Madan Jampani | 2546111 | 2015-02-17 14:17:29 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2015 Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Madan Jampani | 0934270 | 2015-02-05 23:32:40 -0800 | [diff] [blame] | 17 | package org.onosproject.store.consistent.impl; |
| 18 | |
| 19 | import static com.google.common.base.Preconditions.checkState; |
| 20 | |
| 21 | import java.util.Map; |
| 22 | |
| 23 | import com.google.common.base.Charsets; |
| 24 | import com.google.common.collect.ImmutableSortedMap; |
| 25 | import com.google.common.hash.Hashing; |
| 26 | |
| 27 | /** |
| 28 | * Partitioner for mapping table entries to individual database partitions. |
| 29 | * <p> |
| 30 | * By default a md5 hash of the hash key (key or table name) is used to pick a |
| 31 | * partition. |
| 32 | */ |
| 33 | public abstract class DatabasePartitioner implements Partitioner<String> { |
| 34 | // Database partitions sorted by their partition name. |
| 35 | protected final Database[] sortedPartitions; |
| 36 | |
| 37 | public DatabasePartitioner(Map<String, Database> partitionMap) { |
| 38 | checkState(partitionMap != null && !partitionMap.isEmpty(), "Partition map cannot be null or empty"); |
| 39 | sortedPartitions = ImmutableSortedMap.<String, Database>copyOf(partitionMap).values().toArray(new Database[]{}); |
| 40 | } |
| 41 | |
| 42 | protected int hash(String key) { |
| 43 | return Math.abs(Hashing.md5().newHasher().putBytes(key.getBytes(Charsets.UTF_8)).hash().asInt()); |
| 44 | } |
| 45 | |
| 46 | } |