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.clients.consumer.internals;
  
  import org.apache.kafka.clients.consumer.ConsumerRecord;
  import org.apache.kafka.common.KafkaException;
  import org.apache.kafka.common.TopicIdPartition;
  import org.apache.kafka.common.errors.TopicAuthorizationException;
  import org.apache.kafka.common.protocol.Errors;
  import org.apache.kafka.common.record.RecordBatch;
  import org.apache.kafka.common.requests.ShareFetchResponse;
  import org.apache.kafka.common.utils.LogContext;
  
  import org.slf4j.Logger;
  
  import java.util.Collections;
  
  import static org.apache.kafka.clients.consumer.internals.FetchUtils.requestMetadataUpdate;
  
  /**
   * {@code ShareFetchCollector} operates at the {@link RecordBatch} level, as that is what is stored in the
   * {@link ShareFetchBuffer}. Each {@link org.apache.kafka.common.record.Record} in the {@link RecordBatch} is converted
   * to a {@link ConsumerRecord} and added to the returned {@link Fetch}.
   *
   * @param <K> Record key type
   * @param <V> Record value type
   */
  public class ShareFetchCollector<K, V> {
  
      private final Logger log;
      private final ConsumerMetadata metadata;
      private final SubscriptionState subscriptions;
      private final FetchConfig fetchConfig;
      private final Deserializers<K, V> deserializers;
  
      public ShareFetchCollector(final LogContext logContext,
                                 final ConsumerMetadata metadata,
                                 final SubscriptionState subscriptions,
                                 final FetchConfig fetchConfig,
                                 final Deserializers<K, V> deserializers) {
          this.log = logContext.logger(ShareFetchCollector.class);
          this.metadata = metadata;
          this.subscriptions = subscriptions;
          this.fetchConfig = fetchConfig;
          this.deserializers = deserializers;
      }
  
      /**
       * Return the fetched {@link ConsumerRecord records}.
       *
       * @param fetchBuffer {@link ShareFetchBuffer} from which to retrieve the {@link ConsumerRecord records}
       *
       * @return A {@link ShareFetch} for the requested partitions
       * @throws TopicAuthorizationException If there is TopicAuthorization error in fetchResponse.
       */
      public ShareFetch<K, V> collect(final ShareFetchBuffer fetchBuffer) {
          ShareFetch<K, V> fetch = ShareFetch.empty();
          int recordsRemaining = fetchConfig.maxPollRecords;
  
          try {
              while (recordsRemaining > 0) {
                  final ShareCompletedFetch nextInLineFetch = fetchBuffer.nextInLineFetch();
  
                  if (nextInLineFetch == null || nextInLineFetch.isConsumed()) {
                      final ShareCompletedFetch completedFetch = fetchBuffer.peek();
  
                      if (completedFetch == null) {
                          break;
                      }
  
                      if (!completedFetch.isInitialized()) {
                          try {
                              fetchBuffer.setNextInLineFetch(initialize(completedFetch));
                          } catch (Exception e) {
                              if (fetch.isEmpty()) {
                                  fetchBuffer.poll();
                              }
                              throw e;
                          }
                      } else {
                          fetchBuffer.setNextInLineFetch(completedFetch);
                      }
  
                      fetchBuffer.poll();
                  } else {
                      final TopicIdPartition tp = nextInLineFetch.partition;
  
                      ShareInFlightBatch<K, V> batch = nextInLineFetch.fetchRecords(
                              deserializers,
                              recordsRemaining,
                              fetchConfig.checkCrcs);
  
                      if (batch.isEmpty()) {
                          nextInLineFetch.drain();
                      }
  
                      recordsRemaining -= batch.numRecords();
                      fetch.add(tp, batch);
  
                      if (batch.getException() != null) {
                          throw batch.getException();
                      } else if (batch.hasCachedException()) {
                          break;
                      }
                  }
              }
          } catch (KafkaException e) {
              if (fetch.isEmpty()) {
                  throw e;
              }
          }
  
          return fetch;
      }
  
      /**
       * Initialize a ShareCompletedFetch object.
       */
      protected ShareCompletedFetch initialize(final ShareCompletedFetch completedFetch) {
          final Errors error = Errors.forCode(completedFetch.partitionData.errorCode());
  
          if (error == Errors.NONE) {
              return handleInitializeSuccess(completedFetch);
          } else {
              handleInitializeErrors(completedFetch, error);
              return null;
          }
      }
  
      private ShareCompletedFetch handleInitializeSuccess(final ShareCompletedFetch completedFetch) {
          log.trace("Preparing to read {} bytes of data for partition {}",
                  ShareFetchResponse.recordsSize(completedFetch.partitionData),
                  completedFetch.partition.topicPartition());
  
          completedFetch.setInitialized();
          return completedFetch;
      }
  
      private void handleInitializeErrors(final ShareCompletedFetch completedFetch, final Errors error) {
          final TopicIdPartition tp = completedFetch.partition;
  
          if (error == Errors.NOT_LEADER_OR_FOLLOWER ||
                  error == Errors.REPLICA_NOT_AVAILABLE ||
                  error == Errors.KAFKA_STORAGE_ERROR ||
                  error == Errors.FENCED_LEADER_EPOCH ||
                  error == Errors.OFFSET_NOT_AVAILABLE) {
              log.debug("Error in fetch for partition {}: {}", tp, error.exceptionName());
              requestMetadataUpdate(metadata, subscriptions, tp.topicPartition());
          } else if (error == Errors.UNKNOWN_TOPIC_OR_PARTITION) {
              log.warn("Received unknown topic or partition error in fetch for partition {}.", tp);
              requestMetadataUpdate(metadata, subscriptions, tp.topicPartition());
          } else if (error == Errors.UNKNOWN_TOPIC_ID) {
              log.warn("Received unknown topic ID error in fetch for partition {}.", tp);
              requestMetadataUpdate(metadata, subscriptions, tp.topicPartition());
          } else if (error == Errors.INCONSISTENT_TOPIC_ID) {
              log.warn("Received inconsistent topic ID error in fetch for partition {}.", tp);
              requestMetadataUpdate(metadata, subscriptions, tp.topicPartition());
          } else if (error == Errors.TOPIC_AUTHORIZATION_FAILED) {
              // Log the actual partition and not just the topic to help with ACL propagation issues in large clusters
              log.warn("Not authorized to read from partition {}.", tp.topicPartition());
              throw new TopicAuthorizationException(Collections.singleton(tp.topic()));
          } else if (error == Errors.UNKNOWN_LEADER_EPOCH) {
              log.debug("Received unknown leader epoch error in fetch for partition {}.", tp);
          } else if (error == Errors.UNKNOWN_SERVER_ERROR) {
              log.warn("Unknown server error while fetching topic-partition {}.",
                      tp.topicPartition());
          } else if (error == Errors.CORRUPT_MESSAGE) {
              throw new KafkaException("Encountered corrupt message when fetching topic-partition "
                      + tp.topicPartition());
          } else {
              throw new IllegalStateException("Unexpected error code " + error.code()
                      + " while fetching from topic-partition " + tp.topicPartition());
          }
      }
  }
  