alluxio.master.journalv0.ufs

Class UfsJournalReader

java.lang.Object

alluxio.master.journalv0.ufs.UfsJournalReader

All Implemented Interfaces:

JournalReader

@NotThreadSafe
public class UfsJournalReader
extends Object
implements JournalReader

Implementation of JournalReader based on UFS.

Method Summary

Modifier and Type	Method and Description
JournalInputStream	getCheckpointInputStream() Gets the JournalInputStream for the journal checkpoint.
long	getCheckpointLastModifiedTimeMs()
JournalInputStream	getNextInputStream()
boolean	isValid() Checks to see if the journal checkpoint has not been updated.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isValid

public boolean isValid()

Description copied from interface: JournalReader

Checks to see if the journal checkpoint has not been updated. If it has been updated since the creation of this reader, this reader is no longer valid.

Specified by:

isValid in interface JournalReader

Returns:

true if the checkpoint has not been updated

getCheckpointInputStream

public JournalInputStream getCheckpointInputStream()
                                            throws IOException

Description copied from interface: JournalReader

Gets the JournalInputStream for the journal checkpoint. This must be called before calling JournalReader.getNextInputStream().

Specified by:

getCheckpointInputStream in interface JournalReader

Returns:

the JournalInputStream for the journal checkpoint

Throws:

IOException

getNextInputStream

public JournalInputStream getNextInputStream()
                                      throws IOException

Specified by:

getNextInputStream in interface JournalReader

Returns:

the input stream for the next completed log. Will return null if the next completed log does not exist yet.

Throws:

IOException

getCheckpointLastModifiedTimeMs

public long getCheckpointLastModifiedTimeMs()
                                     throws IOException

Specified by:

getCheckpointLastModifiedTimeMs in interface JournalReader

Returns:

the last modified time of the checkpoint in ms

Throws:

IOException