/// <summary>
/// Returns the <see cref="UniqueVisitor" /> instance from the current
/// HTTP context for the end user making the request generating a new
/// instance as necessary.
/// </summary>
/// <returns>The <see cref="UniqueVisitor" /> instance.</returns>
/// <exception cref="InvalidOperationException">Thrown if the method is not called within the processing context of a HTTP request.</exception>
/// <remarks>
/// <para>
/// This method retrieves the visitor identifier from the <b>__lt-uv</b>
/// cookie in the request and if necessary, adds newly generated cookies
/// to the HTTP response.
/// </para>
/// <note>
/// Unique visitor instances <b>will not</b> be created for known web crawlers.
/// </note>
/// </remarks>
public static UniqueVisitor GetUniqueVisitor()
{
HttpCookie cookie;
UniqueVisitor visitor;
if (HttpContext.Current == null)
{
throw new InvalidOperationException(NoHttpContextMsg);
}
if (HttpContext.Current.Request.Browser.Crawler)
{
return(null);
}
cookie = GetCookie(UniqueVisitorCookie);
if (cookie == null)
{
// There is no visitor cookie so generate a new visitor ID
// and send it back in the HTTP response with an approximate
// 100 year lifetime (essentially forever).
visitor = new UniqueVisitor();
cookie = new HttpCookie(UniqueVisitorCookie, visitor.ToString());
cookie.Expires = DateTime.UtcNow + TimeSpan.FromDays(365 * 100);
SetCookie(cookie);
return(visitor);
}
try
{
return(new UniqueVisitor(cookie.Value));
}
catch (Exception e)
{
SysLog.LogException(e, "Probable invalid HTTP visitor cookie. Generating a new cookie.");
visitor = new UniqueVisitor();
cookie = new HttpCookie(UniqueVisitorCookie, visitor.ToString());
cookie.Expires = DateTime.UtcNow + TimeSpan.FromDays(365 * 100);
SetCookie(cookie);
return(visitor);
}
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="visitorCookie">The unique visitor cookie or <c>null</c>.</param>
/// <param name="logTag">The log tag.</param>
/// <param name="logEntry">The log entry.</param>
internal LogAnalyzerArgs(string visitorCookie, string logTag, string logEntry)
{
this.VisitorCookie = visitorCookie;
this.LogTag = logTag;
this.LogEntry = logEntry;
if (!logTag.StartsWith("PageView") && !logTag.StartsWith("BotView"))
{
return; // Not for a HTTP request.
}
// Process the HTTP request line and headers.
using (var reader = new StringReader(logEntry))
{
string line;
string[] fields;
char[] headerSplit = new char[] { ':' };
line = reader.ReadLine();
fields = line.Split(' ');
Method = fields[0].ToUpper();
Path = fields[1];
Headers = new ArgCollection(ArgCollectionType.Unconstrained);
for (line = reader.ReadLine(); line != null; line = reader.ReadLine())
{
fields = line.Split(headerSplit, 2);
Headers[fields[0].Trim()] = fields[1].Trim();
}
Headers.IsReadOnly = true;
}
// Extract the common header values.
this.Host = Headers["Host"];
IPAddress address;
if (Headers.ContainsKey("X-Remote-Address") && IPAddress.TryParse(Headers["X-Remote-Address"], out address))
{
this.RemoteAddress = address;
}
if (Headers.ContainsKey("Referer"))
{
try
{
this.Referer = new Uri(Headers["Referer"]);
}
catch
{
// Ignore
}
}
// Try to extract the standard LillTek unique visitor cookie if we didn't have
// one passed.
string cookieHeader;
if (VisitorCookie == null && Headers.TryGetValue("Cookie", out cookieHeader))
{
try
{
var cookies = new ArgCollection(cookieHeader, '=', ';');
string visitor;
if (cookies.TryGetValue(WebHelper.UniqueVisitorCookie, out visitor))
{
try
{
VisitorCookie = new UniqueVisitor(visitor).ID.ToString("D").ToUpper();
}
catch
{
VisitorCookie = visitor;
}
}
}
catch (Exception e)
{
SysLog.LogException(e);
}
}
}
