org.mbari.siam.core
Class DevicePacketAggregator

java.lang.Object
  org.mbari.siam.core.DevicePacketAggregator

All Implemented Interfaces:

java.util.EventListener, ServiceListener

public class DevicePacketAggregator
extends java.lang.Object
implements ServiceListener

DevicePacketAggregator implements two new method signatures of getDevicePackets() on behalf of the Node interface. These method signatures add the following capabilities to getDevicePackets

1. It aggregates DevicePacketSets returned from Instrument or NodeManager._log, creating larger DevicePacketSets that can be transferred more efficiently over the telemetry system. The amount of aggregation is specified by the numBytes parameter to the two new methods.
2. It provides a timeout parameter to these methods. This allows the calling object (e.g. Portal) to limit the amount of time waiting for non-responsive Instruments, and thus allows it (the Portal) to move on to collecting data from the other Instruments and subnodes.

The first capability is implemented by repeatedly calling the data source (as specified by the isiId) until we get at least numBytes bytes. Note that the data source (e.g. Instrument or NodeManager log) returns DevicePacketSets aggregated using its own native DevicePacketSet size. Thus the DevicePacketAggregator can return a DevicePacketSet containing a number of bytes that exceeds the request by one "native" DevicePacketSet from the isiId.

The second capability is implemented using threads. The calling method simply passes the request to a worker thread, and waits for the worker thread to signal that it's done. It uses Object.wait(timeout) to accomplish this, thus implementing the timeout function. To guard against the possibility that a "stuck" Instrument can block the entire system, we use a worker thread for each ISI ID. Thus a "stuck" Instrument can block later requests on that same Instrument, but will not block requests for a different Instrument.

This class implements ServiceListener. The reason is that we need to be notified when a user does a shutdownPort. In that case, we destroy the associated DevicePacketWorker. If the user then does a scanPort and later calls getDevicePackets() for that isiId, we'll generate a new worker with the new Device reference that resulted from the scanPort.

Nested Class Summary

protected class	DevicePacketAggregator.DeviceInstrumentSource Implementation of DevicePacketSource that uses an Instrument as its packet source.
protected class	DevicePacketAggregator.DeviceLogSource Implementation of DevicePacketSource that uses a FilteredDeviceLog as its packet source.
class	DevicePacketAggregator.DeviceLogTestSource Implementation of DevicePacketSource used for testing with tests.Aggregator.
protected class	DevicePacketAggregator.DevicePacketRequest Class representing one getDevicePackets() request and response
static interface	DevicePacketAggregator.DevicePacketSource Interface class that defines a source of DevicePackets.
protected class	DevicePacketAggregator.DevicePacketWorker Worker thread that actually fetches the DevicePacketSet data.

Field Summary

protected java.lang.String	_directory
protected static org.apache.log4j.Logger	_log4j Log4j logger
protected NodeService	_node
protected long	_testDelay
protected boolean	_testing
protected java.util.Vector	_workers

Constructor Summary

DevicePacketAggregator(NodeService node)
Normal constructor when operating in SIAM

DevicePacketAggregator(java.lang.String directory, long delay)
Test constructor, used by tests.Aggregator

Method Summary

void	exitWorkers() Tell all DevicePacketWorkers to exit
DevicePacketSet	getDevicePackets(long isiId, long startKey, long endKey, int numBytes, int timeout) Get a DevicePacketSet.
DevicePacketSet	getDevicePackets(long isiId, long startKey, long endKey, int numBytes, int typeMask, int timeout) Get a DevicePacketSet.
protected DevicePacketAggregator.DevicePacketSource	getDevicePacketSource(long deviceID) Creates a DevicePacketSource for this deviceID
protected DevicePacketAggregator.DevicePacketWorker	getWorker(long isiId) Find the DevicePacketWorker that is servicing this isiId.
void	serviceInstalled(ServiceEvent e) serviceInstalled method for the ServiceListener interface.
void	serviceRemoved(ServiceEvent e) serviceRemoved method for the ServiceListener interface.
void	serviceRequestComplete(ServiceEvent e) serviceRequestComplete method for the ServiceListener interface.
void	serviceSampleLogged(LogSampleServiceEvent e) serviceSampleLogged method for the ServiceListener interface.

Methods inherited from class java.lang.Object

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

Field Detail

_log4j

protected static org.apache.log4j.Logger _log4j

Log4j logger

_workers

protected java.util.Vector _workers

_node

protected NodeService _node

_testing

protected boolean _testing

_directory

protected java.lang.String _directory

_testDelay

protected long _testDelay

Constructor Detail

DevicePacketAggregator

public DevicePacketAggregator(NodeService node)

Normal constructor when operating in SIAM

DevicePacketAggregator

public DevicePacketAggregator(java.lang.String directory,
                              long delay)

Test constructor, used by tests.Aggregator

Method Detail

getDevicePackets

public DevicePacketSet getDevicePackets(long isiId,
                                        long startKey,
                                        long endKey,
                                        int numBytes,
                                        int typeMask,
                                        int timeout)
                                 throws TimeoutException,
                                        java.lang.IllegalArgumentException,
                                        DeviceNotFound,
                                        NoDataException

Get a DevicePacketSet.

Parameters:

isiId - = Device id

startKey - = Earliest time (key) to request

endKey - = End time of request

numBytes - = Requested size of DevicePacketSet, in bytes

typeMask - = Mask to filter requested packets. See DevicePacket.

timeout - = timeout in milliseconds

Throws:

TimeoutException

java.lang.IllegalArgumentException

DeviceNotFound

NoDataException

getDevicePackets

public DevicePacketSet getDevicePackets(long isiId,
                                        long startKey,
                                        long endKey,
                                        int numBytes,
                                        int timeout)
                                 throws TimeoutException,
                                        java.lang.IllegalArgumentException,
                                        DeviceNotFound,
                                        NoDataException

Get a DevicePacketSet.

Parameters:

isiId - = Device id

startKey - = Earliest time (key) to request

endKey - = End time of request

numBytes - = Requested size of DevicePacketSet, in bytes

timeout - = timeout in milliseconds

Throws:

TimeoutException

java.lang.IllegalArgumentException

DeviceNotFound

NoDataException

getDevicePacketSource

protected DevicePacketAggregator.DevicePacketSource getDevicePacketSource(long deviceID)
                                                                   throws DeviceNotFound,
                                                                          NoDataException

Creates a DevicePacketSource for this deviceID

Throws:

DeviceNotFound

NoDataException

getWorker

protected DevicePacketAggregator.DevicePacketWorker getWorker(long isiId)
                                                       throws DeviceNotFound,
                                                              NoDataException

Find the DevicePacketWorker that is servicing this isiId. If none exists, create a new one.

Throws:

DeviceNotFound

NoDataException

exitWorkers

public void exitWorkers()

Tell all DevicePacketWorkers to exit

serviceInstalled

public void serviceInstalled(ServiceEvent e)

serviceInstalled method for the ServiceListener interface. Action performed when service installed. We ignore this event.

Specified by:

serviceInstalled in interface ServiceListener

serviceRemoved

public void serviceRemoved(ServiceEvent e)

serviceRemoved method for the ServiceListener interface. Action performed when service removed. We look for a DevicePacketWorker for the corresponding ISI ID, and shut it down if it exists.

Specified by:

serviceRemoved in interface ServiceListener

serviceRequestComplete

public void serviceRequestComplete(ServiceEvent e)

serviceRequestComplete method for the ServiceListener interface. Action performed when service installed. We ignore this event.

Specified by:

serviceRequestComplete in interface ServiceListener

serviceSampleLogged

public void serviceSampleLogged(LogSampleServiceEvent e)

serviceSampleLogged method for the ServiceListener interface. Action performed when service logs a device sample. We ignore this event.