private static void ProcessStartOfRequest <T>(ExecutionState <T> executionState, string startLogMessage, CancellationTokenSource timeoutTokenSource = null)
{
RESTCommand <T> restCMD = executionState.RestCMD;
executionState.CurrentOperation = ExecutorOperation.BeginOperation;
HttpContent arg = (restCMD.BuildContent != null) ? restCMD.BuildContent(restCMD, executionState.OperationContext) : null;
Uri uri = restCMD.StorageUri.GetUri(executionState.CurrentLocation);
Uri uri2 = restCMD.Credentials.TransformUri(uri);
Logger.LogInformational(executionState.OperationContext, "Starting asynchronous request to {0}.", uri2);
UriQueryBuilder arg2 = new UriQueryBuilder(executionState.RestCMD.Builder);
executionState.Req = restCMD.BuildRequest(restCMD, uri2, arg2, arg, restCMD.ServerTimeoutInSeconds, executionState.OperationContext);
ExecutionStateUtils.ApplyUserHeaders(executionState);
ExecutionStateUtils.FireSendingRequest(executionState);
if (executionState.OperationExpiryTime.HasValue)
{
timeoutTokenSource?.CancelAfter(executionState.RemainingTimeout);
}
else
{
timeoutTokenSource?.CancelAfter(int.MaxValue);
}
}
public static async Task <T> ExecuteAsync <T>(RESTCommand <T> cmd, IRetryPolicy policy, OperationContext operationContext, CancellationToken token)
{
using (ExecutionState <T> executionState = new ExecutionState <T>(cmd, policy, operationContext))
{
using (CancellationTokenSource timeoutTokenSource = CancellationTokenSource.CreateLinkedTokenSource(token))
{
CancellationToken timeoutToken = timeoutTokenSource.Token;
bool shouldRetry = false;
TimeSpan delay = TimeSpan.Zero;
HttpClient client = cmd.HttpClient ?? HttpClientFactory.Instance;
do
{
try
{
executionState.Init();
ExecutionStateUtils.StartRequestAttempt(executionState);
ProcessStartOfRequest(executionState, "Starting asynchronous request to {0}.", timeoutTokenSource);
ExecutionStateUtils.CheckTimeout(executionState, throwOnTimeout: true);
}
catch (Exception ex)
{
Logger.LogError(executionState.OperationContext, "Exception thrown while initializing request: {0}.", ex.Message);
StorageException ex2 = await ExecutionStateUtils.TranslateExceptionBasedOnParseErrorAsync(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseErrorAsync, timeoutToken).ConfigureAwait(continueOnCapturedContext: false);
ex2.IsRetryable = false;
executionState.ExceptionRef = ex2;
throw executionState.ExceptionRef;
}
try
{
executionState.CurrentOperation = ExecutorOperation.BeginGetResponse;
Logger.LogInformational(executionState.OperationContext, "Waiting for response.");
ExecutionState <T> executionState2 = executionState;
executionState2.Resp = await client.SendAsync(executionState.Req, HttpCompletionOption.ResponseHeadersRead, timeoutToken).ConfigureAwait(continueOnCapturedContext: false);
executionState.CurrentOperation = ExecutorOperation.EndGetResponse;
if (!executionState.Resp.IsSuccessStatusCode)
{
executionState2 = executionState;
executionState2.ExceptionRef = await StorageExceptionTranslator.PopulateStorageExceptionFromHttpResponseMessage(executionState.Resp, executionState.Cmd.CurrentResult, timeoutToken, executionState.Cmd.ParseErrorAsync).ConfigureAwait(continueOnCapturedContext: false);
}
Logger.LogInformational(executionState.OperationContext, "Response received. Status code = {0}, Request ID = {1}, Content-MD5 = {2}, ETag = {3}.", executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
ExecutionStateUtils.FireResponseReceived(executionState);
if (cmd.PreProcessResponse != null)
{
executionState.CurrentOperation = ExecutorOperation.PreProcess;
try
{
executionState.Result = cmd.PreProcessResponse(cmd, executionState.Resp, executionState.ExceptionRef, executionState.OperationContext);
executionState.ExceptionRef = null;
}
catch (Exception exceptionRef)
{
executionState.ExceptionRef = exceptionRef;
}
Logger.LogInformational(executionState.OperationContext, "Response headers were processed successfully, proceeding with the rest of the operation.");
}
executionState.CurrentOperation = ExecutorOperation.GetResponseStream;
cmd.ResponseStream = new MemoryStream();
await(await executionState.Resp.Content.ReadAsStreamAsync()).WriteToAsync(cmd.ResponseStream, executionState, timeoutTokenSource.Token);
cmd.ResponseStream.Position = 0L;
if (executionState.ExceptionRef != null)
{
executionState.CurrentOperation = ExecutorOperation.BeginDownloadResponse;
Logger.LogInformational(executionState.OperationContext, "Downloading error response body.");
try
{
executionState2 = executionState;
executionState2.ExceptionRef = await StorageExceptionTranslator.TranslateExceptionWithPreBufferedStreamAsync(executionState.ExceptionRef, executionState.Cmd.CurrentResult, cmd.ResponseStream, executionState.Resp, executionState.Cmd.ParseErrorAsync, timeoutToken);
throw executionState.ExceptionRef;
}
finally
{
cmd.ResponseStream.Dispose();
cmd.ResponseStream = null;
}
}
await ProcessEndOfRequestAsync(executionState, timeoutToken).ConfigureAwait(continueOnCapturedContext: false);
ExecutionStateUtils.FinishRequestAttempt(executionState);
return(executionState.Result);
}
catch (Exception ex3)
{
Exception ex4 = ex3;
Logger.LogWarning(executionState.OperationContext, "Exception thrown during the operation: {0}.", ex4.Message);
ExecutionStateUtils.FinishRequestAttempt(executionState);
if (ex4 is OperationCanceledException && executionState.OperationExpiryTime.HasValue && DateTime.Now.CompareTo(executionState.OperationExpiryTime.Value) > 0)
{
ex4 = new TimeoutException("The client could not finish the operation within specified timeout.", ex4);
}
Exception ex6 = executionState.ExceptionRef = await ExecutionStateUtils.TranslateExceptionBasedOnParseErrorAsync(ex4, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseErrorAsync, timeoutToken).ConfigureAwait(continueOnCapturedContext: false);
Logger.LogInformational(executionState.OperationContext, "Checking if the operation should be retried. Retry count = {0}, HTTP status code = {1}, Retryable exception = {2}, Exception = {3}.", executionState.RetryCount, executionState.Cmd.CurrentResult.HttpStatusCode, ((StorageException)ex6).IsRetryable ? "yes" : "no", ex6.Message);
shouldRetry = false;
if (((StorageException)ex6).IsRetryable && executionState.RetryPolicy != null)
{
executionState.CurrentLocation = ExecutionStateUtils.GetNextLocation(executionState.CurrentLocation, cmd.LocationMode);
Logger.LogInformational(executionState.OperationContext, "The next location has been set to {0}, based on the location mode.", executionState.CurrentLocation);
IExtendedRetryPolicy extendedRetryPolicy = executionState.RetryPolicy as IExtendedRetryPolicy;
if (extendedRetryPolicy != null)
{
RetryInfo retryInfo = extendedRetryPolicy.Evaluate(new RetryContext(executionState.RetryCount++, cmd.CurrentResult, executionState.CurrentLocation, cmd.LocationMode), executionState.OperationContext);
if (retryInfo != null)
{
Logger.LogInformational(executionState.OperationContext, "The extended retry policy set the next location to {0} and updated the location mode to {1}.", retryInfo.TargetLocation, retryInfo.UpdatedLocationMode);
shouldRetry = true;
executionState.CurrentLocation = retryInfo.TargetLocation;
cmd.LocationMode = retryInfo.UpdatedLocationMode;
delay = retryInfo.RetryInterval;
}
}
else
{
shouldRetry = executionState.RetryPolicy.ShouldRetry(executionState.RetryCount++, cmd.CurrentResult.HttpStatusCode, executionState.ExceptionRef, out delay, executionState.OperationContext);
}
if (delay < TimeSpan.Zero || delay > TableRestConstants.MaximumRetryBackoff)
{
delay = TableRestConstants.MaximumRetryBackoff;
}
}
}
finally
{
if (executionState.Resp != null)
{
executionState.Resp.Dispose();
executionState.Resp = null;
}
}
if (!shouldRetry || (executionState.OperationExpiryTime.HasValue && (DateTime.Now + delay).CompareTo(executionState.OperationExpiryTime.Value) > 0))
{
Logger.LogError(executionState.OperationContext, shouldRetry ? "Operation cannot be retried because the maximum execution time has been reached. Failing with {0}." : "Retry policy did not allow for a retry. Failing with {0}.", executionState.ExceptionRef.Message);
throw executionState.ExceptionRef;
}
cmd.RecoveryAction?.Invoke(cmd, executionState.Cmd.CurrentResult.Exception, executionState.OperationContext);
if (delay > TimeSpan.Zero)
{
await Task.Delay(delay, timeoutToken).ConfigureAwait(continueOnCapturedContext: false);
}
Logger.LogInformational(executionState.OperationContext, "Retrying failed operation.");
ExecutionStateUtils.FireRetrying(executionState);
}while (shouldRetry);
throw new NotImplementedException("Unexpected internal storage client error.");
}
}
}
