com.gigaspaces.internal.server.space.redolog

Interface IRedoLogFile<T extends IReplicationOrderedPacket>

All Superinterfaces:

IRedoLogFileStatistics

All Known Implementing Classes:

DBMemoryRedoLogFile, DBSwapRedoLogFile, FixedSizeSwapRedoLogFile, MemoryRedoLogFile

public interface IRedoLogFile<T extends IReplicationOrderedPacket>
extends IRedoLogFileStatistics

Acts as the redo log packets storage MemoryRedoLogFile Implementor should support concurrent readers or a single writer, in other words, the implementor can assume access to this structure are guarded with a reader writer lock according to the operation type An exception is getApproximateSize() method which should not assume a reader lock is held.

Since:

7.1

Author:

eitany

Method Summary

Modifier and Type	Method and Description
void	add(T replicationPacket) Add a replication packet to the file as the latest packet
void	close() Closes the redo log file
void	deleteOldestPackets(long packetsCount) Deletes the oldest packets, starting from the oldest up until the specified batch size
default int	flushToStorage() Flush redo-log packets from memory to underlying storage.
long	getApproximateSize() Gets an approximation of the number of replication packets held in the file, implementation of this method should not assume a reader lock is held and hence can return a result which is not accurate if it cannot do so without a lock.
T	getOldest()
long	getWeight()
boolean	isEmpty()
CompactionResult	performCompaction(long from, long to)
ReadOnlyIterator<T>	readOnlyIterator(long fromKey)
T	removeOldest() Remove and returns the oldest replication packet in the file
long	size()
void	validateIntegrity() Validates the integrity of the redo log file

Methods inherited from interface com.gigaspaces.cluster.replication.IRedoLogFileStatistics

getExternalStoragePacketsCount, getExternalStoragePacketsWeight, getExternalStorageSpaceUsed, getMemoryPacketsCount, getMemoryPacketsWeight

Method Detail

removeOldest

T removeOldest()

Remove and returns the oldest replication packet in the file

Returns:

returns the oldest replication packet in the file

getOldest

T getOldest()

Returns:

Gets the oldest replication packet in the file

add

void add(T replicationPacket)

Add a replication packet to the file as the latest packet

Parameters:

replicationPacket - packet to add

size

long size()

Specified by:

size in interface IRedoLogFileStatistics

Returns:

the number of replication packets held in the file

getApproximateSize

long getApproximateSize()

Gets an approximation of the number of replication packets held in the file, implementation of this method should not assume a reader lock is held and hence can return a result which is not accurate if it cannot do so without a lock.

Returns:

an approximation of the replication packets held in the file

isEmpty

boolean isEmpty()

Returns:

true if the file has no replication packets stored

readOnlyIterator

ReadOnlyIterator<T> readOnlyIterator(long fromKey)

Parameters:

fromKey - index to start from

Returns:

read only iterator over the packets in the file that will start from the given index, where 0 specified the oldest packet

deleteOldestPackets

void deleteOldestPackets(long packetsCount)

Deletes the oldest packets, starting from the oldest up until the specified batch size

Parameters:

packetsCount - number of oldest packets to delete

validateIntegrity

void validateIntegrity()
                throws RedoLogFileCompromisedException

Validates the integrity of the redo log file

Throws:

RedoLogFileCompromisedException

close

void close()

Closes the redo log file

getWeight

long getWeight()

performCompaction

CompactionResult performCompaction(long from,
                                   long to)

Parameters:

from - key to start searching transient packet from

to - key to end searching transient packet from

Returns:

number of discarded packets

flushToStorage

default int flushToStorage()

Flush redo-log packets from memory to underlying storage. Not thread safe, should be called under lock and only when the space is in quiesce mode.

Returns:

number of flushed packets

Since:

16.2