org.xmlBlaster.util.queue.cache
Class CacheQueueInterceptorPlugin

java.lang.Object
  org.xmlBlaster.util.queue.cache.CacheQueueInterceptorPlugin

All Implemented Interfaces:

I_AdminPlugin, I_AdminQueue, I_AdminUsage, I_Plugin, CacheQueueInterceptorPluginMBean, I_Queue, I_Storage, I_StoragePlugin, I_StorageProblemListener, I_StorageProblemNotifier

public class CacheQueueInterceptorPlugin
extends java.lang.Object
implements I_Queue, I_StoragePlugin, I_StorageProblemListener, CacheQueueInterceptorPluginMBean

Implements a queue cache. Internally it utilizes a RAM queue and a JDBC queue and manages the cache logic.

Author:

michele@laghi.eu, xmlBlaster@marcelruff.info

See Also:

The queue.cache requirement

Field Summary

private ContextNode	contextNode
private Global	glob
private boolean	isConnected
(package private) boolean	isDown
private static java.util.logging.Logger	log
private long	maxFetchSize
private java.lang.Object	mbeanHandle My JMX registration
private java.lang.String	ME
private boolean	notifiedAboutAddOrRemove
private java.lang.Object	peekSync this is the sync between the peaks and the swapping: no peak should be allowed while swapping
private I_Queue	persistentQueue
private PluginInfo	pluginInfo object used to control the swapping performance
private QueuePropertyBase	property
private I_QueuePutListener	putListener
private StorageId	queueId
private StorageSizeListenerHelper	storageSizeListenerHelper
private I_Queue	transientQueue

Fields inherited from interface org.xmlBlaster.util.queue.I_Queue

IGNORE_PUT_INTERCEPTOR, USE_PUT_INTERCEPTOR

Fields inherited from interface org.xmlBlaster.util.queue.I_StorageProblemListener

AVAILABLE, UNAVAILABLE, UNDEF

Constructor Summary

CacheQueueInterceptorPlugin()

Method Summary

void	addPutListener(I_QueuePutListener l) Register a listener which wants to be informed on put() events.
void	addStorageSizeListener(I_StorageSizeListener listener) Adds a storage size listener to the storage.
private long	checkEntriesAvailable(I_Queue queue, long valueToCheckAgainst, boolean ifFullThrowException, java.lang.String extraTxt)
private long	checkSpaceAvailable(I_Queue queue, long valueToCheckAgainst, boolean ifFullThrowException, java.lang.String extraTxt) Helper method to check the space left on a given queue.
long	clear() Clears everything and removes the queue (i.e.
private QueuePropertyBase	createRamCopy(QueuePropertyBase queuePropertyBase) We set the cache props to the real props for RAM queue running under a cacheQueue
java.lang.String	dumpEmbeddedObjects() Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed
java.lang.String	dumpEmbeddedObjectsToFile(java.lang.String fileName) Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed
long	embeddedObjectsToXml(java.io.OutputStream out, java.util.Properties props) Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed
long	embeddedQueueObjectsToXml(java.io.OutputStream out, java.util.Properties props) NOTE: rename from embeddedObjectsToXml to embeddedQueueObjectsToXml as it used the map lookup and lost priority info Dump all entries of this queue to the given output stream.
java.util.List<I_Entry>	getEntries(I_EntryFilter entryFilter) Gets a copy of the entries (e.g the messages) in the queue.
long[]	getEntryReferences() Gets the references of the entries in the queue.
PluginInfo	getInfo() Enforced by I_StoragePlugin
long	getMaxNumOfBytes() Access the configured capacity (maximum bytes) for this queue
long	getMaxNumOfEntries() Returns the maximum number of elements for this queue
long	getNumOfBytes() Returns the amount of bytes currently in the queue.
long	getNumOfEntries() It returns the size of the queue.
long	getNumOfPersistentBytes() Returns the amount of bytes used by the persistent entries in the queue If the implementation of this interface is not able to return the correct number of entries (for example if the implementation must make a remote call to a DB which is temporarly not available) it will return -1.
long	getNumOfPersistentEntries() It returns the size of persistent entries in the queue.
I_Queue	getPersistentQueue() returns the persistent queue (null if no one defined)
java.lang.Object	getProperties() Access the current queue configuration
java.lang.String	getPropertyStr() Access the current queue configuration
java.lang.String	getQueueName() Returns the unique ID of this queue as found in the database XB_ENTRIES.queueName column.
StorageId	getStorageId() Returns the unique ID of this queue
I_StorageSizeListener[]	getStorageSizeListeners()
I_Queue	getTransientQueue() returns the transient queue (null if no one defined)
java.lang.String	getType() Enforced by I_Plugin
java.lang.String	getUsageUrl()
java.lang.String	getVersion() Enforced by I_Plugin
boolean	hasStorageSizeListener(I_StorageSizeListener listener) Checks wether the specified listener is registered.
private boolean	hasTransientsSwapped()
private boolean	hasUncachedEntries()
void	init(Global glob, PluginInfo pluginInfo) Enforced by I_Plugin
void	initialize(StorageId uniqueQueueId, java.lang.Object userData) Is called after the instance is created.
boolean	isNotifiedAboutAddOrRemove() Defaults to false.
private boolean	isPersistenceAvailable()
boolean	isShutdown() Check status
boolean	isTransient()
private int	loadFromPersistence() Loads from the persistence so much data as it fits into the transient queue.
I_QueueEntry	peek() Returns the first element in the queue but does not remove it from that queue (leaves it untouched).
java.util.List<I_Entry>	peek(int numOfEntries, long numOfBytes) Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched).
java.lang.String[]	peekEntries(int numOfEntries) Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched).
java.util.List<I_Entry>	peekLowest(int numOfEntries, long numOfBytes, I_QueueEntry limitEntry, boolean leaveOne) Aware: peekLowest is not implemented!!
java.util.List<I_Entry>	peekSamePriority(int numOfEntries, long numOfBytes) Returns maximum the first num element in the queue of highest priority but does not remove it from that queue (leaves it untouched).
java.util.List<I_Entry>	peekStartAt(int numOfEntries, long numOfBytes, I_QueueEntry firstEntryExlusive) Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched).
java.lang.String	peekStr() Returns the first element in the queue but does not remove it from that queue (leaves it untouched).
java.util.List<I_Entry>	peekWithLimitEntry(I_QueueEntry limitEntry) Deprecated.
java.util.List<I_Entry>	peekWithPriority(int numOfEntries, long numOfBytes, int minPriority, int maxPriority) Returns maximum given number of entries from the queue (none blocking).
void	put(I_QueueEntry[] queueEntries, boolean ignorePutInterceptor) All entries are stored into the transient queue.
void	put(I_QueueEntry queueEntry, boolean ignorePutInterceptor) Puts one queue entry on top of the queue.
boolean	registerStorageProblemListener(I_StorageProblemListener listener) registers a new listener to be notified.
int	remove() Removes the first element in the queue This method does not block.
long	removeHead(I_QueueEntry toEntry) removes the head of the queue until (but not included) the entry specified as the argument.
long	removeNum(long numOfEntries) Removes max num messages.
private boolean[]	removePossibleSwappedEntries(boolean[] ret, I_Entry[] queueEntries) The given ret array will be updated with the result of the removing from the persistent queue.
void	removePutListener(I_QueuePutListener l) Remove the listener which wanted to be informed on put() events.
int	removeRandom(I_Entry entry) Removes the given entry.
boolean[]	removeRandom(I_Entry[] queueEntries) Removes the given entries.
int	removeRandom(long dataId) Removes the given entry.
long	removeRandom(long[] dataIdArray) Removes the given entries.
private boolean[]	removeRandomNoNotify(I_Entry[] queueEntries)
void	removeStorageSizeListener(I_StorageSizeListener listener) Removes the specified listener from the queue.
int	removeTransient() Removes all the transient entries (the ones which have the flag 'persistent' set to false.
long	removeWithLimitEntry(I_QueueEntry limitEntry, boolean inclusive) It removes the entries which are higher than the entry specified in the argument list.
long	removeWithPriority(long numOfEntries, long numOfBytes, int minPriority, int maxPriority) Removes max numOfEntries messages (or less depending on the numOfBytes).
void	setNotifiedAboutAddOrRemove(boolean notify)
void	setProperties(java.lang.Object userData) Allows to overwrite properties which where passed on initialize() The properties which support hot configuration are depending on the used implementation
void	setUsageUrl(java.lang.String url)
void	shutdown() Shutdown the implementation, sync with data store
void	storageAvailable(int oldStatus) Invoked by the I_StorageProblemNotifier when the storage becomes available again (for example on a DB when the jdbc connection is broken).
void	storageUnavailable(int oldStatus) Invoked by the I_StorageProblemNotifier when the storage becomes unavailable (for example on a DB when the jdbc connection is broken).
java.util.List<I_Entry>	takeLowest(int numOfEntries, long numOfBytes, I_QueueEntry limitEntry, boolean leaveOne) Aware: takeLowest for more than one entry is not implemented!!
java.util.List<I_Entry>	takeWithPriority(int numOfEntries, long numOfBytes, int minPriority, int maxPriority) Takes given number of entries out of the queue.
java.lang.String	toXml() Dump state to XML string.
java.lang.String	toXml(java.lang.String extraOffset) Dump state to XML string.
boolean	unRegisterStorageProblemListener(I_StorageProblemListener listener) unregisters a listener.
int	update(I_QueueEntry queueEntry) Updates the given message queue entry with a new value.
java.lang.String	usage() JMX help

Methods inherited from class java.lang.Object

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

Field Detail

log

private static java.util.logging.Logger log

ME

private java.lang.String ME

contextNode

private ContextNode contextNode

property

private QueuePropertyBase property

notifiedAboutAddOrRemove

private boolean notifiedAboutAddOrRemove

isDown

boolean isDown

queueId

private StorageId queueId

putListener

private I_QueuePutListener putListener

transientQueue

private I_Queue transientQueue

persistentQueue

private I_Queue persistentQueue

glob

private Global glob

isConnected

private boolean isConnected

pluginInfo

private PluginInfo pluginInfo

object used to control the swapping performance

peekSync

private java.lang.Object peekSync

this is the sync between the peaks and the swapping: no peak should be allowed while swapping

mbeanHandle

private java.lang.Object mbeanHandle

My JMX registration

maxFetchSize

private long maxFetchSize

storageSizeListenerHelper

private StorageSizeListenerHelper storageSizeListenerHelper

Constructor Detail

CacheQueueInterceptorPlugin

public CacheQueueInterceptorPlugin()

Method Detail

isTransient

public boolean isTransient()

Specified by:

isTransient in interface I_AdminQueue

Specified by:

isTransient in interface I_Storage

Returns:

true for RAM based queue, false for other types like CACHE and JDBC queues

checkSpaceAvailable

private final long checkSpaceAvailable(I_Queue queue,
                                       long valueToCheckAgainst,
                                       boolean ifFullThrowException,
                                       java.lang.String extraTxt)
                                throws XmlBlasterException

Helper method to check the space left on a given queue.

Parameters:

queue - the queue on which to calculate the space left.

valueToCheckAgainst - the amount of bytes which are subtracted (needed in the queue) in this check.

ifFullThrowException - if 'true' this method will throw an exception if the return value would be negative

Returns:

long the space left on the specified queue after having occupied the queue with what is specified in 'valueToCheckAgainst'

Throws:

XmlBlasterException - if the 'ifFullThrowException' flag has been set to 'true' and the return value would be negative.

checkEntriesAvailable

private final long checkEntriesAvailable(I_Queue queue,
                                         long valueToCheckAgainst,
                                         boolean ifFullThrowException,
                                         java.lang.String extraTxt)
                                  throws XmlBlasterException

Throws:

XmlBlasterException

storageUnavailable

public void storageUnavailable(int oldStatus)

Description copied from interface: I_StorageProblemListener

Invoked by the I_StorageProblemNotifier when the storage becomes unavailable (for example on a DB when the jdbc connection is broken).

Specified by:

storageUnavailable in interface I_StorageProblemListener

Parameters:

oldStatus - the status before the storage became unavailable.

See Also:

I_StorageProblemListener.storageUnavailable(int)

storageAvailable

public void storageAvailable(int oldStatus)

Description copied from interface: I_StorageProblemListener

Invoked by the I_StorageProblemNotifier when the storage becomes available again (for example on a DB when the jdbc connection is broken). Note that this method is invoked ONLY after the connection has become unavailable, it is NOT invoked the at startup, i.e. the first time the connection becomes available.

Specified by:

storageAvailable in interface I_StorageProblemListener

See Also:

I_StorageProblemListener.storageAvailable(int)

initialize

public void initialize(StorageId uniqueQueueId,
                       java.lang.Object userData)
                throws XmlBlasterException

Is called after the instance is created.

Specified by:

initialize in interface I_Queue

Parameters:

uniqueQueueId - A unique name, allowing to create a unique name for a persistent store (e.g. file name)

userData - For example a Properties object or a String[] args object passing the configuration data

Throws:

XmlBlasterException

See Also:

I_Queue.initialize(StorageId, Object)

createRamCopy

private QueuePropertyBase createRamCopy(QueuePropertyBase queuePropertyBase)

We set the cache props to the real props for RAM queue running under a cacheQueue

setProperties

public void setProperties(java.lang.Object userData)
                   throws XmlBlasterException

Description copied from interface: I_Queue

Allows to overwrite properties which where passed on initialize() The properties which support hot configuration are depending on the used implementation

Specified by:

setProperties in interface I_Queue

Throws:

XmlBlasterException

See Also:

I_Queue.setProperties(Object)

getPropertyStr

public java.lang.String getPropertyStr()

Description copied from interface: I_AdminQueue

Access the current queue configuration

Specified by:

getPropertyStr in interface I_AdminQueue

getProperties

public java.lang.Object getProperties()

Access the current queue configuration

Specified by:

getProperties in interface I_Queue

setNotifiedAboutAddOrRemove

public void setNotifiedAboutAddOrRemove(boolean notify)

Specified by:

setNotifiedAboutAddOrRemove in interface I_Queue

isNotifiedAboutAddOrRemove

public boolean isNotifiedAboutAddOrRemove()

Description copied from interface: I_AdminQueue

Defaults to false.

Specified by:

isNotifiedAboutAddOrRemove in interface I_AdminQueue

Specified by:

isNotifiedAboutAddOrRemove in interface I_Queue

Returns:

true The I_QueueEntry.addedToQueue() and removedFromQueue() are invoked
false The entries are not informed

addPutListener

public void addPutListener(I_QueuePutListener l)

Description copied from interface: I_Queue

Register a listener which wants to be informed on put() events.

Only one listener is currently supported.

Specified by:

addPutListener in interface I_Queue

See Also:

I_Queue.addPutListener(I_QueuePutListener)

removePutListener

public void removePutListener(I_QueuePutListener l)

Description copied from interface: I_Queue

Remove the listener which wanted to be informed on put() events.

The currently registered listener is removed. If no listener is registered, this call is silently ignored

Specified by:

removePutListener in interface I_Queue

See Also:

I_Queue.removePutListener(I_QueuePutListener)

getPersistentQueue

public I_Queue getPersistentQueue()

returns the persistent queue (null if no one defined)

getTransientQueue

public I_Queue getTransientQueue()

returns the transient queue (null if no one defined)

getEntryReferences

public long[] getEntryReferences()
                          throws XmlBlasterException

Gets the references of the entries in the queue. Note that the data which is referenced here may be changed by other threads.

Specified by:

getEntryReferences in interface I_AdminQueue

Specified by:

getEntryReferences in interface I_Queue

Returns:

Array with reference numbers

Throws:

XmlBlasterException

getEntries

public java.util.List<I_Entry> getEntries(I_EntryFilter entryFilter)
                                   throws XmlBlasterException

Description copied from interface: I_Queue

Gets a copy of the entries (e.g the messages) in the queue. If the queue is modified, this copy will not be affected. This method is useful for client browsing, the entries are not removed

Specified by:

getEntries in interface I_Queue

Parameters:

entryFilter - if not null the you can control which entries to return with the callback entryFilter.intercept(I_Entry).

Returns:

The found entries

Throws:

XmlBlasterException

See Also:

I_Queue.getEntries(I_EntryFilter)

put

public void put(I_QueueEntry queueEntry,
                boolean ignorePutInterceptor)
         throws XmlBlasterException

Description copied from interface: I_Queue

Puts one queue entry on top of the queue. See the other put() for a detailed description.

Specified by:

put in interface I_Queue

ignorePutInterceptor - if set to 'IGNORE_PUT_INTERCEPTOR=true' the put will not inform the QueuePutListener that a put occurred.

Throws:

XmlBlasterException - in case an error occurs. Possible causes of error can be a communication exception of the underlying implementation (jdbc, file system etc).

See Also:

I_Queue.put(I_QueueEntry, boolean)

put

public void put(I_QueueEntry[] queueEntries,
                boolean ignorePutInterceptor)
         throws XmlBlasterException

All entries are stored into the transient queue. All persistent messages are stored also in the persistent queue. The exceeding size in the transient queue is calculated. If it is positive it means we need to swap. The overflowing messages are taken from the ram queue. The volatile between them are stored in the persistent storage (since the persistent ones have been previously stored).

Specified by:

put in interface I_Queue

ignorePutInterceptor - if set to 'IGNORE_PUT_INTERCEPTOR=true' the put will not inform the QueuePutListener that a put occurred.

Throws:

XmlBlasterException - in case an error occurs. Possible causes of error can be a communication exception of the underlying implementation (jdbc, file system etc).

See Also:

I_Queue.put(I_QueueEntry[], boolean)

getQueueName

public java.lang.String getQueueName()

Description copied from interface: I_AdminQueue

Returns the unique ID of this queue as found in the database XB_ENTRIES.queueName column.

Specified by:

getQueueName in interface I_AdminQueue

Returns:

For example "history_heronhello"

getStorageId

public StorageId getStorageId()

Returns the unique ID of this queue

Specified by:

getStorageId in interface I_Storage

Returns:

For example "history_heronhello"

takeWithPriority

public java.util.List<I_Entry> takeWithPriority(int numOfEntries,
                                                long numOfBytes,
                                                int minPriority,
                                                int maxPriority)
                                         throws XmlBlasterException

Description copied from interface: I_AdminQueue

Takes given number of entries out of the queue. The ordering is first priority and secondly timestamp. This method blocks until at least one entry is found

Specified by:

takeWithPriority in interface I_AdminQueue

Specified by:

takeWithPriority in interface I_Queue

Parameters:

numOfEntries - Take numOfEntries entries, if -1 take all entries currently found

numOfBytes - so many entries are returned as not to exceed the amount specified. If the first entry is bigger than this amount, it is returned anyway.

minPriority - The lower priority (inclusive), usually 0 lowest, 9 highest

maxPriority - The higher priority (inclusive), usually 0 lowest, 9 highest

Returns:

list with I_QueueEntry, the least elements with respect to the given ordering, or size()==0

Throws:

XmlBlasterException - in case the underlying implementation gets an exception while retrieving the element.

See Also:

I_Queue.takeWithPriority(int,long,int,int)

hasTransientsSwapped

private final boolean hasTransientsSwapped()

isPersistenceAvailable

private final boolean isPersistenceAvailable()

hasUncachedEntries

private final boolean hasUncachedEntries()

peekLowest

public java.util.List<I_Entry> peekLowest(int numOfEntries,
                                          long numOfBytes,
                                          I_QueueEntry limitEntry,
                                          boolean leaveOne)
                                   throws XmlBlasterException

Aware: peekLowest is not implemented!!

Specified by:

peekLowest in interface I_Queue

Throws:

XmlBlasterException

See Also:

I_Queue.peekLowest(int, long, I_QueueEntry, boolean)

takeLowest

public java.util.List<I_Entry> takeLowest(int numOfEntries,
                                          long numOfBytes,
                                          I_QueueEntry limitEntry,
                                          boolean leaveOne)
                                   throws XmlBlasterException

Aware: takeLowest for more than one entry is not implemented!!

Specified by:

takeLowest in interface I_Queue

Parameters:

numOfEntries - inclusive, zero up to numOfEntries, if -1 up to the whole queue

numOfBytes - inclusive, and minimum one is returned (but not if limitEntry suppress it)

leaveOne - Usually set to false. (true for cache queue to never flush transient queue totally)

Returns:

the list containing all 'I_QueueEntry' entries which fit into the constrains, never null.

Throws:

XmlBlasterException

See Also:

I_Queue.takeLowest(int, long, I_QueueEntry, boolean)

peekStr

public java.lang.String peekStr()
                         throws java.lang.Exception

Description copied from interface: I_AdminQueue

Returns the first element in the queue but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peekStr in interface I_AdminQueue

Returns:

I_QueueEntry the least element with respect to the given ordering or null if the queue is empty.

Throws:

java.lang.Exception - if the underlying implementation gets an exception.

peekEntries

public java.lang.String[] peekEntries(int numOfEntries)
                               throws java.lang.Exception

Description copied from interface: I_AdminQueue

Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peekEntries in interface I_AdminQueue

Parameters:

numOfEntries - Access num entries, if -1 access all entries currently found

Returns:

list with I_QueueEntry.toString(), the least elements with respect to the given ordering, or size()==0

Throws:

java.lang.Exception - if the underlying implementation gets an exception.

peek

public I_QueueEntry peek()
                  throws XmlBlasterException

Description copied from interface: I_Queue

Returns the first element in the queue but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peek in interface I_Queue

Returns:

I_QueueEntry the least element with respect to the given ordering or null if the queue is empty.

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

See Also:

I_Queue.peek()

peek

public java.util.List<I_Entry> peek(int numOfEntries,
                                    long numOfBytes)
                             throws XmlBlasterException

Description copied from interface: I_Queue

Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peek in interface I_Queue

Parameters:

numOfEntries - Access num entries, if -1 access all entries currently found

numOfBytes - is the maximum size in bytes of the array to return, -1 is unlimited .

Returns:

list with I_QueueEntry, the least elements with respect to the given ordering, or size()==0

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

See Also:

I_Queue.peek(int,long)

peekStartAt

public java.util.List<I_Entry> peekStartAt(int numOfEntries,
                                           long numOfBytes,
                                           I_QueueEntry firstEntryExlusive)
                                    throws XmlBlasterException

Description copied from interface: I_Queue

Returns maximum the first num element in the queue but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peekStartAt in interface I_Queue

Parameters:

numOfEntries - Access num entries, if -1 access all entries currently found

numOfBytes - is the maximum size in bytes of the array to return, -1 is unlimited .

Returns:

list with I_QueueEntry, the least elements with respect to the given ordering, or size()==0

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

peekSamePriority

public java.util.List<I_Entry> peekSamePriority(int numOfEntries,
                                                long numOfBytes)
                                         throws XmlBlasterException

Description copied from interface: I_Queue

Returns maximum the first num element in the queue of highest priority but does not remove it from that queue (leaves it untouched). This method does not block.

Specified by:

peekSamePriority in interface I_Queue

Parameters:

numOfEntries - Access num entries, if -1 access all entries currently found

numOfBytes - so many entries are returned as not to exceed the amount specified. If the first entry is bigger than this amount, it is returned anyway. -1 is unlimited.

Returns:

list with I_QueueEntry, the least elements with respect to the given ordering, or size()==0

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

See Also:

I_Queue.peekSamePriority(int, long)

peekWithPriority

public java.util.List<I_Entry> peekWithPriority(int numOfEntries,
                                                long numOfBytes,
                                                int minPriority,
                                                int maxPriority)
                                         throws XmlBlasterException

Description copied from interface: I_Queue

Returns maximum given number of entries from the queue (none blocking).

Specified by:

peekWithPriority in interface I_Queue

Parameters:

numOfEntries - Access num entries, if -1 take all entries currently found

numOfBytes - so many entries are returned as not to exceed the amount specified. If the first entry is bigger than this amount, it is returned anyway.

minPriority - The lower priority (inclusive), usually 0 lowest, 9 highest, <0 is not allowed

maxPriority - The higher priority (inclusive), usually 0 lowest, 9 highest, <0 is not allowed

Returns:

list with I_QueueEntry, the least elements with respect to the given ordering, or size()==0

Throws:

XmlBlasterException - in case the underlying implementation gets an exception while retrieving the element.

See Also:

I_Queue.peekWithPriority(int, long, int, int)

peekWithLimitEntry

public java.util.List<I_Entry> peekWithLimitEntry(I_QueueEntry limitEntry)
                                           throws XmlBlasterException

Deprecated.

Description copied from interface: I_Queue

It returns the entries which are higher than the entry specified in the argument list.

Specified by:

peekWithLimitEntry in interface I_Queue

Parameters:

limitEntry - the entry which limits the peek. Only entries of higher order, i.e. entries having a higher priority, or same priority and lower uniqueId are returned. If entryLimit is null or no entries are higher than entryLimit, an empty list is returned. Note: The limitEntry does not need to be in the queue.

Throws:

XmlBlasterException

See Also:

I_Queue.peekWithLimitEntry(I_QueueEntry)

removeWithLimitEntry

public long removeWithLimitEntry(I_QueueEntry limitEntry,
                                 boolean inclusive)
                          throws XmlBlasterException

Description copied from interface: I_Queue

It removes the entries which are higher than the entry specified in the argument list.

Specified by:

removeWithLimitEntry in interface I_Queue

Parameters:

limitEntry - the entry which limits the remove. Only entries of higher order, i.e. entries having a higher priority, or same priority and lower uniqueId are deleted. If entryLimit is null or no entries are higher than entryLimit, an empty list is returned.

inclusive - if 'true', then also the entry specified will be removed (if it exists). If false the remove is exclusive, i.e. the specified entry is left in the queue. Note: The limitEntry does not need to be in the queue.

Throws:

XmlBlasterException

See Also:

I_Queue.removeWithLimitEntry(I_QueueEntry, boolean)

remove

public int remove()
           throws XmlBlasterException

Removes the first element in the queue This method does not block.

Specified by:

remove in interface I_AdminQueue

Specified by:

remove in interface I_Queue

Returns:

Number of messages erased (0 or 1)

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

removeNum

public long removeNum(long numOfEntries)
               throws XmlBlasterException

Removes max num messages. This method does not block.

Specified by:

removeNum in interface I_AdminQueue

Specified by:

removeNum in interface I_Queue

Parameters:

num - Erase num entries or less if less entries are available, -1 erases everything

Returns:

Number of entries erased

Throws:

XmlBlasterException - if the underlying implementation gets an exception.

removeRandom

public int removeRandom(long dataId)
                 throws XmlBlasterException

Removes the given entry.

Parameters:

dataId - the unique id. It must be unique within the storage area of the implementing queue. In other words, if the underlying implementation is on RAM, then the storage area is the JVM, that is the queue must be unique in the same JVM. If the queue is a jdbc, the dataId is unique in the DB used.

Throws:

XmlBlasterException

removeRandom

public long removeRandom(long[] dataIdArray)
                  throws XmlBlasterException

Removes the given entries.

Parameters:

msgQueueEntry - the entry to erase.

Throws:

XmlBlasterException

removeRandom

public int removeRandom(I_Entry entry)
                 throws XmlBlasterException

Description copied from interface: I_Queue

Removes the given entry.

Specified by:

removeRandom in interface I_Queue

Parameters:

entry - The entry to erase.

Returns:

the number of elements erased.

Throws:

XmlBlasterException

See Also:

I_Queue.removeRandom(I_Entry)

removePossibleSwappedEntries

private final boolean[] removePossibleSwappedEntries(boolean[] ret,
                                                     I_Entry[] queueEntries)

The given ret array will be updated with the result of the removing from the persistent queue.

removeRandomNoNotify

private final boolean[] removeRandomNoNotify(I_Entry[] queueEntries)
                                      throws XmlBlasterException

Throws:

XmlBlasterException

See Also:

I_Queue.removeRandom(I_Entry[])

removeRandom

public final boolean[] removeRandom(I_Entry[] queueEntries)
                             throws XmlBlasterException

Description copied from interface: I_Queue

Removes the given entries.

Specified by:

removeRandom in interface I_Queue

Parameters:

queueEntries - the entries to erase.

Returns:

a boolean array of the same size as the queueEntries array. If an entry is true it means it could be removed, if false it means it could not be removed (probably already removed)

Throws:

XmlBlasterException

See Also:

I_Queue.removeRandom(I_Entry[])

loadFromPersistence

private final int loadFromPersistence()
                               throws XmlBlasterException

Loads from the persistence so much data as it fits into the transient queue.

Throws:

XmlBlasterException

removeWithPriority

public long removeWithPriority(long numOfEntries,
                               long numOfBytes,
                               int minPriority,
                               int maxPriority)
                        throws XmlBlasterException

Description copied from interface: I_AdminQueue

Removes max numOfEntries messages (or less depending on the numOfBytes). This method does not block.

Specified by:

removeWithPriority in interface I_AdminQueue

Specified by:

removeWithPriority in interface I_Queue

Parameters:

numOfEntries - Erase num entries or less if less entries are available, -1 erases everything

numOfBytes - so many entries are returned as not to exceed the amout specified. If the first entry is bigger than this amount, it is returned anyway.

minPriority - The lower priority (inclusive), usually 0 lowest, 9 highest

maxPriority - The higher priority (inclusive), usually 0 lowest, 9 highest

Returns:

Number of entries erased

Throws:

XmlBlasterException - in case the underlying implementation gets an exception while retrieving the element.

See Also:

I_Queue.removeWithPriority(long, long, int, int)

removeTransient

public int removeTransient()
                    throws XmlBlasterException

Description copied from interface: I_AdminQueue

Removes all the transient entries (the ones which have the flag 'persistent' set to false.

Specified by:

removeTransient in interface I_AdminQueue

Throws:

XmlBlasterException

See Also:

I_Queue#removeTransient()

getNumOfEntries

public long getNumOfEntries()

It returns the size of the queue. Note that this call will return the size stored in cache, i.e. it will NOT make a call to the underlying DB.

Specified by:

getNumOfEntries in interface I_AdminQueue

Specified by:

getNumOfEntries in interface I_Storage

Returns:

int the number of elements currently in the queue

See Also:

I_Storage.getNumOfEntries()

getNumOfPersistentEntries

public long getNumOfPersistentEntries()

It returns the size of persistent entries in the queue. Note that this call will return the size stored in cache, i.e. it will NOT make a call to the underlying DB.

Specified by:

getNumOfPersistentEntries in interface I_AdminQueue

Specified by:

getNumOfPersistentEntries in interface I_Queue

Returns:

int the number of elements currently in the queue

See Also:

I_Queue.getNumOfPersistentEntries()

getMaxNumOfEntries

public long getMaxNumOfEntries()

Description copied from interface: I_AdminQueue

Returns the maximum number of elements for this queue

Specified by:

getMaxNumOfEntries in interface I_AdminQueue

Specified by:

getMaxNumOfEntries in interface I_Storage

Returns:

The maximum number of elements in the queue

See Also:

I_Storage.getMaxNumOfEntries()

getNumOfBytes

public long getNumOfBytes()

Description copied from interface: I_AdminQueue

Returns the amount of bytes currently in the queue. If the implementation of this interface is not able to return the correct number of entries (for example if the implementation must make a remote call to a DB which is temporarly not available) it will return -1.

Specified by:

getNumOfBytes in interface I_AdminQueue

Specified by:

getNumOfBytes in interface I_Storage

Returns:

The amount of bytes currently in the queue

See Also:

I_Storage.getNumOfBytes()

getNumOfPersistentBytes

public long getNumOfPersistentBytes()

Description copied from interface: I_AdminQueue

Returns the amount of bytes used by the persistent entries in the queue If the implementation of this interface is not able to return the correct number of entries (for example if the implementation must make a remote call to a DB which is temporarly not available) it will return -1.

Specified by:

getNumOfPersistentBytes in interface I_AdminQueue

Specified by:

getNumOfPersistentBytes in interface I_Queue

Returns:

The amount of bytes currently in the queue

See Also:

I_Queue.getNumOfPersistentBytes()

getMaxNumOfBytes

public long getMaxNumOfBytes()

Description copied from interface: I_AdminQueue

Access the configured capacity (maximum bytes) for this queue

Specified by:

getMaxNumOfBytes in interface I_AdminQueue

Specified by:

getMaxNumOfBytes in interface I_Queue

Returns:

The maximum capacity for the queue in bytes

See Also:

I_Queue.getMaxNumOfBytes()

update

public int update(I_QueueEntry queueEntry)
           throws XmlBlasterException

Updates the given message queue entry with a new value. Note that this can be used if an entry with the unique id already exists. ?? Does this really make sense here since we need to store history ?? ?? Should we define a switch which can deactivate storage of history ??

Throws:

XmlBlasterException

clear

public long clear()

Clears everything and removes the queue (i.e. frees the associated table) This method is not synchronized because of the callback in remove which must be outside the synchronized.

Specified by:

clear in interface I_AdminQueue

Specified by:

clear in interface I_Queue

Returns:

The number of entries erased

removeHead

public long removeHead(I_QueueEntry toEntry)
                throws XmlBlasterException

Description copied from interface: I_Queue

removes the head of the queue until (but not included) the entry specified as the argument.

Specified by:

removeHead in interface I_Queue

Parameters:

toEntry - the entry until to remove.

Returns:

long the number of entries deleted.

Throws:

XmlBlasterException

See Also:

I_Queue.removeHead(I_QueueEntry)

shutdown

public void shutdown()

Shutdown the implementation, sync with data store

Specified by:

shutdown in interface I_AdminPlugin

Specified by:

shutdown in interface I_AdminQueue

Specified by:

shutdown in interface I_Plugin

Specified by:

shutdown in interface I_Queue

isShutdown

public boolean isShutdown()

Description copied from interface: I_AdminPlugin

Check status

Specified by:

isShutdown in interface I_AdminPlugin

Specified by:

isShutdown in interface I_AdminQueue

Specified by:

isShutdown in interface I_Storage

Returns:

true if down

usage

public java.lang.String usage()

JMX help

Specified by:

usage in interface I_AdminUsage

Specified by:

usage in interface I_Queue

Returns:

a human readable usage help string

getUsageUrl

public java.lang.String getUsageUrl()

Specified by:

getUsageUrl in interface I_AdminUsage

Returns:

A link for JMX usage

setUsageUrl

public void setUsageUrl(java.lang.String url)

Specified by:

setUsageUrl in interface I_AdminUsage

toXml

public final java.lang.String toXml()

Description copied from interface: I_AdminQueue

Dump state to XML string.

Specified by:

toXml in interface I_AdminQueue

Returns:

An xml encoded dump

toXml

public final java.lang.String toXml(java.lang.String extraOffset)

Description copied from interface: I_Queue

Dump state to XML string.

Specified by:

toXml in interface I_Queue

Parameters:

extraOffset - Indent the dump with given ASCII blanks

Returns:

Internal state as an XML ASCII string

init

public void init(Global glob,
                 PluginInfo pluginInfo)

Enforced by I_Plugin

Specified by:

init in interface I_Plugin

See Also:

I_Plugin.init(org.xmlBlaster.util.Global, PluginInfo)

getType

public java.lang.String getType()

Enforced by I_Plugin

Specified by:

getType in interface I_AdminPlugin

Specified by:

getType in interface I_Plugin

Returns:

"CACHE"

getVersion

public java.lang.String getVersion()

Enforced by I_Plugin

Specified by:

getVersion in interface I_AdminPlugin

Specified by:

getVersion in interface I_Plugin

Returns:

"1.0"

getInfo

public PluginInfo getInfo()

Enforced by I_StoragePlugin

Specified by:

getInfo in interface I_StoragePlugin

Returns:

the pluginInfo object.

registerStorageProblemListener

public boolean registerStorageProblemListener(I_StorageProblemListener listener)

Description copied from interface: I_StorageProblemNotifier

registers a new listener to be notified. If the registration was not done (for example if the implementation only allows one listener and there is already one), then a 'false' is returned, otherwise 'true' is returned.

Specified by:

registerStorageProblemListener in interface I_StorageProblemNotifier

See Also:

I_StorageProblemNotifier.registerStorageProblemListener(I_StorageProblemListener)

unRegisterStorageProblemListener

public boolean unRegisterStorageProblemListener(I_StorageProblemListener listener)

Description copied from interface: I_StorageProblemNotifier

unregisters a listener. If there is no such listener 'false' is returned, otherwise 'true' is returned.

Specified by:

unRegisterStorageProblemListener in interface I_StorageProblemNotifier

See Also:

I_StorageProblemNotifier.unRegisterStorageProblemListener(I_StorageProblemListener)

addStorageSizeListener

public void addStorageSizeListener(I_StorageSizeListener listener)

Description copied from interface: I_Storage

Adds a storage size listener to the storage. Every time the number of storage entries changes we will fire a changed() event.

The changed() invocation is guaranteed to NOT be in any Queue specific synchronize

You can use this for example to add a threshold warning system.

Specified by:

addStorageSizeListener in interface I_Storage

Parameters:

listener - the listener to be added, adding the same listener multiple times will only remember one and fire once

See Also:

I_Storage.addStorageSizeListener(I_StorageSizeListener)

removeStorageSizeListener

public void removeStorageSizeListener(I_StorageSizeListener listener)

Description copied from interface: I_Storage

Removes the specified listener from the queue.

Specified by:

removeStorageSizeListener in interface I_Storage

Parameters:

listener - the listener to be removed. Currently only one. If you pass null, all queueSizeListeners are removed.

See Also:

I_Storage.removeStorageSizeListener(I_StorageSizeListener)

hasStorageSizeListener

public boolean hasStorageSizeListener(I_StorageSizeListener listener)

Description copied from interface: I_Storage

Checks wether the specified listener is registered.

Specified by:

hasStorageSizeListener in interface I_Storage

Parameters:

listener - the listener to check against. If you pass null it checks if at least one listener exists.

Returns:

true if the specified listener exists, false otherwise. If you passed null in the argument list it returns true if a listener exists.

See Also:

I_Storage.hasStorageSizeListener(I_StorageSizeListener)

getStorageSizeListeners

public I_StorageSizeListener[] getStorageSizeListeners()

Specified by:

getStorageSizeListeners in interface I_Storage

Returns:

the array of storage size listeners for this storage. It never returns null.

See Also:

I_Storage.getStorageSizeListeners()

embeddedQueueObjectsToXml

public long embeddedQueueObjectsToXml(java.io.OutputStream out,
                                      java.util.Properties props)
                               throws java.lang.Exception

Description copied from interface: I_Queue

NOTE: rename from embeddedObjectsToXml to embeddedQueueObjectsToXml as it used the map lookup and lost priority info Dump all entries of this queue to the given output stream. The messages are XML formatted.

Specified by:

embeddedQueueObjectsToXml in interface I_Queue

Parameters:

out - The output stream to dump the entries

props - Configuration properties, not yet specified, just pass null

Returns:

Number of entries dumped

Throws:

java.lang.Exception

embeddedObjectsToXml

public long embeddedObjectsToXml(java.io.OutputStream out,
                                 java.util.Properties props)
                          throws java.lang.Exception

Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed

Throws:

java.lang.Exception

See Also:

I_Queue#embeddedObjectsToXml(OutputStream, Properties)

dumpEmbeddedObjectsToFile

public java.lang.String dumpEmbeddedObjectsToFile(java.lang.String fileName)
                                           throws java.lang.Exception

Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed

Specified by:

dumpEmbeddedObjectsToFile in interface I_AdminQueue

Parameters:

fileName - The file name to dump, may contain a path.

Returns:

Status string

Throws:

java.lang.Exception

See Also:

I_AdminQueue.dumpEmbeddedObjectsToFile(String)

dumpEmbeddedObjects

public java.lang.String dumpEmbeddedObjects()

Currently ONLY PERSISTENT entries are dumped (TODO add transients) Currently PRIORITY is always set to 5 (see ClientEntryFactory#createEntry as ref is null and guessed

Specified by:

dumpEmbeddedObjects in interface I_AdminQueue

Returns:

messages