private UriCircuitBreaker GetCircuitBreaker(Uri uri)
{
uri = new Uri(uri.GetLeftPart(UriPartial.Path));
UriCircuitBreaker ucb;
Monitor.Enter(m_pool);
try
{
if ((m_evictionScan = (m_evictionScan + 1) % c_evictionScanFrequency) == 0)
{
var staleUris = from kvp in m_pool
where kvp.Value.LastAttempt.Add(m_evictionStaleTime) < DateTime.UtcNow
select kvp.Key;
foreach (var staleUri in staleUris.ToArray())
{
m_pool.Remove(staleUri);
}
}
if (!m_pool.TryGetValue(uri, out ucb))
{
m_pool.Add(uri, ucb = new UriCircuitBreaker());
}
}
finally
{
Monitor.Exit(m_pool);
}
return(ucb);
}
protected override async Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
UriCircuitBreaker ucb = GetCircuitBreaker(request.RequestUri);
ucb.ThrowIfOpen(m_failuresToOpen, m_timeToStayOpen);
// If we get here, we're closed
try {
HttpResponseMessage t = await base.SendAsync(request, cancellationToken);
ucb.ReportAttempt(t.IsSuccessStatusCode, m_failuresToOpen);
return(t);
}
catch (Exception /*ex*/) { ucb.ReportAttempt(false, m_failuresToOpen); throw; }
}