Shawyeok commented on code in PR #21681: URL: https://github.com/apache/pulsar/pull/21681#discussion_r1422230556
########## pulsar-common/src/main/java/org/apache/pulsar/common/util/AsyncTokenBucket.java: ########## @@ -0,0 +1,483 @@ +/* + * 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.pulsar.common.util; + +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicLongFieldUpdater; +import java.util.concurrent.atomic.LongAdder; +import java.util.function.LongSupplier; + +/** + * An asynchronous token bucket algorithm implementation that is optimized for performance with highly concurrent + * use. CAS (compare-and-swap) operations are used and multiple levels of CAS fields are used to minimize contention + * when using CAS fields. The {@link LongAdder} class is used in the hot path to hold the sum of consumed tokens. + * It is eventually consistent, meaning that the tokens are not updated on every call to the "consumeTokens" method. + * <p>Main usage flow: + * 1. tokens are consumed by calling the "consumeTokens" method. + * 2. the "calculateThrottlingDuration" method is called to calculate the duration of a possible needed pause when the + * tokens + * are fully consumed. Review Comment: - It would be clearer if we could inform the user about how to determine whether the tokens are fully consumed. - Is it possible to indicate whether any tokens are available after the `consumeTokens` method exits? This could make the `consumeTokens` method more convenient. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pulsar.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
