/// <summary>
/// Send a CDM request with the retry logic helper function.
/// </summary>
/// <param name="cdmRequest">The CDM Http request.</param>
/// <param name="callback">The callback that gets executed after the request finishes.</param>
/// <returns>The <see cref="Task"/>, representing CDM Http response.</returns>
private async Task <CdmHttpResponse> SendAsyncHelper(CdmHttpRequest cdmRequest, Callback callback = null, CdmCorpusContext ctx = null)
{
string fullUrl;
if (isApiEndpointSet)
{
fullUrl = Combine(this.apiEndpoint, cdmRequest.RequestedUrl);
}
else
{
fullUrl = cdmRequest.RequestedUrl;
}
// If the number of retries is 0, we only try once, otherwise we retry the specified number of times.
for (int retryNumber = 0; retryNumber <= cdmRequest.NumberOfRetries; retryNumber++)
{
var requestMessage = new HttpRequestMessage(cdmRequest.Method, fullUrl);
foreach (var item in cdmRequest.Headers)
{
requestMessage.Headers.Add(item.Key, item.Value);
}
// GET requests might not have any content.
if (cdmRequest.Content != null)
{
requestMessage.Content = new StringContent(cdmRequest.Content, Encoding.UTF8, cdmRequest.ContentType);
}
CdmHttpResponse cdmHttpResponse = null;
var hasFailed = false;
try
{
Task <HttpResponseMessage> request;
DateTimeOffset startTime = DateTimeOffset.UtcNow;
if (ctx != null)
{
Logger.Info(nameof(CdmHttpClient), ctx, $"Sending request {cdmRequest.RequestId}, request type: {requestMessage.Method}, request url: {cdmRequest.StripSasSig()}, retry number: {retryNumber}.", nameof(SendAsyncHelper));
}
// The check is added to fix a known issue in .net http client when reading HEAD request > 2GB.
// .net http client tries to write content even when the request is HEAD request.
if (cdmRequest.Method.Equals(HttpMethod.Head))
{
request = Task.Run(async() => await this.client.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead));
}
else
{
request = Task.Run(async() => await this.client.SendAsync(requestMessage));
}
if (!request.Wait((TimeSpan)cdmRequest.Timeout))
{
if (ctx != null && cdmRequest.Timeout != null)
{
Logger.Info(nameof(CdmHttpClient), ctx, $"Request {cdmRequest.RequestId} timeout after {cdmRequest.Timeout?.Seconds} s.", nameof(SendAsyncHelper));
}
throw new CdmTimedOutException("Request timeout.");
}
HttpResponseMessage response = request.Result;
if (ctx != null)
{
DateTimeOffset endTime = DateTimeOffset.UtcNow;
Logger.Info(nameof(CdmHttpClient), ctx, $"Response for request {cdmRequest.RequestId} received, elapsed time: {endTime.Subtract(startTime).TotalMilliseconds} ms.", nameof(SendAsyncHelper));
}
if (response != null)
{
cdmHttpResponse = new CdmHttpResponse(response.StatusCode)
{
Reason = response.ReasonPhrase,
Content = response.Content,
IsSuccessful = response.IsSuccessStatusCode
};
foreach (var item in response.Headers)
{
cdmHttpResponse.ResponseHeaders.Add(item.Key, string.Join(",", item.Value));
}
}
}
catch (Exception ex)
{
if (ex is AggregateException aggrEx)
{
ex = aggrEx.InnerException;
}
hasFailed = true;
// Only throw an exception if another retry is not expected anymore.
if (callback == null || retryNumber == cdmRequest.NumberOfRetries)
{
if (retryNumber != 0)
{
throw new CdmNumberOfRetriesExceededException(ex.Message);
}
else
{
throw ex;
}
}
}
// Check whether we have a callback function set and whether this is not our last retry.
if (callback != null && retryNumber != cdmRequest.NumberOfRetries)
{
// Call the callback function with the retry numbers starting from 1.
var waitTime = callback(cdmHttpResponse, hasFailed, retryNumber + 1);
// Callback returned back that we do not want to retry anymore (probably successful request, client can set up what they want here).
if (waitTime == null)
{
return(cdmHttpResponse);
}
else
{
// Sleep time specified by the callback.
Thread.Sleep((int)waitTime.Value.TotalMilliseconds);
}
}
else
{
// CDM Http Response exists, could be successful or bad (e.g. 403/404), it is up to caller to deal with it.
if (cdmHttpResponse != null)
{
return(cdmHttpResponse);
}
else
{
if (retryNumber == 0)
{
return(null);
}
else
{
// If response doesn't exist repeatedly, just throw that the number of retries has exceeded (we don't have any other information).
throw new CdmNumberOfRetriesExceededException();
}
}
}
}
// Should never come here, but just in case throw this exception.
throw new CdmNumberOfRetriesExceededException();
}
/// <summary>
/// Send a CDM request with the retry logic helper function.
/// </summary>
/// <param name="cdmRequest">The CDM Http request.</param>
/// <param name="callback">The callback that gets executed after the request finishes.</param>
/// <returns>The <see cref="Task"/>, representing CDM Http response.</returns>
private async Task <CdmHttpResponse> SendAsyncHelper(CdmHttpRequest cdmRequest, Callback callback = null)
{
string fullUrl;
if (isApiEndpointSet)
{
fullUrl = Combine(this.apiEndpoint, cdmRequest.RequestedUrl);
}
else
{
fullUrl = cdmRequest.RequestedUrl;
}
// If the number of retries is 0, we only try once, otherwise we retry the specified number of times.
for (int retryNumber = 0; retryNumber <= cdmRequest.NumberOfRetries; retryNumber++)
{
var requestMessage = new HttpRequestMessage(cdmRequest.Method, fullUrl);
foreach (var item in cdmRequest.Headers)
{
requestMessage.Headers.Add(item.Key, item.Value);
}
// GET requests might not have any content.
if (cdmRequest.Content != null)
{
requestMessage.Content = new StringContent(cdmRequest.Content, Encoding.UTF8, cdmRequest.ContentType);
}
HttpResponseMessage response = null;
CdmHttpResponse cdmHttpResponse = null;
var cts = new CancellationTokenSource();
cts.CancelAfter((TimeSpan)cdmRequest.Timeout);
var hasFailed = false;
try
{
response = await this.client.SendAsync(requestMessage);
cts.Token.ThrowIfCancellationRequested();
if (response != null)
{
cdmHttpResponse = new CdmHttpResponse(response.StatusCode)
{
Reason = response.ReasonPhrase,
Content = response.Content,
IsSuccessful = response.IsSuccessStatusCode
};
foreach (var item in response.Headers)
{
cdmHttpResponse.ResponseHeaders.Add(item.Key, string.Join(",", item.Value));
}
}
}
catch (Exception ex)
{
hasFailed = true;
// Only throw an exception if another retry is not expected anymore.
if (callback == null || retryNumber == cdmRequest.NumberOfRetries)
{
if (retryNumber != 0)
{
throw new CdmNumberOfRetriesExceededException(ex.Message);
}
else
{
throw (ex is OperationCanceledException) ? new CdmTimedOutException(ex.Message) : ex;
}
}
}
// Check whether we have a callback function set and whether this is not our last retry.
if (callback != null && retryNumber != cdmRequest.NumberOfRetries)
{
// Call the callback function with the retry numbers starting from 1.
var waitTime = callback(cdmHttpResponse, hasFailed, retryNumber + 1);
// Callback returned back that we do not want to retry anymore (probably successful request, client can set up what they want here).
if (waitTime == null)
{
return(cdmHttpResponse);
}
else
{
// Sleep time specified by the callback.
System.Threading.Thread.Sleep((int)waitTime.Value.TotalMilliseconds);
}
}
else
{
// CDM Http Response exists, could be successful or bad (e.g. 403/404), it is up to caller to deal with it.
if (cdmHttpResponse != null)
{
return(cdmHttpResponse);
}
else
{
if (retryNumber == 0)
{
return(null);
}
else
{
// If response doesn't exist repeatedly, just throw that the number of retries has exceeded (we don't have any other information).
throw new CdmNumberOfRetriesExceededException();
}
}
}
}
// Should never come here, but just in case throw this exception.
throw new CdmNumberOfRetriesExceededException();
}
