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.kafka.streams.state.internals;
  
  import org.apache.kafka.clients.consumer.ConsumerRecord;
  import org.apache.kafka.common.utils.Bytes;
  import org.apache.kafka.streams.KeyValue;
  import org.apache.kafka.streams.errors.ProcessorStateException;
  import org.apache.kafka.streams.kstream.Window;
  import org.apache.kafka.streams.kstream.Windowed;
  import org.apache.kafka.streams.processor.internals.ChangelogRecordDeserializationHelper;
  import org.apache.kafka.streams.state.KeyValueIterator;
  import org.apache.kafka.streams.state.internals.PrefixedSessionKeySchemas.KeyFirstSessionKeySchema;
  import org.apache.kafka.streams.state.internals.PrefixedSessionKeySchemas.TimeFirstSessionKeySchema;
  
  import org.rocksdb.RocksDBException;
  import org.rocksdb.WriteBatch;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  
  /**
   * A RocksDB backed time-ordered segmented bytes store for session key schema.
   */
  public class RocksDBTimeOrderedSessionSegmentedBytesStore extends AbstractRocksDBTimeOrderedSegmentedBytesStore {
  
      private class SessionKeySchemaIndexToBaseStoreIterator extends IndexToBaseStoreIterator {
          SessionKeySchemaIndexToBaseStoreIterator(final KeyValueIterator<Bytes, byte[]> indexIterator) {
              super(indexIterator);
          }
  
          @Override
          protected Bytes getBaseKey(final Bytes indexKey) {
              final Window window = KeyFirstSessionKeySchema.extractWindow(indexKey.get());
              final byte[] key = KeyFirstSessionKeySchema.extractKeyBytes(indexKey.get());
  
              return TimeFirstSessionKeySchema.toBinary(Bytes.wrap(key), window.start(), window.end());
          }
      }
  
      RocksDBTimeOrderedSessionSegmentedBytesStore(final String name,
                                                   final String metricsScope,
                                                   final long retention,
                                                   final long segmentInterval,
                                                   final boolean withIndex) {
          super(name, metricsScope, retention, segmentInterval, new TimeFirstSessionKeySchema(),
              Optional.ofNullable(withIndex ? new KeyFirstSessionKeySchema() : null));
      }
  
      public byte[] fetchSession(final Bytes key,
                                 final long sessionStartTime,
                                 final long sessionEndTime) {
          return get(TimeFirstSessionKeySchema.toBinary(
              key,
              sessionStartTime,
              sessionEndTime
          ));
      }
  
      public KeyValueIterator<Bytes, byte[]> fetchSessions(final long earliestSessionEndTime,
                                                           final long latestSessionEndTime) {
          final List<KeyValueSegment> searchSpace = segments.segments(earliestSessionEndTime, latestSessionEndTime, true);
  
          // here we want [0, latestSE, FF] as the upper bound to cover any possible keys,
          // but since we can only get upper bound based on timestamps, we use a slight larger upper bound as [0, latestSE+1]
          final Bytes binaryFrom = baseKeySchema.lowerRangeFixedSize(null, earliestSessionEndTime);
          final Bytes binaryTo = baseKeySchema.lowerRangeFixedSize(null, latestSessionEndTime + 1);
  
          return new SegmentIterator<>(
                  searchSpace.iterator(),
                  iterator -> {
                      while (iterator.hasNext()) {
                          final Bytes bytes = iterator.peekNextKey();
  
                          final Windowed<Bytes> windowedKey = TimeFirstSessionKeySchema.from(bytes);
                          final long endTime = windowedKey.window().end();
  
                          if (endTime <= latestSessionEndTime && endTime >= earliestSessionEndTime) {
                              return true;
                          }
                          iterator.next();
                      }
                      return false;
                  },
                  binaryFrom,
                  binaryTo,
                  true);
      }
  
      public void remove(final Windowed<Bytes> key) {
          remove(TimeFirstSessionKeySchema.toBinary(key));
      }
  
      public void put(final Windowed<Bytes> sessionKey, final byte[] aggregate) {
          put(TimeFirstSessionKeySchema.toBinary(sessionKey), aggregate);
      }
  
      @Override
      protected KeyValue<Bytes, byte[]> getIndexKeyValue(final Bytes baseKey, final byte[] baseValue) {
          final Window window = TimeFirstSessionKeySchema.extractWindow(baseKey.get());
          final byte[] key = TimeFirstSessionKeySchema.extractKeyBytes(baseKey.get());
          return KeyValue.pair(KeyFirstSessionKeySchema.toBinary(Bytes.wrap(key), window.start(), window.end()), new byte[0]);
      }
  
      @Override
      Map<KeyValueSegment, WriteBatch> getWriteBatches(
          final Collection<ConsumerRecord<byte[], byte[]>> records) {
          // advance stream time to the max timestamp in the batch
          for (final ConsumerRecord<byte[], byte[]> record : records) {
              final long timestamp = SessionKeySchema.extractEndTimestamp(record.key());
              observedStreamTime = Math.max(observedStreamTime, timestamp);
          }
  
          final Map<KeyValueSegment, WriteBatch> writeBatchMap = new HashMap<>();
          for (final ConsumerRecord<byte[], byte[]> record : records) {
              final long timestamp = SessionKeySchema.extractEndTimestamp(record.key());
              final long segmentId = segments.segmentId(timestamp);
              final KeyValueSegment segment = segments.getOrCreateSegmentIfLive(segmentId, internalProcessorContext, observedStreamTime);
              if (segment != null) {
                  ChangelogRecordDeserializationHelper.applyChecksAndUpdatePosition(
                      record,
                      consistencyEnabled,
                      position
                  );
                  try {
                      final WriteBatch batch = writeBatchMap.computeIfAbsent(segment, s -> new WriteBatch());
  
                      // Assuming changelog record is serialized using SessionKeySchema
                      // from ChangeLoggingSessionBytesStore. Reconstruct key/value to restore
                      if (hasIndex()) {
                          final byte[] indexKey = KeyFirstSessionKeySchema.prefixNonPrefixSessionKey(record.key());
                          // Take care of tombstone
                          final byte[] value = record.value() == null ? null : new byte[0];
                          segment.addToBatch(new KeyValue<>(indexKey, value), batch);
                      }
  
                      final byte[] baseKey = TimeFirstSessionKeySchema.extractWindowBytesFromNonPrefixSessionKey(record.key());
                      segment.addToBatch(new KeyValue<>(baseKey, record.value()), batch);
                  } catch (final RocksDBException e) {
                      throw new ProcessorStateException("Error restoring batch to store " + name(), e);
                  }
              }
          }
          return writeBatchMap;
      }
  
      @Override
      protected IndexToBaseStoreIterator getIndexToBaseStoreIterator(
          final SegmentIterator<KeyValueSegment> segmentIterator) {
          return new SessionKeySchemaIndexToBaseStoreIterator(segmentIterator);
      }
  }