Package org.apache.cassandra.io.util

Class ChannelProxy

java.lang.Object

org.apache.cassandra.utils.concurrent.SharedCloseableImpl

org.apache.cassandra.io.util.ChannelProxy

All Implemented Interfaces:

AutoCloseable, SharedCloseable

public final class ChannelProxy
extends SharedCloseableImpl

A proxy of a FileChannel that: - implements reference counting - exports only thread safe FileChannel operations - wraps IO exceptions into runtime exceptions Tested by RandomAccessReaderTest.

Constructor Summary

Constructors

Constructor	Description
ChannelProxy(String path)
ChannelProxy(ChannelProxy copy)
ChannelProxy(File file)
ChannelProxy(File file, FileChannel channel)

Method Summary

Modifier and Type	Method	Description
File	file()
String	filePath()
int	getFileDescriptor()
MappedByteBuffer	map(FileChannel.MapMode mode, long position, long size)
final ChannelProxy	newChannel()	sharedCopy() can not be used if thread will be interruped, as the backing channel will be closed.
static FileChannel	openChannel(File file)
int	read(ByteBuffer buffer, long position)
ChannelProxy	sharedCopy()
long	size()
String	toString()
long	transferTo(long position, long count, WritableByteChannel target)

Methods inherited from class org.apache.cassandra.utils.concurrent.SharedCloseableImpl

addTo, close, close, isCleanedUp

Methods inherited from class java.lang.Object

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

Constructor Details

ChannelProxy

public ChannelProxy(String path)

ChannelProxy

public ChannelProxy(File file)

ChannelProxy

public ChannelProxy(File file,
 FileChannel channel)

ChannelProxy

public ChannelProxy(ChannelProxy copy)

Method Details

openChannel

public static FileChannel openChannel(File file)

newChannel

public final ChannelProxy newChannel()

sharedCopy() can not be used if thread will be interruped, as the backing channel will be closed.

Returns:

a new channel instance

sharedCopy

public ChannelProxy sharedCopy()

Returns:

a new instance of the object representing the same state and backed by the same underlying resources. Coordinates with the original (and other instances) when the underlying resource should be closed. Throws an exception if the shared resource has already been closed.

filePath

public String filePath()

file

public File file()

read

public int read(ByteBuffer buffer,
 long position)

transferTo

public long transferTo(long position,
 long count,
 WritableByteChannel target)

map

public MappedByteBuffer map(FileChannel.MapMode mode,
 long position,
 long size)

size

public long size()

getFileDescriptor

public int getFileDescriptor()

toString

public String toString()

Overrides:

toString in class Object