Package org.apache.hadoop.net.unix

Class DomainSocket

java.lang.Object

org.apache.hadoop.net.unix.DomainSocket

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

@LimitedPrivate("HDFS")
public class DomainSocket
extends java.lang.Object
implements java.io.Closeable

The implementation of UNIX domain sockets in Java. See DomainSocket for more information about UNIX domain sockets.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	DomainSocket.DomainChannel
class	DomainSocket.DomainInputStream	Input stream for UNIX domain sockets.
class	DomainSocket.DomainOutputStream	Output stream for UNIX domain sockets.

Field Summary

Fields

Modifier and Type	Field	Description
static int	RECEIVE_BUFFER_SIZE
static int	RECEIVE_TIMEOUT
static int	SEND_BUFFER_SIZE
static int	SEND_TIMEOUT

Method Summary

Modifier and Type	Method	Description
DomainSocket	accept()	Accept a new UNIX domain connection.
static DomainSocket	bindAndListen(java.lang.String path)	Create a new DomainSocket listening on the given path.
void	close()	Close the Socket.
static DomainSocket	connect(java.lang.String path)	Create a new DomainSocket connected to the given path.
static void	disableBindPathValidation()	Disable validation of the server bind paths.
int	getAttribute(int type)
DomainSocket.DomainChannel	getChannel()
static java.lang.String	getEffectivePath(java.lang.String path, int port)	Given a path and a port, compute the effective path by replacing occurrences of _PORT with the port.
DomainSocket.DomainInputStream	getInputStream()
static java.lang.String	getLoadingFailureReason()	Return true only if UNIX domain sockets are available.
DomainSocket.DomainOutputStream	getOutputStream()
java.lang.String	getPath()
boolean	isOpen()	Return true if the file descriptor is currently open.
int	recvFileInputStreams(java.io.FileInputStream[] streams, byte[] buf, int offset, int length)	Receive some FileDescriptor objects from the process on the other side of this socket, and wrap them in FileInputStream objects.
void	sendFileDescriptors(java.io.FileDescriptor[] descriptors, byte[] jbuf, int offset, int length)	Send some FileDescriptor objects to the process on the other side of this socket.
void	setAttribute(int type, int size)
void	shutdown()	Call shutdown(SHUT_RDWR) on the UNIX domain socket.
static DomainSocket[]	socketpair()	Create a pair of UNIX domain sockets which are connected to each other by calling socketpair(2).
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

SEND_BUFFER_SIZE

public static final int SEND_BUFFER_SIZE

See Also:

Constant Field Values

RECEIVE_BUFFER_SIZE

public static final int RECEIVE_BUFFER_SIZE

See Also:

Constant Field Values

SEND_TIMEOUT

public static final int SEND_TIMEOUT

See Also:

Constant Field Values

RECEIVE_TIMEOUT

public static final int RECEIVE_TIMEOUT

See Also:

Constant Field Values

Method Detail

getLoadingFailureReason

public static java.lang.String getLoadingFailureReason()

Return true only if UNIX domain sockets are available.

Returns:

loadingFailureReason.

disableBindPathValidation

@VisibleForTesting
public static void disableBindPathValidation()

Disable validation of the server bind paths.

getEffectivePath

public static java.lang.String getEffectivePath(java.lang.String path,
                                                int port)

Given a path and a port, compute the effective path by replacing occurrences of _PORT with the port. This is mainly to make it possible to run multiple DataNodes locally for testing purposes.

Parameters:

path - The source path

port - Port number to use

Returns:

The effective path

bindAndListen

public static DomainSocket bindAndListen(java.lang.String path)
                                  throws java.io.IOException

Create a new DomainSocket listening on the given path.

Parameters:

path - The path to bind and listen on.

Returns:

The new DomainSocket.

Throws:

java.io.IOException - raised on errors performing I/O.

socketpair

public static DomainSocket[] socketpair()
                                 throws java.io.IOException

Create a pair of UNIX domain sockets which are connected to each other by calling socketpair(2).

Returns:

An array of two UNIX domain sockets connected to each other.

Throws:

java.io.IOException - on error.

accept

public DomainSocket accept()
                    throws java.io.IOException

Accept a new UNIX domain connection. This method can only be used on sockets that were bound with bind().

Returns:

The new connection.

Throws:

java.io.IOException - If there was an I/O error performing the accept-- such as the socket being closed from under us. Particularly when the accept is timed out, it throws SocketTimeoutException.

connect

public static DomainSocket connect(java.lang.String path)
                            throws java.io.IOException

Create a new DomainSocket connected to the given path.

Parameters:

path - The path to connect to.

Returns:

The new DomainSocket.

Throws:

java.io.IOException - If there was an I/O error performing the connect.

isOpen

public boolean isOpen()

Return true if the file descriptor is currently open.

Returns:

True if the file descriptor is currently open.

getPath

public java.lang.String getPath()

Returns:

The socket path.

getInputStream

public DomainSocket.DomainInputStream getInputStream()

Returns:

The socket InputStream

getOutputStream

public DomainSocket.DomainOutputStream getOutputStream()

Returns:

The socket OutputStream

getChannel

public DomainSocket.DomainChannel getChannel()

Returns:

The socket Channel

setAttribute

public void setAttribute(int type,
                         int size)
                  throws java.io.IOException

Throws:

java.io.IOException

getAttribute

public int getAttribute(int type)
                 throws java.io.IOException

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Close the Socket.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

shutdown

public void shutdown()
              throws java.io.IOException

Call shutdown(SHUT_RDWR) on the UNIX domain socket.

Throws:

java.io.IOException - raised on errors performing I/O.

sendFileDescriptors

public void sendFileDescriptors(java.io.FileDescriptor[] descriptors,
                                byte[] jbuf,
                                int offset,
                                int length)
                         throws java.io.IOException

Send some FileDescriptor objects to the process on the other side of this socket.

Parameters:

descriptors - The file descriptors to send.

jbuf - Some bytes to send. You must send at least one byte.

offset - The offset in the jbuf array to start at.

length - Length of the jbuf array to use.

Throws:

java.io.IOException - raised on errors performing I/O.

recvFileInputStreams

public int recvFileInputStreams(java.io.FileInputStream[] streams,
                                byte[] buf,
                                int offset,
                                int length)
                         throws java.io.IOException

Receive some FileDescriptor objects from the process on the other side of this socket, and wrap them in FileInputStream objects.

Parameters:

streams - input stream.

buf - input buf.

offset - input offset.

length - input length.

Returns:

wrap them in FileInputStream objects.

Throws:

java.io.IOException - raised on errors performing I/O.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object