| /* |
| * 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.bookkeeper.clients.impl.routing; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| |
| import java.util.Map; |
| import java.util.concurrent.ThreadLocalRandom; |
| import java.util.concurrent.locks.StampedLock; |
| import javax.annotation.Nullable; |
| import javax.annotation.concurrent.ThreadSafe; |
| import lombok.extern.slf4j.Slf4j; |
| import org.apache.bookkeeper.clients.impl.internal.api.HashStreamRanges; |
| import org.apache.bookkeeper.common.router.HashRouter; |
| import org.apache.bookkeeper.stream.proto.RangeProperties; |
| |
| /** |
| * A router that used to route the events to ranges. |
| */ |
| @ThreadSafe |
| @Slf4j |
| public class RangeRouter<K> { |
| |
| private final HashRouter<K> keyRouter; |
| private final StampedLock lock; |
| private HashStreamRanges ranges; |
| |
| public RangeRouter(HashRouter<K> keyRouter) { |
| this.keyRouter = keyRouter; |
| this.lock = new StampedLock(); |
| } |
| |
| /** |
| * Get the range to route the given {@code key}. |
| * |
| * <p>If <i>key</i> is null, a range is picked randomly. Otherwise, the range is picked |
| * according to the hash code of {@code key}. |
| * |
| * <p>This function should be called after {@link #setRanges(HashStreamRanges)}. |
| * |
| * @param key the key to route |
| * @return the range to write. |
| * @throws IllegalStateException if ranges is empty. |
| */ |
| public long getRange(@Nullable K key) { |
| return getRangeProperties(key).getRangeId(); |
| } |
| |
| public RangeProperties getRangeProperties(@Nullable K key) { |
| long routingKey; |
| if (null != key) { |
| routingKey = keyRouter.getRoutingKey(key); |
| } else { |
| routingKey = ThreadLocalRandom.current().nextLong(); |
| } |
| HashStreamRanges rs; |
| long stamp = lock.tryOptimisticRead(); |
| rs = ranges; |
| if (!lock.validate(stamp)) { |
| stamp = lock.readLock(); |
| try { |
| rs = ranges; |
| } finally { |
| lock.unlockRead(stamp); |
| } |
| } |
| checkState(null != rs, "No range is available"); |
| |
| Map.Entry<Long, RangeProperties> ceilingEntry = rs.getRanges().floorEntry(routingKey); |
| return ceilingEntry.getValue(); |
| } |
| |
| public HashStreamRanges getRanges() { |
| HashStreamRanges rs; |
| long stamp = lock.tryOptimisticRead(); |
| rs = ranges; |
| if (!lock.validate(stamp)) { |
| stamp = lock.readLock(); |
| try { |
| rs = ranges; |
| } finally { |
| lock.unlockRead(stamp); |
| } |
| } |
| return rs; |
| } |
| |
| public HashStreamRanges setRanges(HashStreamRanges ranges) { |
| long stamp = lock.writeLock(); |
| try { |
| // we only update the routing only when see new active ranges |
| if ((this.ranges == null) |
| || (ranges.getMaxRangeId() > this.ranges.getMaxRangeId())) { |
| HashStreamRanges oldRanges = this.ranges; |
| this.ranges = ranges; |
| return oldRanges; |
| } else { |
| return null; |
| } |
| } finally { |
| lock.unlockWrite(stamp); |
| } |
| } |
| |
| } |