RedisTemplate操作命令 - Hash

/*
 * Copyright 2011-2019 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.data.redis.core;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.springframework.lang.Nullable;

/**
 * Redis map specific operations working on a hash.
 *
 * @author Costin Leau
 * @author Christoph Strobl
 * @author Ninad Divadkar
 */
public interface HashOperations<H, HK, HV> {

    /**
     * Delete given hash {@code hashKeys}.
     *
     * @param key must not be {@literal null}.
     * @param hashKeys must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    Long delete(H key, Object... hashKeys);

    /**
     * Determine if given hash {@code hashKey} exists.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    Boolean hasKey(H key, Object hashKey);

    /**
     * Get value for given {@code hashKey} from hash at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @return {@literal null} when key or hashKey does not exist or used in pipeline / transaction.
     */
    @Nullable
    HV get(H key, Object hashKey);

    /**
     * Get values for given {@code hashKeys} from hash at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @param hashKeys must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    List<HV> multiGet(H key, Collection<HK> hashKeys);

    /**
     * Increment {@code value} of a hash {@code hashKey} by the given {@code delta}.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @param delta
     * @return {@literal null} when used in pipeline / transaction.
     */
    Long increment(H key, HK hashKey, long delta);

    /**
     * Increment {@code value} of a hash {@code hashKey} by the given {@code delta}.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @param delta
     * @return {@literal null} when used in pipeline / transaction.
     */
    Double increment(H key, HK hashKey, double delta);

    /**
     * Get key set (fields) of hash at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    Set<HK> keys(H key);

    /**
     * Returns the length of the value associated with {@code hashKey}. If either the {@code key} or the {@code hashKey}
     * do not exist, {@code 0} is returned.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     * @since 2.1
     */
    @Nullable
    Long lengthOfValue(H key, HK hashKey);

    /**
     * Get size of hash at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    Long size(H key);

    /**
     * Set multiple hash fields to multiple values using data provided in {@code m}.
     *
     * @param key must not be {@literal null}.
     * @param m must not be {@literal null}.
     */
    void putAll(H key, Map<? extends HK, ? extends HV> m);

    /**
     * Set the {@code value} of a hash {@code hashKey}.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @param value
     */
    void put(H key, HK hashKey, HV value);

    /**
     * Set the {@code value} of a hash {@code hashKey} only if {@code hashKey} does not exist.
     *
     * @param key must not be {@literal null}.
     * @param hashKey must not be {@literal null}.
     * @param value
     * @return {@literal null} when used in pipeline / transaction.
     */
    Boolean putIfAbsent(H key, HK hashKey, HV value);

    /**
     * Get entry set (values) of hash at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    List<HV> values(H key);

    /**
     * Get entire hash stored at {@code key}.
     *
     * @param key must not be {@literal null}.
     * @return {@literal null} when used in pipeline / transaction.
     */
    Map<HK, HV> entries(H key);

    /**
     * Use a {@link Cursor} to iterate over entries in hash at {@code key}. <br />
     * <strong>Important:</strong> Call {@link Cursor#close()} when done to avoid resource leak.
     *
     * @param key must not be {@literal null}.
     * @param options
     * @return {@literal null} when used in pipeline / transaction.
     * @since 1.4
     */
    Cursor<Map.Entry<HK, HV>> scan(H key, ScanOptions options);

    /**
     * @return never {@literal null}.
     */
    RedisOperations<H, ?> getOperations();
}