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.service.reads;
  
  import java.util.concurrent.TimeUnit;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import com.google.common.base.Objects;
  
  import org.apache.cassandra.exceptions.ConfigurationException;
  import org.apache.cassandra.metrics.SnapshottingTimer;
  import org.apache.cassandra.schema.TableParams;
  
  public class FixedSpeculativeRetryPolicy implements SpeculativeRetryPolicy
  {
      private static final Pattern PATTERN = Pattern.compile("^(?<val>[0-9.]+)ms$", Pattern.CASE_INSENSITIVE);
  
      private final int speculateAtMilliseconds;
  
      FixedSpeculativeRetryPolicy(int speculateAtMilliseconds)
      {
          this.speculateAtMilliseconds = speculateAtMilliseconds;
      }
  
      @Override
      public long calculateThreshold(SnapshottingTimer latency, long existingValue)
      {
          return TimeUnit.MILLISECONDS.toMicros(speculateAtMilliseconds);
      }
  
      @Override
      public Kind kind()
      {
          return Kind.FIXED;
      }
  
      @Override
      public boolean equals(Object obj)
      {
          if (!(obj instanceof FixedSpeculativeRetryPolicy))
              return false;
          FixedSpeculativeRetryPolicy rhs = (FixedSpeculativeRetryPolicy) obj;
          return speculateAtMilliseconds == rhs.speculateAtMilliseconds;
      }
  
      @Override
      public int hashCode()
      {
          return Objects.hashCode(kind(), speculateAtMilliseconds);
      }
  
      @Override
      public String toString()
      {
          return String.format("%dms", speculateAtMilliseconds);
      }
  
      static FixedSpeculativeRetryPolicy fromString(String str)
      {
          Matcher matcher = PATTERN.matcher(str);
  
          if (!matcher.matches())
              throw new IllegalArgumentException();
  
          String val = matcher.group("val");
          try
          {
               // historically we've always parsed this as double, but treated as int; so we keep doing it for compatibility
              return new FixedSpeculativeRetryPolicy((int) Double.parseDouble(val));
          }
          catch (IllegalArgumentException e)
          {
              throw new ConfigurationException(String.format("Invalid value %s for option '%s'", str, TableParams.Option.SPECULATIVE_RETRY));
          }
      }
  
      static boolean stringMatches(String str)
      {
          return PATTERN.matcher(str).matches();
      }
  }
  