private static async Task InputAsync(CrawlerEngine engine)
{
await Task.Factory.StartNew(() =>
{
var key = Console.ReadKey().Key;
var stepsize = 10;
while (key != ConsoleKey.Q)
{
if (key == ConsoleKey.UpArrow)
{
engine.MaxConcurrency += stepsize;
}
else if (key == ConsoleKey.DownArrow)
{
engine.MaxConcurrency = engine.MaxConcurrency - stepsize > 0
? engine.MaxConcurrency - stepsize
: 0;
}
else if (key == ConsoleKey.LeftArrow)
{
stepsize -= 10;
}
else if (key == ConsoleKey.RightArrow)
{
stepsize += 10;
}
key = Console.ReadKey().Key;
}
Environment.Exit(0);
});
}
private static async Task ConsoleAsync(CrawlerEngine engine, bool interactive)
{
var requestRate = new RollingAverage(40);
var lastCrawled = 0l;
var lastSample = DateTime.Now;
Console.Clear();
while (true)
{
if (interactive)
{
Console.SetCursorPosition(0, 0);
Console.WriteLine($"Crawling from root:{engine.StartUrl} Logfile:{engine.LogFile}");
}
Console.WriteLine(
$"Crawled:{engine.Crawled.ToString("N0")}/{engine.Found.ToString("N0")} Queued:{engine.Queued.ToString("N0").PadRight(8)} Errored:{engine.Errored.ToString("N0"),6} Request Rate:{(requestRate.GetAverage() / 1000f).ToString("N2").PadLeft(6)} r/s RobotDomains:{engine.RobotDomains.ToString().PadRight(6)} Concurrency:{engine.CurrentConcurrency.ToString().PadLeft(5)}/{engine.MaxConcurrency.ToString().PadRight(5)}"
.PadRight(Console.WindowWidth));
await Task.Delay(TimeSpan.FromMilliseconds(500));
requestRate.AddSample((long)((engine.Crawled - lastCrawled) / ((DateTime.Now - lastSample).TotalMilliseconds / 1000000f)));
lastCrawled = engine.Crawled;
lastSample = DateTime.Now;
}
}
private static void Main(string[] args)
{
var startUrl = args.Length > 0 ? args[0] : "https://www.google.com";
int concurrency;
var engine = new CrawlerEngine(new ResultsLogger(ConfigurationManager.AppSettings["Logfile"] ?? $".\\crawl.log"), int.TryParse(ConfigurationManager.AppSettings["MaxConcurrency"], out concurrency) ? concurrency : 20);
var mainTasks = new List <Task>();
var crawlTask = engine.CrawlAsync(startUrl);
mainTasks.Add(crawlTask);
if (string.Equals(ConfigurationManager.AppSettings["Interactive"] ?? "true", "false", StringComparison.OrdinalIgnoreCase))
{
mainTasks.Add(ConsoleAsync(engine, false));
}
else
{
mainTasks.Add(ConsoleAsync(engine, true));
mainTasks.Add(InputAsync(engine));
}
Task.WaitAll(mainTasks.ToArray());
Console.WriteLine($"Crawled {crawlTask.Result} pages");
}