the rule engine based on golang
- this is a rule engine named Gengine based on golang and AST, it can help you to load your code(rules) to run while you did not need to restart your application.
- Gengine's code structure is Modular design, logic is easy to understand, and it passed the necessary testing！
- it is also a high performance engine
the execute model of rules
Grammar support by Gengine
- support the priority of the rules list and the priority scope is -int64 to int64
- support rule's description
- support define a local variable in a rule, and it invisible between rules
- support 'if..else' and it's Nested structure
- support complex logic operation
- support complex Arithmetic (+ - * /)
- support method of golang's structure
- support single line comment(//)
- support elegant check error, if there is an error in one rule, gengine will not load the rules to run to forbidden the harm to data
- to make it easy to use,Gengine just supports one return value function's or method's Assignment and support return struct, but support call multi return value function
- support directly inject function to run, and rename function
- support switch to help user to decide when a rule execute error in the list whether continue to execute the last rules
- support use '@name' to get rule's name in rule content
- support map and array with base data type, but not support to set Array's value by index
Gengine not support grammar
- not support 'else if', beacase the creator hates 'else if'
- not support Multi-level call such as 'user.ip.ipRisk()'，because it not meet the "Dimit rule", and multi-level call make it hard to understand, so it just support this call type: 'ip.ipRisk()'
- not support multi line comment (/* comment */)
- not support multi return value, if you want, you can use return struct
- not support nil
something need your attention
- if you not declare the rules' priority, the rules will be execute in unknown sort
- every rule's name should be different from each other
- string
- bool
- int, int8, int16, int32, int64
- float32, float64
support compared operation
- +
- -
- *
- /
- support string and string's plus
- if you want get high performance, please do as the test case do: separate the rule build process and the rule execute process
- when you rules contains Very time-consuming operation, such as operate database, you should use engine.ExecuteConcurrent(...), if not ,you should still use engine.Execute(...)
//rule
rule "测试" "测试描述" salience 0
begin
// rename function test; @name represent the rule name "测试"
Sout(@name)
// common function test
Hello()
//struct's method test
User.Say()
// if
if !(7 == User.GetNum(7)) || !(7 > 8) {
//define variable and string's plus; @name is just a string
variable = "hello" + (" world" + "zeze")+"@name"
// inner function
User.Name = "hhh" + strconv.FormatBool(true)
//struct's field
User.Age = User.GetNum(8976) / 1000+ 3*(1+1)
//bool set test
User.Male = false
//use inner variable test
User.Print(variable)
//float test
f = 9.56
PrintReal(f)
//if-else test
if false {
Sout("sout true")
}else{
Sout("sout false")
}
}else{ //else
//struct field set value test
User.Name = "yyyy"
}
end
- you can find all code in test package
import (
"fmt"
"gengine/base"
"gengine/builder"
"gengine/context"
"gengine/engine"
"github.com/sirupsen/logrus"
"testing"
"time"
)
type User struct {
Name string
Age int
Male bool
}
func (u *User)GetNum(i int64) int64 {
return i
}
func (u *User)Print(s string){
fmt.Println(s)
}
func (u *User)Say(){
fmt.Println("hello world")
}
const (
rule2 = `
rule "测试" "测试描述" salience 0
begin
// 重命名函数 测试
Sout(@name)
// 普通函数 测试
Hello()
//结构提方法 测试
User.Say()
// if
if 7 == User.GetNum(7){
//自定义变量 和 加法 测试
variable = "hello" + " world"
// 加法 与 内建函数 测试
User.Name = "hhh" + strconv.FormatBool(true)
//结构体属性、方法调用 和 除法 测试
User.Age = User.GetNum(89767999999) / 10000000
//布尔值设置 测试
User.Male = false
//规则内自定义变量调用 测试
User.Print(variable)
//float测试 也支持科学计数法
f = 9.56
PrintReal(f)
//嵌套if-else测试
if false {
Sout("嵌套if测试")
}else{
Sout("嵌套else测试")
}
}else{ //else
//字符串设置 测试
User.Name = "yyyy"
}
end`)
func Hello() {
fmt.Println("hello")
}
func PrintReal(real float64){
fmt.Println(real)
}
func exe(user *User){
/**
不要注入除函数和结构体指针以外的其他类型(如变量)
*/
dataContext := context.NewDataContext()
//注入结构体指针
dataContext.Add("User", user)
//重命名函数,并注入
dataContext.Add("Sout",fmt.Println)
//直接注入函数
dataContext.Add("Hello",Hello)
dataContext.Add("PrintReal",PrintReal)
//初始化规则引擎
knowledgeContext := base.NewKnowledgeContext()
ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext)
//读取规则
err := ruleBuilder.BuildRuleFromString(rule2)
if err != nil{
logrus.Errorf("err:%s ", err)
}else{
eng := engine.NewGengine()
start := time.Now().UnixNano()
// true: means when there are many rules， if one rule execute error，continue to execute rules after the occur error rule
err := eng.Execute(ruleBuilder, true)
end := time.Now().UnixNano()
if err != nil{
logrus.Errorf("execute rule error: %v", err)
}
logrus.Infof("execute rule cost %d ns",end-start)
logrus.Infof("user.Age=%d,Name=%s,Male=%t", user.Age, user.Name, user.Male)
}
}
func Test_Base(t *testing.T){
user := &User{
Name: "Calo",
Age: 0,
Male: true,
}
exe(user)
}
- Gengine是一款基于AST(Abstract Syntax Tree)和golang语言实现的规则引擎。能够让你在golang这种静态语言上，在不停服务的情况下实现动态加载与配置规则。
- 代码结构松散，逻辑极其简单，但经过了必要且详尽的测试
- Gengine所支持的规则，就是一门DSL(领域专用语言)
- 支持规则优先级和规则执行条件，优先级高的先执行，优先级低的后执行；
- 支持的优先级范围 -int64 ～ int64
- 支持中文规则名与中文规则描述
- 支持规则内定义变量，但规则内定义的变量在规则与规则之间的不可见
- 支持 if../if..else.. 代码块和其代码块嵌套
- 支持复杂逻辑运算
- 支持复杂数学四则运算(+ - * /)
- 支持结构体方法调用
- 支持单行注释(//)
- 支持优雅的规则检错机制(是的,你没看错,就是检错,不是检测!):如果待加载的一批规则中有一个规则有语法错误，那么规则引擎就不会加载这批规则去执行,防止对数据造成不可预知的危害
- 支持仅有一个返回值的函数赋值，且返回值为基础类型或结构体; 支持多返回值函数的调用，但无法处理其返回值
- 支持直接注入函数并执行，并允许函数重命名
- 支持规则链中有规则执行失败时，是否继续执行后续规则开关
- 支持一些内置函数
- 支持使用@name 在规则体内获得当前规则的名称
- 支持基础类型的map和array，但是不支持基于数组的下标去设置数组的值
- 不支持else if, 因为作者讨厌使用else if
- 不支持形如user.ip.ipRisk()这种多级调用，因为它不符合"迪米特法则"，并且会使代码变得难以理解；只支持ip.ipRisk()这种单级调用
- 不支持函数多个返回值，当需要返回多个值时，请使用返回结构体
- 不支持多行注释，因为不想支持
- 不支持nil
- 如果规则的优先级不指定，多个规则将以未知次序执行
- 同一批待加载的规则中不能有重名规则
- string
- bool
- int, int8, int16, int32, int64
- float32, float64
- == 等于
- != 不等于
- > 大于
- < 小于
- >= 大于等于
- <= 小于等于
- + 加
- - 减
- * 乘
- / 除
- 支持int,uint,float任意两者之间的加减乘除, 以及string与string之间的加法
- 单目运算符非(!) > 算术运算符 > 比较运算符 > 逻辑运算符
//规则
rule "测试" "测试描述" salience 0
begin
// 重命名函数 测试
Sout("XXXXXXXXXX")
// 普通函数 测试
Hello()
//结构提方法 测试
User.Say()
// if
if !(7 == User.GetNum(7)) || !(7 > 8) {
//自定义变量 和 加法 测试
variable = "hello" + (" world" + "zeze")
// 加法 与 内建函数 测试
User.Name = "hhh" + strconv.FormatBool(true)
//结构体属性、方法调用 和 除法 测试
User.Age = User.GetNum(8976) / 1000+ 3*(1+1)
//布尔值设置 测试
User.Male = false
//规则内自定义变量调用 测试
User.Print(variable)
//float测试 也支持科学计数法
f = 9.56
PrintReal(f)
//嵌套if-else测试
if false {
Sout("嵌套if测试")
}else{
Sout("嵌套else测试")
}
}else{ //else
//字符串设置 测试
User.Name = "yyyy"
}
endimport (
"fmt"
"gengine/base"
"gengine/builder"
"gengine/context"
"gengine/engine"
"github.com/sirupsen/logrus"
"testing"
"time"
)
type User struct {
Name string
Age int
Male bool
}
func (u *User)GetNum(i int64) int64 {
return i
}
func (u *User)Print(s string){
fmt.Println(s)
}
func (u *User)Say(){
fmt.Println("hello world")
}
const (
rule2 = `
rule "测试" "测试描述" salience 0
begin
// 重命名函数 测试
Sout("XXXXXXXXXX")
// 普通函数 测试
Hello()
//结构提方法 测试
User.Say()
// if
if 7 == User.GetNum(7){
//自定义变量 和 加法 测试
variable = "hello" + " world"
// 加法 与 内建函数 测试
User.Name = "hhh" + strconv.FormatBool(true)
//结构体属性、方法调用 和 除法 测试
User.Age = User.GetNum(89767999999) / 10000000
//布尔值设置 测试
User.Male = false
//规则内自定义变量调用 测试
User.Print(variable)
//float测试 也支持科学计数法
f = 9.56
PrintReal(f)
//嵌套if-else测试
if false {
Sout("嵌套if测试")
}else{
Sout("嵌套else测试")
}
}else{ //else
//字符串设置 测试
User.Name = "yyyy"
}
end`)
func Hello() {
fmt.Println("hello")
}
func PrintReal(real float64){
fmt.Println(real)
}
func exe(user *User){
/**
不要注入除函数和结构体指针以外的其他类型(如变量)
*/
dataContext := context.NewDataContext()
//注入结构体指针
dataContext.Add("User", user)
//重命名函数,并注入
dataContext.Add("Sout",fmt.Println)
//直接注入函数
dataContext.Add("Hello",Hello)
dataContext.Add("PrintReal",PrintReal)
//初始化规则引擎
knowledgeContext := base.NewKnowledgeContext()
ruleBuilder := builder.NewRuleBuilder(knowledgeContext, dataContext)
//读取规则
err := ruleBuilder.BuildRuleFromString(rule2)
if err != nil{
logrus.Errorf("err:%s ", err)
}else{
eng := engine.NewGengine()
start := time.Now().UnixNano()
// true: means when there are many rules， if one rule execute error，continue to execute rules after the occur error rule
err := eng.Execute(ruleBuilder, true)
end := time.Now().UnixNano()
if err != nil{
logrus.Errorf("execute rule error: %v", err)
}
logrus.Infof("execute rule cost %d ns",end-start)
logrus.Infof("user.Age=%d,Name=%s,Male=%t", user.Age, user.Name, user.Male)
}
}
func Test_Base(t *testing.T){
user := &User{
Name: "Calo",
Age: 0,
Male: true,
}
exe(user)
}
- 如果你想获得高执行效率，请将 规则的构建过程和规则的执行过程相分离
- 如果你的规则中包含耗时，比如操作数据库，那么建议你用engine.ExecuteConcurrent(...) ,如果没有,建议你仍然用engine.Execute(...)
- 规则引擎支持混合执行模式，优先执行一个最高优先级的规则，剩下的规则以并发的模式执行
