| /* |
| * Copyright 2015 Open Networking Laboratory |
| * |
| * Licensed 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.onosproject.store.consistent.impl; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| |
| import java.util.List; |
| import com.google.common.base.Charsets; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.hash.Hashing; |
| |
| /** |
| * Partitioner for mapping table entries to individual database partitions. |
| * <p> |
| * By default a md5 hash of the hash key (key or table name) is used to pick a |
| * partition. |
| */ |
| public abstract class DatabasePartitioner implements Partitioner<String> { |
| // Database partitions sorted by their partition name. |
| protected final List<Database> partitions; |
| |
| public DatabasePartitioner(List<Database> partitions) { |
| checkState(partitions != null && !partitions.isEmpty(), "Partitions cannot be null or empty"); |
| this.partitions = ImmutableList.copyOf(partitions); |
| } |
| |
| protected int hash(String key) { |
| return Math.abs(Hashing.md5().newHasher().putBytes(key.getBytes(Charsets.UTF_8)).hash().asInt()); |
| } |
| |
| } |