org.apache.hadoop.hdfs.server.protocol.RemoteEditLogManifest Maven / Gradle / Ivy
/**
* 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.hadoop.hdfs.server.protocol;
import java.util.Collections;
import java.util.List;
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
/**
* An enumeration of logs available on a remote NameNode.
*/
public class RemoteEditLogManifest {
private List logs;
private long committedTxnId = HdfsServerConstants.INVALID_TXID;
public RemoteEditLogManifest() {
}
public RemoteEditLogManifest(List logs) {
this(logs, HdfsServerConstants.INVALID_TXID);
}
public RemoteEditLogManifest(List logs, long committedTxnId) {
this.logs = logs;
this.committedTxnId = committedTxnId;
checkState();
}
/**
* Check that the logs are non-overlapping sequences of transactions,
* in sorted order. They do not need to be contiguous.
* @throws IllegalStateException if incorrect
*/
private void checkState() {
Preconditions.checkNotNull(logs);
RemoteEditLog prev = null;
for (RemoteEditLog log : logs) {
if (prev != null) {
if (log.getStartTxId() <= prev.getEndTxId()) {
throw new IllegalStateException(
"Invalid log manifest (log " + log + " overlaps " + prev + ")\n"
+ this);
}
}
prev = log;
}
}
public List getLogs() {
return Collections.unmodifiableList(logs);
}
public long getCommittedTxnId() {
return committedTxnId;
}
@Override
public String toString() {
return "[" + Joiner.on(", ").join(logs) + "]" + " CommittedTxId: "
+ committedTxnId;
}
}