/**
 * 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.
 */
import { MessageView } from '../message';
import { FifoConsumeService } from './FifoConsumeService';
import { MessageListener } from './MessageListener';
import type { ProcessQueue } from './ProcessQueue';
/**
 * FIFO consume service for lite push consumer.
 *
 * <p>Similar to {@link FifoConsumeService}, but groups messages by lite topic
 * instead of message group. This ensures messages with the same lite topic are
 * consumed sequentially, while messages with different lite topics can be
 * consumed in parallel when the accelerator is enabled.</p>
 *
 * <p>When the message listener returns {@link ConsumeResultSuspend}, all
 * remaining messages with the same lite topic in the current batch are also
 * suspended, while messages with different lite topics continue to be consumed.</p>
 */
export declare class LiteFifoConsumeService extends FifoConsumeService {
    #private;
    constructor(clientId: string, messageListener: MessageListener, enableFifoConsumeAccelerator?: boolean);
    /**
     * Use lite topic as the group key for FIFO consumption.
     *
     * @param messageView - The message view
     * @return {string} The lite topic, empty string if not present
     */
    protected getMessageGroupKey(messageView: MessageView): string;
    protected consumeIteratively(pq: ProcessQueue, messageViews: MessageView[], startIndex: number): Promise<void>;
}