org.apache.cassandra.io.util

Class SequentialWriter

java.lang.Object

java.io.OutputStream

org.apache.cassandra.io.util.SequentialWriter

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

Direct Known Subclasses:

CompressedSequentialWriter

public class SequentialWriter
extends java.io.OutputStream

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

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buffer
protected long	bufferOffset
protected long	current
protected boolean	isDirty
protected java.io.RandomAccessFile	out
java.io.DataOutputStream	stream
protected boolean	syncNeeded
protected int	validBufferBytes

Constructor Summary

Constructors

Constructor and Description
SequentialWriter(java.io.File file, int bufferSize, boolean skipIOCache)

Method Summary

Methods

Modifier and Type	Method and Description
void	abort()
void	close()
void	flush() If buffer is dirty, flush it's contents to the operating system.
protected void	flushData() Override this method instead of overriding flush()
protected void	flushInternal()
long	getFilePointer()
long	getOnDiskFilePointer() Return the current file pointer of the underlying on-disk file.
java.lang.String	getPath()
long	length()
FileMark	mark()
static SequentialWriter	open(java.io.File file)
static SequentialWriter	open(java.io.File file, boolean skipIOCache)
static SequentialWriter	open(java.io.File file, int bufferSize, boolean skipIOCache)
protected void	reBuffer()
void	resetAndTruncate(FileMark mark)
protected void	resetBuffer()
void	setDataIntegrityWriter(DataIntegrityMetadata.ChecksumWriter writer) Turn on digest computation on this writer.
void	sync() Synchronize file contents with disk.
protected void	syncDataOnlyInternal()
protected void	syncInternal()
void	truncate(long toSize)
void	write(byte[] buffer)
void	write(byte[] data, int offset, int length)
void	write(int value)

Methods inherited from class java.lang.Object

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

Field Detail

isDirty

protected boolean isDirty

syncNeeded

protected boolean syncNeeded

buffer

protected byte[] buffer

current

protected long current

bufferOffset

protected long bufferOffset

validBufferBytes

protected int validBufferBytes

out

protected final java.io.RandomAccessFile out

stream

public final java.io.DataOutputStream stream

Constructor Detail

SequentialWriter

public SequentialWriter(java.io.File file,
                int bufferSize,
                boolean skipIOCache)

Method Detail

open

public static SequentialWriter open(java.io.File file)

open

public static SequentialWriter open(java.io.File file,
                    boolean skipIOCache)

open

public static SequentialWriter open(java.io.File file,
                    int bufferSize,
                    boolean skipIOCache)

write

public void write(int value)
           throws java.nio.channels.ClosedChannelException

Specified by:

write in class java.io.OutputStream

Throws:

java.nio.channels.ClosedChannelException

write

public void write(byte[] buffer)
           throws java.nio.channels.ClosedChannelException

Overrides:

write in class java.io.OutputStream

Throws:

java.nio.channels.ClosedChannelException

write

public void write(byte[] data,
         int offset,
         int length)
           throws java.nio.channels.ClosedChannelException

Overrides:

write in class java.io.OutputStream

Throws:

java.nio.channels.ClosedChannelException

sync

public void sync()

Synchronize file contents with disk.

syncDataOnlyInternal

protected void syncDataOnlyInternal()

syncInternal

protected void syncInternal()

flush

public void flush()

If buffer is dirty, flush it's contents to the operating system. Does not imply fsync(). Currently, for implementation reasons, this also invalidates the buffer.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

flushInternal

protected void flushInternal()

flushData

protected void flushData()

Override this method instead of overriding flush()

Throws:

FSWriteError - on any I/O error.

getFilePointer

public long getFilePointer()

getOnDiskFilePointer

public long getOnDiskFilePointer()

Return 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

length

public long length()

getPath

public java.lang.String getPath()

reBuffer

protected void reBuffer()

resetBuffer

protected void resetBuffer()

mark

public FileMark mark()

resetAndTruncate

public void resetAndTruncate(FileMark mark)

truncate

public void truncate(long toSize)

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

abort

public void abort()

setDataIntegrityWriter

public void setDataIntegrityWriter(DataIntegrityMetadata.ChecksumWriter writer)

Turn on digest computation on this writer. This can only be called before any data is written to this write, otherwise an IllegalStateException is thrown.