public static void InitRequest <T, INTERMEDIATE_TYPE>(ExecutionState <T> executionState)
        {
            try
            {
                executionState.Init();

                // 0. Begin Request
                TableExecutor.StartRequestAttempt(executionState);

                if (TableExecutor.CheckTimeout <T>(executionState, false))
                {
                    TableExecutor.EndOperation <T, INTERMEDIATE_TYPE>(executionState);
                    return;
                }

                lock (executionState.CancellationLockerObject)
                {
                    if (TableExecutor.CheckCancellation(executionState))
                    {
                        TableExecutor.EndOperation <T, INTERMEDIATE_TYPE>(executionState);
                        return;
                    }

                    TableCommand <T, INTERMEDIATE_TYPE> tableCommandRef = executionState.Cmd as TableCommand <T, INTERMEDIATE_TYPE>;

                    // Execute Call
                    Logger.LogInformational(executionState.OperationContext, SR.TraceStartRequestAsync, tableCommandRef.Context.BaseUri);
                    tableCommandRef.Begin(
                        (res) =>
                    {
                        executionState.UpdateCompletedSynchronously(res.CompletedSynchronously);
                        INTERMEDIATE_TYPE tResult = default(INTERMEDIATE_TYPE);

                        try
                        {
                            tResult = tableCommandRef.End(res);

                            executionState.Result = tableCommandRef.ParseResponse(tResult, executionState.Cmd.CurrentResult, tableCommandRef);

                            if (executionState.Req != null)
                            {
                                DataServiceResponse dataServiceResponse = tResult as DataServiceResponse;
                                QueryOperationResponse queryResponse    = tResult as QueryOperationResponse;

                                if (dataServiceResponse != null)
                                {
                                    if (dataServiceResponse.IsBatchResponse)
                                    {
                                        // Attempt to populate response headers
                                        if (executionState.Req != null)
                                        {
                                            SetExecutionStateCommandResult(executionState, dataServiceResponse);
                                            Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                                        }
                                    }
                                    else
                                    {
                                        int index = 0;
                                        foreach (OperationResponse operationResponse in dataServiceResponse)
                                        {
                                            // Attempt to populate response headers
                                            if (executionState.Req != null)
                                            {
                                                SetStorageCmdRequestResults(executionState.Cmd.RequestResults.ElementAt(index), operationResponse);
                                                Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.RequestResults.ElementAt(index).HttpStatusCode, executionState.Cmd.RequestResults.ElementAt(index).ServiceRequestID, executionState.Cmd.RequestResults.ElementAt(index).ContentMd5, executionState.Cmd.RequestResults.ElementAt(index).Etag);
                                                index++;
                                            }
                                        }
                                    }
                                }
                                else if (queryResponse != null)
                                {
                                    // Attempt to populate response headers
                                    if (executionState.Req != null)
                                    {
                                        SetStorageCmdRequestResults(executionState.Cmd.CurrentResult, queryResponse);
                                        Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                                    }
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            Logger.LogWarning(executionState.OperationContext, SR.TraceGenericError, ex.Message);

                            lock (executionState.CancellationLockerObject)
                            {
                                if (executionState.CancelRequested)
                                {
                                    // Ignore DSC exception if request was canceled.
                                    return;
                                }
                            }

                            // Store exception and invoke callback here. All operations in this try would be non-retryable by default
                            if (executionState.ExceptionRef == null || !(executionState.ExceptionRef is StorageException))
                            {
                                executionState.ExceptionRef = ExecutorBase.TranslateDataServiceExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Cmd.ParseDataServiceError);
                            }

                            try
                            {
                                executionState.Result = tableCommandRef.ParseResponse(tResult, executionState.Cmd.CurrentResult, tableCommandRef);

                                // clear exception
                                executionState.ExceptionRef = null;
                            }
                            catch (Exception parseEx)
                            {
                                Logger.LogWarning(executionState.OperationContext, SR.TraceGenericError, ex.Message);
                                executionState.ExceptionRef = parseEx;
                            }
                        }
                        finally
                        {
                            EndOperation <T, INTERMEDIATE_TYPE>(executionState);
                        }
                    },
                        null);

                    if (tableCommandRef.Context != null)
                    {
                        executionState.CancelDelegate = tableCommandRef.Context.InternalCancel;
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.LogWarning(executionState.OperationContext, SR.TraceGenericError, ex.Message);

                // Store exception and invoke callback here. All operations in this try would be non-retryable by default
                if (executionState.ExceptionRef == null || !(executionState.ExceptionRef is StorageException))
                {
                    executionState.ExceptionRef = ExecutorBase.TranslateDataServiceExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Cmd.ParseDataServiceError);
                }

                executionState.OnComplete();
            }
        }
        public static T ExecuteSync <T, INTERMEDIATE_TYPE>(TableCommand <T, INTERMEDIATE_TYPE> cmd, IRetryPolicy policy, OperationContext operationContext)
        {
            // Note all code below will reference state, not params directly, this will allow common code with async executor
            ExecutionState <T> executionState = new ExecutionState <T>(cmd, policy, operationContext);

            TableExecutor.AcquireContext(cmd.Context, executionState);
            bool     shouldRetry = false;
            TimeSpan delay       = TimeSpan.Zero;

            try
            {
                // Enter Retryable Section of execution
                do
                {
                    executionState.Init();

                    // 0. Begin Request
                    TableExecutor.StartRequestAttempt(executionState);

                    TableExecutor.CheckTimeout <T>(executionState, true);

                    try
                    {
                        INTERMEDIATE_TYPE tempResult = default(INTERMEDIATE_TYPE);

                        try
                        {
                            Logger.LogInformational(executionState.OperationContext, SR.TraceStartRequestSync, cmd.Context.BaseUri);
                            tempResult = cmd.ExecuteFunc();

                            executionState.Result = cmd.ParseResponse(tempResult, executionState.Cmd.CurrentResult, cmd);

                            DataServiceResponse    dataServiceResponse = tempResult as DataServiceResponse;
                            QueryOperationResponse queryResponse       = tempResult as QueryOperationResponse;

                            if (dataServiceResponse != null)
                            {
                                if (dataServiceResponse.IsBatchResponse)
                                {
                                    // Attempt to populate response headers
                                    if (executionState.Req != null)
                                    {
                                        SetExecutionStateCommandResult(executionState, dataServiceResponse);
                                        Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                                    }
                                }
                                else
                                {
                                    int index = 0;
                                    foreach (OperationResponse operationResponse in dataServiceResponse)
                                    {
                                        // Attempt to populate response headers
                                        if (executionState.Req != null)
                                        {
                                            SetStorageCmdRequestResults(executionState.Cmd.RequestResults.ElementAt(index), operationResponse);
                                            Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.RequestResults.ElementAt(index).HttpStatusCode, executionState.Cmd.RequestResults.ElementAt(index).ServiceRequestID, executionState.Cmd.RequestResults.ElementAt(index).ContentMd5, executionState.Cmd.RequestResults.ElementAt(index).Etag);
                                            index++;
                                        }
                                    }
                                }
                            }
                            else if (queryResponse != null)
                            {
                                // Attempt to populate response headers
                                if (executionState.Req != null)
                                {
                                    SetStorageCmdRequestResults(executionState.Cmd.CurrentResult, queryResponse);
                                    Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            Logger.LogWarning(executionState.OperationContext, SR.TraceGenericError, ex.Message);

                            // Store exception and invoke callback here. All operations in this try would be non-retryable by default
                            if (executionState.ExceptionRef == null || !(executionState.ExceptionRef is StorageException))
                            {
                                executionState.ExceptionRef = ExecutorBase.TranslateDataServiceExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Cmd.ParseDataServiceError);
                            }

                            executionState.Result = cmd.ParseResponse(tempResult, executionState.Cmd.CurrentResult, cmd);

                            // clear exception
                            executionState.ExceptionRef = null;
                        }

                        TableExecutor.FinishRequestAttempt(executionState);

                        Logger.LogInformational(executionState.OperationContext, SR.TraceSuccess);
                        return(executionState.Result);
                    }
                    catch (Exception e)
                    {
                        TableExecutor.FinishRequestAttempt(executionState);

                        StorageException translatedException = ExecutorBase.TranslateDataServiceExceptionBasedOnParseError(e, executionState.Cmd.CurrentResult, executionState.Cmd.ParseDataServiceError);
                        executionState.ExceptionRef = translatedException;
                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetryCheck, executionState.RetryCount, executionState.Cmd.CurrentResult.HttpStatusCode, translatedException.IsRetryable ? "yes" : "no", translatedException.Message);

                        shouldRetry = false;
                        if (translatedException.IsRetryable && (executionState.RetryPolicy != null))
                        {
                            shouldRetry = executionState.RetryPolicy.ShouldRetry(
                                executionState.RetryCount++,
                                executionState.Cmd.CurrentResult.HttpStatusCode,
                                executionState.ExceptionRef,
                                out delay,
                                executionState.OperationContext);

                            if ((delay < TimeSpan.Zero) || (delay > Constants.MaximumRetryBackoff))
                            {
                                delay = Constants.MaximumRetryBackoff;
                            }
                        }
                    }

                    if (!shouldRetry || (executionState.OperationExpiryTime.HasValue && (DateTime.Now + delay).CompareTo(executionState.OperationExpiryTime.Value) > 0))
                    {
                        Logger.LogError(executionState.OperationContext, shouldRetry ? SR.TraceRetryDecisionTimeout : SR.TraceRetryDecisionPolicy, executionState.ExceptionRef.Message);
                        throw executionState.ExceptionRef;
                    }
                    else
                    {
                        if (executionState.Cmd.RecoveryAction != null)
                        {
                            // I.E. Rewind stream etc.
                            executionState.Cmd.RecoveryAction(executionState.Cmd, executionState.ExceptionRef, executionState.OperationContext);
                        }

                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetryDelay, (int)delay.TotalMilliseconds);
                        if (delay > TimeSpan.Zero)
                        {
                            Thread.Sleep(delay);
                        }

                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetry);
                    }
                }while (shouldRetry);

                // should never get here, either return, or throw;
                throw new NotImplementedException(SR.InternalStorageError);
            }
            finally
            {
                ReleaseContext(cmd.Context);
            }
        }
        private static void EndOperation <T, INTERMEDIATE_TYPE>(ExecutionState <T> executionState)
        {
            TableExecutor.FinishRequestAttempt(executionState);

            lock (executionState.CancellationLockerObject)
            {
                executionState.CancelDelegate = null;

                TableExecutor.CheckCancellation(executionState);

                // Handle Success
                if (executionState.ExceptionRef == null)
                {
                    Logger.LogInformational(executionState.OperationContext, SR.TraceSuccess);
                    executionState.OnComplete();
                    return;
                }
            }

            // Handle Retry
            try
            {
                StorageException translatedException = ExecutorBase.TranslateDataServiceExceptionBasedOnParseError(executionState.ExceptionRef, executionState.Cmd.CurrentResult, executionState.Cmd.ParseDataServiceError);

                executionState.ExceptionRef = translatedException;
                Logger.LogInformational(executionState.OperationContext, SR.TraceRetryCheck, executionState.RetryCount, executionState.Cmd.CurrentResult.HttpStatusCode, translatedException.IsRetryable ? "yes" : "no", translatedException.Message);

                bool     shouldRetry = false;
                TimeSpan delay       = TimeSpan.Zero;
                if (translatedException.IsRetryable && (executionState.RetryPolicy != null))
                {
                    shouldRetry = executionState.RetryPolicy.ShouldRetry(
                        executionState.RetryCount++,
                        executionState.Cmd.CurrentResult.HttpStatusCode,
                        executionState.ExceptionRef,
                        out delay,
                        executionState.OperationContext);

                    if ((delay < TimeSpan.Zero) || (delay > Constants.MaximumRetryBackoff))
                    {
                        delay = Constants.MaximumRetryBackoff;
                    }
                }

                if (!shouldRetry || (executionState.OperationExpiryTime.HasValue && (DateTime.Now + delay).CompareTo(executionState.OperationExpiryTime.Value) > 0))
                {
                    Logger.LogError(executionState.OperationContext, shouldRetry ? SR.TraceRetryDecisionTimeout : SR.TraceRetryDecisionPolicy, executionState.ExceptionRef.Message);

                    // No Retry
                    executionState.OnComplete();
                }
                else
                {
                    if (executionState.Cmd.RecoveryAction != null)
                    {
                        // I.E. Rewind stream etc.
                        executionState.Cmd.RecoveryAction(executionState.Cmd, executionState.ExceptionRef, executionState.OperationContext);
                    }

                    if (delay > TimeSpan.Zero)
                    {
                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetryDelay, (int)delay.TotalMilliseconds);

                        executionState.UpdateCompletedSynchronously(false);
                        if (executionState.BackoffTimer == null)
                        {
                            executionState.BackoffTimer = new Timer(
                                TableExecutor.RetryRequest <T, INTERMEDIATE_TYPE>,
                                executionState,
                                (int)delay.TotalMilliseconds,
                                Timeout.Infinite);
                        }
                        else
                        {
                            executionState.BackoffTimer.Change((int)delay.TotalMilliseconds, Timeout.Infinite);
                        }

                        executionState.CancelDelegate = () =>
                        {
                            // Disabling the timer here, but there is still a scenario where the user calls cancel after
                            // the timer starts the next retry but before it sets the CancelDelegate back to null. However, even
                            // if that happens, next retry will start and then stop immediately because of the cancelled flag.
                            Timer backoffTimer = executionState.BackoffTimer;
                            if (backoffTimer != null)
                            {
                                executionState.BackoffTimer = null;
                                backoffTimer.Dispose();
                            }

                            Logger.LogWarning(executionState.OperationContext, SR.TraceAbortRetry);
                            TableExecutor.CheckCancellation(executionState);
                            executionState.OnComplete();
                        };
                    }
                    else
                    {
                        // Start Next Request Immediately
                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetry);
                        InitRequest <T, INTERMEDIATE_TYPE>(executionState);
                    }
                }
            }
            catch (Exception ex)
            {
                // Catch all ( i.e. users retry policy throws etc.)
                Logger.LogWarning(executionState.OperationContext, SR.TraceRetryError, ex.Message);
                executionState.ExceptionRef = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);

                executionState.OnComplete();
            }
        }
Beispiel #4
0
        public static T ExecuteSync <T>(RESTCommand <T> cmd, IRetryPolicy policy, OperationContext operationContext)
        {
            // Note all code below will reference state, not params directly, this will allow common code with async executor
            using (ExecutionState <T> executionState = new ExecutionState <T>(cmd, policy, operationContext))
            {
                bool     shouldRetry = false;
                TimeSpan delay       = TimeSpan.Zero;

                do
                {
                    try
                    {
                        executionState.Init();

                        // 0. Begin Request
                        Executor.StartRequestAttempt(executionState);

                        // Steps 1-4
                        Executor.ProcessStartOfRequest(executionState, SR.TraceStartRequestSync);

                        Executor.CheckTimeout <T>(executionState, true);
                    }
                    catch (Exception ex)
                    {
                        Logger.LogError(executionState.OperationContext, SR.TraceInitRequestError, ex.Message);

                        // Store exception and throw here. All operations in this try would be non-retryable by default. At this point, the request is not even made.
                        // Therefore, we will not get extended error info. Hence ParseError doesn't matter here.
                        StorageException storageEx = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);

                        storageEx.IsRetryable       = false;
                        executionState.ExceptionRef = storageEx;
                        throw executionState.ExceptionRef;
                    }

                    // Enter Retryable Section of execution
                    try
                    {
                        // 5. potentially upload data
                        if (cmd.SendStream != null)
                        {
                            executionState.CurrentOperation = ExecutorOperation.BeginGetRequestStream;
                            Logger.LogInformational(executionState.OperationContext, SR.TracePrepareUpload);
                            executionState.Req.Timeout = (int)executionState.RemainingTimeout.TotalMilliseconds;
                            executionState.ReqStream   = executionState.Req.GetRequestStream();

                            executionState.CurrentOperation = ExecutorOperation.BeginUploadRequest;
                            Logger.LogInformational(executionState.OperationContext, SR.TraceUpload);
                            MultiBufferMemoryStream multiBufferMemoryStream = cmd.SendStream as MultiBufferMemoryStream;

                            try
                            {
                                if (multiBufferMemoryStream != null && !cmd.SendStreamLength.HasValue)
                                {
                                    multiBufferMemoryStream.FastCopyTo(executionState.ReqStream, executionState.OperationExpiryTime);
                                }
                                else
                                {
                                    // don't calculate md5 here as we should have already set this for auth purposes
                                    executionState.RestCMD.SendStream.WriteToSync(executionState.ReqStream, cmd.SendStreamLength, null /* maxLength */, false, true, executionState, null /* streamCopyState */);
                                }

                                executionState.ReqStream.Flush();
                                executionState.ReqStream.Dispose();
                                executionState.ReqStream = null;
                            }
                            catch (Exception)
                            {
                                executionState.Req.Abort();
                                throw;
                            }
                        }

                        // 6. Get response
                        try
                        {
                            executionState.CurrentOperation = ExecutorOperation.BeginGetResponse;
                            Logger.LogInformational(executionState.OperationContext, SR.TraceGetResponse);
                            executionState.Req.Timeout      = (int)executionState.RemainingTimeout.TotalMilliseconds;
                            executionState.Resp             = (HttpWebResponse)executionState.Req.GetResponse();
                            executionState.CurrentOperation = ExecutorOperation.EndGetResponse;
                        }
                        catch (WebException ex)
                        {
                            Logger.LogWarning(executionState.OperationContext, SR.TraceGetResponseError, ex.Message);
                            executionState.Resp = (HttpWebResponse)ex.Response;

                            if (ex.Status == WebExceptionStatus.Timeout || executionState.ReqTimedOut)
                            {
                                throw new TimeoutException();
                            }

                            if (executionState.Resp == null)
                            {
                                throw;
                            }
                            else
                            {
                                executionState.ExceptionRef = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);
                            }
                        }

                        // Response
                        Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                        Executor.FireResponseReceived(executionState);

                        // 7. Do Response parsing (headers etc, no stream available here)
                        if (cmd.PreProcessResponse != null)
                        {
                            executionState.CurrentOperation = ExecutorOperation.PreProcess;
                            executionState.Result           = cmd.PreProcessResponse(cmd, executionState.Resp, executionState.ExceptionRef, executionState.OperationContext);

                            // clear exception
                            executionState.ExceptionRef = null;
                            Logger.LogInformational(executionState.OperationContext, SR.TracePreProcessDone);
                        }

                        // 8. (Potentially reads stream from server)
                        executionState.CurrentOperation = ExecutorOperation.GetResponseStream;
                        cmd.ResponseStream = executionState.Resp.GetResponseStream();

                        if (!cmd.RetrieveResponseStream)
                        {
                            cmd.DestinationStream = Stream.Null;
                        }

                        if (cmd.DestinationStream != null)
                        {
                            if (cmd.StreamCopyState == null)
                            {
                                cmd.StreamCopyState = new StreamDescriptor();
                            }

                            try
                            {
                                executionState.CurrentOperation = ExecutorOperation.BeginDownloadResponse;
                                Logger.LogInformational(executionState.OperationContext, SR.TraceDownload);
                                cmd.ResponseStream.WriteToSync(cmd.DestinationStream, null /* copyLength */, null /* maxLength */, cmd.CalculateMd5ForResponseStream, false, executionState, cmd.StreamCopyState);
                            }
                            finally
                            {
                                cmd.ResponseStream.Dispose();
                                cmd.ResponseStream = null;
                            }
                        }

                        // Step 9 - This will not be called if an exception is raised during stream copying
                        Executor.ProcessEndOfRequest(executionState);

                        Executor.FinishRequestAttempt(executionState);
                        return(executionState.Result);
                    }
                    catch (Exception e)
                    {
                        Logger.LogWarning(executionState.OperationContext, SR.TraceGenericError, e.Message);
                        Executor.FinishRequestAttempt(executionState);

                        StorageException translatedException = ExecutorBase.TranslateExceptionBasedOnParseError(e, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);

                        executionState.ExceptionRef = translatedException;
                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetryCheck, executionState.RetryCount, executionState.Cmd.CurrentResult.HttpStatusCode, translatedException.IsRetryable ? "yes" : "no", translatedException.Message);

                        shouldRetry = false;
                        if (translatedException.IsRetryable && (executionState.RetryPolicy != null))
                        {
                            executionState.CurrentLocation = Executor.GetNextLocation(executionState.CurrentLocation, cmd.LocationMode);
                            Logger.LogInformational(executionState.OperationContext, SR.TraceNextLocation, executionState.CurrentLocation);

                            IExtendedRetryPolicy extendedRetryPolicy = executionState.RetryPolicy as IExtendedRetryPolicy;
                            if (extendedRetryPolicy != null)
                            {
                                RetryContext retryContext = new RetryContext(
                                    executionState.RetryCount++,
                                    cmd.CurrentResult,
                                    executionState.CurrentLocation,
                                    cmd.LocationMode);

                                RetryInfo retryInfo = extendedRetryPolicy.Evaluate(retryContext, executionState.OperationContext);
                                if (retryInfo != null)
                                {
                                    Logger.LogInformational(executionState.OperationContext, SR.TraceRetryInfo, 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 > Constants.MaximumRetryBackoff))
                            {
                                delay = Constants.MaximumRetryBackoff;
                            }
                        }
                    }
                    finally
                    {
                        if (executionState.Resp != null)
                        {
                            executionState.Resp.Close();
                            executionState.Resp = null;
                        }
                    }

                    if (!shouldRetry || (executionState.OperationExpiryTime.HasValue && (DateTime.Now + delay).CompareTo(executionState.OperationExpiryTime.Value) > 0))
                    {
                        Logger.LogError(executionState.OperationContext, shouldRetry ? SR.TraceRetryDecisionTimeout : SR.TraceRetryDecisionPolicy, executionState.ExceptionRef.Message);
                        throw executionState.ExceptionRef;
                    }
                    else
                    {
                        if (executionState.Cmd.RecoveryAction != null)
                        {
                            // I.E. Rewind stream etc.
                            executionState.Cmd.RecoveryAction(executionState.Cmd, executionState.ExceptionRef, executionState.OperationContext);
                        }

                        if (delay > TimeSpan.Zero)
                        {
                            Logger.LogInformational(executionState.OperationContext, SR.TraceRetryDelay, (int)delay.TotalMilliseconds);
                            Thread.Sleep(delay);
                        }

                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetry);
                    }

                    Executor.FireRetrying(executionState);
                }while (shouldRetry);
            }

            // should never get here, either return, or throw;
            throw new NotImplementedException(SR.InternalStorageError);
        }
Beispiel #5
0
        private static void EndOperation <T>(ExecutionState <T> executionState)
        {
            Executor.FinishRequestAttempt(executionState);

            try
            {
                // If an operation has been canceled of timed out this should overwrite any exception
                Executor.CheckCancellation(executionState);
                Executor.CheckTimeout(executionState, true);

                // Success
                if (executionState.ExceptionRef == null)
                {
                    // Step 9 - This will not be called if an exception is raised during stream copying
                    Executor.ProcessEndOfRequest(executionState);
                    executionState.OnComplete();
                    return;
                }
            }
            catch (Exception ex)
            {
                Logger.LogWarning(executionState.OperationContext, SR.TracePostProcessError, ex.Message);
                executionState.ExceptionRef = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);
            }
            finally
            {
                try
                {
                    if (executionState.ReqStream != null)
                    {
                        executionState.ReqStream.Dispose();
                        executionState.ReqStream = null;
                    }

                    if (executionState.Resp != null)
                    {
                        executionState.Resp.Close();
                        executionState.Resp = null;
                    }
                }
                catch (Exception)
                {
                    // no op
                }
            }

            // Handle Retry
            try
            {
                StorageException translatedException = TranslateExceptionBasedOnParseError(executionState.ExceptionRef, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);
                executionState.ExceptionRef = translatedException;
                Logger.LogInformational(executionState.OperationContext, SR.TraceRetryCheck, executionState.RetryCount, executionState.Cmd.CurrentResult.HttpStatusCode, translatedException.IsRetryable ? "yes" : "no", translatedException.Message);

                bool     shouldRetry = false;
                TimeSpan delay       = TimeSpan.Zero;
                if (translatedException.IsRetryable && (executionState.RetryPolicy != null))
                {
                    executionState.CurrentLocation = Executor.GetNextLocation(executionState.CurrentLocation, executionState.RestCMD.LocationMode);
                    Logger.LogInformational(executionState.OperationContext, SR.TraceNextLocation, executionState.CurrentLocation);

                    IExtendedRetryPolicy extendedRetryPolicy = executionState.RetryPolicy as IExtendedRetryPolicy;
                    if (extendedRetryPolicy != null)
                    {
                        RetryContext retryContext = new RetryContext(
                            executionState.RetryCount++,
                            executionState.Cmd.CurrentResult,
                            executionState.CurrentLocation,
                            executionState.RestCMD.LocationMode);

                        RetryInfo retryInfo = extendedRetryPolicy.Evaluate(retryContext, executionState.OperationContext);
                        if (retryInfo != null)
                        {
                            Logger.LogInformational(executionState.OperationContext, SR.TraceRetryInfo, retryInfo.TargetLocation, retryInfo.UpdatedLocationMode);
                            shouldRetry = true;
                            executionState.CurrentLocation      = retryInfo.TargetLocation;
                            executionState.RestCMD.LocationMode = retryInfo.UpdatedLocationMode;
                            delay = retryInfo.RetryInterval;
                        }
                    }
                    else
                    {
                        shouldRetry = executionState.RetryPolicy.ShouldRetry(
                            executionState.RetryCount++,
                            executionState.Cmd.CurrentResult.HttpStatusCode,
                            executionState.ExceptionRef,
                            out delay,
                            executionState.OperationContext);
                    }

                    if ((delay < TimeSpan.Zero) || (delay > Constants.MaximumRetryBackoff))
                    {
                        delay = Constants.MaximumRetryBackoff;
                    }
                }

                if (!shouldRetry || (executionState.OperationExpiryTime.HasValue && (DateTime.Now + delay).CompareTo(executionState.OperationExpiryTime.Value) > 0))
                {
                    Logger.LogError(executionState.OperationContext, shouldRetry ? SR.TraceRetryDecisionTimeout : SR.TraceRetryDecisionPolicy, executionState.ExceptionRef.Message);

                    // No Retry
                    executionState.OnComplete();
                }
                else
                {
                    if (executionState.Cmd.RecoveryAction != null)
                    {
                        // I.E. Rewind stream etc.
                        executionState.Cmd.RecoveryAction(executionState.Cmd, executionState.ExceptionRef, executionState.OperationContext);
                    }

                    if (delay > TimeSpan.Zero)
                    {
                        Logger.LogInformational(executionState.OperationContext, SR.TraceRetryDelay, (int)delay.TotalMilliseconds);

                        executionState.UpdateCompletedSynchronously(false);
                        if (executionState.BackoffTimer == null)
                        {
                            executionState.BackoffTimer = new Timer(
                                Executor.RetryRequest <T>,
                                executionState,
                                (int)delay.TotalMilliseconds,
                                Timeout.Infinite);
                        }
                        else
                        {
                            executionState.BackoffTimer.Change((int)delay.TotalMilliseconds, Timeout.Infinite);
                        }

                        executionState.CancelDelegate = () =>
                        {
                            // Disabling the timer here, but there is still a scenario where the user calls cancel after
                            // the timer starts the next retry but before it sets the CancelDelegate back to null. However, even
                            // if that happens, next retry will start and then stop immediately because of the cancelled flag.
                            Timer backoffTimer = executionState.BackoffTimer;
                            if (backoffTimer != null)
                            {
                                executionState.BackoffTimer = null;
                                backoffTimer.Dispose();
                            }

                            Logger.LogWarning(executionState.OperationContext, SR.TraceAbortRetry);
                            Executor.CheckCancellation(executionState);
                            executionState.OnComplete();
                        };
                    }
                    else
                    {
                        // Start next request immediately
                        Executor.RetryRequest <T>(executionState);
                    }
                }
            }
            catch (Exception ex)
            {
                // Catch all ( i.e. users retry policy throws etc.)
                Logger.LogWarning(executionState.OperationContext, SR.TraceRetryError, ex.Message);
                executionState.ExceptionRef = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);
                executionState.OnComplete();
            }
        }
Beispiel #6
0
        private static void EndGetResponse <T>(IAsyncResult getResponseResult)
        {
            ExecutionState <T> executionState = (ExecutionState <T>)getResponseResult.AsyncState;

            executionState.CurrentOperation = ExecutorOperation.EndGetResponse;

            try
            {
                executionState.UpdateCompletedSynchronously(getResponseResult.CompletedSynchronously);

                try
                {
                    executionState.Resp = executionState.Req.EndGetResponse(getResponseResult) as HttpWebResponse;
                }
                catch (WebException ex)
                {
                    Logger.LogWarning(executionState.OperationContext, SR.TraceGetResponseError, ex.Message);
                    executionState.Resp = (HttpWebResponse)ex.Response;

                    if (ex.Status == WebExceptionStatus.Timeout || executionState.ReqTimedOut)
                    {
                        throw new TimeoutException();
                    }

                    if (executionState.Resp == null)
                    {
                        throw;
                    }
                    else
                    {
                        // Store this exception for now. It will be parsed/thrown after the stream is read in step 8
                        executionState.ExceptionRef = ex;
                    }
                }

                Logger.LogInformational(executionState.OperationContext, SR.TraceResponse, executionState.Cmd.CurrentResult.HttpStatusCode, executionState.Cmd.CurrentResult.ServiceRequestID, executionState.Cmd.CurrentResult.ContentMd5, executionState.Cmd.CurrentResult.Etag);
                Executor.FireResponseReceived(executionState);

                // 7. Do Response parsing (headers etc, no stream available here)
                if (executionState.RestCMD.PreProcessResponse != null)
                {
                    executionState.CurrentOperation = ExecutorOperation.PreProcess;

                    try
                    {
                        executionState.Result = executionState.RestCMD.PreProcessResponse(executionState.RestCMD, executionState.Resp, executionState.ExceptionRef, executionState.OperationContext);

                        // clear exception
                        executionState.ExceptionRef = null;
                        Logger.LogInformational(executionState.OperationContext, SR.TracePreProcessDone);
                    }
                    catch (Exception ex)
                    {
                        executionState.ExceptionRef = ex;
                    }
                }

                Executor.CheckCancellation(executionState);

                executionState.CurrentOperation       = ExecutorOperation.GetResponseStream;
                executionState.RestCMD.ResponseStream = executionState.Resp.GetResponseStream();

                // 8. (Potentially reads stream from server)
                if (executionState.ExceptionRef != null)
                {
                    executionState.CurrentOperation = ExecutorOperation.BeginDownloadResponse;
                    Logger.LogInformational(executionState.OperationContext, SR.TraceDownloadError);

                    executionState.RestCMD.ErrorStream = new MemoryStream();
                    executionState.RestCMD.ResponseStream.WriteToAsync(executionState.RestCMD.ErrorStream, null /* copyLength */, null /* maxLength */, false /* calculateMd5 */, executionState, new StreamDescriptor(), EndResponseStreamCopy);
                }
                else
                {
                    if (!executionState.RestCMD.RetrieveResponseStream)
                    {
                        executionState.RestCMD.DestinationStream = Stream.Null;
                    }

                    if (executionState.RestCMD.DestinationStream != null)
                    {
                        if (executionState.RestCMD.StreamCopyState == null)
                        {
                            executionState.RestCMD.StreamCopyState = new StreamDescriptor();
                        }

                        executionState.CurrentOperation = ExecutorOperation.BeginDownloadResponse;
                        Logger.LogInformational(executionState.OperationContext, SR.TraceDownload);
                        executionState.RestCMD.ResponseStream.WriteToAsync(executionState.RestCMD.DestinationStream, null /* copyLength */, null /* maxLength */, executionState.RestCMD.CalculateMd5ForResponseStream, executionState, executionState.RestCMD.StreamCopyState, EndResponseStreamCopy);
                    }
                    else
                    {
                        // Dont want to copy stream, just want to consume it so end
                        Executor.EndOperation(executionState);
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.LogWarning(executionState.OperationContext, SR.TracePreProcessError, ex.Message);
                executionState.ExceptionRef = ExecutorBase.TranslateExceptionBasedOnParseError(ex, executionState.Cmd.CurrentResult, executionState.Resp, executionState.Cmd.ParseError);
                Executor.EndOperation(executionState);
            }
        }