interface{}, expr []byte) (interface{}, error) {
+	// 防止因nil参数导致panic
+	if value == nil {
+		value = ""
+	}
+
+	// 空表达式直接返回
+	if len(expr) == 0 || len(bytes.TrimSpace(expr)) == 0 {
+		return value, nil
+	}
+
+	identifier := []byte{}
+
+	isInQuote := false
+	isQuoted := false
+	quoteByte := byte(0)
+	funcCode := ""
+	args := []interface{}{value}
+
+	for index, b := range expr {
+		switch b {
+		case '|':
+			if isInQuote {
+				identifier = append(identifier, b)
+			} else { // end function
+				if len(funcCode) == 0 {
+					funcCode = string(identifier)
+				} else if len(identifier) > 0 {
+					return value, errors.New("invalid identifier '" + string(identifier) + "'")
+				}
+				value, err := callFunc(funcCode, args)
+				if err != nil {
+					return value, err
+				}
+				return RunFuncExpr(value, expr[index+1:])
+			}
+		case '(':
+			if isInQuote {
+				identifier = append(identifier, b)
+			} else {
+				funcCode = string(identifier)
+				identifier = []byte{}
+			}
+		case ',', ')':
+			if isInQuote {
+				identifier = append(identifier, b)
+			} else {
+				if isQuoted {
+					isQuoted = false
+					args = append(args, string(identifier))
+				} else {
+					arg, err := checkLiteral(string(identifier))
+					if err != nil {
+						return value, err
+					}
+					args = append(args, arg)
+				}
+				identifier = []byte{}
+			}
+		case '\\':
+			if isInQuote && (index == len(expr)-1 || expr[index+1] != quoteByte) {
+				identifier = append(identifier, b)
+			} else {
+				continue
+			}
+		case '\'', '"':
+			if isInQuote {
+				if quoteByte == b && expr[index-1] != '\\' {
+					isInQuote = false
+					break
+				}
+			} else if index == 0 || expr[index-1] != '\\' {
+				isInQuote = true
+				isQuoted = true
+				quoteByte = b
+				break
+			}
+			identifier = append(identifier, b)
+		case ' ', '\t':
+			if isInQuote {
+				identifier = append(identifier, b)
+			}
+		default:
+			identifier = append(identifier, b)
+		}
+	}
+
+	if len(funcCode) == 0 {
+		funcCode = string(identifier)
+	} else if len(identifier) > 0 {
+		return value, errors.New("invalid identifier '" + string(identifier) + "'")
+	}
+
+	return callFunc(funcCode, args)
+}
+
+// RegisterFunc 注册一个函数
+func RegisterFunc(code string, f interface{}) {
+	funcMap[code] = reflect.ValueOf(f)
+}
+
+// 调用一个函数
+func callFunc(funcCode string, args []interface{}) (value interface{}, err error) {
+	fn, ok := funcMap[funcCode]
+	if !ok {
+		return value, errors.New("function '" + funcCode + "' not found")
+	}
+	argValues := []reflect.Value{}
+	for _, arg := range args {
+		argValues = append(argValues, reflect.ValueOf(arg))
+	}
+	result := fn.Call(argValues)
+	if len(result) == 0 {
+		value = nil
+	} else {
+		value = result[0].Interface()
+	}
+	return
+}
+
+// 检查字面量，支持true, false, null, nil和整数数字、浮点数数字（不支持e）
+func checkLiteral(identifier string) (result interface{}, err error) {
+	if len(identifier) == 0 {
+		return "", nil
+	}
+	switch strings.ToLower(identifier) {
+	case "true":
+		result = true
+		return
+	case "false":
+		result = false
+		return
+	case "null", "nil":
+		result = nil
+		return
+	default:
+		if shared.RegexpAllDigitNumber.MatchString(identifier) {
+			result = types.Int64(identifier)
+			return
+		}
+		if shared.RegexpAllFloatNumber.MatchString(identifier) {
+			result = types.Float64(identifier)
+			return
+		}
+	}
+
+	err = errors.New("undefined identifier '" + identifier + "'")
+	return
+}