org.apache.activemq.broker.region.cursors

Interface PendingMessageCursor

All Superinterfaces:

org.apache.activemq.Service

All Known Implementing Classes:

AbstractPendingMessageCursor, AbstractStoreCursor, FilePendingMessageCursor, StoreDurableSubscriberCursor, StoreQueueCursor, VMPendingMessageCursor

public interface PendingMessageCursor
extends org.apache.activemq.Service

Interface to pending message (messages awaiting disptach to a consumer) cursor

Field Summary

Fields

Modifier and Type	Field and Description
static long	INFINITE_WAIT

Method Summary

Modifier and Type	Method and Description
void	add(ConnectionContext context, Destination destination) Add a destination
void	addMessageFirst(org.apache.activemq.broker.region.MessageReference node) add message to await dispatch
boolean	addMessageLast(org.apache.activemq.broker.region.MessageReference node) add message to await dispatch
void	addRecoveredMessage(org.apache.activemq.broker.region.MessageReference node) Add a message recovered from a retroactive policy
void	clear() clear all pending messages
void	destroy() destroy the cursor
void	gc() free up any internal buffers
int	getMaxAuditDepth()
int	getMaxBatchSize()
int	getMaxProducersToAudit()
int	getMemoryUsageHighWaterMark()
org.apache.activemq.ActiveMQMessageAudit	getMessageAudit()
SystemUsage	getSystemUsage()
boolean	hasMessagesBufferedToDeliver()
boolean	hasNext()
boolean	hasSpace()
boolean	isCacheEnabled()
boolean	isEmpty()
boolean	isEmpty(Destination destination) check if a Destination is Empty for this cursor
boolean	isEnableAudit()
boolean	isFull()
boolean	isRecoveryRequired() Informs the Broker if the subscription needs to intervention to recover it's state e.g.
boolean	isTransient()
boolean	isUseCache()
long	messageSize()
org.apache.activemq.broker.region.MessageReference	next()
LinkedList<org.apache.activemq.broker.region.MessageReference>	pageInList(int maxItems) Page in a restricted number of messages and increment the reference count
void	rebase()
void	release() hint to the cursor to release any locks it might have grabbed after a reset
void	remove() remove the message at the cursor position
List<org.apache.activemq.broker.region.MessageReference>	remove(ConnectionContext context, Destination destination) remove a destination
void	remove(org.apache.activemq.broker.region.MessageReference node) remove a node
void	reset() reset the cursor
void	resetForGC() Give the cursor a hint that we are about to remove messages from memory only
void	rollback(org.apache.activemq.command.MessageId id) remove from auditing the message id
void	setEnableAudit(boolean enableAudit)
void	setMaxAuditDepth(int depth) Set the maximum depth of message ids to track
void	setMaxBatchSize(int maxBatchSize) Set the max batch size
void	setMaxProducersToAudit(int value) set the maximum number of producers to track at one time
void	setMemoryUsageHighWaterMark(int memoryUsageHighWaterMark)
void	setMessageAudit(org.apache.activemq.ActiveMQMessageAudit audit) set the audit
void	setSystemUsage(SystemUsage systemUsage) Set the UsageManager
void	setUseCache(boolean useCache) use a cache to improve performance
int	size()
boolean	tryAddMessageLast(org.apache.activemq.broker.region.MessageReference node, long maxWaitTime) add message to await dispatch - if it can

Methods inherited from interface org.apache.activemq.Service

start, stop

Field Detail

INFINITE_WAIT

static final long INFINITE_WAIT

See Also:

Constant Field Values

Method Detail

add

void add(ConnectionContext context,
         Destination destination)
  throws Exception

Add a destination

Parameters:

context -

destination -

Throws:

Exception

remove

List<org.apache.activemq.broker.region.MessageReference> remove(ConnectionContext context,
                                                                Destination destination)
                                                         throws Exception

remove a destination

Parameters:

context -

destination -

Throws:

Exception

isEmpty

boolean isEmpty()

Returns:

true if there are no pending messages

isEmpty

boolean isEmpty(Destination destination)

check if a Destination is Empty for this cursor

Parameters:

destination -

Returns:

true id the Destination is empty

reset

void reset()

reset the cursor

release

void release()

hint to the cursor to release any locks it might have grabbed after a reset

addMessageLast

boolean addMessageLast(org.apache.activemq.broker.region.MessageReference node)
                throws Exception

add message to await dispatch

Parameters:

node -

Returns:

boolean true if successful, false if cursor traps a duplicate

Throws:

IOException

Exception

tryAddMessageLast

boolean tryAddMessageLast(org.apache.activemq.broker.region.MessageReference node,
                          long maxWaitTime)
                   throws Exception

add message to await dispatch - if it can

Parameters:

node -

maxWaitTime -

Returns:

true if successful

Throws:

IOException

Exception

addMessageFirst

void addMessageFirst(org.apache.activemq.broker.region.MessageReference node)
              throws Exception

add message to await dispatch

Parameters:

node -

Throws:

Exception

addRecoveredMessage

void addRecoveredMessage(org.apache.activemq.broker.region.MessageReference node)
                  throws Exception

Add a message recovered from a retroactive policy

Parameters:

node -

Throws:

Exception

hasNext

boolean hasNext()

Returns:

true if there pending messages to dispatch

next

org.apache.activemq.broker.region.MessageReference next()

Returns:

the next pending message with its reference count increment

remove

void remove()

remove the message at the cursor position

size

int size()

Returns:

the number of pending messages

messageSize

long messageSize()

clear

void clear()

clear all pending messages

isRecoveryRequired

boolean isRecoveryRequired()

Informs the Broker if the subscription needs to intervention to recover it's state e.g. DurableTopicSubscriber may do

Returns:

true if recovery required

getMaxBatchSize

int getMaxBatchSize()

Returns:

the maximum batch size

setMaxBatchSize

void setMaxBatchSize(int maxBatchSize)

Set the max batch size

Parameters:

maxBatchSize -

resetForGC

void resetForGC()

Give the cursor a hint that we are about to remove messages from memory only

remove

void remove(org.apache.activemq.broker.region.MessageReference node)

remove a node

Parameters:

node -

gc

void gc()

free up any internal buffers

setSystemUsage

void setSystemUsage(SystemUsage systemUsage)

Set the UsageManager

Parameters:

systemUsage -

See Also:

SystemUsage

getSystemUsage

SystemUsage getSystemUsage()

Returns:

the usageManager

getMemoryUsageHighWaterMark

int getMemoryUsageHighWaterMark()

Returns:

the memoryUsageHighWaterMark

setMemoryUsageHighWaterMark

void setMemoryUsageHighWaterMark(int memoryUsageHighWaterMark)

Parameters:

memoryUsageHighWaterMark - the memoryUsageHighWaterMark to set

isFull

boolean isFull()

Returns:

true if the cursor is full

hasSpace

boolean hasSpace()

Returns:

true if the cursor has space to page messages into

hasMessagesBufferedToDeliver

boolean hasMessagesBufferedToDeliver()

Returns:

true if the cursor has buffered messages ready to deliver

destroy

void destroy()
      throws Exception

destroy the cursor

Throws:

Exception

pageInList

LinkedList<org.apache.activemq.broker.region.MessageReference> pageInList(int maxItems)

Page in a restricted number of messages and increment the reference count

Parameters:

maxItems -

Returns:

a list of paged in messages

setMaxProducersToAudit

void setMaxProducersToAudit(int value)

set the maximum number of producers to track at one time

Parameters:

value -

getMaxProducersToAudit

int getMaxProducersToAudit()

Returns:

the maximum number of producers to audit

setMaxAuditDepth

void setMaxAuditDepth(int depth)

Set the maximum depth of message ids to track

Parameters:

depth -

getMaxAuditDepth

int getMaxAuditDepth()

Returns:

the audit depth

isEnableAudit

boolean isEnableAudit()

Returns:

the enableAudit

setEnableAudit

void setEnableAudit(boolean enableAudit)

Parameters:

enableAudit - the enableAudit to set

isTransient

boolean isTransient()

Returns:

true if the underlying state of this cursor disappears when the broker shuts down

setMessageAudit

void setMessageAudit(org.apache.activemq.ActiveMQMessageAudit audit)

set the audit

Parameters:

audit -

getMessageAudit

org.apache.activemq.ActiveMQMessageAudit getMessageAudit()

Returns:

the audit - could be null

setUseCache

void setUseCache(boolean useCache)

use a cache to improve performance

Parameters:

useCache -

isUseCache

boolean isUseCache()

Returns:

true if a cache may be used

rollback

void rollback(org.apache.activemq.command.MessageId id)

remove from auditing the message id

Parameters:

id -

isCacheEnabled

boolean isCacheEnabled()

Returns:

true if cache is being used

rebase

void rebase()