edu.umass.cs.gigapaxos.paxosutil

Class LargeCheckpointer

java.lang.Object

edu.umass.cs.gigapaxos.paxosutil.LargeCheckpointer

public class LargeCheckpointer
extends java.lang.Object

Author:

arun A utility class for helping applications create and restore from large checkpoints.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LargeCheckpointer.Keys The random number suffixes below are in order to make it unlikely that an application checkpoint is JSON-formatted exactly as a checkpoint handle.
static class	LargeCheckpointer.LargeCheckpointerTest

Constructor Summary

Constructors

Constructor and Description
LargeCheckpointer(java.lang.String myID)
LargeCheckpointer(java.lang.String dir, java.lang.String myID)

Method Summary

Modifier and Type	Method and Description
void	close()
static java.lang.String	createCheckpointHandle(java.lang.String filename) Replicable applications can use this method to create a checkpoint handle after they have created a checkpoint in the file filename.
static boolean	isCheckpointHandle(java.lang.String string)
static void	main(java.lang.String[] args)
static java.lang.String	restoreCheckpointHandle(java.lang.String handle, java.lang.String localFilename) Replicable applications can use this method to fetch the checkpoint represented by the handle to a local file localFilename.
java.lang.String	toString()
static Replicable	wrap(Replicable pi, LargeCheckpointer lcp)

Methods inherited from class java.lang.Object

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

Constructor Detail

LargeCheckpointer

public LargeCheckpointer(java.lang.String dir,
                         java.lang.String myID)

Parameters:

dir -

myID - A unique ID for the node using this LargeCheckpointer instance.

LargeCheckpointer

public LargeCheckpointer(java.lang.String myID)

Parameters:

myID -

Method Detail

restoreCheckpointHandle

public static java.lang.String restoreCheckpointHandle(java.lang.String handle,
                                                       java.lang.String localFilename)

Replicable applications can use this method to fetch the checkpoint represented by the handle to a local file localFilename. This method is useful in Replicable.restore(String, String). The parent directory of the file localFilename must exist, otherwise NoSuchFileException will be thrown. Applications are expected to delete localFilename after they are done restoring from it.

Parameters:

handle -

localFilename -

Returns:

The file holding the checkpoint.

createCheckpointHandle

public static java.lang.String createCheckpointHandle(java.lang.String filename)

Replicable applications can use this method to create a checkpoint handle after they have created a checkpoint in the file filename.

Parameters:

filename -

Returns:

filname formatted as a paxos checkpoint handle.

isCheckpointHandle

public static boolean isCheckpointHandle(java.lang.String string)

Parameters:

string -

Returns:

True if string is a correctly formatted checkpoint handle.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

close

public void close()

main

public static void main(java.lang.String[] args)

Parameters:

args -

wrap

public static Replicable wrap(Replicable pi,
                              LargeCheckpointer lcp)

Parameters:

pi -

lcp -

Returns:

Wrapped Replicable application that stows away checkpoint created by the application at a system location.