protected override async Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
var ctx = new HandlingContext
{
Request = request,
HandleAsync = base.SendAsync,
ResponsSource = new TaskCompletionSource <HttpResponseMessage>(cancellationToken),
CancellationToken = cancellationToken
};
try
{
await _dispather.AcceptThenDispatchAsync(ctx);
}
catch (Exception ex)
{
_logger.LogError(ex, ex.Message);
ctx.ResponsSource.SetException(ex);
}
return(await ctx.ResponsSource.Task);
}
/// <returns>是否尝试了“下一个”上游服务端</returns>
private async Task <bool> NextPeerAsync(
HandlingContext handlingContext,
UpstreamPeer peer,
HttpResponseMessage response,
Uri originUri,
bool isTimeout = false)
{
if (peer == null)
{
return(false);
}
if (handlingContext.IsSingle)
{
return(false);
}
handlingContext.Start = handlingContext.Start ?? DateTime.Now;
if (NextWhen.Never == (peer.NextWhen & NextWhen.Never))
{
return(false);
}
var request = handlingContext.Request;
if (request.Method != HttpMethod.Get &&
NextWhen.GetOnly == (peer.NextWhen & NextWhen.GetOnly))
{
return(false);
}
handlingContext.Tries = handlingContext.Tries ?? (peer.NextTries == 0 ? int.MaxValue : peer.NextTries);
if (handlingContext.Tries == 0)
{
return(false);
}
var when = NextWhen.None;
if (isTimeout)
{
when |= NextWhen.Timeout;
}
else if (response == null)
{
when |= NextWhen.Error;
}
else
{
if (response.IsSuccessStatusCode)
{
return(false);
}
switch (response.StatusCode)
{
case HttpStatusCode.InternalServerError:
when |= NextWhen.Http500;
break;
case HttpStatusCode.BadGateway:
when |= NextWhen.Http502;
break;
case HttpStatusCode.ServiceUnavailable:
when |= NextWhen.Http503;
break;
case HttpStatusCode.RequestTimeout:
case HttpStatusCode.GatewayTimeout:
when |= NextWhen.Timeout;
break;
case HttpStatusCode.Forbidden:
when |= NextWhen.Http403;
break;
case HttpStatusCode.NotFound:
when |= NextWhen.Http404;
break;
default:
return(false);
}
}
#if NETSTANDARD2_0
if (request.Method == HttpMethod.Post || request.Method.Method == "PATCH")
#elif NETSTANDARD2_1
if (request.Method == HttpMethod.Post || request.Method == HttpMethod.Patch)
#endif
{
when |= NextWhen.NonIdemponent;
}
if (when != (when & peer.NextWhen))
{
return(false);
}
if (DateTime.Now - handlingContext.Start >= peer.NextTimeout)
{
return(false);
}
handlingContext.Request = request.Clone(originUri);
//保持上下文重试
var next = await _dispatcher.AcceptThenDispatchAsync(handlingContext);
handlingContext.Tries--;
return(next);
}
