asyncMultiGetSortKeys

异步获取某个HashKey下SortKey列表。

public static class MultiGetSortKeysResult {
    /**
     * return value for multiGetSortkeys
     * @param allFetched true if all data on the server are fetched; false if only partial data are fetched.
     * @param keys the got keys.
     *             The output keys are in order.
     */
    public boolean allFetched;
    public List<byte[]> keys;
};
 
public static interface MultiGetSortKeysListener extends GenericFutureListener<Future<MultiGetSortKeysResult>> {
    /**
     * This function will be called when listened asyncMultiGetSortKeys future is done.
     * @param future the listened future
     * @throws Exception
     *
     * Notice: User shouldn't do any operations that may block or time-consuming
     */
    @Override
    public void operationComplete(Future<MultiGetSortKeysResult> future) throws Exception;
}
 
/**
 * get all the sortKeys for the same hashKey
 * @param hashKey used to decide which partition the key may exist
 *                should not be null or empty.
 * @param maxFetchCount max count of kv pairs to be fetched
 *                      maxFetchCount <= 0 means no limit. default value is 100
 * @param maxFetchSize max size of kv pairs to be fetched.
 *                     maxFetchSize <= 0 means no limit. default value is 1000000.
 * @param timeout how long will the operation timeout in milliseconds.
 *                if timeout > 0, it is a timeout value for current op,
 *                else the timeout value in the configuration file will be used.
 *
 * @return the future for current op
 *
 * Future return:
 *      On success: An object of type MultiGetSortKeysResult
 *      On failure: a throwable, which is an instance of PException
 *
 * Thread safety:
 *      All the listeners for the same table are guaranteed to be dispatched in the same thread, so all the
 *      listeners for the same future are guaranteed to be executed as the same order as the listeners added.
 *      But listeners for different tables are not guaranteed to be dispatched in the same thread.
 */
public Future<MultiGetSortKeysResult> asyncMultiGetSortKeys(byte[] hashKey, int maxFetchCount, int maxFetchSize, int timeout/*ms*/);
public Future<MultiGetSortKeysResult> asyncMultiGetSortKeys(byte[] hashKey, int timeout/*ms*/);

注：

• 提供了两个版本的接口，其中第一个接口可以指定maxFetchCount和maxFetchSize。
• 参数：需传入HashKey、timeout；选择性传入maxFetchCount、maxFetchSize。
  • timeout单位为毫秒，如果<=0，表示使用配置文件中的默认超时。
  • maxFetchCount和maxFetchSize用于限制读取的数据量，maxFetchCount表示最多读取的数据条数，maxFetchSize表示最多读取的数据字节数，两者任一达到限制就停止读取。
• 返回值：Future。
  • allFetched：如果用户指定了maxFetchCount或者maxFetchSize，单次查询可能只获取到部分结果。如果所有满足条件的数据都已经获取到，则设置为true；否则设置为false。