#359 - Logger Rate Limiter

Problem Description

Design a logger system that receives a stream of messages along with their timestamps.

Each unique message should only be printed at most every 10 seconds (i.e. a message printed at timestamp t will prevent other identical messages from being printed until timestamp t + 10).

All messages will come in chronological order. Several messages may arrive at the same timestamp.

Implement the Logger class:

Logger() Initializes the logger object.
bool shouldPrintMessage(int timestamp, string message) Returns true if the message should be printed in the given timestamp, otherwise returns false.

Solution

var Logger = function() {
  this.messageTimestamps = new Map();
};

/**
 * @param {number} timestamp
 * @param {string} message
 * @return {boolean}
 */
Logger.prototype.shouldPrintMessage = function(timestamp, message) {
  const nextAllowed = this.messageTimestamps.get(message) || 0;
  if (timestamp >= nextAllowed) {
    this.messageTimestamps.set(message, timestamp + 10);
    return true;
  }
  return false;
};