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.common.utils.Bytes;
  import org.apache.kafka.streams.state.internals.SegmentedBytesStore.KeySchema;
  
  import java.nio.ByteBuffer;
  
  class SegmentedCacheFunction implements CacheFunction {
  
      private static final int SEGMENT_ID_BYTES = 8;
  
      private final KeySchema keySchema;
      private final long segmentInterval;
  
      SegmentedCacheFunction(final KeySchema keySchema, final long segmentInterval) {
          this.keySchema = keySchema;
          this.segmentInterval = segmentInterval;
      }
  
      @Override
      public Bytes key(final Bytes cacheKey) {
          return Bytes.wrap(bytesFromCacheKey(cacheKey));
      }
  
      @Override
      public Bytes cacheKey(final Bytes key) {
          return cacheKey(key, segmentId(key));
      }
  
      Bytes cacheKey(final Bytes key, final long segmentId) {
          final byte[] keyBytes = key.get();
          final ByteBuffer buf = ByteBuffer.allocate(SEGMENT_ID_BYTES + keyBytes.length);
          buf.putLong(segmentId).put(keyBytes);
          return Bytes.wrap(buf.array());
      }
  
      static byte[] bytesFromCacheKey(final Bytes cacheKey) {
          final byte[] binaryKey = new byte[cacheKey.get().length - SEGMENT_ID_BYTES];
          System.arraycopy(cacheKey.get(), SEGMENT_ID_BYTES, binaryKey, 0, binaryKey.length);
          return binaryKey;
      }
  
      public long segmentId(final Bytes key) {
          return segmentId(keySchema.segmentTimestamp(key));
      }
  
      long segmentId(final long timestamp) {
          return timestamp / segmentInterval;
      }
  
      long getSegmentInterval() {
          return segmentInterval;
      }
  
      int compareSegmentedKeys(final Bytes cacheKey, final Bytes storeKey) {
          final long storeSegmentId = segmentId(storeKey);
          final long cacheSegmentId = ByteBuffer.wrap(cacheKey.get()).getLong();
  
          final int segmentCompare = Long.compare(cacheSegmentId, storeSegmentId);
          if (segmentCompare == 0) {
              final byte[] cacheKeyBytes = cacheKey.get();
              final byte[] storeKeyBytes = storeKey.get();
              return Bytes.BYTES_LEXICO_COMPARATOR.compare(
                  cacheKeyBytes, SEGMENT_ID_BYTES, cacheKeyBytes.length - SEGMENT_ID_BYTES,
                  storeKeyBytes, 0, storeKeyBytes.length
              );
          } else {
              return segmentCompare;
          }
      }
  }
  