private async Task <bool> CheckProxy(string proxyUrl)
{
var uri = new Uri(_baseUrl);
var builder = new UriBuilder(uri)
{
Path = String.Empty
};
uri = builder.Uri;
var handler = new HttpClientHandler {
Proxy = new WebProxy(new Uri(proxyUrl)), AllowAutoRedirect = true
};
var client = new HttpClient(handler)
{
Timeout = TimeSpan.FromSeconds(_requestTimeout)
};
try
{
var req = new HttpRequestMessage(HttpMethod.Head, uri);
req.Headers.UserAgent.ParseAdd(UserAgentSelector.GetRandomAgent());
var resp = await client.SendAsync(req);
return(resp.IsSuccessStatusCode);
}
catch (Exception)
{
return(false);
}
}
private async Task InitializeHttpClient()
{
var userAgent = UserAgentSelector.GetRandomAgent();
var httpHandler = new HttpClientHandler();
var httpClient = new HttpClient(httpHandler)
{
BaseAddress = new Uri(_baseUrl),
Timeout = TimeSpan.FromSeconds(_requestTimeout)
};
if (_proxyProvider != null)
{
var proxyUrl = await _proxyProvider.GetProxyAsync(CheckProxy);
if (!String.IsNullOrEmpty(proxyUrl))
{
httpHandler.Proxy = new WebProxy(new Uri(proxyUrl));
_logger.Info("UzService uses proxy " + proxyUrl);
}
else
{
_logger.Warning("Cannot obtain proxy, requesting unproxied");
}
}
_httpClient = httpClient;
_httpHandler = httpHandler;
_userAgent = userAgent;
}