com.bigdata.service
Class DistributedTransactionService.SnapshotHelper

java.lang.Object
  com.bigdata.service.DistributedTransactionService.SnapshotHelper

Enclosing class:

DistributedTransactionService

public static class DistributedTransactionService.SnapshotHelper
extends Object

A helper class for reading and writing snapshots of the commit time index. The image contains the commit timestamps in order.

Note: The caller must prevent concurrent changes to the index.

Version:

$Id: DistributedTransactionService.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

TODO:

write counters into the files since the system clock could be messed with on before a restart but the counters will always be valid. we would then either read both and choose one, or have a method to report the header with the earlier counter., Checksum the commit time log file? this is easily done either using a ByteBuffer or using Adler32.

Constructor Summary

DistributedTransactionService.SnapshotHelper()

Method Summary

static int	read(CommitTimeIndex ndx, DataInputStream is)
static int	read(CommitTimeIndex ndx, File file)
static int	write(CommitTimeIndex ndx, DataOutputStream os)
static int	write(CommitTimeIndex ndx, File file)

Methods inherited from class java.lang.Object

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

Constructor Detail

DistributedTransactionService.SnapshotHelper

public DistributedTransactionService.SnapshotHelper()

Method Detail

read

public static int read(CommitTimeIndex ndx,
                       File file)
                throws IOException

Throws:

IOException

read

public static int read(CommitTimeIndex ndx,
                       DataInputStream is)
                throws IOException

Throws:

IOException

write

public static int write(CommitTimeIndex ndx,
                        File file)
                 throws IOException

Throws:

IOException

write

public static int write(CommitTimeIndex ndx,
                        DataOutputStream os)
                 throws IOException

Throws:

IOException