public bool Crawl()
{
int beatId = myCrawlListener.CrawlBeatBegin(sessionId);
Dictionary <string, Node> newNodes = new Dictionary <string, Node>();
foreach (var valuePair in myBaseline)
{
NodeContent nodeContent = valuePair.Value;
string current = ReadUri(nodeContent.Node.Uri, out HttpStatusCode status, out string contentType, out long contentLength);
myCrawlListener.NodeStatusReported(beatId, nodeContent, ((int)status).ToString());
if (myPruner.Compare(nodeContent, current) != 0)
{
if (nodeContent.Content.Length > 0)
{
//Only notify a change if previous content wasn't zero
myCrawlListener.NodeChangeDetected(beatId, nodeContent, current, contentType, contentLength, ((int)status).ToString());
}
nodeContent.Update(current, contentType, contentLength);
List <Link> newLinks = myPruner.EvalLinks(nodeContent);
if (myPruner.Compare(nodeContent, newLinks) != 0)
{
if (nodeContent.Links.Count > 0)
{
//Only notify a change if previous links weren't empty
myCrawlListener.NodeLinkChangeDetected(beatId, nodeContent, newLinks);
}
nodeContent.Links = newLinks;
foreach (Link link in nodeContent.Links)
{
Node node = new Node(link.Uri.ToString());
if (!myBaseline.ContainsKey(node.Key) && !newNodes.ContainsKey(node.Key))
{
if (myPruner.ShouldPursue(node.Uri))
{
newNodes.Add(node.Key, node);
}
}
}
}
}
}
myCrawlListener.MessageLogged("Adding " + newNodes.Count.ToString() + " node(s) from crawl evaluation of links");
foreach (var node in newNodes)
{
NodeContent newNodeContent = new NodeContent(node.Value);
myBaseline.Add(newNodeContent.Node.Key, newNodeContent);
myCrawlListener.NodeRegistered(beatId, newNodeContent, ((int)HttpStatusCode.NoContent).ToString());
}
myCrawlListener.CrawlBeatEnd(beatId);
return(true);
}
public Spider(Baseline baseline, Pruner pruner, ICrawlRecorder crawlerReport)
{
myPruner = pruner;
myCrawlListener = crawlerReport ?? throw new ArgumentNullException(nameof(crawlerReport));
sessionId = myCrawlListener.CrawlSessionBegin();
int beatId = myCrawlListener.CrawlBeatBegin(sessionId);
myBaseline = baseline ?? throw new ArgumentNullException(nameof(baseline));
Dictionary <string, Node> extraNodes = new Dictionary <string, Node>();
foreach (var valuePair in myBaseline)
{
NodeContent nodeContent = valuePair.Value;
string current = ReadUri(nodeContent.Node.Uri, out HttpStatusCode status, out string contentType, out long contentLength);
nodeContent.Update(current, contentType, contentLength);
nodeContent.Links = myPruner.EvalLinks(nodeContent);
myCrawlListener.NodeRegistered(beatId, nodeContent, ((int)status).ToString());
foreach (Link link in nodeContent.Links)
{
Node node = new Node(link.Uri.ToString());
if (!myBaseline.ContainsKey(node.Key) && !extraNodes.ContainsKey(node.Key))
{
if (myPruner.ShouldPursue(node.Uri))
{
extraNodes.Add(node.Key, node);
}
}
}
}
myCrawlListener.MessageLogged("Adding " + extraNodes.Count.ToString() + " node(s) from first evaluation of links");
foreach (var extra in extraNodes)
{
NodeContent extraNodeContent = new NodeContent(extra.Value);
myBaseline.Add(extraNodeContent.Node.Key, extraNodeContent);
myCrawlListener.NodeRegistered(beatId, extraNodeContent, ((int)HttpStatusCode.NoContent).ToString());
}
myCrawlListener.CrawlBeatEnd(beatId);
}
