/// <summary>
/// 检查是否满足重试条件
/// </summary>
/// <param name="option"></param>
/// <param name="record"></param>
/// <param name="retryCount"></param>
/// <returns></returns>
private bool CanRetry(RetryOption option, RequestRecord record, int retryCount)
{
if (option == null ||
option.RetryCount <= 0 ||
retryCount >= option.RetryCount)
{
return(false);
}
if (option.CanRetry != null)
{
return(option.CanRetry(record));
}
if ((option.TransientErrorRetry ?? false) && record.Exception != null)
{
if (record.Exception is TimeoutException ||
record.Exception is OperationCanceledException ||
record.Exception is HttpRequestException)
{
return(true);
}
return(false);
}
var statusCode = (int)record.Response.StatusCode;
var method = record.Response.RequestMessage.Method.ToString();
if (option.RetryStatusCodes?.Contains(statusCode) ?? false &&
(option.RetryMethods?.Contains(method, StringComparer.CurrentCultureIgnoreCase) ?? false))
{
return(true);
}
return(false);
}
/// <summary>
///
/// </summary>
/// <param name="argument"></param>
/// <returns></returns>
public async Task <ResponseWrapperResult> ProcessAsync(RetryPolicyArgument argument)
{
var fusedResult = TryGetFuseResult(argument.Service, argument.Module);
if (fusedResult != null)
{
return(fusedResult);
}
var records = new List <RequestRecord>();
var option = argument.Option;
await HandleException(argument.Request, async() =>
{
var timeoutToken = (option?.TotalTimeout ?? 0) > 0
? new CancellationTokenSource(TimeSpan.FromMilliseconds(option.TotalTimeout))
: new CancellationTokenSource();
return(await SendWithRetryAsync(option, argument.Request, argument.Sending, records, timeoutToken.Token));
}, record =>
{
//只有执行超时才会抛ExecutionHttpException，意味着重试结束
if (record.Exception is ExecutionHttpException executionEx)
{
record.Request = executionEx.Request;
record.Exception = executionEx.InnerException;
record.Duration = GetDuration(record.Request.TimeStamp);
records.Add(record);
}
return(record);
});
var result = new ResponseWrapperResult
{
Request = argument.Request,
Records = records,
Duration = GetDuration(argument.Request.TimeStamp),
RetryCount = records.Count() > 1 ? records.Count() - 1 : 0
};
//获取有效请求记录
RequestRecord vaildRecord = result.Records.LastOrDefault(x => x.Response != null)
?? result.Records.LastOrDefault();
result.Response = vaildRecord?.Response;
result.Exception = vaildRecord?.Exception;
_logger.LogInformation($"请求{argument.Request.RequestUri}执行完毕，用时:{result.Duration}ms");
SetFunseResult(argument, result);
return(result);
}
/// <summary>
///
/// </summary>
/// <param name="request"></param>
/// <param name="running"></param>
/// <param name="callback"></param>
/// <returns></returns>
private async Task <RequestRecord> HandleException(HttpRequest request, Func <Task <RequestRecord> > running, Func <RequestRecord, RequestRecord> callback)
{
RequestRecord record = default;
try
{
record = await running();
}
catch (Exception ex)
{
record = new RequestRecord
{
Request = request,
Exception = ex,
Duration = GetDuration(request.TimeStamp)
};
}
return(callback(record));
}
/// <summary>
/// 重试逻辑
/// </summary>
/// <param name="option"></param>
/// <param name="request"></param>
/// <param name="sending"></param>
/// <param name="records"></param>
/// <param name="timeoutToken"></param>
/// <param name="retryCount"></param>
/// <returns></returns>
private async Task <RequestRecord> SendWithRetryAsync(RetryOption option, HttpRequest request,
Func <HttpRequest, Task <HttpResponse> > sending,
List <RequestRecord> records, CancellationToken timeoutToken, int retryCount = 0)
{
if (timeoutToken.IsCancellationRequested)
{
throw new ExecutionHttpException(request, new TimeoutException($"请求超时，在{option.TotalTimeout}ms内未获取到结果"));
}
records = records ?? new List <RequestRecord>();
var record = await HandleException(request, async() =>
{
var response = await sending(request);
var requestRecord = new RequestRecord
{
Request = request,
Response = response,
Duration = response.Duration
};
return(requestRecord);
}, requestRecord =>
{
records.Add(requestRecord);
return(requestRecord);
});
if (!CanRetry(option, record, retryCount))
{
return(record);
}
//重试间隔时间
var waitTime = option.WaitIntervals[retryCount];
//等待重试间隔时间
await Waiting(request, waitTime, option.TotalTimeout, timeoutToken);
request = request.Clone();
//开始重试
return(await SendWithRetryAsync(option, request, sending, records, timeoutToken, ++retryCount));
}