/** * 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 com.twitter.distributedlog; import com.twitter.distributedlog.exceptions.OverCapacityException; import com.twitter.distributedlog.util.PermitLimiter; public class WriteLimiter { String streamName; final PermitLimiter streamLimiter; final PermitLimiter globalLimiter; public WriteLimiter(String streamName, PermitLimiter streamLimiter, PermitLimiter globalLimiter) { this.streamName = streamName; this.streamLimiter = streamLimiter; this.globalLimiter = globalLimiter; } public void acquire() throws OverCapacityException { if (!streamLimiter.acquire()) { throw new OverCapacityException(String.format("Stream write capacity exceeded for stream %s", streamName)); } try { if (!globalLimiter.acquire()) { throw new OverCapacityException("Global write capacity exceeded"); } } catch (OverCapacityException ex) { streamLimiter.release(1); throw ex; } } public void release() { release(1); } public void release(int permits) { streamLimiter.release(permits); globalLimiter.release(permits); } }