/*
* The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
* (the "License"). You may not use this work except in compliance with the License, which is
* available at www.apache.org/licenses/LICENSE-2.0
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied, as more fully set forth in the License.
*
* See the NOTICE file distributed with this work for information regarding copyright ownership.
*/
package alluxio.master.journalv0;
import alluxio.master.journalv0.ufs.UfsJournal;
import alluxio.util.URIUtils;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import javax.annotation.concurrent.ThreadSafe;
/**
* The read-only journal. It prevents access to a {@link JournalWriter}.
*/
@ThreadSafe
public interface Journal {
/**
* A {@link Journal} factory.
*/
@ThreadSafe
final class Factory implements JournalFactory {
private final URI mBase;
/**
* Creates a read-only journal factory with the specified base location. When journals are
* created, their names are appended to the base location.
*
* @param base the base location for journals created by this factory
*/
public Factory(URI base) {
mBase = base;
}
@Override
public Journal create(String name) {
try {
return new UfsJournal(URIUtils.appendPath(mBase, name));
} catch (URISyntaxException e) {
throw new RuntimeException(e);
}
}
/**
* Creates a new read-only journal using the given location.
*
* @param location the journal location
* @return a new instance of {@link Journal}
*/
public static Journal create(URI location) {
return new UfsJournal(location);
}
}
/**
* @return the journal location
*/
URI getLocation();
/**
* @return the {@link JournalReader} for this journal
*/
JournalReader getReader();
/**
* @return whether the journal has been formatted
*/
boolean isFormatted() throws IOException;
}