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/**
 * setImmediate callbacks are fired off the event loop, once per iteration in the order that they were queued. 
 * So on the first iteration of the event loop, callback A is fired.
 * Then on the second iteration of the event loop, callback B is fired, then on the third iteration of the event loop callback C is fired, etc.
 * This prevents the event loop from being blocked and allows other I/O or timer callbacks to be called in the mean time (as is the case of the 0ms timeout, which is fired on the 1st or 2nd loop iteration).
 */

setImmediate(function A() {
  setImmediate(function B() {
    console.log(1);

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package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	var wg sync.WaitGroup

StarpTech

package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	var wg sync.WaitGroup

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"use strict";

const _ = require("lodash");

function groupByTimeWindow(start, end) {
  return function(o) {
    const date = new Date(o.timestamp);
    if (date.getUTCHours() >= start && date.getUTCHours() <= end)
      return o.consumption_Wh;
    return 0;

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// initialize
// The maximum number of requests is equal to 
// maxSockets * 2 with keepAlive: true or equal to maxSockets with keepAlive: false.
const arangodb = new Arangojs.Database({
  url: "http://localhost:8529", // Base URL of the ArangoDB server or list of server URLs.
  agentOptions: {
    maxSockets: 100,
    keepAlive: true
  }, 
  loadBalancingStrategy: 'ROUND_ROBIN'

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/**
 * Small library to validate numeric data structures in a functional-style
 * All functions are right associative
 * If you are looking for more sophisticated features have a look at
 * https://ramdajs.com/
 */

export interface FabPattern {
  [index: string]: (input: number) => boolean;
}

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Graphql cache challenges

How to practice HTTP Caching?

GraphQL queries are usually POST requests. POST request aren't cached by nature. This means that we need different solutions to deliver our content efficiently.

• Apollo Server provide a apollo-cache-control in order to configure how long a query should be cached. Cache hint inside the schema.

• Automatic persisted queries (APQs) is a performance technique which allows a hash to be sent to the server instead of the entire GraphQL query string. It is possible to use APQs with GET requests here. In that way we can also benefit from CDN. How it works. In theory it's the same mechani

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'use strict';

const assert = require('assert');

/**
* The redis client is https://github.com/luin/ioredis
*/

/*
const redisClient = new Redis({

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// Inspired by https://www.robinwieruch.de/react-hooks-fetch-data/

const dataFetchReducer = (state, action) => {
  switch (action.type) {
    case 'REQUEST_INIT':
      return { ...state, isLoading: true, isError: false };
    case 'REQUEST_SUCCESS':
      return { ...state, isLoading: false, isError: false, data: action.payload };
    case 'REQUEST_FAILURE':
      return { ...state, isLoading: false, isError: true };

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version: '3.4'

services:
  cypress:
    container_name: 'cypress-e2e'
    image: 'cypress/included:3.4.1'
    working_dir: /e2e
    volumes:
      - .:/e2e
    environment: