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.processor.internals;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.nio.ByteBuffer;
  import java.util.Base64;
  import java.util.Objects;
  
  /**
   * Metadata to be committed together with TopicPartition offset
   */
  public class TopicPartitionMetadata {
  
      private static final Logger LOG = LoggerFactory.getLogger(TopicPartitionMetadata.class);
  
      // visible for testing
      static final byte LATEST_MAGIC_BYTE = 2;
  
      private final long partitionTime;
      private final ProcessorMetadata processorMetadata;
  
      public TopicPartitionMetadata(final long partitionTime, final ProcessorMetadata processorMetadata) {
          Objects.requireNonNull(processorMetadata);
          this.partitionTime = partitionTime;
          this.processorMetadata = processorMetadata;
      }
  
      public long partitionTime() {
          return partitionTime;
      }
  
      public ProcessorMetadata processorMetadata() {
          return processorMetadata;
      }
  
      public String encode() {
          final byte[] serializedMeta = processorMetadata.serialize();
          // Format: MAGIC_BYTE(1) + PartitionTime(8) + processMeta
          final ByteBuffer buffer = ByteBuffer.allocate(Byte.BYTES + Long.BYTES + serializedMeta.length);
          buffer.put(LATEST_MAGIC_BYTE);
          buffer.putLong(partitionTime);
          buffer.put(serializedMeta);
          return Base64.getEncoder().encodeToString(buffer.array());
      }
  
      public static TopicPartitionMetadata decode(final String encryptedString) {
          long timestamp = RecordQueue.UNKNOWN;
          ProcessorMetadata metadata = new ProcessorMetadata();
  
          if (encryptedString.isEmpty()) {
              return new TopicPartitionMetadata(timestamp, metadata);
          }
          try {
              final ByteBuffer buffer = ByteBuffer.wrap(Base64.getDecoder().decode(encryptedString));
              final byte version = buffer.get();
              switch (version) {
                  case (byte) 1:
                      timestamp = buffer.getLong();
                      break;
                  case LATEST_MAGIC_BYTE:
                      timestamp = buffer.getLong();
                      if (buffer.remaining() > 0) {
                          final byte[] metaBytes = new byte[buffer.remaining()];
                          buffer.get(metaBytes);
                          metadata = ProcessorMetadata.deserialize(metaBytes);
                      }
                      break;
                  default:
                      LOG.warn(
                          "Unsupported offset metadata version found. Supported version <= {}. Found version {}.",
                          LATEST_MAGIC_BYTE, version);
              }
          } catch (final Exception exception) {
              LOG.warn("Unsupported offset metadata found");
          }
          return new TopicPartitionMetadata(timestamp, metadata);
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(partitionTime, processorMetadata);
      }
  
      @Override
      public boolean equals(final Object obj) {
          if (obj == null || obj.getClass() != getClass()) {
              return false;
          }
  
          if (obj == this) {
              return true;
          }
  
          return partitionTime == ((TopicPartitionMetadata) obj).partitionTime
              && Objects.equals(processorMetadata, ((TopicPartitionMetadata) obj).processorMetadata);
      }
  }
  