/**
* 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;
import com.twitter.distributedlog.exceptions.DLInterruptedException;
import com.twitter.distributedlog.exceptions.ZKException;
import com.twitter.distributedlog.util.DLUtils;
import org.apache.bookkeeper.meta.ZkVersion;
import org.apache.bookkeeper.versioning.Version;
import org.apache.bookkeeper.versioning.Versioned;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
/**
* Utility class for storing and reading max ledger sequence number
*/
class MaxLogSegmentSequenceNo {
static final Logger LOG = LoggerFactory.getLogger(MaxLogSegmentSequenceNo.class);
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 {
version = new ZkVersion(-1);
}
}
}
synchronized int getZkVersion() {
return ((ZkVersion) version).getZnodeVersion();
}
synchronized long getSequenceNumber() {
return maxSeqNo;
}
synchronized MaxLogSegmentSequenceNo update(int zkVersion, long logSegmentSeqNo) {
return update(new ZkVersion(zkVersion), logSegmentSeqNo);
}
synchronized MaxLogSegmentSequenceNo update(ZkVersion version, long logSegmentSeqNo) {
if (version.compare(this.version) == Version.Occurred.AFTER) {
this.version = version;
this.maxSeqNo = logSegmentSeqNo;
}
return this;
}
synchronized void store(ZooKeeperClient zkc, String path, long logSegmentSeqNo) throws IOException {
try {
Stat stat = zkc.get().setData(path,
DLUtils.serializeLogSegmentSequenceNumber(logSegmentSeqNo), getZkVersion());
update(stat.getVersion(), logSegmentSeqNo);
} catch (KeeperException ke) {
throw new ZKException("Error writing max ledger sequence number " + logSegmentSeqNo + " to "
+ path + " : ", ke);
} catch (ZooKeeperClient.ZooKeeperConnectionException zce) {
throw new IOException("Error writing max ledger sequence number " + logSegmentSeqNo + " to "
+ path + " : ", zce);
} catch (InterruptedException e) {
throw new DLInterruptedException("Error writing max ledger sequence number " + logSegmentSeqNo + " to "
+ path + " : ", e);
}
}
}