| /** |
| * 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.bk; |
| |
| import com.twitter.distributedlog.util.Transaction; |
| import com.twitter.distributedlog.util.Transaction.OpListener; |
| import com.twitter.util.Future; |
| import org.apache.bookkeeper.client.LedgerHandle; |
| |
| import java.io.IOException; |
| |
| /** |
| * Delegator of the underlying allocator. If it owns the allocator, it takes |
| * the responsibility of start the allocator and close the allocator. |
| */ |
| public class LedgerAllocatorDelegator implements LedgerAllocator { |
| |
| private final LedgerAllocator allocator; |
| private final boolean ownAllocator; |
| |
| /** |
| * Create an allocator's delegator. |
| * |
| * @param allocator |
| * the underlying allocator |
| * @param ownAllocator |
| * whether to own the allocator |
| */ |
| public LedgerAllocatorDelegator(LedgerAllocator allocator, |
| boolean ownAllocator) |
| throws IOException { |
| this.allocator = allocator; |
| this.ownAllocator = ownAllocator; |
| if (this.ownAllocator) { |
| this.allocator.start(); |
| } |
| } |
| |
| @Override |
| public void start() throws IOException { |
| // no-op |
| } |
| |
| @Override |
| public Future<Void> delete() { |
| return Future.exception(new UnsupportedOperationException("Can't delete an allocator by delegator")); |
| } |
| |
| @Override |
| public void allocate() throws IOException { |
| this.allocator.allocate(); |
| } |
| |
| @Override |
| public Future<LedgerHandle> tryObtain(Transaction<Object> txn, |
| OpListener<LedgerHandle> listener) { |
| return this.allocator.tryObtain(txn, listener); |
| } |
| |
| @Override |
| public Future<Void> asyncClose() { |
| if (ownAllocator) { |
| return this.allocator.asyncClose(); |
| } else { |
| return Future.value(null); |
| } |
| } |
| } |