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package org.apache.kafka.server.group.consumer;

public interface PartitionAssignor {

    class AssignmentSpec {
        /**
         * The members keyed by member id.
         */
        Map<String, AssignmentMemberSpec> members;

        /**
         * The topics' metadata keyed by topic id
         */
        Map<Uuid, AssignmentTopicMetadata> topics;
    }

    class AssignmentMemberSpec {
        /**
         * The instance ID if provided.
         */
        Optional<String> instanceId;

        /**
         * The rack ID if provided.
         */
        Optional<String> rackId;

        /**
         * The set of topic IDstopics that the member is subscribed to.
         */
        List<Uuid>List<String> subscribedTopicIdssubscribedTopics;

        /**
         * The current target partitions of the member.
         */
        List<TopicIdPartition>List<TopicPartition> targetPartitions;
    }

    class AssignmentTopicMetadata {
        /**
         * The topic name.
         */
        String topicName;

        /**
		 * The number of partitions.
		 */
		int numPartitions; 
    }

    class GroupAssignment {
        /**
         * The member assignments keyed by member id.
         */
        Map<String, MemberAssignment> members;
    }

    class MemberAssignment {
        /**
         * The target partitions assigned to this member.
         */
        List<TopicIdPartition>List<TopicPartition> targetPartitions;
    }

    /**
     * Unique name for this assignor.
     */
    String name();

    /**
     * Perform the group assignment given the current members and
     * topic metadata.
     *
     * @param assignmentSpec The assignment spec.
     * @return The new assignment for the group.
     */
    GroupAssignment assign(AssignmentSpec assignmentSpec) throws PartitionAssignorException;
}

package org.apache.kafka.clients.consumer;
  
public interface PartitionAssignor {

    class Metadata {
        /**
         * The metadata version.
         */
        int version;

        /**
         * The metadata bytes.
         */
        ByteBuffer bytes;
    }

    class AssignmentSpec {
        /**
         * The members keyed by member id.
         */
        Map<String, AssignmentMemberSpec> members;

        /**
         * The topics' metadata keyed by topic id
         */
        Map<Uuid, AssignmentTopicMetadata> topics;
    }

    class AssignmentMemberSpec {
        /**
         * The instance ID if provided.
         */
        Optional<String> instanceId;

        /**
         * The rack ID if provided.
         */
        Optional<String> rackId;

        /**
         * The set of topic IDstopics that the member is subscribed to.
         */
        List<Uuid>List<String> subscribedTopicIdssubscribedTopics;

   		/**
		 * The reason reported by the member.
		 */
		byte reason;  

		/**
		 * The metadata reported by the member.
		 */
        Metadata metadata;

        /**
         * The current target partitions of the member.
         */
        List<TopicIdPartition>List<TopicPartition> targetPartitions;
    }

    class AssignmentTopicMetadata {
        /**
         * The topic name.
         */
        String topicName;

        /**
		 * The number of partitions.
		 */
		int numPartitions; 
    }

    class GroupAssignment {
        /**
         * The assignment error.
         */
		byte error;

        /**
         * The member assignments keyed by member id.
         */
        Map<String, MemberAssignment> members;
    }

    class MemberAssignment {
        /**
         * The target partitions assigned to this member.
         */
        List<TopicIdPartition>List<TopicPartition> targetPartitions;

 		/**
		 * The metadata.
		 */
		Metadata metadata;
    }

	class AssignorMetadata {
   		/**
		 * The reason reported by the assignor.
		 */
		byte reason; 

 		/**
		 * The metadata reported by the assignor.
		 */
		Metadata metadata;
    }

    /**
     * Unique name for this assignor.
     */
    String name();

    /**
     * The minimum version.
     */
    int minimumVersion();

    /**
     * The maximum version.
     */
    int maximumVersion();

    /**
     * Return assignor metadata that will be sent to the assignor.
     */
    AssignorMetadata metadata();

    /**
     * Perform the group assignment given the current members and
     * topic metadata.
     *
     * @param assignmentSpec The assignment spec.
     * @return The new assignment for the group.
     */
    GroupAssignment assign(AssignmentSpec assignmentSpec);

    /**
     * Callback which is invoked when the member received a new assignment 
     * from the assignor/group coordinator. This is called once per epoch
     * and contains the target partitions for this members. This means that
     * partitions may not be assigned to the member yet. The rebalance
     * listener must be used to know this.
     * 
     * @param byte The error reported by the assignor.
     * @param assignment The assignment computed by the assignor.
     * @param consumerGroupMetadata The group metadata.
     */
    void onAssignment(byte error, MemberAssignment assignment, ConsumerGroupMetadata consumerGroupMetadata);
}