Package com.yahoo.documentapi.messagebus

Class MessageBusVisitorSession

java.lang.Object

com.yahoo.documentapi.messagebus.MessageBusVisitorSession

All Implemented Interfaces:

VisitorControlSession, VisitorSession

public class MessageBusVisitorSession
extends Object
implements VisitorSession

A visitor session for tracking progress for and potentially receiving data from a visitor using a MessageBus source and destination session. The source session is used to initiate visiting by sending create visitor messages to storage and the destination session is used for receiving progress. If the visitor is not set up to send data to a remote destination, data will also be received through the destination session.

Create the visitor session by calling the DocumentAccess.createVisitorSession method.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MessageBusVisitorSession.AsyncTaskExecutor
static interface	MessageBusVisitorSession.Clock
static class	MessageBusVisitorSession.MessageBusReceiver
static class	MessageBusVisitorSession.MessageBusReceiverFactory
static class	MessageBusVisitorSession.MessageBusSender	Message bus implementations of interfaces
static class	MessageBusVisitorSession.MessageBusSenderFactory
static class	MessageBusVisitorSession.RealClock
static interface	MessageBusVisitorSession.Receiver	Abstract away notion of destination session into a generic Receiver interface to allow easy mocking.
static interface	MessageBusVisitorSession.ReceiverFactory
static interface	MessageBusVisitorSession.Sender	Abstract away notion of source session into a generic Sender interface to allow easy mocking.
static interface	MessageBusVisitorSession.SenderFactory
static class	MessageBusVisitorSession.State
class	MessageBusVisitorSession.StateDescription
static class	MessageBusVisitorSession.ThreadAsyncTaskExecutor
static class	MessageBusVisitorSession.VisitingProgress

Constructor Summary

Constructors

Constructor	Description
MessageBusVisitorSession(VisitorParameters visitorParameters, MessageBusVisitorSession.AsyncTaskExecutor taskExecutor, MessageBusVisitorSession.SenderFactory senderFactory, MessageBusVisitorSession.ReceiverFactory receiverFactory, com.yahoo.messagebus.routing.RoutingTable routingTable)
MessageBusVisitorSession(VisitorParameters visitorParameters, MessageBusVisitorSession.AsyncTaskExecutor taskExecutor, MessageBusVisitorSession.SenderFactory senderFactory, MessageBusVisitorSession.ReceiverFactory receiverFactory, com.yahoo.messagebus.routing.RoutingTable routingTable, MessageBusVisitorSession.Clock clock)

Method Summary

Modifier and Type	Method	Description
void	abort()	Aborts the session.
void	ack(AckToken token)	Acknowledges a response previously retrieved by the getNext method.
static MessageBusVisitorSession	createForMessageBus(com.yahoo.messagebus.MessageBus mbus, ScheduledExecutorService scheduledExecutorService, VisitorParameters params)
void	destroy()	Destroys this session and frees up any resources it has held.
VisitorResponse	getNext()	Returns the next response of this session.
VisitorResponse	getNext(int timeoutMilliseconds)	Returns the next response of this session.
ProgressToken	getProgress()	Retrieves the last progress token gotten for this visitor.
String	getSessionName()
com.yahoo.messagebus.Trace	getTrace()	Returns the tracing information so far about the visitor.
boolean	isDestroying()	For unit test purposes only, not to be used by any external parties.
boolean	isDone()	Checks if visiting is done.
void	start()
boolean	waitUntilDone(long timeoutMs)	Waits until visiting is done, or the given timeout (in ms) expires.

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageBusVisitorSession

public MessageBusVisitorSession(VisitorParameters visitorParameters,
                                MessageBusVisitorSession.AsyncTaskExecutor taskExecutor,
                                MessageBusVisitorSession.SenderFactory senderFactory,
                                MessageBusVisitorSession.ReceiverFactory receiverFactory,
                                com.yahoo.messagebus.routing.RoutingTable routingTable)
                         throws com.yahoo.document.select.parser.ParseException

Throws:

com.yahoo.document.select.parser.ParseException

MessageBusVisitorSession

public MessageBusVisitorSession(VisitorParameters visitorParameters,
                                MessageBusVisitorSession.AsyncTaskExecutor taskExecutor,
                                MessageBusVisitorSession.SenderFactory senderFactory,
                                MessageBusVisitorSession.ReceiverFactory receiverFactory,
                                com.yahoo.messagebus.routing.RoutingTable routingTable,
                                MessageBusVisitorSession.Clock clock)
                         throws com.yahoo.document.select.parser.ParseException

Throws:

com.yahoo.document.select.parser.ParseException

Method Detail

createForMessageBus

public static MessageBusVisitorSession createForMessageBus(com.yahoo.messagebus.MessageBus mbus,
                                                           ScheduledExecutorService scheduledExecutorService,
                                                           VisitorParameters params)
                                                    throws com.yahoo.document.select.parser.ParseException

Throws:

com.yahoo.document.select.parser.ParseException

start

public void start()

getSessionName

public String getSessionName()

isDone

public boolean isDone()

Description copied from interface: VisitorSession

Checks if visiting is done.

Specified by:

isDone in interface VisitorSession

Returns:

True if visiting is done (either by error or success).

getProgress

public ProgressToken getProgress()

Description copied from interface: VisitorSession

Retrieves the last progress token gotten for this visitor.

Specified by:

getProgress in interface VisitorSession

Returns:

The progress token.

getTrace

public com.yahoo.messagebus.Trace getTrace()

Description copied from interface: VisitorSession

Returns the tracing information so far about the visitor.

Specified by:

getTrace in interface VisitorSession

Returns:

Returns the trace.

waitUntilDone

public boolean waitUntilDone(long timeoutMs)
                      throws InterruptedException

Description copied from interface: VisitorSession

Waits until visiting is done, or the given timeout (in ms) expires. Will wait forever if timeout is 0.

Specified by:

waitUntilDone in interface VisitorSession

Parameters:

timeoutMs - The maximum amount of milliseconds to wait.

Returns:

True if visiting is done (either by error or success).

Throws:

InterruptedException - If an interrupt signal was received while waiting.

ack

public void ack(AckToken token)

Description copied from interface: VisitorControlSession

Acknowledges a response previously retrieved by the getNext method.

Specified by:

ack in interface VisitorControlSession

Parameters:

token - The ack token. You must get this from the visitor response returned by the getNext method.

abort

public void abort()

Description copied from interface: VisitorControlSession

Aborts the session.

Specified by:

abort in interface VisitorControlSession

getNext

public VisitorResponse getNext()

Description copied from interface: VisitorControlSession

Returns the next response of this session. This method returns immediately.

Specified by:

getNext in interface VisitorControlSession

Returns:

the next response, or null if no response is ready at this time

getNext

public VisitorResponse getNext(int timeoutMilliseconds)
                        throws InterruptedException

Description copied from interface: VisitorControlSession

Returns the next response of this session. This will block until a response is ready or until the given timeout is reached

Specified by:

getNext in interface VisitorControlSession

Parameters:

timeoutMilliseconds - the max time to wait for a response. If the number is 0, this will block without any timeout limit

Returns:

the next response, or null if no response becomes ready before the timeout expires

Throws:

InterruptedException - if this thread is interrupted while waiting

isDestroying

public boolean isDestroying()

For unit test purposes only, not to be used by any external parties.

Returns:

true if destroy() has been--or is being--invoked.

destroy

public void destroy()

Description copied from interface: VisitorControlSession

Destroys this session and frees up any resources it has held.

Specified by:

destroy in interface VisitorControlSession