private void ConfigureStorageDirectories()
{
var storageDirectory = new DirectoryInfo(ExtractorParams.StorageDir);
if (!storageDirectory.Exists)
{
storageDirectory.Create();
}
string websitePath = HtmlFileUtils.GetWebsitePathFromUri(ExtractorParams.Scope, ExtractorParams.RootUrl);
ContentDirectory = new DirectoryInfo(Path.Combine(storageDirectory.FullName, websitePath));
if (!ContentDirectory.Exists)
{
ContentDirectory.Create();
}
}
public static string GetWebsitePathFromUri(ExtractionScope scope, Uri rootUri)
{
string websitePath = null;
switch (scope)
{
case ExtractionScope.Domain:
websitePath = HtmlFileUtils.GetPathValidChars(GetBaseDomain(rootUri));
break;
case ExtractionScope.SubDomain:
websitePath = HtmlFileUtils.GetPathValidChars(GetSubDomain(rootUri));
break;
//case ExtractionScope.Path:
default:
websitePath = HtmlFileUtils.GetPathValidChars(GetSubDomain(rootUri) + GetRootPath(rootUri.AbsolutePath).Replace("/", "_"));
break;
}
return(websitePath);
}
private void ConfigureWebCrawler()
{
CrawlConfiguration config = new CrawlConfiguration();
config.MaxConcurrentThreads = Environment.ProcessorCount;
config.MaxPagesToCrawl = 0;
config.MaxPagesToCrawlPerDomain = 0;
config.MaxPageSizeInBytes = 0;
config.UserAgentString = "Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko";
config.HttpProtocolVersion = HttpProtocolVersion.NotSpecified;
config.CrawlTimeoutSeconds = 0;
config.IsUriRecrawlingEnabled = false;
config.IsExternalPageCrawlingEnabled = false;
config.IsExternalPageLinksCrawlingEnabled = false;
config.IsRespectUrlNamedAnchorOrHashbangEnabled = false;
config.DownloadableContentTypes = "text/html, text/plain";
config.HttpServicePointConnectionLimit = 200;
config.HttpRequestTimeoutInSeconds = 15;
config.HttpRequestMaxAutoRedirects = 7;
config.IsHttpRequestAutoRedirectsEnabled = true;
config.IsHttpRequestAutomaticDecompressionEnabled = true;
config.IsSendingCookiesEnabled = false;
config.IsSslCertificateValidationEnabled = false;
config.MinAvailableMemoryRequiredInMb = 0;
config.MaxMemoryUsageInMb = 0;
config.MaxMemoryUsageCacheTimeInSeconds = 0;
config.MaxCrawlDepth = 1000;
config.MaxLinksPerPage = 1000;
config.IsForcedLinkParsingEnabled = false;
config.MaxRetryCount = 0;
config.MinRetryDelayInMilliseconds = 0;
config.IsRespectRobotsDotTextEnabled = true;
config.UrlPatternsToExclude = ExtractorParams.UrlPatternsToExclude;
config.IsRespectMetaRobotsNoFollowEnabled = true;
config.IsRespectHttpXRobotsTagHeaderNoFollowEnabled = true;
config.IsRespectAnchorRelNoFollowEnabled = true;
config.IsIgnoreRobotsDotTextIfRootDisallowedEnabled = false;
config.RobotsDotTextUserAgentString = "bingbot";
config.MinCrawlDelayPerDomainMilliSeconds = ExtractorParams.MinCrawlDelay;
config.MaxRobotsDotTextCrawlDelayInSeconds = 5;
config.IsAlwaysLogin = false;
config.LoginUser = "";
config.LoginPassword = "";
config.UseDefaultCredentials = false;
if (!DoContinue)
{
scheduler = new Scheduler(config.IsUriRecrawlingEnabled, null, null);
}
else
{
using (FileStream fs = new FileStream(Path.Combine(ContentDirectory.FullName, LogsDirName, CheckpointFileName), FileMode.Open))
{
scheduler = Scheduler.Deserialize(fs);
}
}
crawler = new PoliteWebCrawler(config, null, null, scheduler, null, null, null, null, null);
crawler.IsInternalUri((candidateUri, rootUri) => HtmlFileUtils.ShouldCrawlUri(ExtractorParams.Scope, candidateUri, rootUri));
crawler.ShouldCrawlPageLinks(WebCrawler_ShouldCrawlPageLinks);
crawler.PageCrawlCompletedAsync += WebCrawler_PageCrawlCompletedAsync;
// DEBUG: uncomment to debug Abot crawl progress
// crawler.PageCrawlStartingAsync += WebCrawler_PageCrawlStartingAsync;
// DEBUG: uncomment to debug Abot crawling decisions
// crawler.PageCrawlDisallowedAsync += WebCrawler_PageCrawlDisallowedAsync;
// crawler.PageLinksCrawlDisallowedAsync += WebCrawler_PageLinksCrawlDisallowedAsync;
}
// => called each time a page has been crawled by the web crawler
private void WebCrawler_PageCrawlCompletedAsync(object sender, PageCrawlCompletedArgs e)
{
try
{
CrawledPage crawledPage = e.CrawledPage;
// Exit if the page wasn't crawled successfully
if (crawledPage.WebException != null || crawledPage.HttpWebResponse.StatusCode != HttpStatusCode.OK)
{
LogRequest(crawledPage, 0);
if (crawledPage.WebException != null)
{
Perfs.AddCrawlError();
}
else if (crawledPage.HttpWebResponse != null)
{
int statusCode = (int)crawledPage.HttpWebResponse.StatusCode;
if (statusCode != 404 && statusCode >= 400)
{
Perfs.AddCrawlError();
}
}
return;
}
// Exit if the page had non content
if (string.IsNullOrEmpty(crawledPage.Content.Text))
{
LogRequest(crawledPage, 0);
return;
}
// Get the page and its Css dependencies parsed by Abot whith Anglesharp
var htmlDocumentUri = crawledPage.HttpWebResponse.ResponseUri;
var htmlDocument = crawledPage.AngleSharpHtmlDocument;
// Visit the Html page syntax tree and convert it to NLPTextDocument
Stopwatch timer = Stopwatch.StartNew();
var htmlConverter = new HtmlDocumentConverter(htmlDocumentUri.AbsoluteUri, htmlDocument);
var normalizedTextDocument = htmlConverter.ConvertToNLPTextDocument();
timer.Stop();
// Check the percentage of text blocks which are new & unique in this page
var percentUnique = Perfs.SetPercentUniqueForLastDoc(normalizedTextDocument);
// Log the request results
LogRequest(crawledPage, percentUnique);
// Write the NLPTextDocument as a text file on disk
if (percentUnique > 0)
{
var fileInfo = HtmlFileUtils.GetFilePathFromUri(ContentDirectory, htmlDocumentUri);
if (!fileInfo.Directory.Exists)
{
fileInfo.Directory.Create();
}
NLPTextDocumentWriter.WriteToFile(normalizedTextDocument, fileInfo.FullName);
Perfs.AddTextConversion(timer.ElapsedMilliseconds, fileInfo.Length);
}
// Test stopping conditions
bool stopCrawl = false;
string stopMessage = null;
if (userCancelEventReceived)
{
stopCrawl = true;
stopMessage = "Extraction interrupted by the user";
}
else if (ExtractorParams.MaxDuration > 0 && TimeSpan.FromMilliseconds(Perfs.ElapsedTime).Minutes >= ExtractorParams.MaxDuration)
{
stopCrawl = true;
stopMessage = "Extraction stopped because the extraction duration exceeded " + ExtractorParams.MaxDuration + " minutes";
}
else if (ExtractorParams.MaxPageCount > 0 && Perfs.HtmlPagesCount >= ExtractorParams.MaxPageCount)
{
stopCrawl = true;
stopMessage = "Extraction stopped because the number of extracted pages exceeded " + ExtractorParams.MaxPageCount;
}
else if (ExtractorParams.MinUniqueText > 0 && Perfs.PercentUniqueForLastDocs < (ExtractorParams.MinUniqueText / 100.0))
{
stopCrawl = true;
stopMessage = "Extraction stopped because the % of new textblocks fell below " + ExtractorParams.MinUniqueText + "%";
}
else if (ExtractorParams.MaxSizeOnDisk > 0 && Perfs.TotalSizeOnDisk >= (ExtractorParams.MaxSizeOnDisk * 1024L * 1024L))
{
stopCrawl = true;
stopMessage = "Extraction stopped because the files size on disk exceeded " + ExtractorParams.MaxSizeOnDisk + " MB";
}
// Write current status to screen (and to file if stopping)
if (!stopCrawl)
{
Perfs.WriteStatus(Console.Out);
}
else
{
DisplayMessages(Perfs.WriteStatus);
}
// Write one checkpoint every one minute
// to enable the "continue" crawl feature
lock (CheckpointFileName)
{
if (stopCrawl || DateTime.Now.Subtract(lastCheckpointTime).Minutes >= 1)
{
lastCheckpointTime = DateTime.Now;
using (FileStream fs = new FileStream(Path.Combine(ContentDirectory.FullName, LogsDirName, CheckpointFileName), FileMode.Create))
{
scheduler.Serialize(fs);
}
}
if (stopCrawl)
{
DisplayMessages(WriteEndMessage, stopMessage);
Environment.Exit(0);
}
}
}
catch (Exception ex)
{
// Safeguard to make sure that an error
// during the processing of a single page
// can't stop the whole crawl process
WriteError("Error while processing the page : " + e.CrawledPage.HttpWebResponse.ResponseUri.AbsoluteUri, ex);
}
}
