Rate Limiter

// # Create a Rate Limiting Rule Class/Function that will take in a rule which will be evaluated against incoming messages.

// # The rule must contain: // # 1. The threshold (maximum number of matching messages allowed by a person) // # 2. The evaluation time window in seconds (the time window over which counts are tracked)

// # The class should support the below operation:

// # should_throttle(message, current_time int) bool -> Which will take in a message, a monotonically increasing timestamp (seconds) // # and return true if it breaches the rule threshold for the current time window, or false otherwise.

// # Example:

// # If we have the below rule:

// # rule = RateLimitingRule(1, 10)

// # And the following messages: // # message1 = {“name” : “John”} // # message2 = {“name” : “Josh”} // # message3 = {“name” : “John”} // # message4 = {“name” : “Josh”} // # message5 = {“name” : “John”} // # message6 = {“name” : “Josh”}

// # Calling should_throttle with the below arguments should result in result3 being true // # result1 = rule.should_throttle(message1, 5) # should return false // # result2 = rule.should_throttle(message2, 6) # should return false // # result3 = rule.should_throttle(message3, 9) # should return true because this is the second occurrence within the time window // # result4 = rule.should_throttle(message4, 11) # should return true // # result5 = rule.should_throttle(message5, 16) # should return false since the message is now outside of the time window // # result6 = rule.should_throttle(message6, 16) # should return true because this is the second occurrence within the time window // 20 1 20-1 19 >threshold=10

// 20
package main import “fmt” type RuleLimit struct{ MessageThreshold int EvalTime int //userReQuestMap }

//20

func (ruleLimit RuleLimit)should_throttle(message User, current_time int) bool{ // userReQuestMap[userName][len(userReQuestMap[userName])-1]//15 currentRequestTime:=current_time //20 // currentRequestTime-userReQuestMap[userName][len(userReQuestMap[userName])-1]>timeWindow 5>10 userName:=message.Name var returnResult bool if(!userReQuestMap[userName]||(currentRequestTime-userReQuestMap[userName][len(userReQuestMap[userName])-1]>ruleLimit.EvalTime && len(userReQuestMap[userName])<=ruleLimit.MessageThreshold)){ //allow it //add to the list //syncMAP LOadOrStore and GET userReQuestMap[userName]=append(userReQuestMap[userName],currentRequestTime)

}else{ returnResult= true; }

//Current Time 55 //evaluation time window is 10 //2,4,5[_____]

// because 55-10=44 //

20=currentTIme EvalTime=10 josh =[1,2,15] 1 is gone , for userName,requestGatheredTimes:=range userReQuestMap{ var allowedRequest []int for timeIdx:=0;timeIdx<len(requestGatheredTimes);timeIdx++ { if(requestGatheredTimes[timeIdx]<(currentRequestTime-ruleLimit.EvalTime) ){//len(userReQuestMap[userName])<=ruleLimit.MessageThreshold) //dont take these/

  }else{
    allowedRequest=append(allowedRequest,requestGatheredTimes[timeIdx])
  }

}//
userReQuestMap[userName]=allowedRequest

}

return returnResult   }

type User struct{ Name string }

var userReQuestMap map[string][]int func main(){ // fmt.Printf(“Hello”)

// user[“john”]=[5] // [“josh”]=[6] ruleLimit:=RuleLimit{ MessageThreshold : 1, EvalTime :10,

} userReQuestMap=make(map[string][]int)//requestTime user vs his allowedRequestTImes

message1 := User{Name: “John”} message2 :=User{Name: “Josh”} message3 := User{Name: “John”} message4 := User{Name: “Josh”} message5 :=User{Name: “John”} message6 :=User{Name: “Josh”}

// Calling should_throttle with the below arguments should result in result3 being true result1 = ruleLimit.should_throttle(message1, 5)// # should return false fmt.Println(result1) result2 = ruleLimit.should_throttle(message2, 6) //# should return false fmt.Println(result2)

result3 = ruleLimit.should_throttle(message3, 9) //# should return true because this is the second occurrence within the time window fmt.Println(result3)

// result4 = ruleLimit.should_throttle(message4, 11) //# should return true // result5 = ruleLimit.should_throttle(message5, 16) //# should return false since the message is now outside of the time window // result6 = ruleLimit.should_throttle(message6, 16) //# should return true because this is the second occurrence within the time window

}