Package edu.ucsb.nceas.metacat.index.queue

Class IndexGenerator

java.lang.Object

edu.ucsb.nceas.metacat.shared.BaseService

edu.ucsb.nceas.metacat.index.queue.IndexGenerator

public class IndexGenerator
extends BaseService

The IndexGenerator class will publish (send) the index information to a RabbitMQ queue. An index worker will consume the information.

Author:

tao

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CREATE_INDEX_TYPE
static final String	DELETE_INDEX_TYPE
static final int	LOW_PRIORITY
static final int	MEDIUM_PRIORITY
static final int	MEDIUM_RESOURCEMAP_PRIORITY
static final String	SYSMETA_CHANGE_TYPE

Fields inherited from class edu.ucsb.nceas.metacat.shared.BaseService

_serviceName

Method Summary

Modifier and Type	Method	Description
protected void	doRefresh()
protected static org.apache.commons.pool2.impl.GenericObjectPool<com.rabbitmq.client.Channel>	getChannelPool()	Get the channel pool of this object.
protected static Set<Future>	getFutures()	Get the feature set of this object.
static IndexGenerator	getInstance()	Implement a Singleton pattern using "double checked locking" pattern.
protected static String	getLastSubdir(String path)	Get the last sub-directory in the path.
void	publish(org.dataone.service.types.v1.Identifier id, String index_type, int priority)	Publish the given information to the index queue
boolean	refreshable()	This service is not refreshable
static void	refreshInstance()	This method sets the instance to null and forces the getInstance method to create a new instance.
static void	removeCompleteFuture(Set<Future> futures)	This method removes the Future objects from a set which have the done status.
protected static void	setChannelPool(org.apache.commons.pool2.impl.GenericObjectPool<com.rabbitmq.client.Channel> pool)	This method is used for testing to replace the channel pool by a mock pool
int	size()	Get the number of messages in the index queue
void	stop()	Stop the service

Methods inherited from class edu.ucsb.nceas.metacat.shared.BaseService

refresh

Methods inherited from class java.lang.Object

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

Field Details

CREATE_INDEX_TYPE

public static final String CREATE_INDEX_TYPE

See Also:

• Constant Field Values

DELETE_INDEX_TYPE

public static final String DELETE_INDEX_TYPE

See Also:

• Constant Field Values

SYSMETA_CHANGE_TYPE

public static final String SYSMETA_CHANGE_TYPE

See Also:

• Constant Field Values

MEDIUM_PRIORITY

public static final int MEDIUM_PRIORITY

See Also:

• Constant Field Values

MEDIUM_RESOURCEMAP_PRIORITY

public static final int MEDIUM_RESOURCEMAP_PRIORITY

See Also:

• Constant Field Values

LOW_PRIORITY

public static final int LOW_PRIORITY

See Also:

• Constant Field Values

Method Details

getLastSubdir

protected static String getLastSubdir(String path)

Get the last sub-directory in the path. If the path is /var/data, data will be returned.

Parameters:

path - the path will be analyzed.

Returns:

the last part of path

getInstance

public static IndexGenerator getInstance()
                                  throws ServiceException

Implement a Singleton pattern using "double checked locking" pattern.

Returns:

a singleton instance of the RabbitMQService class.

Throws:

ServiceException

refreshInstance

public static void refreshInstance()

This method sets the instance to null and forces the getInstance method to create a new instance. This method is only used for a testing purpose!

publish

public void publish(org.dataone.service.types.v1.Identifier id,
 String index_type,
 int priority)
             throws ServiceException,
org.dataone.service.exceptions.InvalidRequest

Publish the given information to the index queue

Parameters:

id - the identifier of the object which will be indexed

index_type - the type of indexing, it can be - delete, create or sysmeta

priority - the priority of the index task

Throws:

ServiceException

org.dataone.service.exceptions.InvalidRequest

refreshable

public boolean refreshable()

This service is not refreshable

Specified by:

refreshable in class BaseService

doRefresh

protected void doRefresh()
                  throws ServiceException

Specified by:

doRefresh in class BaseService

Throws:

ServiceException

stop

public void stop()
          throws ServiceException

Stop the service

Specified by:

stop in class BaseService

Throws:

ServiceException

size

public int size()

Get the number of messages in the index queue

Returns:

the number of messages

setChannelPool

protected static void setChannelPool(org.apache.commons.pool2.impl.GenericObjectPool<com.rabbitmq.client.Channel> pool)

This method is used for testing to replace the channel pool by a mock pool

Parameters:

pool -

getChannelPool

protected static org.apache.commons.pool2.impl.GenericObjectPool<com.rabbitmq.client.Channel> getChannelPool()

Get the channel pool of this object. It is for testing only.

Returns:

the channel pool object

getFutures

protected static Set<Future> getFutures()

Get the feature set of this object. It is for testing only

Returns:

the feature set

removeCompleteFuture

public static void removeCompleteFuture(Set<Future> futures)

This method removes the Future objects from a set which have the done status. So the free space can be used again. If it cannot remove any one, it will wait and try again until some space was freed up.

Parameters:

futures - the set which hold the futures to be checked