org.elasticsearch.index.translog

Class TranslogReader

java.lang.Object

org.elasticsearch.index.translog.TranslogReader

All Implemented Interfaces:

Closeable, AutoCloseable, Comparable<TranslogReader>

Direct Known Subclasses:

ImmutableTranslogReader, TranslogWriter

public abstract class TranslogReader
extends Object
implements Closeable, Comparable<TranslogReader>

A base class for all classes that allows reading ops from translog files

Field Summary

Fields

Modifier and Type	Field and Description
protected FileChannel	channel
protected org.elasticsearch.index.translog.ChannelReference	channelReference
protected AtomicBoolean	closed
protected long	firstOperationOffset
protected long	generation
static int	UNKNOWN_OP_COUNT

Constructor Summary

Constructors

Constructor and Description
TranslogReader(long generation, org.elasticsearch.index.translog.ChannelReference channelReference, long firstOperationOffset)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
int	compareTo(TranslogReader o)
protected void	ensureOpen()
long	getFirstOperationOffset()
long	getGeneration()
protected boolean	isClosed()
protected Translog.Snapshot	newReaderSnapshot(int totalOperations, ByteBuffer reusableBuffer)
Translog.Snapshot	newSnapshot()
static ImmutableTranslogReader	open(org.elasticsearch.index.translog.ChannelReference channelReference, org.elasticsearch.index.translog.Checkpoint checkpoint, String translogUUID) Given a file, return a VersionedTranslogStream based on an optionally-existing header in the file.
Path	path()
protected Translog.Operation	read(BufferedChecksumStreamInput inStream)
Translog.Operation	read(Translog.Location location)
protected abstract void	readBytes(ByteBuffer buffer, long position) reads bytes at position into the given buffer, filling it.
abstract long	sizeInBytes()
String	toString()
abstract int	totalOperations()

Methods inherited from class java.lang.Object

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

Field Detail

UNKNOWN_OP_COUNT

public static final int UNKNOWN_OP_COUNT

See Also:

Constant Field Values

generation

protected final long generation

channelReference

protected final org.elasticsearch.index.translog.ChannelReference channelReference

channel

protected final FileChannel channel

closed

protected final AtomicBoolean closed

firstOperationOffset

protected final long firstOperationOffset

Constructor Detail

TranslogReader

public TranslogReader(long generation,
              org.elasticsearch.index.translog.ChannelReference channelReference,
              long firstOperationOffset)

Method Detail

getGeneration

public long getGeneration()

sizeInBytes

public abstract long sizeInBytes()

totalOperations

public abstract int totalOperations()

getFirstOperationOffset

public final long getFirstOperationOffset()

read

public Translog.Operation read(Translog.Location location)
                        throws IOException

Throws:

IOException

newSnapshot

public Translog.Snapshot newSnapshot()

read

protected Translog.Operation read(BufferedChecksumStreamInput inStream)
                           throws IOException

Throws:

IOException

readBytes

protected abstract void readBytes(ByteBuffer buffer,
             long position)
                           throws IOException

reads bytes at position into the given buffer, filling it.

Throws:

IOException

close

public final void close()
                 throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

isClosed

protected final boolean isClosed()

ensureOpen

protected void ensureOpen()

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(TranslogReader o)

Specified by:

compareTo in interface Comparable<TranslogReader>

open

public static ImmutableTranslogReader open(org.elasticsearch.index.translog.ChannelReference channelReference,
                           org.elasticsearch.index.translog.Checkpoint checkpoint,
                           String translogUUID)
                                    throws IOException

Given a file, return a VersionedTranslogStream based on an optionally-existing header in the file. If the file does not exist, or has zero length, returns the latest version. If the header does not exist, assumes Version 0 of the translog file format.

Throws:

IOException

path

public Path path()

newReaderSnapshot

protected Translog.Snapshot newReaderSnapshot(int totalOperations,
                                  ByteBuffer reusableBuffer)