org.apache.cassandra.io.util

Class SequentialWriter

java.lang.Object

java.io.OutputStream

org.apache.cassandra.io.util.DataOutputStreamPlus

org.apache.cassandra.io.util.BufferedDataOutputStreamPlus

org.apache.cassandra.io.util.SequentialWriter

All Implemented Interfaces:

java.io.Closeable, java.io.DataOutput, java.io.Flushable, java.lang.AutoCloseable, DataOutputPlus, Transactional

Direct Known Subclasses:

ChecksummedSequentialWriter, CompressedSequentialWriter

public class SequentialWriter
extends BufferedDataOutputStreamPlus
implements Transactional

Adds buffering, mark, and fsyncing to OutputStream. We always fsync on close; we may also fsync incrementally if Config.trickle_fsync is enabled.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	SequentialWriter.BufferedFileWriterMark Class to hold a mark to the position of the file
protected class	SequentialWriter.TransactionalProxy

Nested classes/interfaces inherited from interface org.apache.cassandra.utils.concurrent.Transactional

Transactional.AbstractTransactional

Field Summary

Fields

Modifier and Type	Field and Description
protected long	bufferOffset
protected java.nio.channels.FileChannel	fchannel
protected long	lastFlushOffset
protected java.lang.Runnable	runPostFlush

Fields inherited from class org.apache.cassandra.io.util.BufferedDataOutputStreamPlus

buffer

Fields inherited from class org.apache.cassandra.io.util.DataOutputStreamPlus

channel

Constructor Summary

Constructors

Constructor and Description
SequentialWriter(java.io.File file) Create heap-based, non-compressed SequenialWriter with default buffer size(64k).
SequentialWriter(java.io.File file, SequentialWriterOption option) Create SequentialWriter for given file with specific writer option.
SequentialWriter(java.io.File file, SequentialWriterOption option, boolean strictFlushing) Create SequentialWriter for given file with specific writer option.

Method Summary

Modifier and Type	Method and Description
java.lang.Throwable	abort(java.lang.Throwable accumulate)
void	close()
java.lang.Throwable	commit(java.lang.Throwable accumulate)
protected long	current()
protected void	doFlush(int count)
void	finish()
protected void	flushData() Override this method instead of overriding flush()
long	getEstimatedOnDiskBytesWritten()
long	getLastFlushOffset()
long	getOnDiskFilePointer() Returns the current file pointer of the underlying on-disk file.
java.lang.String	getPath()
boolean	hasPosition() If the implementation supports providing a position, this method returns true, otherwise false.
boolean	isOpen()
long	length()
DataPosition	mark()
long	position() Returns the current position of the underlying target like a file-pointer or the position withing a buffer.
void	prepareToCommit()
void	resetAndTruncate(DataPosition mark) Drops all buffered data that's past the limits of our new file mark + buffer capacity, or syncs and truncates the underlying file to the marked position
protected void	resetBuffer()
void	setPostFlushListener(java.lang.Runnable runPostFlush)
void	skipBytes(int numBytes)
void	sync() Synchronize file contents with disk.
protected void	syncDataOnlyInternal()
protected void	syncInternal()
void	truncate(long toSize)
protected SequentialWriter.TransactionalProxy	txnProxy()
int	writeDirectlyToChannel(java.nio.ByteBuffer buf)

Methods inherited from class org.apache.cassandra.io.util.BufferedDataOutputStreamPlus

flush, order, write, write, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Methods inherited from class org.apache.cassandra.io.util.DataOutputStreamPlus

newDefaultChannel, retrieveTemporaryBuffer

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.io.util.DataOutputPlus

write, writeUnsignedVInt, writeVInt

Field Detail

bufferOffset

protected long bufferOffset

fchannel

protected final java.nio.channels.FileChannel fchannel

lastFlushOffset

protected long lastFlushOffset

runPostFlush

protected java.lang.Runnable runPostFlush

Constructor Detail

SequentialWriter

public SequentialWriter(java.io.File file)

Create heap-based, non-compressed SequenialWriter with default buffer size(64k).

Parameters:

file - File to write

SequentialWriter

public SequentialWriter(java.io.File file,
                        SequentialWriterOption option)

Create SequentialWriter for given file with specific writer option.

Parameters:

file - File to write

option - Writer option

SequentialWriter

public SequentialWriter(java.io.File file,
                        SequentialWriterOption option,
                        boolean strictFlushing)

Create SequentialWriter for given file with specific writer option.

Parameters:

file -

option -

strictFlushing -

Method Detail

skipBytes

public void skipBytes(int numBytes)
               throws java.io.IOException

Throws:

java.io.IOException

sync

public void sync()

Synchronize file contents with disk.

syncDataOnlyInternal

protected void syncDataOnlyInternal()

syncInternal

protected void syncInternal()

doFlush

protected void doFlush(int count)

Overrides:

doFlush in class BufferedDataOutputStreamPlus

setPostFlushListener

public void setPostFlushListener(java.lang.Runnable runPostFlush)

flushData

protected void flushData()

Override this method instead of overriding flush()

Throws:

FSWriteError - on any I/O error.

hasPosition

public boolean hasPosition()

Description copied from interface: DataOutputPlus

If the implementation supports providing a position, this method returns true, otherwise false.

Specified by:

hasPosition in interface DataOutputPlus

position

public long position()

Description copied from interface: DataOutputPlus

Returns the current position of the underlying target like a file-pointer or the position withing a buffer. Not every implementation may support this functionality. Whether or not this functionality is supported can be checked via the DataOutputPlus.hasPosition().

Specified by:

position in interface DataOutputPlus

getOnDiskFilePointer

public long getOnDiskFilePointer()

Returns the current file pointer of the underlying on-disk file. Note that since write works by buffering data, the value of this will increase by buffer size and not every write to the writer will modify this value. Furthermore, for compressed files, this value refers to compressed data, while the writer getFilePointer() refers to uncompressedFile

Returns:

the current file pointer

getEstimatedOnDiskBytesWritten

public long getEstimatedOnDiskBytesWritten()

length

public long length()

getPath

public java.lang.String getPath()

resetBuffer

protected void resetBuffer()

current

protected long current()

mark

public DataPosition mark()

resetAndTruncate

public void resetAndTruncate(DataPosition mark)

Drops all buffered data that's past the limits of our new file mark + buffer capacity, or syncs and truncates the underlying file to the marked position

getLastFlushOffset

public long getLastFlushOffset()

truncate

public void truncate(long toSize)

isOpen

public boolean isOpen()

prepareToCommit

public final void prepareToCommit()

Specified by:

prepareToCommit in interface Transactional

commit

public final java.lang.Throwable commit(java.lang.Throwable accumulate)

Specified by:

commit in interface Transactional

abort

public final java.lang.Throwable abort(java.lang.Throwable accumulate)

Specified by:

abort in interface Transactional

close

public final void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface Transactional

Overrides:

close in class BufferedDataOutputStreamPlus

writeDirectlyToChannel

public int writeDirectlyToChannel(java.nio.ByteBuffer buf)
                           throws java.io.IOException

Throws:

java.io.IOException

finish

public final void finish()

txnProxy

protected SequentialWriter.TransactionalProxy txnProxy()