/*
 * 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.inlong.sort.iceberg.sink;

import org.apache.flink.api.common.functions.RichMapFunction;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.shaded.guava18.com.google.common.util.concurrent.RateLimiter;

/**
 * Function that limit the rate.
 */
public class RateLimitMapFunction<T> extends RichMapFunction<T, T> {

    /**
     * Rate limit per second for all subtasks added up.
     */
    private final double totalLimit;
    private transient RateLimiter rateLimiter;

    public RateLimitMapFunction(long totalLimit) {
        this.totalLimit = totalLimit;
    }

    @Override
    public void open(Configuration parameters) throws Exception {
        super.open(parameters);
        this.rateLimiter = RateLimiter.create(
                totalLimit / getRuntimeContext().getNumberOfParallelSubtasks());
    }

    @Override
    public T map(T value) throws Exception {
        rateLimiter.acquire();
        return value;
    }
}
