private <X, Y extends AmazonWebServiceRequest> X invoke(
      Request<Y> request, Unmarshaller<X, StaxUnmarshallerContext> unmarshaller) {
    request.setEndpoint(endpoint);
    request.setTimeOffset(timeOffset);
    for (Entry<String, String> entry :
        request.getOriginalRequest().copyPrivateRequestParameters().entrySet()) {
      request.addParameter(entry.getKey(), entry.getValue());
    }

    AWSCredentials credentials = awsCredentialsProvider.getCredentials();
    AmazonWebServiceRequest originalRequest = request.getOriginalRequest();
    if (originalRequest != null && originalRequest.getRequestCredentials() != null) {
      credentials = originalRequest.getRequestCredentials();
    }

    ExecutionContext executionContext = createExecutionContext();
    executionContext.setSigner(signer);
    executionContext.setCredentials(credentials);

    StaxResponseHandler<X> responseHandler = new StaxResponseHandler<X>(unmarshaller);
    DefaultErrorResponseHandler errorResponseHandler =
        new DefaultErrorResponseHandler(exceptionUnmarshallers);

    return (X) client.execute(request, responseHandler, errorResponseHandler, executionContext);
  }
 /** Applies any additional options set in the request. */
 private void applyRequestData(Request<?> request) {
   if (request.getOriginalRequest() != null
       && request.getOriginalRequest().getRequestClientOptions() != null
       && request.getOriginalRequest().getRequestClientOptions().getClientMarker() != null) {
     request.addHeader(
         "User-Agent",
         createUserAgentString(
             config.getUserAgent(),
             request.getOriginalRequest().getRequestClientOptions().getClientMarker()));
   }
 }
  private <X, Y extends AmazonWebServiceRequest> Response<X> invoke(
      Request<Y> request,
      HttpResponseHandler<AmazonWebServiceResponse<X>> responseHandler,
      ExecutionContext executionContext) {
    request.setEndpoint(endpoint);
    request.setTimeOffset(timeOffset);

    AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
    AWSCredentials credentials;
    awsRequestMetrics.startEvent(Field.CredentialsRequestTime);
    try {
      credentials = awsCredentialsProvider.getCredentials();
    } finally {
      awsRequestMetrics.endEvent(Field.CredentialsRequestTime);
    }

    AmazonWebServiceRequest originalRequest = request.getOriginalRequest();
    if (originalRequest != null && originalRequest.getRequestCredentials() != null) {
      credentials = originalRequest.getRequestCredentials();
    }

    executionContext.setCredentials(credentials);

    DefaultErrorResponseHandler errorResponseHandler =
        new DefaultErrorResponseHandler(exceptionUnmarshallers);

    return client.execute(request, responseHandler, errorResponseHandler, executionContext);
  }
  /**
   * Handles a successful response from a service call by unmarshalling the results using the
   * specified response handler.
   *
   * @param <T> The type of object expected in the response.
   * @param request The original request that generated the response being handled.
   * @param responseHandler The response unmarshaller used to interpret the contents of the
   *     response.
   * @param method The HTTP method that was invoked, and contains the contents of the response.
   * @param executionContext Extra state information about the request currently being executed.
   * @return The contents of the response, unmarshalled using the specified response handler.
   * @throws IOException If any problems were encountered reading the response contents from the
   *     HTTP method object.
   */
  private <T> T handleResponse(
      Request<?> request,
      HttpResponseHandler<AmazonWebServiceResponse<T>> responseHandler,
      HttpRequestBase method,
      org.apache.http.HttpResponse apacheHttpResponse,
      ExecutionContext executionContext)
      throws IOException {

    HttpResponse httpResponse = createResponse(method, request, apacheHttpResponse);
    if (responseHandler.needsConnectionLeftOpen() && method instanceof HttpEntityEnclosingRequest) {
      HttpEntityEnclosingRequest httpEntityEnclosingRequest = (HttpEntityEnclosingRequest) method;
      httpResponse.setContent(new HttpMethodReleaseInputStream(httpEntityEnclosingRequest));
    }

    try {
      CountingInputStream countingInputStream = null;
      if (System.getProperty(PROFILING_SYSTEM_PROPERTY) != null) {
        countingInputStream = new CountingInputStream(httpResponse.getContent());
        httpResponse.setContent(countingInputStream);
      }

      long startTime = System.currentTimeMillis();
      AmazonWebServiceResponse<? extends T> awsResponse = responseHandler.handle(httpResponse);
      long endTime = System.currentTimeMillis();

      if (System.getProperty(PROFILING_SYSTEM_PROPERTY) != null) {
        if (executionContext.getTimingInfo() != null) {
          TimingInfo timingInfo = executionContext.getTimingInfo();
          TimingInfo responseProcessingTiming = new TimingInfo(startTime, endTime);
          timingInfo.addSubMeasurement(
              RESPONSE_PROCESSING_SUBMEASUREMENT, responseProcessingTiming);

          if (countingInputStream != null) {
            responseProcessingTiming.addCounter(
                BYTES_PROCESSED_COUNTER, countingInputStream.getByteCount());
          }
        }
      }

      if (awsResponse == null) throw new RuntimeException("Unable to unmarshall response metadata");

      responseMetadataCache.add(request.getOriginalRequest(), awsResponse.getResponseMetadata());

      if (requestLog.isDebugEnabled()) {
        requestLog.debug(
            "Received successful response: "
                + apacheHttpResponse.getStatusLine().getStatusCode()
                + ", AWS Request ID: "
                + awsResponse.getRequestId());
      }

      return awsResponse.getResult();
    } catch (Exception e) {
      String errorMessage = "Unable to unmarshall response (" + e.getMessage() + ")";
      log.warn(errorMessage, e);
      throw new AmazonClientException(errorMessage, e);
    }
  }
  /**
   * Handles a successful response from a service call by unmarshalling the results using the
   * specified response handler.
   *
   * @param <T> The type of object expected in the response.
   * @param request The original request that generated the response being handled.
   * @param responseHandler The response unmarshaller used to interpret the contents of the
   *     response.
   * @param method The HTTP method that was invoked, and contains the contents of the response.
   * @param executionContext Extra state information about the request currently being executed.
   * @return The contents of the response, unmarshalled using the specified response handler.
   * @throws IOException If any problems were encountered reading the response contents from the
   *     HTTP method object.
   */
  private <T> T handleResponse(
      Request<?> request,
      HttpResponseHandler<AmazonWebServiceResponse<T>> responseHandler,
      HttpRequestBase method,
      org.apache.http.HttpResponse apacheHttpResponse,
      ExecutionContext executionContext)
      throws IOException {

    HttpResponse httpResponse = createResponse(method, request, apacheHttpResponse);
    if (responseHandler.needsConnectionLeftOpen() && method instanceof HttpEntityEnclosingRequest) {
      HttpEntityEnclosingRequest httpEntityEnclosingRequest = (HttpEntityEnclosingRequest) method;
      httpResponse.setContent(new HttpMethodReleaseInputStream(httpEntityEnclosingRequest));
    }

    try {
      CountingInputStream countingInputStream = null;
      if (System.getProperty(PROFILING_SYSTEM_PROPERTY) != null) {
        countingInputStream = new CountingInputStream(httpResponse.getContent());
        httpResponse.setContent(countingInputStream);
      }

      AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
      awsRequestMetrics.startEvent(Field.ResponseProcessingTime.name());
      AmazonWebServiceResponse<? extends T> awsResponse = responseHandler.handle(httpResponse);
      awsRequestMetrics.endEvent(Field.ResponseProcessingTime.name());
      if (countingInputStream != null) {
        awsRequestMetrics.setCounter(
            Field.BytesProcessed.name(), countingInputStream.getByteCount());
      }

      if (awsResponse == null) throw new RuntimeException("Unable to unmarshall response metadata");

      responseMetadataCache.add(request.getOriginalRequest(), awsResponse.getResponseMetadata());

      if (requestLog.isDebugEnabled()) {
        requestLog.debug(
            "Received successful response: "
                + apacheHttpResponse.getStatusLine().getStatusCode()
                + ", AWS Request ID: "
                + awsResponse.getRequestId());
      }
      awsRequestMetrics.addProperty(Field.AWSRequestID.name(), awsResponse.getRequestId());

      return awsResponse.getResult();
    } catch (CRC32MismatchException e) {
      throw e;
    } catch (Exception e) {
      String errorMessage = "Unable to unmarshall response (" + e.getMessage() + ")";
      throw new AmazonClientException(errorMessage, e);
    }
  }
 /** Sets a User-Agent for the specified request, taking into account any custom data. */
 private void setUserAgent(Request<?> request) {
   String userAgent = config.getUserAgent();
   if (!userAgent.equals(ClientConfiguration.DEFAULT_USER_AGENT)) {
     userAgent += ", " + ClientConfiguration.DEFAULT_USER_AGENT;
   }
   if (userAgent != null) {
     request.addHeader(HEADER_USER_AGENT, userAgent);
   }
   AmazonWebServiceRequest awsreq = request.getOriginalRequest();
   if (awsreq != null) {
     RequestClientOptions opts = awsreq.getRequestClientOptions();
     if (opts != null) {
       String userAgentMarker = opts.getClientMarker(Marker.USER_AGENT);
       if (userAgentMarker != null) {
         request.addHeader(HEADER_USER_AGENT, createUserAgentString(userAgent, userAgentMarker));
       }
     }
   }
 }
  private <X, Y extends AmazonWebServiceRequest> Response<X> invoke(
      Request<Y> request,
      Unmarshaller<X, StaxUnmarshallerContext> unmarshaller,
      ExecutionContext executionContext) {
    request.setEndpoint(endpoint);
    request.setTimeOffset(timeOffset);
    AmazonWebServiceRequest originalRequest = request.getOriginalRequest();

    AWSCredentials credentials = awsCredentialsProvider.getCredentials();
    if (originalRequest.getRequestCredentials() != null) {
      credentials = originalRequest.getRequestCredentials();
    }

    executionContext.setCredentials(credentials);

    StaxResponseHandler<X> responseHandler = new StaxResponseHandler<X>(unmarshaller);
    DefaultErrorResponseHandler errorResponseHandler =
        new DefaultErrorResponseHandler(exceptionUnmarshallers);
    return client.execute(request, responseHandler, errorResponseHandler, executionContext);
  }
  /**
   * Internal method to execute the HTTP method given.
   *
   * @see AmazonHttpClient#execute(Request, HttpResponseHandler, HttpResponseHandler)
   * @see AmazonHttpClient#execute(Request, HttpResponseHandler, HttpResponseHandler,
   *     ExecutionContext)
   */
  private <T> Response<T> executeHelper(
      Request<?> request,
      HttpResponseHandler<AmazonWebServiceResponse<T>> responseHandler,
      HttpResponseHandler<AmazonServiceException> errorResponseHandler,
      ExecutionContext executionContext)
      throws AmazonClientException, AmazonServiceException {
    /*
     * Depending on which response handler we end up choosing to handle the
     * HTTP response, it might require us to leave the underlying HTTP
     * connection open, depending on whether or not it reads the complete
     * HTTP response stream from the HTTP connection, or if delays reading
     * any of the content until after a response is returned to the caller.
     */
    boolean leaveHttpConnectionOpen = false;
    AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
    /* add the service endpoint to the logs. You can infer service name from service endpoint */
    awsRequestMetrics.addProperty(Field.ServiceName, request.getServiceName());
    awsRequestMetrics.addProperty(Field.ServiceEndpoint, request.getEndpoint());
    // Apply whatever request options we know how to handle, such as user-agent.
    setUserAgent(request);
    int requestCount = 0;
    URI redirectedURI = null;
    HttpEntity entity = null;
    AmazonClientException retriedException = null;

    // Make a copy of the original request params and headers so that we can
    // permute it in this loop and start over with the original every time.
    Map<String, String> originalParameters = new LinkedHashMap<String, String>();
    originalParameters.putAll(request.getParameters());
    Map<String, String> originalHeaders = new HashMap<String, String>();
    originalHeaders.putAll(request.getHeaders());
    final AWSCredentials credentials = executionContext.getCredentials();
    Signer signer = null;

    while (true) {
      ++requestCount;
      awsRequestMetrics.setCounter(Field.RequestCount, requestCount);
      if (requestCount > 1) { // retry
        request.setParameters(originalParameters);
        request.setHeaders(originalHeaders);
      }
      HttpRequestBase httpRequest = null;
      org.apache.http.HttpResponse apacheResponse = null;

      try {
        // Sign the request if a signer was provided
        if (signer == null) signer = executionContext.getSignerByURI(request.getEndpoint());
        if (signer != null && credentials != null) {
          awsRequestMetrics.startEvent(Field.RequestSigningTime);
          try {
            signer.sign(request, credentials);
          } finally {
            awsRequestMetrics.endEvent(Field.RequestSigningTime);
          }
        }

        if (requestLog.isDebugEnabled()) {
          requestLog.debug("Sending Request: " + request.toString());
        }

        httpRequest = httpRequestFactory.createHttpRequest(request, config, executionContext);

        if (httpRequest instanceof HttpEntityEnclosingRequest) {
          entity = ((HttpEntityEnclosingRequest) httpRequest).getEntity();
        }

        if (redirectedURI != null) {
          httpRequest.setURI(redirectedURI);
        }

        if (requestCount > 1) { // retry
          awsRequestMetrics.startEvent(Field.RetryPauseTime);
          try {
            pauseBeforeNextRetry(
                request.getOriginalRequest(),
                retriedException,
                requestCount,
                config.getRetryPolicy());
          } finally {
            awsRequestMetrics.endEvent(Field.RetryPauseTime);
          }
        }

        if (entity != null) {
          InputStream content = entity.getContent();
          if (requestCount > 1) { // retry
            if (content.markSupported()) {
              content.reset();
              content.mark(-1);
            }
          } else {
            if (content.markSupported()) {
              content.mark(-1);
            }
          }
        }

        captureConnectionPoolMetrics(httpClient.getConnectionManager(), awsRequestMetrics);
        HttpContext httpContext = new BasicHttpContext();
        httpContext.setAttribute(AWSRequestMetrics.class.getSimpleName(), awsRequestMetrics);
        retriedException = null;
        awsRequestMetrics.startEvent(Field.HttpRequestTime);
        try {
          apacheResponse = httpClient.execute(httpRequest, httpContext);
        } finally {
          awsRequestMetrics.endEvent(Field.HttpRequestTime);
        }

        if (isRequestSuccessful(apacheResponse)) {
          awsRequestMetrics.addProperty(
              Field.StatusCode, apacheResponse.getStatusLine().getStatusCode());
          /*
           * If we get back any 2xx status code, then we know we should
           * treat the service call as successful.
           */
          leaveHttpConnectionOpen = responseHandler.needsConnectionLeftOpen();
          HttpResponse httpResponse = createResponse(httpRequest, request, apacheResponse);
          T response =
              handleResponse(
                  request,
                  responseHandler,
                  httpRequest,
                  httpResponse,
                  apacheResponse,
                  executionContext);
          return new Response<T>(response, httpResponse);
        } else if (isTemporaryRedirect(apacheResponse)) {
          /*
           * S3 sends 307 Temporary Redirects if you try to delete an
           * EU bucket from the US endpoint. If we get a 307, we'll
           * point the HTTP method to the redirected location, and let
           * the next retry deliver the request to the right location.
           */
          Header[] locationHeaders = apacheResponse.getHeaders("location");
          String redirectedLocation = locationHeaders[0].getValue();
          log.debug("Redirecting to: " + redirectedLocation);
          redirectedURI = URI.create(redirectedLocation);
          httpRequest.setURI(redirectedURI);
          awsRequestMetrics.addProperty(
              Field.StatusCode, apacheResponse.getStatusLine().getStatusCode());
          awsRequestMetrics.addProperty(Field.RedirectLocation, redirectedLocation);
          awsRequestMetrics.addProperty(Field.AWSRequestID, null);

        } else {
          leaveHttpConnectionOpen = errorResponseHandler.needsConnectionLeftOpen();
          AmazonServiceException ase =
              handleErrorResponse(request, errorResponseHandler, httpRequest, apacheResponse);
          awsRequestMetrics.addProperty(Field.AWSRequestID, ase.getRequestId());
          awsRequestMetrics.addProperty(Field.AWSErrorCode, ase.getErrorCode());
          awsRequestMetrics.addProperty(Field.StatusCode, ase.getStatusCode());

          if (!shouldRetry(
              request.getOriginalRequest(),
              httpRequest,
              ase,
              requestCount,
              config.getRetryPolicy())) {
            throw ase;
          }

          // Cache the retryable exception
          retriedException = ase;
          /*
           * Checking for clock skew error again because we don't want to set the
           * global time offset for every service exception.
           */
          if (RetryUtils.isClockSkewError(ase)) {
            int timeOffset = parseClockSkewOffset(apacheResponse, ase);
            SDKGlobalConfiguration.setGlobalTimeOffset(timeOffset);
          }
          resetRequestAfterError(request, ase);
        }
      } catch (IOException ioe) {
        if (log.isInfoEnabled()) {
          log.info("Unable to execute HTTP request: " + ioe.getMessage(), ioe);
        }
        awsRequestMetrics.incrementCounter(Field.Exception);
        awsRequestMetrics.addProperty(Field.Exception, ioe);
        awsRequestMetrics.addProperty(Field.AWSRequestID, null);

        AmazonClientException ace =
            new AmazonClientException("Unable to execute HTTP request: " + ioe.getMessage(), ioe);
        if (!shouldRetry(
            request.getOriginalRequest(),
            httpRequest,
            ace,
            requestCount,
            config.getRetryPolicy())) {
          throw ace;
        }

        // Cache the retryable exception
        retriedException = ace;
        resetRequestAfterError(request, ioe);
      } catch (RuntimeException e) {
        throw handleUnexpectedFailure(e, awsRequestMetrics);
      } catch (Error e) {
        throw handleUnexpectedFailure(e, awsRequestMetrics);
      } finally {
        /*
         * Some response handlers need to manually manage the HTTP
         * connection and will take care of releasing the connection on
         * their own, but if this response handler doesn't need the
         * connection left open, we go ahead and release the it to free
         * up resources.
         */
        if (!leaveHttpConnectionOpen) {
          try {
            if (apacheResponse != null
                && apacheResponse.getEntity() != null
                && apacheResponse.getEntity().getContent() != null) {
              apacheResponse.getEntity().getContent().close();
            }
          } catch (IOException e) {
            log.warn("Cannot close the response content.", e);
          }
        }
      }
    } /* end while (true) */
  }