Class DefaultRetryer

core/src/main/java/feign/DefaultRetryer.java:20–86

import static java.util.concurrent.TimeUnit.SECONDS;

public class DefaultRetryer implements Retryer {

  private final int maxAttempts;
  private final long period;
  private final long maxPeriod;
  int attempt;
  long sleptForMillis;

  public DefaultRetryer() {
    this(100, SECONDS.toMillis(1), 5);
  }

  public DefaultRetryer(long period, long maxPeriod, int maxAttempts) {
    this.period = period;
    this.maxPeriod = maxPeriod;
    this.maxAttempts = maxAttempts;
    this.attempt = 1;
  }

  // visible for testing;
  protected long currentTimeMillis() {
    return System.currentTimeMillis();
  }

  public void continueOrPropagate(RetryableException e) {
    if (attempt++ >= maxAttempts) {
      throw e;
    }

    long interval;
    if (e.retryAfter() != null) {
      interval = e.retryAfter() - currentTimeMillis();
      if (interval > maxPeriod) {
        interval = maxPeriod;
      }
      if (interval < 0) {
        return;
      }
    } else {
      interval = nextMaxInterval();
    }
    try {
      Thread.sleep(interval);
    } catch (InterruptedException ignored) {
      Thread.currentThread().interrupt();
      throw e;
    }
    sleptForMillis += interval;
  }

  /**
   * Calculates the time interval to a retry attempt.<br>
   * The interval increases exponentially with each attempt, at a rate of nextInterval *= 1.5 (where
   * 1.5 is the backoff factor), to the maximum interval.
   *
   * @return time in milliseconds from now until the next attempt.
   */
  long nextMaxInterval() {