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.io.sstable.format;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  
  import com.google.common.collect.Lists;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.io.sstable.AbstractRowIndexEntry;
  import org.apache.cassandra.io.sstable.Descriptor;
  import org.apache.cassandra.io.sstable.SSTableReadsListener;
  import org.apache.cassandra.io.sstable.filter.BloomFilterTracker;
  import org.apache.cassandra.utils.IFilter;
  
  import static org.apache.cassandra.utils.concurrent.SharedCloseable.sharedCopyOrNull;
  
  public abstract class SSTableReaderWithFilter extends SSTableReader
  {
      private final IFilter filter;
      private final BloomFilterTracker filterTracker;
  
      protected SSTableReaderWithFilter(Builder<?, ?> builder, Owner owner)
      {
          super(builder, owner);
          this.filter = Objects.requireNonNull(builder.getFilter());
          this.filterTracker = new BloomFilterTracker();
      }
  
      @Override
      protected List<AutoCloseable> setupInstance(boolean trackHotness)
      {
          ArrayList<AutoCloseable> closeables = Lists.newArrayList(filter);
          closeables.addAll(super.setupInstance(trackHotness));
          return closeables;
      }
  
      protected final <B extends Builder<?, B>> B unbuildTo(B builder, boolean sharedCopy)
      {
          B b = super.unbuildTo(builder, sharedCopy);
          if (builder.getFilter() == null)
              b.setFilter(sharedCopy ? sharedCopyOrNull(filter) : filter);
          return b;
      }
  
      protected boolean isPresentInFilter(IFilter.FilterKey key)
      {
          return filter.isPresent(key);
      }
  
      @Override
      public boolean mayContainAssumingKeyIsInRange(DecoratedKey key)
      {
          // if we don't have bloom filter(bf_fp_chance=1.0 or filter file is missing),
          // we check index file instead.
          return !filter.isInformative() && getPosition(key, Operator.EQ, false) >= 0 || filter.isPresent(key);
      }
  
      @Override
      protected void notifySelected(SSTableReadsListener.SelectionReason reason, SSTableReadsListener localListener, Operator op, boolean updateStats, AbstractRowIndexEntry entry)
      {
          super.notifySelected(reason, localListener, op, updateStats, entry);
  
          if (!(updateStats && op == SSTableReader.Operator.EQ))
              return;
  
          filterTracker.addTruePositive();
      }
  
      @Override
      protected void notifySkipped(SSTableReadsListener.SkippingReason reason, SSTableReadsListener localListener, Operator op, boolean updateStats)
      {
          super.notifySkipped(reason, localListener, op, updateStats);
  
          if (!updateStats)
              return;
  
          switch (reason)
          {
              case BLOOM_FILTER:
                  filterTracker.addTrueNegative();
                  break;
              case MIN_MAX_KEYS:
                  // checking bloom filter against keys outside the sstable range make no sense so collecting
                  // statistics on that makes no sense either
                  break;
              default:
                  if (op == SSTableReader.Operator.EQ)
                      filterTracker.addFalsePositive();
          }
      }
  
      public BloomFilterTracker getFilterTracker()
      {
          return filterTracker;
      }
  
      public long getFilterSerializedSize()
      {
          return filter.serializedSize(descriptor.version.hasOldBfFormat());
      }
  
      public long getFilterOffHeapSize()
      {
          return filter.offHeapSize();
      }
  
      public abstract SSTableReaderWithFilter cloneAndReplace(IFilter filter);
  
      public abstract static class Builder<R extends SSTableReaderWithFilter, B extends Builder<R, B>> extends SSTableReader.Builder<R, B>
      {
          private IFilter filter;
  
          public Builder(Descriptor descriptor)
          {
              super(descriptor);
          }
  
          public B setFilter(IFilter filter)
          {
              this.filter = filter;
              return (B) this;
          }
  
          public IFilter getFilter()
          {
              return this.filter;
          }
      }
  }
  