/**
* Invoke request and return response
*/
private T Invoke <T>(IDictionary <string, string> parameters)
{
string actionName = parameters["Action"];
T response = default(T);
HttpStatusCode statusCode = default(HttpStatusCode);
/* Add required request parameters */
AddRequiredParameters(parameters);
string queryString = AWSSDKUtils.GetParametersAsString(parameters);
byte[] requestData = Encoding.UTF8.GetBytes(queryString);
bool shouldRetry = true;
int retries = 0;
int maxRetries = config.IsSetMaxErrorRetry() ? config.MaxErrorRetry : AWSSDKUtils.DefaultMaxRetry;
do
{
string responseBody = null;
HttpWebRequest request = ConfigureWebRequest(requestData.Length, config);
/* Submit the request and read response body */
try
{
using (Stream requestStream = request.GetRequestStream())
{
requestStream.Write(requestData, 0, requestData.Length);
}
using (HttpWebResponse httpResponse = request.GetResponse() as HttpWebResponse)
{
if (httpResponse == null)
{
throw new WebException(
"The Web Response for a successful request is null!",
WebExceptionStatus.ProtocolError
);
}
statusCode = httpResponse.StatusCode;
using (StreamReader reader = new StreamReader(httpResponse.GetResponseStream(), Encoding.UTF8))
{
responseBody = reader.ReadToEnd();
}
}
/* Perform response transformation */
if (responseBody.Trim().EndsWith(String.Concat(actionName, "Response>")))
{
responseBody = Transform(responseBody, this.GetType());
}
/* Attempt to deserialize response into <Action> Response type */
XmlSerializer serializer = new XmlSerializer(typeof(T));
using (XmlTextReader sr = new XmlTextReader(new StringReader(responseBody)))
{
response = (T)serializer.Deserialize(sr);
}
shouldRetry = false;
}
/* Web exception is thrown on unsucessful responses */
catch (WebException we)
{
shouldRetry = false;
using (HttpWebResponse httpErrorResponse = we.Response as HttpWebResponse)
{
if (httpErrorResponse == null)
{
// Abort the unsuccessful request
request.Abort();
throw we;
}
statusCode = httpErrorResponse.StatusCode;
using (StreamReader reader = new StreamReader(httpErrorResponse.GetResponseStream(), Encoding.UTF8))
{
responseBody = reader.ReadToEnd();
}
// Abort the unsuccessful request
request.Abort();
}
if (statusCode == HttpStatusCode.InternalServerError ||
statusCode == HttpStatusCode.ServiceUnavailable)
{
shouldRetry = true;
PauseOnRetry(++retries, maxRetries, statusCode);
}
else
{
/* Attempt to deserialize response into ErrorResponse type */
try
{
using (XmlTextReader sr = new XmlTextReader(new StringReader(responseBody)))
{
XmlSerializer serializer = new XmlSerializer(typeof(ErrorResponse));
ErrorResponse errorResponse = (ErrorResponse)serializer.Deserialize(sr);
Error error = errorResponse.Error[0];
/* Throw formatted exception with information available from the error response */
throw new AmazonCloudWatchException(
error.Message,
statusCode,
error.Code,
error.Type,
errorResponse.RequestId,
errorResponse.ToXML()
);
}
}
/* Rethrow on deserializer error */
catch (Exception e)
{
if (e is AmazonCloudWatchException)
{
throw;
}
else
{
throw ReportAnyErrors(responseBody, statusCode);
}
}
}
}
/* Catch other exceptions, attempt to convert to formatted exception,
* else rethrow wrapped exception */
catch (Exception)
{
// Abort the unsuccessful request
request.Abort();
throw;
}
} while (shouldRetry);
return(response);
}
