anon.client

Class ChannelTable

java.lang.Object

anon.client.ChannelTable

All Implemented Interfaces:

IDataChannelCreator

public class ChannelTable
extends java.lang.Object
implements IDataChannelCreator

The channel table is used to keep track of the currently open communication channels, over which Mix Packets are sent and received. This includes both Data and Control Channels. It can create data channels using a Data Channel Factory and close all of them, once the table is not useful anymore.

Author:

Stefan Lieske

Field Summary

Fields

Modifier and Type	Field and Description
static int	CONTROL_CHANNEL_ID_DUMMY
static int	CONTROL_CHANNEL_ID_PAY
static int	CONTROL_CHANNEL_ID_REPLAY
static int	CONTROL_CHANNEL_ID_TEST

Constructor Summary

Constructors

Constructor and Description
ChannelTable(IDataChannelFactory a_dataChannelFactory, java.security.SecureRandom a_channelIdGenerator, int maxDataChannels) Creates a channel table to hold data and control channels.

Method Summary

Modifier and Type	Method and Description
void	closeChannelTable() This method notifies all channels in the table, that it will be closed and clears itself afterwards.
AbstractDataChannel	createDataChannel(AbstractDataChain a_parentDataChain) This method creates a new channel using the channel factory specified at construction time and inserts it into the table with a random, available ID.
AbstractChannel	getChannel(int a_channelId) Returns the channel for a given ID.
boolean	isControlChannelId(int a_channelId) Checks if the given integer number is reserved for control channel IDs.
boolean	isSendingControlMessage() Returns true if any of the control channels in this table is sending control messages at that moment.
void	registerControlChannel(int a_channelId, AbstractControlChannel a_controlChannel) Registers a given control channel under the given ID in the channel table and the control channel table.
void	removeChannel(int a_channelId) Remove a channel with the given ID from the channel table and notify threads of the new available channel spot, if the removed channel was a data channel.

Methods inherited from class java.lang.Object

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

Field Detail

CONTROL_CHANNEL_ID_PAY

public static final int CONTROL_CHANNEL_ID_PAY

See Also:

Constant Field Values

CONTROL_CHANNEL_ID_REPLAY

public static final int CONTROL_CHANNEL_ID_REPLAY

See Also:

Constant Field Values

CONTROL_CHANNEL_ID_DUMMY

public static final int CONTROL_CHANNEL_ID_DUMMY

See Also:

Constant Field Values

CONTROL_CHANNEL_ID_TEST

public static final int CONTROL_CHANNEL_ID_TEST

See Also:

Constant Field Values

Constructor Detail

ChannelTable

public ChannelTable(IDataChannelFactory a_dataChannelFactory,
                    java.security.SecureRandom a_channelIdGenerator,
                    int maxDataChannels)

Creates a channel table to hold data and control channels. Data channels can be created using the given DataChannelFactory.

Parameters:

a_dataChannelFactory - a factory used for creating data channels

a_channelIdGenerator - a secure random number generator used to generate the channel IDs

maxDataChannels - max number of data channels, default (50) if -1

Method Detail

getChannel

public AbstractChannel getChannel(int a_channelId)

Returns the channel for a given ID.

Parameters:

a_channelId -

Returns:

the channel for a given ID. null if the ID is not used

removeChannel

public void removeChannel(int a_channelId)

Remove a channel with the given ID from the channel table and notify threads of the new available channel spot, if the removed channel was a data channel.

Parameters:

a_channelId -

isSendingControlMessage

public boolean isSendingControlMessage()

Returns true if any of the control channels in this table is sending control messages at that moment.

Returns:

true if a channel is sending, otherwise false

registerControlChannel

public void registerControlChannel(int a_channelId,
                                   AbstractControlChannel a_controlChannel)

Registers a given control channel under the given ID in the channel table and the control channel table.

If the table is closed, the given channel will be closed, without adding it.

Control Channels register themselves on Construction with a channel ID previously agreed upon with the Channel Table.

Parameters:

a_channelId -

a_controlChannel -

isControlChannelId

public boolean isControlChannelId(int a_channelId)

Checks if the given integer number is reserved for control channel IDs.

Parameters:

a_channelId - Integer to be tested.

Returns:

true if in the reserved range, otherwise false

createDataChannel

public AbstractDataChannel createDataChannel(AbstractDataChain a_parentDataChain)

This method creates a new channel using the channel factory specified at construction time and inserts it into the table with a random, available ID.

This method blocks, if there are no available data channel slots left at that moment and the table is not closed.

If the table is closed a dummy channel is created and closed immediately by calling multiplexerClosed().

Specified by:

createDataChannel in interface IDataChannelCreator

Returns:

The created channel object. May be null if an error occurs.

closeChannelTable

public void closeChannelTable()

This method notifies all channels in the table, that it will be closed and clears itself afterwards.