org.xmlBlaster.engine
Class MsgUnitWrapper

java.lang.Object
  org.xmlBlaster.engine.MsgUnitWrapper

All Implemented Interfaces:

java.io.Serializable, I_ChangeCallback, I_MapEntry, I_Timeout, I_Entry

public final class MsgUnitWrapper
extends java.lang.Object
implements I_MapEntry, I_Timeout, I_ChangeCallback

Wraps a publish() message into an entry for a persistence cache.

There are two options to make this object persistent (measure on a 2GHz Intel Linux laptop with Postgres):

1. QoS and Key are stored as XML ASCII strings, the content as byte[]
This variant takes about 50 microsec to serialize (toXml()) and 380 microsec to create the object again (SAX parse). The size for an empty content is approx. 80 bytes for a medium sized key and QoS.

2. The whole object is java.io.Serialized
This variant takes about 160 microsec to serialize and 750 microsec to deserialize.

So we have chosen the XML variant as it is faster, has no versioning problems and has smaller size

Author:

xmlBlaster@marcelruff.info

See Also:

ServerEntryFactory.main(String[]), Serialized Form

Field Summary

private static int	ALIVE
private static int	DESTROYED
private Timeout	destroyTimer This topic is destroyed after given timeout The timer is activated on state change to UNREFERENCED and removed on change to ALIVE
private java.lang.String	embeddedType
private static int	EXPIRED
private ServerScope	glob
private int	historyReferenceCounter
private long	immutableSizeInBytes
private static java.util.logging.Logger	log
private MsgUnit	msgUnit
private I_Map	ownerCache
private static int	PRE_EXPIRED
private int	referenceCounter
private java.lang.Object	returnObj
private static long	serialVersionUID
private Timestamp	sortTimestamp
private int	state
private StorageId	storageId
private boolean	stored
private boolean	swapped
private Timestamp	timerKey
private long	uniqueId
private java.lang.String	uniqueIdStr
private boolean	wantReturnObj used to tell to the MsgQueueEntry if a return value is desidered

Constructor Summary

MsgUnitWrapper(ServerScope glob, MsgUnit msgUnit, I_Map ownerCache, int referenceCounter, int historyReferenceCounter, long sizeInBytes)
Used when message is created from TopicHandler.publish

MsgUnitWrapper(ServerScope glob, MsgUnit msgUnit, I_Map ownerCache, StorageId storageId, int referenceCounter, int historyReferenceCounter, java.lang.String embeddedType, long sizeInBytes)
Used when message comes from persistence, the owning I_Map is unknown

MsgUnitWrapper(ServerScope glob, MsgUnit msgUnit, StorageId storageId)
Testsuite

MsgUnitWrapper(ServerScope glob, MsgUnit msgUnit, StorageId storageId, int referenceCounter, int historyReferenceCounter, long sizeInBytes)
Used when message comes from persistence, the owning I_Map is unknown

Method Summary

void	added(StorageId storageId) Notification if this entry is added to storage
I_MapEntry	changeEntry(I_MapEntry entry) Callback invoked by I_Map.change inside the synchronization point.
java.lang.Object	clone() Returns a shallow clone
void	embeddedObjectToXml(java.io.OutputStream out, java.util.Properties props) Dump content to xml representation
void	finalize() Cleanup timer, it is a weak reference on us therefor it is a 'nice to have'.
java.lang.String	getContentMime()
java.lang.String	getContentMimeExtended()
java.lang.String	getDomain()
java.lang.Object	getEmbeddedObject() The embedded object.
java.lang.String	getEmbeddedType() Gets the type of the object embedded in this entry, how the object is serialized.
int	getHistoryReferenceCounter()
java.lang.String	getKeyOid()
java.lang.String	getLogId() Return a human readable identifier for logging output.
XBMeat	getMeat() For the new queues
MsgKeyData	getMsgKeyData()
MsgQosData	getMsgQosData()
MsgUnit	getMsgUnit()
int	getPriority() Returns a dummy only as sorting is not important in this context.
XBRef	getRef() For the new queues
int	getReferenceCounter()
java.lang.Object	getReturnObj()
ServerScope	getServerScope()
long	getSizeInBytes() returns the size in bytes of this entry.
Timestamp	getSortTimestamp() Can be used by cache implementation to implement LRU
java.lang.String	getStateStr()
StorageId	getStorageId() Must be filled if retrieved from database.
long	getUniqueId() The unique ID for this entry = getMsgQosData().getRcvTimestamp().getTimestamp()
java.lang.String	getUniqueIdStr()
boolean	getWantReturnObj()
boolean	hasRemainingLife() The state may still be alive.
void	incrementReferenceCounter(int count, StorageId storageId) Invoked by ReferenceEntry.java and TopicHandler.java to support reference counting
private boolean	isAlive()
boolean	isDestroyed()
boolean	isExpired()
boolean	isInternal()
boolean	isPersistent() Returns true if the entry is persistent (persistent on HD), false otherwise.
boolean	isStored()
boolean	isSwapped() The cache sets it to true when the entry is swapped away.
void	isSwapped(boolean swapped) Used by the cache implementation to mark entries which will be swapped to the persistent store.
void	removed(StorageId storageId) Notification if this entry is removed from storage
void	setMsgUnit(MsgUnit msg)
(package private) void	setReferenceCounter(int count) Internal use for TopicHandler
void	setReturnObj(java.lang.Object returnObj) Set the object to be carried as return value.
void	setSortTimestamp(Timestamp timestamp) Can be used by cache implementation to implement LRU
void	setStored(boolean stored) Is invoked by the storage implementation with 'true' when the entry is put in a storage and with 'false' when the entry is removed from the storage.
void	setWantReturnObj(boolean wantReturnObj) Sets this flag to true/false.
void	startExpiryTimer()
void	timeout(java.lang.Object userData) This timeout occurs after a configured expiration delay
void	toDestroyed() Called by TopicHandler.java or ReferenceEntry.java
private void	toExpired()
java.lang.String	toXml()
java.lang.String	toXml(java.lang.String extraOffset, boolean forceReadable) Dumps the message.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

glob

private final transient ServerScope glob

log

private static java.util.logging.Logger log

historyReferenceCounter

private transient int historyReferenceCounter

referenceCounter

private transient int referenceCounter

uniqueId

private final transient long uniqueId

uniqueIdStr

private final transient java.lang.String uniqueIdStr

ownerCache

private transient I_Map ownerCache

embeddedType

private final transient java.lang.String embeddedType

wantReturnObj

private transient boolean wantReturnObj

used to tell to the MsgQueueEntry if a return value is desidered

returnObj

private transient java.lang.Object returnObj

destroyTimer

private transient Timeout destroyTimer

This topic is destroyed after given timeout The timer is activated on state change to UNREFERENCED and removed on change to ALIVE

timerKey

private transient Timestamp timerKey

ALIVE

private static final int ALIVE

See Also:

Constant Field Values

PRE_EXPIRED

private static final int PRE_EXPIRED

See Also:

Constant Field Values

EXPIRED

private static final int EXPIRED

See Also:

Constant Field Values

DESTROYED

private static final int DESTROYED

See Also:

Constant Field Values

state

private transient int state

msgUnit

private MsgUnit msgUnit

immutableSizeInBytes

private final long immutableSizeInBytes

stored

private boolean stored

swapped

private transient boolean swapped

sortTimestamp

private transient Timestamp sortTimestamp

storageId

private transient StorageId storageId

Constructor Detail

MsgUnitWrapper

public MsgUnitWrapper(ServerScope glob,
                      MsgUnit msgUnit,
                      StorageId storageId)
               throws XmlBlasterException

Testsuite

Throws:

XmlBlasterException

MsgUnitWrapper

public MsgUnitWrapper(ServerScope glob,
                      MsgUnit msgUnit,
                      I_Map ownerCache,
                      int referenceCounter,
                      int historyReferenceCounter,
                      long sizeInBytes)
               throws XmlBlasterException

Used when message is created from TopicHandler.publish

Throws:

XmlBlasterException

MsgUnitWrapper

public MsgUnitWrapper(ServerScope glob,
                      MsgUnit msgUnit,
                      StorageId storageId,
                      int referenceCounter,
                      int historyReferenceCounter,
                      long sizeInBytes)
               throws XmlBlasterException

Used when message comes from persistence, the owning I_Map is unknown

Throws:

XmlBlasterException

MsgUnitWrapper

public MsgUnitWrapper(ServerScope glob,
                      MsgUnit msgUnit,
                      I_Map ownerCache,
                      StorageId storageId,
                      int referenceCounter,
                      int historyReferenceCounter,
                      java.lang.String embeddedType,
                      long sizeInBytes)
               throws XmlBlasterException

Used when message comes from persistence, the owning I_Map is unknown

Parameters:

embeddedType - Allows you to control how to make this object persistent:
ServerEntryFactory.ENTRY_TYPE_MSG_XML Dump strings as XML ASCII (which is smaller, faster, portable -> and therefor default)
ServerEntryFactory.ENTRY_TYPE_MSG_SERIAL Dump object with java.io.Serializable

sizeInBytes - The estimated size of this entry in RAM, if -1 we estimate it for you

Throws:

XmlBlasterException

Method Detail

getServerScope

public final ServerScope getServerScope()

finalize

public void finalize()

Cleanup timer, it is a weak reference on us therefor it is a 'nice to have'.

Overrides:

finalize in class java.lang.Object

isSwapped

public boolean isSwapped()

The cache sets it to true when the entry is swapped away. You should not write on a swapped away entry as those changes are lost. Enforced by I_Map

Specified by:

isSwapped in interface I_MapEntry

See Also:

I_Map#isSwapped()

isSwapped

public void isSwapped(boolean swapped)

Used by the cache implementation to mark entries which will be swapped to the persistent store. Enforced by I_Map

Specified by:

isSwapped in interface I_MapEntry

incrementReferenceCounter

public void incrementReferenceCounter(int count,
                                      StorageId storageId)
                               throws XmlBlasterException

Invoked by ReferenceEntry.java and TopicHandler.java to support reference counting

Parameters:

count - The number of ref-counts to add/subtract

storageId -

Throws:

XmlBlasterException

setReferenceCounter

void setReferenceCounter(int count)

Internal use for TopicHandler

changeEntry

public I_MapEntry changeEntry(I_MapEntry entry)
                       throws XmlBlasterException

Callback invoked by I_Map.change inside the synchronization point. Enforced by I_ChangeCallback

Specified by:

changeEntry in interface I_ChangeCallback

Parameters:

entry - the entry to modify.

Returns:

I_MapEntry the modified entry.

Throws:

XmlBlasterException - if something has gone wrong and the change must be rolled back.

getReferenceCounter

public int getReferenceCounter()

Returns:

The number or references on myself (history, callback queue and plugin queues)

getHistoryReferenceCounter

public int getHistoryReferenceCounter()

Returns:

1: Is referenced one time from history queue, else 0

getPriority

public int getPriority()

Returns a dummy only as sorting is not important in this context.

Specified by:

getPriority in interface I_Entry

Returns:

The priority

getMsgQosData

public MsgQosData getMsgQosData()

isPersistent

public boolean isPersistent()

Description copied from interface: I_Entry

Returns true if the entry is persistent (persistent on HD), false otherwise.

Specified by:

isPersistent in interface I_Entry

getMsgKeyData

public MsgKeyData getMsgKeyData()

getMsgUnit

public MsgUnit getMsgUnit()

getKeyOid

public final java.lang.String getKeyOid()

getContentMime

public java.lang.String getContentMime()

getContentMimeExtended

public java.lang.String getContentMimeExtended()

getDomain

public java.lang.String getDomain()

setMsgUnit

public void setMsgUnit(MsgUnit msg)

getSizeInBytes

public long getSizeInBytes()

Description copied from interface: I_Entry

returns the size in bytes of this entry.

Specified by:

getSizeInBytes in interface I_Entry

getUniqueId

public long getUniqueId()

The unique ID for this entry = getMsgQosData().getRcvTimestamp().getTimestamp()

Specified by:

getUniqueId in interface I_Entry

Returns:

The unique Id of this entry.

getUniqueIdStr

public java.lang.String getUniqueIdStr()

Specified by:

getUniqueIdStr in interface I_MapEntry

Returns:

The unique ID as a string (cached for performance)

getLogId

public final java.lang.String getLogId()

Description copied from interface: I_Entry

Return a human readable identifier for logging output.

See the derived class for a syntax description.

Specified by:

getLogId in interface I_Entry

isInternal

public final boolean isInternal()

getEmbeddedType

public java.lang.String getEmbeddedType()

Description copied from interface: I_Entry

Gets the type of the object embedded in this entry, how the object is serialized.

Specified by:

getEmbeddedType in interface I_Entry

Returns:

ServerEntryFactory.ENTRY_TYPE_MSG_XML or ServerEntryFactory.ENTRY_TYPE_MSG_SERIAL

getEmbeddedObject

public java.lang.Object getEmbeddedObject()

The embedded object. Object[] = { this.msgUnit, new Integer(this.referenceCounter) } or
qos.toXml, key.toXml, contentBytes

IMPORTANT NOTE: If you change the data here you need to change MsgQueueUpdateEntry#getEmbeddedObject() as well! Check ServerEntryFactory as well.

Specified by:

getEmbeddedObject in interface I_Entry

clone

public java.lang.Object clone()

Returns a shallow clone

Overrides:

clone in class java.lang.Object

toXml

public final java.lang.String toXml()

embeddedObjectToXml

public final void embeddedObjectToXml(java.io.OutputStream out,
                                      java.util.Properties props)
                               throws java.io.IOException

Description copied from interface: I_Entry

Dump content to xml representation

Specified by:

embeddedObjectToXml in interface I_Entry

Parameters:

out - The stream to dump to

props - Control porperties

Throws:

java.io.IOException

toXml

public java.lang.String toXml(java.lang.String extraOffset,
                              boolean forceReadable)

Dumps the message. NOTE: max 80 bytes of the content are displayed

added

public void added(StorageId storageId)

Notification if this entry is added to storage

Specified by:

added in interface I_Entry

See Also:

I_Entry.added(StorageId)

removed

public void removed(StorageId storageId)

Notification if this entry is removed from storage

Specified by:

removed in interface I_Entry

Parameters:

storageId - The storage id

See Also:

I_Entry.removed(StorageId)

isAlive

private boolean isAlive()

hasRemainingLife

public boolean hasRemainingLife()

The state may still be alive.

Returns:

true is the configured life span is elapsed

startExpiryTimer

public void startExpiryTimer()

isExpired

public boolean isExpired()

toExpired

private void toExpired()
                throws XmlBlasterException

Throws:

XmlBlasterException

isDestroyed

public boolean isDestroyed()

toDestroyed

public void toDestroyed()

Called by TopicHandler.java or ReferenceEntry.java

timeout

public final void timeout(java.lang.Object userData)

This timeout occurs after a configured expiration delay

Specified by:

timeout in interface I_Timeout

Parameters:

userData - You get bounced back your userData which you passed with Timeout.addTimeoutListener()

getStateStr

public java.lang.String getStateStr()

setStored

public final void setStored(boolean stored)

Description copied from interface: I_Entry

Is invoked by the storage implementation with 'true' when the entry is put in a storage and with 'false' when the entry is removed from the storage. The storage is for example a 'cache', a 'ram' or a 'jdbc' implementation.

Note that this callback is guaranteed to be called from within the queue specific synchronized block

Todo: Remove this in favour of added()/removed() (isStored() is currently only used by CacheQueueInterceptorPlugin.java) I'm not sure if this usage relies on being inside sync

This method may never throw any exception

Specified by:

setStored in interface I_Entry

Parameters:

stored - 'true' if the entry will be put into the storage, 'false' if it is removed.

See Also:

I_Entry.setStored(boolean)

isStored

public final boolean isStored()

Specified by:

isStored in interface I_Entry

Returns:

boolean 'true' if the entry is still in the storage, 'false' if the entry has been removed or if it has not been put in the storage yet.

See Also:

I_Entry.isStored()

setWantReturnObj

public void setWantReturnObj(boolean wantReturnObj)

Sets this flag to true/false. This flag can be passed to the MsgQueueEntry

Parameters:

wantReturnObj -

getWantReturnObj

public boolean getWantReturnObj()

Returns:

getReturnObj

public java.lang.Object getReturnObj()

Returns:

returnObj The carried object used as return QoS in sync or async I_Queue.put() mode, can be null.

setReturnObj

public void setReturnObj(java.lang.Object returnObj)

Set the object to be carried as return value. NOTE: This can be used only once as the first call to this method destroys the reference to the clone original instance.

getSortTimestamp

public final Timestamp getSortTimestamp()

Can be used by cache implementation to implement LRU

Specified by:

getSortTimestamp in interface I_MapEntry

Returns:

null if not previously set by setSortTimestamp()

setSortTimestamp

public final void setSortTimestamp(Timestamp timestamp)

Can be used by cache implementation to implement LRU

Specified by:

setSortTimestamp in interface I_MapEntry

getMeat

public XBMeat getMeat()

For the new queues

Specified by:

getMeat in interface I_Entry

getRef

public XBRef getRef()

For the new queues

Specified by:

getRef in interface I_Entry

getStorageId

public StorageId getStorageId()

Description copied from interface: I_MapEntry

Must be filled if retrieved from database.

Specified by:

getStorageId in interface I_MapEntry

Returns:

can be null