Package edu.caltech.nanodb.server

Class EventDispatcher

java.lang.Object

edu.caltech.nanodb.server.EventDispatcher

public class EventDispatcher
extends java.lang.Object

The event dispatcher notifies listeners when specific events occur within the database, related to command execution and row processing operations. It is used, for example, to implement index updates and other such tasks.

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.ArrayList<CommandEventListener>	commandEventListeners	A list of listeners that are registered to receive command event notifications.
private static org.apache.logging.log4j.Logger	logger	A logging object for reporting anything interesting that happens.
private java.util.ArrayList<RowEventListener>	rowEventListeners	A list of listeners that are registered to receive row event notifications.

Constructor Summary

Constructors

Constructor	Description
EventDispatcher()

Method Summary

Modifier and Type	Method	Description
void	addCommandEventListener(CommandEventListener listener)	Add another command-event listener to the event dispatcher.
void	addRowEventListener(RowEventListener listener)	Add another row-event listener to the event dispatcher.
void	fireAfterCommandExecuted(Command cmd)
void	fireAfterRowDeleted(TableInfo tblFileInfo, Tuple oldValues)
void	fireAfterRowInserted(TableInfo tblFileInfo, Tuple newTuple)
void	fireAfterRowUpdated(TableInfo tblFileInfo, Tuple oldValues, Tuple newTuple)
void	fireBeforeCommandExecuted(Command cmd)
void	fireBeforeRowDeleted(TableInfo tblFileInfo, Tuple oldTuple)
void	fireBeforeRowInserted(TableInfo tblFileInfo, Tuple newValues)
void	fireBeforeRowUpdated(TableInfo tblFileInfo, Tuple oldTuple, Tuple newValues)

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static org.apache.logging.log4j.Logger logger

A logging object for reporting anything interesting that happens.

commandEventListeners

private java.util.ArrayList<CommandEventListener> commandEventListeners

A list of listeners that are registered to receive command event notifications.

rowEventListeners

private java.util.ArrayList<RowEventListener> rowEventListeners

A list of listeners that are registered to receive row event notifications.

Constructor Detail

EventDispatcher

public EventDispatcher()

Method Detail

addCommandEventListener

public void addCommandEventListener(CommandEventListener listener)

Add another command-event listener to the event dispatcher. Note that if the same component is added twice, it will receive two notifications for each event.

Parameters:

listener - the command-event listener

addRowEventListener

public void addRowEventListener(RowEventListener listener)

Add another row-event listener to the event dispatcher. Note that if the same component is added twice, it will receive two notifications for each event.

Parameters:

listener - the row-event listener

fireBeforeCommandExecuted

public void fireBeforeCommandExecuted(Command cmd)

Parameters:

cmd - the command that is about to be executed

fireAfterCommandExecuted

public void fireAfterCommandExecuted(Command cmd)

Parameters:

cmd - the command that was just executed

fireBeforeRowInserted

public void fireBeforeRowInserted(TableInfo tblFileInfo,
                                  Tuple newValues)

fireAfterRowInserted

public void fireAfterRowInserted(TableInfo tblFileInfo,
                                 Tuple newTuple)

fireBeforeRowUpdated

public void fireBeforeRowUpdated(TableInfo tblFileInfo,
                                 Tuple oldTuple,
                                 Tuple newValues)

fireAfterRowUpdated

public void fireAfterRowUpdated(TableInfo tblFileInfo,
                                Tuple oldValues,
                                Tuple newTuple)

fireBeforeRowDeleted

public void fireBeforeRowDeleted(TableInfo tblFileInfo,
                                 Tuple oldTuple)

fireAfterRowDeleted

public void fireAfterRowDeleted(TableInfo tblFileInfo,
                                Tuple oldValues)