org.xmlBlaster.engine.queuemsg
Class TopicEntry

java.lang.Object
  org.xmlBlaster.engine.queuemsg.TopicEntry

All Implemented Interfaces:

I_Entry, I_MapEntry, java.io.Serializable

public final class TopicEntry

extends java.lang.Object

implements I_MapEntry

Wraps an 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 java.lang.String	embeddedType
private long	immutableSizeInBytes
private static java.util.logging.Logger	log
private java.lang.String	ME
private MsgUnit	msgUnit
private static long	serialVersionUID
private Timestamp	sortTimestamp
private boolean	stored
private boolean	swapped
private long	uniqueId
private java.lang.String	uniqueIdStr

Constructor Summary

TopicEntry(ServerScope glob, MsgUnit msgUnit)
Use this constructor if a new message object is fed by method publish().

TopicEntry(ServerScope glob, MsgUnit msgUnit, java.lang.String embeddedType, 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
java.lang.Object	clone() Returns a shallow clone
void	embeddedObjectToXml(java.io.OutputStream out, java.util.Properties props) Dump content to xml representation
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.
java.lang.String	getKeyOid()
java.lang.String	getLogId() Return a human readable identifier for logging output.
MsgKeyData	getMsgKeyData()
MsgQosData	getMsgQosData()
MsgUnit	getMsgUnit()
int	getPriority() Returns a dummy only as sorting is not important in this context.
long	getSizeInBytes() returns the size in bytes of this entry.
Timestamp	getSortTimestamp() Can be used by cache implementation to implement LRU
long	getUniqueId() The unique ID for this entry = getMsgQosData().getRcvTimestamp().getTimestamp()
java.lang.String	getUniqueIdStr()
boolean	isExpired()
boolean	isInternal()
boolean	isPersistent() Returns true if the entry is persistent (persistent on HD), false otherwise.
boolean	isStored()
boolean	isSwapped() Enforced by I_Map
void	isSwapped(boolean swapped) Enforced by I_Map
static void	main(java.lang.String[] args) Measure size for XML-ASCII versus java.io.Serializable persistence.
void	removed(StorageId storageId) Notification if this entry is removed from storage
void	setMsgUnit(MsgUnit msg)
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.
java.lang.String	toXml()
java.lang.String	toXml(java.lang.String extraOffset)

Methods inherited from class java.lang.Object

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

Field Detail

log

private static java.util.logging.Logger log

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

ME

private final transient java.lang.String ME

uniqueId

private final transient long uniqueId

uniqueIdStr

private final transient java.lang.String uniqueIdStr

embeddedType

private final transient java.lang.String embeddedType

msgUnit

private MsgUnit msgUnit

immutableSizeInBytes

private final long immutableSizeInBytes

stored

private transient boolean stored

swapped

private transient boolean swapped

sortTimestamp

private transient Timestamp sortTimestamp

Constructor Detail

TopicEntry

public TopicEntry(ServerScope glob,
                  MsgUnit msgUnit)
           throws XmlBlasterException

Use this constructor if a new message object is fed by method publish().

Parameters:

msgUnit - The raw data

TopicEntry

public TopicEntry(ServerScope glob,
                  MsgUnit msgUnit,
                  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_TOPIC_XML Dump strings as XML ASCII (which is smaller, faster, portable -> and therefor default)
ServerEntryFactory.ENTRY_TYPE_TOPIC_SERIAL Dump object with java.io.Serializable

Method Detail

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 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 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_TOPIC_XML or ServerEntryFactory.ENTRY_TYPE_TOPIC_SERIAL

getEmbeddedObject

public java.lang.Object getEmbeddedObject()

The embedded object. Object[] = { this.msgUnit } or
qos.toXml, key.toXml, contentBytes

Specified by:

getEmbeddedObject in interface I_Entry

clone

public java.lang.Object clone()

Returns a shallow clone

toXml

public final java.lang.String toXml()

toXml

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

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)

isExpired

public boolean isExpired()

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()

isSwapped

public boolean isSwapped()

Enforced by I_Map

Specified by:

isSwapped in interface I_MapEntry

See Also:

I_Map#isSwapped()

isSwapped

public void isSwapped(boolean swapped)

Enforced by I_Map

Specified by:

isSwapped in interface I_MapEntry

See Also:

I_Map#isSwapped(boolean)

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

Returns:

timestamp This is chosen by the cache algorithm

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

main

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

Measure size for XML-ASCII versus java.io.Serializable persistence.

 
 java org.xmlBlaster.engine.TopicEntry
 

Result:

java.io.Serialized file 'TopicEntry.ser' size=1407 bytes versus XML dump=123 bytes