public async Task <bool> Process(ICrawler crawler, PropertyBag propertyBag)
{
string robotsHttpUrl = string.IsNullOrEmpty(_searchPath)
? $"{propertyBag.Step.Uri.GetComponents(UriComponents.SchemeAndServer, UriFormat.Unescaped).ToLowerInvariant()}/robots.txt"
: $"{propertyBag.Step.Uri.GetComponents(UriComponents.SchemeAndServer, UriFormat.Unescaped).ToLowerInvariant()}" + _searchPath;
RobotsTxt.Robots robots;
if (!_robotsInfo.TryGetValue(robotsHttpUrl, out robots))
{
_logger.Verbose("Downloading robots.txt file from {@0}", robotsHttpUrl);
string robotsContext = null;
try
{
robotsContext = await _httpClient.GetStringAsync(robotsHttpUrl);
}
catch (WebException)
{
}
catch (ProtocolViolationException)
{
}
catch (HttpRequestException)
{
}
robots = new RobotsTxt.Robots(robotsContext ?? string.Empty);
_robotsInfo.Add(robotsHttpUrl, robots);
}
if (!robots.HasRules)
{
return(true);
}
long crawlDelay = robots.CrawlDelay(propertyBag.UserAgent);
if (crawlDelay > 0)
{
await Task.Delay((int)crawlDelay);
}
bool result = robots.IsPathAllowed(propertyBag.UserAgent, propertyBag.Step.Uri.ToString());
propertyBag[RobotsIsPathAllowedPropertyName].Name = nameof(RobotsPipelineStep);
propertyBag[RobotsIsPathAllowedPropertyName].Value = result;
return(result);
}
public async Task<bool> Process(ICrawler crawler, PropertyBag propertyBag)
{
string robotsHttpUrl = string.IsNullOrEmpty(_searchPath)
? $"{propertyBag.Step.Uri.GetComponents(UriComponents.SchemeAndServer, UriFormat.Unescaped).ToLowerInvariant()}/robots.txt"
: $"{propertyBag.Step.Uri.GetComponents(UriComponents.SchemeAndServer, UriFormat.Unescaped).ToLowerInvariant()}" + _searchPath;
RobotsTxt.Robots robots;
if (!_robotsInfo.TryGetValue(robotsHttpUrl, out robots))
{
_logger.Verbose("Downloading robots.txt file from {@0}", robotsHttpUrl);
string robotsContext = null;
try
{
robotsContext = await _httpClient.GetStringAsync(robotsHttpUrl);
}
catch (WebException)
{
}
catch (ProtocolViolationException)
{
}
catch (HttpRequestException)
{
}
robots = new RobotsTxt.Robots(robotsContext ?? string.Empty);
_robotsInfo.Add(robotsHttpUrl, robots);
}
if (!robots.HasRules)
{
return true;
}
long crawlDelay = robots.CrawlDelay(propertyBag.UserAgent);
if (crawlDelay > 0)
{
await Task.Delay((int) crawlDelay);
}
bool result = robots.IsPathAllowed(propertyBag.UserAgent, propertyBag.Step.Uri.ToString());
propertyBag[RobotsIsPathAllowedPropertyName].Name = nameof(RobotsPipelineStep);
propertyBag[RobotsIsPathAllowedPropertyName].Value = result;
return result;
}