Class RemoteWindow

java.lang.Object

org.apache.sshd.common.util.logging.AbstractLoggingBean

org.apache.sshd.common.channel.Window

org.apache.sshd.common.channel.RemoteWindow

All Implemented Interfaces:

Closeable, AutoCloseable, ChannelHolder

public class RemoteWindow
extends Window

A Window reflecting this side's view of the peer's LocalWindow. A RemoteWindow is initialized when the peer announces its packet and window sizes in the initial message exchange when opening a channel. Whenever this side wants to send data, it checks whether the remote window has still enough space; if not, it sends only as much data as possible. When data is sent, the remote window size is reduced by the number of data bytes sent. When the window size drops to zero, no data is sent at all, and this side will have to wait for an SSH_MSG_CHANNEL_WINDOW_ADJUST message from the peer, which will increase the available window size again.

Author:

Apache MINA SSHD Project

Field Summary

Fields inherited from class Window

lock

Fields inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

log

Constructor Summary

Constructors

Constructor	Description
RemoteWindow(Channel channel, boolean isClient)

Method Summary

Modifier and Type	Method	Description
long	consume(long len)	Consume len bytes from the window.
void	expand(long increment)
void	init(long size, long packetSize, org.apache.sshd.common.PropertyResolver resolver)	Initializes the RemoteWindow with the packet and window sizes received from the peer.
void	waitAndConsume(long len, long maxWaitTime)	Waits for enough data to become available to consume the specified size
void	waitAndConsume(long len, Duration maxWaitTime)	Waits for enough data to become available to consume the specified size, then consumes it.
protected void	waitForCondition(Predicate<? super Window> predicate, Duration maxWaitTime)	Waits up to a specified amount of time for a condition to be satisfied and signaled via the lock.
long	waitForSpace(long maxWaitTime)	Waits until some data becomes available or timeout expires
long	waitForSpace(Duration maxWaitTime)	Waits until some data becomes available or timeout expires

Methods inherited from class Window

checkInitialized, close, consumeAll, getChannel, getMaxSize, getPacketSize, getSize, isOpen, largerThan, toString, updateSize

Methods inherited from class org.apache.sshd.common.util.logging.AbstractLoggingBean

debug, debug, debug, debug, debug, error, error, error, error, error, getSimplifiedLogger, info, info, warn, warn, warn, warn, warn, warn, warn, warn

Methods inherited from class Object

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

Constructor Details

RemoteWindow

public RemoteWindow(Channel channel,
 boolean isClient)

Method Details

init

public void init(long size,
 long packetSize,
 org.apache.sshd.common.PropertyResolver resolver)

Initializes the RemoteWindow with the packet and window sizes received from the peer.

Overrides:

init in class Window

Parameters:

size - the initial window size

packetSize - the peer's advertised maximum packet size

resolver - PropertyResolver to access properties

consume

public long consume(long len)

Consume len bytes from the window.

Consumes at most the available space in the window. If len > the available space, less than len bytes are consumed.

Also, caps the amount of window space consumed to Math.min(getMaxSize(), getPacketSize()).

Consuming space from the window is a promise to send that much data over an SSH channel. If not all data can be written, this promise has to be retracted by calling expand(long) with the number of bytes not written.

Specified by:

consume in class Window

Parameters:

len - number of bytes to consume

Returns:

the number of bytes by which the window was actually reduced

expand

public void expand(long increment)

waitAndConsume

public void waitAndConsume(long len,
 long maxWaitTime)
                    throws InterruptedException,
WindowClosedException,
SocketTimeoutException

Waits for enough data to become available to consume the specified size

Parameters:

len - Size of data to consume

maxWaitTime - Max. time (millis) to wait for enough data to become available

Throws:

InterruptedException - If interrupted while waiting

WindowClosedException - If window closed while waiting

SocketTimeoutException - If timeout expired before enough data became available

See Also:

• waitForCondition(Predicate, Duration)
• consume(long)

waitAndConsume

public void waitAndConsume(long len,
 Duration maxWaitTime)
                    throws InterruptedException,
WindowClosedException,
SocketTimeoutException

Waits for enough data to become available to consume the specified size, then consumes it.

Parameters:

len - Size of data to consume

maxWaitTime - Max. time to wait for enough data to become available

Throws:

InterruptedException - If interrupted while waiting

WindowClosedException - If window closed while waiting

SocketTimeoutException - If timeout expired before enough data became available

See Also:

• waitForCondition(Predicate, Duration)
• consume(long)

waitForSpace

public long waitForSpace(long maxWaitTime)
                  throws InterruptedException,
WindowClosedException,
SocketTimeoutException

Waits until some data becomes available or timeout expires

Parameters:

maxWaitTime - Max. time (millis) to wait for space to become available

Returns:

Amount of available data - always positive

Throws:

InterruptedException - If interrupted while waiting

WindowClosedException - If window closed while waiting

SocketTimeoutException - If timeout expired before space became available

See Also:

• waitForCondition(Predicate, Duration)

waitForSpace

public long waitForSpace(Duration maxWaitTime)
                  throws InterruptedException,
WindowClosedException,
SocketTimeoutException

Waits until some data becomes available or timeout expires

Parameters:

maxWaitTime - Max. time to wait for space to become available

Returns:

Amount of available data - always positive

Throws:

InterruptedException - If interrupted while waiting

WindowClosedException - If window closed while waiting

SocketTimeoutException - If timeout expired before space became available

See Also:

• waitForCondition(Predicate, Duration)

waitForCondition

protected void waitForCondition(Predicate<? super Window> predicate,
 Duration maxWaitTime)
                         throws WindowClosedException,
InterruptedException,
SocketTimeoutException

Waits up to a specified amount of time for a condition to be satisfied and signaled via the lock. Note: assumes that lock is acquired when this method is called.

Parameters:

predicate - The Predicate to check if the condition has been satisfied - the argument to the predicate is this reference

maxWaitTime - Max. time to wait for the condition to be satisfied

Throws:

WindowClosedException - If window closed while waiting

InterruptedException - If interrupted while waiting

SocketTimeoutException - If timeout expired before condition was satisfied

See Also:

• Window.isOpen()