| /** |
| * 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.distributedlog; |
| |
| import org.apache.distributedlog.util.DLUtils; |
| import org.apache.bookkeeper.versioning.Version; |
| import org.apache.bookkeeper.versioning.Versioned; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Utility class for storing and reading |
| * the max seen txid in zookeeper |
| */ |
| class MaxTxId { |
| static final Logger LOG = LoggerFactory.getLogger(MaxTxId.class); |
| |
| private Version version; |
| private long currentMax; |
| |
| MaxTxId(Versioned<byte[]> maxTxIdData) { |
| if (null != maxTxIdData |
| && null != maxTxIdData.getValue() |
| && null != maxTxIdData.getVersion()) { |
| this.version = maxTxIdData.getVersion(); |
| try { |
| this.currentMax = DLUtils.deserializeTransactionId(maxTxIdData.getValue()); |
| } catch (NumberFormatException e) { |
| LOG.warn("Invalid txn id stored in {}", e); |
| this.currentMax = DistributedLogConstants.INVALID_TXID; |
| } |
| } else { |
| this.currentMax = DistributedLogConstants.INVALID_TXID; |
| if (null != maxTxIdData && null != maxTxIdData.getVersion()) { |
| this.version = maxTxIdData.getVersion(); |
| } else { |
| throw new IllegalStateException("Invalid MaxTxId found - " + maxTxIdData); |
| } |
| } |
| } |
| |
| synchronized void update(Version version, long txId) { |
| if (version.compare(this.version) == Version.Occurred.AFTER) { |
| this.version = version; |
| this.currentMax = txId; |
| } |
| } |
| |
| synchronized long get() { |
| return currentMax; |
| } |
| |
| public synchronized Versioned<Long> getVersionedData(long txId) { |
| return new Versioned<Long>(Math.max(txId, get()), version); |
| } |
| |
| } |