org.xmlBlaster.engine.msgstore.ram
Class MapPlugin

java.lang.Object
  org.xmlBlaster.engine.msgstore.ram.MapPlugin

All Implemented Interfaces:

I_Map, I_Plugin, I_Storage, I_StoragePlugin, I_StorageProblemNotifier

public final class MapPlugin
extends java.lang.Object
implements I_Map, I_StoragePlugin

Mapping messages in RAM only. Please refer to I_Map for Javadoc comments.

Author:

xmlBlaster@marcelruff.info

See Also:

I_MapTest

Nested Class Summary

(package private) class

MapPlugin.LruComparator Sorts the entries in the the last recent added order (no real LRU).

Field Summary

private Global	glob
private boolean	isShutdown
private static java.util.logging.Logger	log
private java.util.Set	lruSet
private StorageId	mapId
private java.lang.String	ME
private long	numOfPersistentEntries
private long	persistentSizeInBytes
private PluginInfo	pluginInfo
private QueuePropertyBase	property
private long	sizeInBytes
private java.util.Map	storage
private StorageSizeListenerHelper	storageSizeListenerHelper

Constructor Summary

MapPlugin()

Method Summary

void	addStorageSizeListener(I_StorageSizeListener listener) Adds a storage size listener to the storage.
I_MapEntry	change(I_MapEntry entry, I_ChangeCallback callback)
I_MapEntry	change(long uniqueId, I_ChangeCallback callback) This method is threadsafe because it makes a lookup for the updated entry within the synchronization point.
long	clear() Delete all entries
void	destroy() destroys all the resources associated to this queue.
long	embeddedObjectsToXml(java.io.OutputStream out, java.util.Properties props) Dump all entries of this map to the given output stream.
I_MapEntry	get(long uniqueId) Lookup entry without removing.
I_MapEntry[]	getAll(I_EntryFilter entryFilter) Retrieve all entries in the storage, please take care on memory consumption.
PluginInfo	getInfo() Enforced by I_StoragePlugin
long	getMaxNumOfBytes() returns the 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 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	getNumOfEntries() Returns the number of elements in this 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() i
java.lang.Object	getProperties() Access the current queue configuration
StorageId	getStorageId() Returns the unique ID of this queue.
I_StorageSizeListener[]	getStorageSizeListeners()
java.lang.String	getType() Enforced by I_Plugin
java.lang.String	getVersion() Enforced by I_Plugin
boolean	hasStorageSizeListener(I_StorageSizeListener listener) Checks wether the specified listener is registered.
void	init(Global glob, PluginInfo pluginInfo) Enforced by I_Plugin
void	initialize(StorageId uniqueMapId, java.lang.Object userData) Is called after the instance is created.
boolean	isShutdown() Performs what has to be done when the Map Plugin shuts down.
boolean	isTransient()
static void	main(java.lang.String[] args) java org.xmlBlaster.engine.msgstore.ram.MapPlugin
int	put(I_MapEntry entry) Adds one entry and automatically increments the reference counter.
boolean	registerStorageProblemListener(I_StorageProblemListener listener) registers a new listener to be notified.
int	remove(I_MapEntry mapEntry)
int	remove(long uniqueId)
I_MapEntry	removeOldest() Remove the oldest entry.
void	removeStorageSizeListener(I_StorageSizeListener listener) Removes the specified listener from the queue.
int	removeTransient()
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	shutdown() Shutdown the implementation, sync with data store, free resources
private void	touch(I_MapEntry entry)
java.lang.String	toXml()
java.lang.String	toXml(java.lang.String extraOffset)
boolean	unRegisterStorageProblemListener(I_StorageProblemListener listener) unregisters a listener.
void	updateCounters(I_MapEntry entry)
java.lang.String	usage()

Methods inherited from class java.lang.Object

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

Field Detail

ME

private java.lang.String ME

mapId

private StorageId mapId

storage

private java.util.Map storage

lruSet

private java.util.Set lruSet

property

private QueuePropertyBase property

glob

private Global glob

log

private static java.util.logging.Logger log

isShutdown

private boolean isShutdown

sizeInBytes

private long sizeInBytes

persistentSizeInBytes

private long persistentSizeInBytes

numOfPersistentEntries

private long numOfPersistentEntries

pluginInfo

private PluginInfo pluginInfo

storageSizeListenerHelper

private StorageSizeListenerHelper storageSizeListenerHelper

Constructor Detail

MapPlugin

public MapPlugin()

Method Detail

initialize

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

Is called after the instance is created.

Specified by:

initialize in interface I_Map

Parameters:

uniqueMapId - A unique name, allowing to create a unique name for a persistent store (e.g. file name) "history:/node/heron/topic/"

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

Throws:

XmlBlasterException

See Also:

I_Map.initialize(StorageId, Object)

setProperties

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

Description copied from interface: I_Map

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_Map

Throws:

XmlBlasterException

getProperties

public java.lang.Object getProperties()

Description copied from interface: I_Map

Access the current queue configuration

Specified by:

getProperties in interface I_Map

getStorageId

public final StorageId getStorageId()

Description copied from interface: I_Storage

Returns the unique ID of this queue.

Specified by:

getStorageId in interface I_Storage

Returns:

For example "history_heronhello"

isTransient

public boolean isTransient()

Specified by:

isTransient in interface I_Storage

Returns:

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

get

public I_MapEntry get(long uniqueId)
               throws XmlBlasterException

Description copied from interface: I_Map

Lookup entry without removing.

Specified by:

get in interface I_Map

Returns:

null if not found

Throws:

XmlBlasterException

See Also:

I_Map.get(long)

touch

private void touch(I_MapEntry entry)

getAll

public I_MapEntry[] getAll(I_EntryFilter entryFilter)
                    throws XmlBlasterException

Description copied from interface: I_Map

Retrieve all entries in the storage, please take care on memory consumption.

Specified by:

getAll in interface I_Map

Parameters:

entryFilter - null to get everything. If specified you can filter by this callback the wanted entries.

Returns:

A current snapshot of all entries

Throws:

XmlBlasterException

See Also:

I_Map#getAll()

put

public int put(I_MapEntry entry)
        throws XmlBlasterException

Description copied from interface: I_Map

Adds one entry and automatically increments the reference counter. Note: If an entry existed already (0 is returned), it is NOT updated in storage

Specified by:

put in interface I_Map

Returns:

Number of new entries added: 0 if entry existed, 1 if new entry added

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_Map.put(I_MapEntry)

remove

public int remove(I_MapEntry mapEntry)
           throws XmlBlasterException

Specified by:

remove in interface I_Map

Returns:

the number of elements erased.

Throws:

XmlBlasterException

See Also:

I_Map.remove(I_MapEntry)

remove

public int remove(long uniqueId)
           throws XmlBlasterException

Specified by:

remove in interface I_Map

Returns:

the number of elements erased.

Throws:

XmlBlasterException

See Also:

I_Map.remove(long)

removeTransient

public int removeTransient()
                    throws XmlBlasterException

Throws:

XmlBlasterException

See Also:

I_Map#removeTransient()

removeOldest

public I_MapEntry removeOldest()
                        throws XmlBlasterException

Description copied from interface: I_Map

Remove the oldest entry. 'Oldest' is defined in the context of the implementation to support an efficient cache, typically it is the LRU (last recent used) entry.

Specified by:

removeOldest in interface I_Map

Returns:

the removed entry

Throws:

XmlBlasterException

See Also:

I_Map.removeOldest()

clear

public long clear()

Description copied from interface: I_Map

Delete all entries

Specified by:

clear in interface I_Map

Returns:

Number of entries removed

getNumOfEntries

public long getNumOfEntries()

Description copied from interface: I_Storage

Returns the number of elements in this 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 temporary not available) it will return -1.

Specified by:

getNumOfEntries in interface I_Storage

Returns:

int the number of elements

See Also:

I_Storage.getNumOfEntries()

getMaxNumOfEntries

public long getMaxNumOfEntries()

Description copied from interface: I_Storage

Returns the maximum number of elements for this queue

Specified by:

getMaxNumOfEntries in interface I_Storage

Returns:

The maximum number of elements in the queue

getNumOfPersistentEntries

public long getNumOfPersistentEntries()

i

Specified by:

getNumOfPersistentEntries in interface I_Map

Returns:

int the number of elements currently in the queue

See Also:

I_Map.getNumOfPersistentEntries()

getNumOfBytes

public long getNumOfBytes()

Description copied from interface: I_Storage

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_Storage

Returns:

The number of elements currently in the queue

See Also:

I_Storage.getNumOfBytes()

getNumOfPersistentBytes

public long getNumOfPersistentBytes()

Description copied from interface: I_Map

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_Map

Returns:

int the number of elements currently in the queue

See Also:

I_Map.getNumOfPersistentBytes()

getMaxNumOfBytes

public final long getMaxNumOfBytes()

Description copied from interface: I_Map

returns the capacity (maximum bytes) for this queue

Specified by:

getMaxNumOfBytes in interface I_Map

Returns:

int the maximum number of elements in the queue

See Also:

I_Map.getMaxNumOfBytes()

shutdown

public final void shutdown()

Description copied from interface: I_Map

Shutdown the implementation, sync with data store, free resources

Specified by:

shutdown in interface I_Map

Specified by:

shutdown in interface I_Plugin

isShutdown

public final boolean isShutdown()

Description copied from interface: I_Storage

Performs what has to be done when the Map Plugin shuts down.

Specified by:

isShutdown in interface I_Storage

destroy

public void destroy()
             throws XmlBlasterException

Description copied from interface: I_Map

destroys all the resources associated to this queue. This means that all temporary and persistent resources are removed.

Specified by:

destroy in interface I_Map

Throws:

XmlBlasterException

usage

public java.lang.String usage()

Specified by:

usage in interface I_Map

Returns:

a human readable usage help string

toXml

public final java.lang.String toXml()

toXml

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

Specified by:

toXml in interface I_Map

Parameters:

extraOffset - Indent the dump with given ASCII blanks

Returns:

An xml encoded dump

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_Plugin

Returns:

"RAM"

getVersion

public java.lang.String getVersion()

Enforced by I_Plugin

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)

change

public I_MapEntry change(I_MapEntry entry,
                         I_ChangeCallback callback)
                  throws XmlBlasterException

Specified by:

change in interface I_Map

Parameters:

entry - the entry to change. This is the old entry, i.e. the entry on which the modification has to take place by callback. Or it is the new entry and you can pass null for callback. IMPORTANT: This method is not threadsafe since it does not make a lookup to get the actual entry. The specified entry could be a dirty read, in which case the current entry would be overwritten with this dirty value. If you want to work threadsafe you should invoke change(long, callback). That method makes a lookup within the same synchronization point.

callback - the object on which the callback method 'changeEntry' is invoked. The modification of the object is done in that method. If you pass null, then the changeEntry is not invoked and the processing continues with entry.

Returns:

I_MapEntry the modified entry.

Throws:

XmlBlasterException - if something goes wrong when making the change (for example if the entry is not in the map) or if the callback throws an exception.

See Also:

I_Map.change(I_MapEntry, I_ChangeCallback)

updateCounters

public void updateCounters(I_MapEntry entry)
                    throws XmlBlasterException

Specified by:

updateCounters in interface I_Map

Parameters:

entry - the entry to change. This is the old entry, i.e. the entry on which the modification has to take place by callback. Or it is the new entry and you can pass null for callback. IMPORTANT: This method is not threadsafe since it does not make a lookup to get the actual entry. The specified entry could be a dirty read, in which case the current entry would be overwritten with this dirty value. If you want to work threadsafe you should invoke change(long, callback). That method makes a lookup within the same synchronization point.

Throws:

XmlBlasterException - if something goes wrong when making the change (for example if the entry is not in the map) or if the callback throws an exception.

See Also:

I_Map.change(I_MapEntry, I_ChangeCallback)

change

public I_MapEntry change(long uniqueId,
                         I_ChangeCallback callback)
                  throws XmlBlasterException

Description copied from interface: I_Map

This method is threadsafe because it makes a lookup for the updated entry within the synchronization point.

Specified by:

change in interface I_Map

Parameters:

uniqueId - the uniqueId of the entry to change. This is the old entry, i.e. the entry on which the modification has to take place.

callback - the object on which the callback method 'changeEntry' is invoked. The modification of the object is done in that method. If you pass null, then the changeEntry is not invoked and the processing continues with entry.

Returns:

I_Entry the modified entry.

Throws:

XmlBlasterException - if something goes wrong when making the change (for example if the entry is not in the map) or if the callback throws an exception.

See Also:

I_Map.change(long, I_ChangeCallback)

embeddedObjectsToXml

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

Description copied from interface: I_Map

Dump all entries of this map to the given output stream. The messages are XML formatted.

Specified by:

embeddedObjectsToXml in interface I_Map

Parameters:

out - The output stream to dump the entries

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

Returns:

Number of entries dumped

See Also:

I_Map.embeddedObjectsToXml(OutputStream, Properties)

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()

main

public static void main(java.lang.String[] args)

java org.xmlBlaster.engine.msgstore.ram.MapPlugin