Package io.debezium.connector.cassandra

Class FileOffsetWriter

java.lang.Object

io.debezium.connector.cassandra.FileOffsetWriter

All Implemented Interfaces:

OffsetWriter

public class FileOffsetWriter
extends Object
implements OffsetWriter

A concrete implementation of OffsetWriter which tracks the progress of events being processed by the SnapshotProcessor and respective commit log processor to property files, snapshot_offset.properties and commitlog_offset.properties, respectively. The property key is the table for the offset, and is serialized in the format of . The property value is the offset position, and is serialized in the format of :. For snapshots, a table is either fully processed or not processed at all, so offset is given a default value of ":-1" , where the filename is an empty string, and file position is -1. For commit logs, the file_name represents the commit log file name and file position represents bytes read in the commit log.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COMMITLOG_OFFSET_FILE
private final File	commitLogOffsetFile
private final FileLock	commitLogOffsetFileLock
private final Properties	commitLogProps
private static final org.slf4j.Logger	LOGGER
static final String	SNAPSHOT_OFFSET_FILE
private final File	snapshotOffsetFile
private final FileLock	snapshotOffsetFileLock
private final Properties	snapshotProps

Constructor Summary

Constructors

Constructor	Description
FileOffsetWriter(String offsetDir)

Method Summary

Modifier and Type	Method	Description
void	close()	Close all resources used by this class.
void	flush()	Flush latest offsets to disk.
private FileLock	init(File offsetFile)
private Path	initLockPath(File offsetFile)
boolean	isOffsetProcessed(String sourceTable, String sourceOffset, boolean isSnapshot)	Determine if an offset has been processed based on the table name, offset position, and whether it is from snapshot or not.
private void	loadOffset(File offsetFile, Properties props)
void	markOffset(String sourceTable, String sourceOffset, boolean isSnapshot)	Update the offset in memory if the provided offset is greater than the existing offset.
private static void	saveOffset(File offsetFile, Properties props)

Methods inherited from class java.lang.Object

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

Field Details

LOGGER

private static final org.slf4j.Logger LOGGER

SNAPSHOT_OFFSET_FILE

public static final String SNAPSHOT_OFFSET_FILE

See Also:

• Constant Field Values

COMMITLOG_OFFSET_FILE

public static final String COMMITLOG_OFFSET_FILE

See Also:

• Constant Field Values

snapshotProps

private final Properties snapshotProps

commitLogProps

private final Properties commitLogProps

snapshotOffsetFile

private final File snapshotOffsetFile

commitLogOffsetFile

private final File commitLogOffsetFile

snapshotOffsetFileLock

private final FileLock snapshotOffsetFileLock

commitLogOffsetFileLock

private final FileLock commitLogOffsetFileLock

Constructor Details

FileOffsetWriter

public FileOffsetWriter(String offsetDir)
                 throws IOException

Throws:

IOException

Method Details

markOffset

public void markOffset(String sourceTable,
 String sourceOffset,
 boolean isSnapshot)

Description copied from interface: OffsetWriter

Update the offset in memory if the provided offset is greater than the existing offset.

Specified by:

markOffset in interface OffsetWriter

Parameters:

sourceTable - string in the format of .

.

sourceOffset - string in the format of :

isSnapshot - whether the offset is coming from a snapshot or commit log

isOffsetProcessed

public boolean isOffsetProcessed(String sourceTable,
 String sourceOffset,
 boolean isSnapshot)

Description copied from interface: OffsetWriter

Determine if an offset has been processed based on the table name, offset position, and whether it is from snapshot or not.

Specified by:

isOffsetProcessed in interface OffsetWriter

Parameters:

sourceTable - string in the format of .

.

sourceOffset - string in the format of :

isSnapshot - whether the offset is coming from a snapshot or commit log

Returns:

true if the offset has been processed, false otherwise.

flush

public void flush()

Description copied from interface: OffsetWriter

Flush latest offsets to disk.

Specified by:

flush in interface OffsetWriter

close

public void close()

Description copied from interface: OffsetWriter

Close all resources used by this class.

Specified by:

close in interface OffsetWriter

saveOffset

private static void saveOffset(File offsetFile,
 Properties props)
                        throws IOException

Throws:

IOException

loadOffset

private void loadOffset(File offsetFile,
 Properties props)
                 throws IOException

Throws:

IOException

init

private FileLock init(File offsetFile)
               throws IOException

Throws:

IOException

initLockPath

private Path initLockPath(File offsetFile)
                   throws IOException

Throws:

IOException