content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.cassandra.config;
  
  import java.util.Objects;
  
  import javax.annotation.Nullable;
  
  import org.apache.cassandra.config.DurationSpec.LongMillisecondsBound;
  import org.apache.cassandra.repair.SharedContext;
  import org.apache.cassandra.service.RetryStrategy;
  import org.apache.cassandra.service.TimeoutStrategy.LatencySourceFactory;
  import org.apache.cassandra.service.WaitStrategy;
  
  public class RetrySpec
  {
      public static class MaxAttempt
      {
          public static final MaxAttempt DISABLED = new MaxAttempt();
  
          public final int value;
  
          public MaxAttempt(int value)
          {
              if (value < 1)
                  throw new IllegalArgumentException("max attempt must be positive; but given " + value);
              this.value = value;
          }
  
          private MaxAttempt()
          {
              value = 0;
          }
  
          @Override
          public boolean equals(Object o)
          {
              if (this == o) return true;
              if (o == null) return false;
              if (o instanceof Integer) return this.value == ((Integer) o).intValue();
              if (getClass() != o.getClass()) return false;
              MaxAttempt that = (MaxAttempt) o;
              return value == that.value;
          }
  
          @Override
          public int hashCode()
          {
              return Objects.hash(value);
          }
  
          @Override
          public String toString()
          {
              return Integer.toString(value);
          }
      }
  
      public static class Partial extends RetrySpec
      {
          public Partial()
          {
              this.maxAttempts = null;
              this.baseSleepTime = null;
              this.maxSleepTime = null;
          }
  
          public RetrySpec withDefaults(RetrySpec defaultValues)
          {
              MaxAttempt maxAttempts = nonNull(this.maxAttempts, defaultValues.getMaxAttempts(), DEFAULT_MAX_ATTEMPTS);
              LongMillisecondsBound baseSleepTime = nonNull(this.baseSleepTime, defaultValues.getBaseSleepTime(), DEFAULT_BASE_SLEEP);
              LongMillisecondsBound maxSleepTime = nonNull(this.maxSleepTime, defaultValues.getMaxSleepTime(), DEFAULT_MAX_SLEEP);
              return new RetrySpec(maxAttempts, baseSleepTime, maxSleepTime);
          }
  
          private static <T> T nonNull(@Nullable T left, @Nullable T right, T defaultValue)
          {
              if (left != null)
                  return left;
              if (right != null)
                  return right;
              return defaultValue;
          }
      }
  
      public static final MaxAttempt DEFAULT_MAX_ATTEMPTS = MaxAttempt.DISABLED;
      public static final LongMillisecondsBound DEFAULT_BASE_SLEEP = new LongMillisecondsBound("200ms");
      public static final LongMillisecondsBound DEFAULT_MAX_SLEEP = new LongMillisecondsBound("1s");
  
      /**
       * Represents how many retry attempts are allowed.  If the value is 2, this will cause 2 retries + 1 original request, for a total of 3 requests!
       * <p/>
       * To disable, set to 0.
       */
      public MaxAttempt maxAttempts = DEFAULT_MAX_ATTEMPTS; // 2 retries, 1 original request; so 3 total
      public LongMillisecondsBound baseSleepTime = DEFAULT_BASE_SLEEP;
      public LongMillisecondsBound maxSleepTime = DEFAULT_MAX_SLEEP;
  
      public RetrySpec()
      {
      }
  
      public RetrySpec(MaxAttempt maxAttempts, LongMillisecondsBound baseSleepTime, LongMillisecondsBound maxSleepTime)
      {
          this.maxAttempts = maxAttempts;
          this.baseSleepTime = baseSleepTime;
          this.maxSleepTime = maxSleepTime;
      }
  
      public boolean isEnabled()
      {
          return maxAttempts != MaxAttempt.DISABLED;
      }
  
      public void setEnabled(boolean enabled)
      {
          if (!enabled)
          {
              maxAttempts = MaxAttempt.DISABLED;
          }
          else if (maxAttempts == MaxAttempt.DISABLED)
          {
              maxAttempts = new MaxAttempt(2);
          }
      }
  
      @Nullable
      public MaxAttempt getMaxAttempts()
      {
          return !isEnabled() ? null : maxAttempts;
      }
  
      @Nullable
      public LongMillisecondsBound getBaseSleepTime()
      {
          return !isEnabled() ? null : baseSleepTime;
      }
  
      public LongMillisecondsBound getMaxSleepTime()
      {
          return !isEnabled() ? null : maxSleepTime;
      }
  
      public static WaitStrategy toStrategy(SharedContext ctx, RetrySpec spec)
      {
          if (!spec.isEnabled())
              return WaitStrategy.None.INSTANCE;
          return RetryStrategy.parse(spec.baseSleepTime.toMilliseconds() + "ms * 2^attempts <= " + spec.maxSleepTime.toMilliseconds() + "ms,retries=" + (spec.maxAttempts.value - 1), LatencySourceFactory.none());
      }
  
      @Override
      public String toString()
      {
          return "RetrySpec{" +
                 "maxAttempts=" + maxAttempts +
                 ", baseSleepTime=" + baseSleepTime +
                 ", maxSleepTime=" + maxSleepTime +
                 '}';
      }
  }
  