kafka StoreQueryParameters 源码

kafka StoreQueryParameters 代码

文件路径：/streams/src/main/java/org/apache/kafka/streams/StoreQueryParameters.java

/*
 * 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;

import org.apache.kafka.streams.state.QueryableStoreType;

import java.util.Objects;

/**
 * {@code StoreQueryParameters} allows you to pass a variety of parameters when fetching a store for interactive query.
 */
public class StoreQueryParameters<T> {

    private final Integer partition;
    private final boolean staleStores;
    private final String storeName;
    private final QueryableStoreType<T> queryableStoreType;

    protected StoreQueryParameters(final String storeName, final QueryableStoreType<T>  queryableStoreType, final Integer partition, final boolean staleStores) {
        this.storeName = storeName;
        this.queryableStoreType = queryableStoreType;
        this.partition = partition;
        this.staleStores = staleStores;
    }

    public static <T> StoreQueryParameters<T> fromNameAndType(final String storeName,
                                                              final QueryableStoreType<T>  queryableStoreType) {
        return new StoreQueryParameters<>(storeName, queryableStoreType, null, false);
    }

    /**
     * Set a specific partition that should be queried exclusively.
     *
     * @param partition   The specific integer partition to be fetched from the stores list by using {@link StoreQueryParameters}.
     *
     * @return StoreQueryParameters a new {@code StoreQueryParameters} instance configured with the specified partition
     */
    public StoreQueryParameters<T> withPartition(final Integer partition) {
        return new StoreQueryParameters<>(storeName, queryableStoreType, partition, staleStores);
    }

    /**
     * Enable querying of stale state stores, i.e., allow to query active tasks during restore as well as standby tasks.
     *
     * @return StoreQueryParameters a new {@code StoreQueryParameters} instance configured with serving from stale stores enabled
     */
    public StoreQueryParameters<T> enableStaleStores() {
        return new StoreQueryParameters<>(storeName, queryableStoreType, partition, true);
    }

    /**
     * Get the name of the state store that should be queried.
     *
     * @return String state store name
     */
    public String storeName() {
        return storeName;
    }

    /**
     * Get the queryable store type for which key is queried by the user.
     *
     * @return QueryableStoreType type of queryable store
     */
    public QueryableStoreType<T> queryableStoreType() {
        return queryableStoreType;
    }

    /**
     * Get the store partition that will be queried.
     * If the method returns {@code null}, it would mean that no specific partition has been requested,
     * so all the local partitions for the store will be queried.
     *
     * @return Integer partition
     */
    public Integer partition() {
        return partition;
    }

    /**
     * Get the flag staleStores. If {@code true}, include standbys and recovering stores along with running stores.
     *
     * @return boolean staleStores
     */
    public boolean staleStoresEnabled() {
        return staleStores;
    }

    @Override
    public boolean equals(final Object obj) {
        if (!(obj instanceof StoreQueryParameters)) {
            return false;
        }
        final StoreQueryParameters storeQueryParameters = (StoreQueryParameters) obj;
        return Objects.equals(storeQueryParameters.partition, partition)
                && Objects.equals(storeQueryParameters.staleStores, staleStores)
                && Objects.equals(storeQueryParameters.storeName, storeName)
                && Objects.equals(storeQueryParameters.queryableStoreType, queryableStoreType);
    }

    @Override
    public String toString() {
        return "StoreQueryParameters {" +
                "partition=" + partition +
                ", staleStores=" + staleStores +
                ", storeName=" + storeName +
                ", queryableStoreType=" + queryableStoreType +
                '}';
    }

    @Override
    public int hashCode() {
        return Objects.hash(partition, staleStores, storeName, queryableStoreType);
    }
}

相关信息

kafka 源码目录

相关文章

kafka KafkaClientSupplier 源码

kafka KafkaStreams 源码

kafka KeyQueryMetadata 源码

kafka KeyValue 源码

kafka LagInfo 源码

kafka StreamsBuilder 源码

kafka StreamsConfig 源码

kafka StreamsMetadata 源码

kafka StreamsMetrics 源码

kafka TaskMetadata 源码