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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 topics that the member is subscribed to.
         */
        Collection<String> subscribedTopics;

        /**
         * The current target partitions of the member.
         */
        Collection<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.
         */
        Collection<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;
}