| /* |
| * 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.iotdb.cluster.partition.slot; |
| |
| import org.apache.iotdb.db.engine.StorageEngine; |
| import org.apache.iotdb.tsfile.utils.Murmur128Hash; |
| |
| import static org.apache.iotdb.cluster.config.ClusterConstant.HASH_SALT; |
| |
| /** SlotStrategy determines which slot a {sg, timestamp} or {sg, partition} belongs. */ |
| public interface SlotStrategy { |
| int calculateSlotByTime(String storageGroupName, long timestamp, int maxSlotNum); |
| |
| int calculateSlotByPartitionNum(String storageGroupName, long partitionId, int maxSlotNum); |
| |
| class DefaultStrategy implements SlotStrategy { |
| |
| @Override |
| public int calculateSlotByTime(String storageGroupName, long timestamp, int maxSlotNum) { |
| long partitionNum = StorageEngine.getTimePartition(timestamp); |
| return calculateSlotByPartitionNum(storageGroupName, partitionNum, maxSlotNum); |
| } |
| |
| @Override |
| public int calculateSlotByPartitionNum( |
| String storageGroupName, long partitionId, int maxSlotNum) { |
| int hash = Murmur128Hash.hash(storageGroupName, partitionId, HASH_SALT); |
| return Math.abs(hash % maxSlotNum); |
| } |
| } |
| } |