package com.atlassian.asap.core.keys.publickey;
   
   import com.google.common.base.Preconditions;
   import org.apache.http.HttpResponse;
   import org.apache.http.client.ServiceUnavailableRetryStrategy;
   import org.apache.http.protocol.HttpContext;
   
   /**
    * A strategy that follows the best practices defined by Amazon for S3 buckets.
   *
   * <p><a href="http://docs.aws.amazon.com/AmazonS3/latest/dev/ErrorBestPractices.html">Amazon S3 error handling best
   * practices</a> recommend to retry any 5xx error when talking to S3. The
   * {@link org.apache.http.impl.client.DefaultServiceUnavailableRetryStrategy} provided by the Apache HTTP client
   * library does not cover all 5xx errors, only 503.
   *
   * <p>This class does not currently implement exponential backoff or jitter.
   */
  public class S3ServiceUnavailableRetryStrategy implements ServiceUnavailableRetryStrategy {
      private final int maxRetries;
      private final long retryInterval;
  
      /**
       * @param maxRetries    maximum number of attempts to make the request
       * @param retryInterval interval (in ms) to wait between retries
       */
      public S3ServiceUnavailableRetryStrategy(int maxRetries, long retryInterval) {
          Preconditions.checkArgument(maxRetries >= 0, "maxRetries must be non-negative");
          Preconditions.checkArgument(retryInterval >= 0, "retryInterval must be non-negative");
  
          this.maxRetries = maxRetries;
          this.retryInterval = retryInterval;
      }
  
      @Override
      public boolean retryRequest(HttpResponse response, int executionCount, HttpContext context) {
          return response.getStatusLine().getStatusCode() / 100 == 5 &&
                  executionCount <= maxRetries;
      }
  
      @Override
      public long getRetryInterval() {
          return retryInterval;
      }
  }