| /** |
| * 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; |
| |
| /** |
| * Utility class for storing and reading max ledger sequence number |
| */ |
| class MaxLogSegmentSequenceNo { |
| |
| Version version; |
| long maxSeqNo; |
| |
| MaxLogSegmentSequenceNo(Versioned<byte[]> logSegmentsData) { |
| if (null != logSegmentsData |
| && null != logSegmentsData.getValue() |
| && null != logSegmentsData.getVersion()) { |
| version = logSegmentsData.getVersion(); |
| try { |
| maxSeqNo = DLUtils.deserializeLogSegmentSequenceNumber(logSegmentsData.getValue()); |
| } catch (NumberFormatException nfe) { |
| maxSeqNo = DistributedLogConstants.UNASSIGNED_LOGSEGMENT_SEQNO; |
| } |
| } else { |
| maxSeqNo = DistributedLogConstants.UNASSIGNED_LOGSEGMENT_SEQNO; |
| if (null != logSegmentsData && null != logSegmentsData.getVersion()) { |
| version = logSegmentsData.getVersion(); |
| } else { |
| throw new IllegalStateException("Invalid MaxLogSegmentSequenceNo found - " + logSegmentsData); |
| } |
| } |
| } |
| |
| synchronized Version getVersion() { |
| return version; |
| } |
| |
| synchronized long getSequenceNumber() { |
| return maxSeqNo; |
| } |
| |
| synchronized MaxLogSegmentSequenceNo update(Version version, long logSegmentSeqNo) { |
| if (version.compare(this.version) == Version.Occurred.AFTER) { |
| this.version = version; |
| this.maxSeqNo = logSegmentSeqNo; |
| } |
| return this; |
| } |
| |
| public synchronized Versioned<Long> getVersionedData(long seqNo) { |
| return new Versioned<Long>(seqNo, version); |
| } |
| |
| } |