Package org.jgroups

Class BaseMessage

java.lang.Object

org.jgroups.BaseMessage

All Implemented Interfaces:

Constructable<Message>, Message, SizeStreamable, Streamable

Direct Known Subclasses:

BatchMessage, BytesMessage, CompositeMessage, EmptyMessage, LongMessage, NioMessage, ObjectMessage

public abstract class BaseMessage
extends java.lang.Object
implements Message

A common superclass for all Message implementations. It contains functionality to manage headers, flags and destination and source addresses.

Since:

5.0

Author:

Bela Ban

Nested Class Summary

Nested classes/interfaces inherited from interface org.jgroups.Message

Message.Flag, Message.TransientFlag

Field Summary

Fields

Modifier and Type	Field	Description
protected Address	dest
protected short	flags
protected Header[]	headers
protected Address	sender
protected byte	transient_flags

Fields inherited from interface org.jgroups.Message

BYTES_MSG, COMPOSITE_MSG, EARLYBATCH_MSG, EMPTY_MSG, FRAG_MSG, LONG_MSG, NIO_MSG, OBJ_MSG

Constructor Summary

Constructors

Constructor	Description
BaseMessage()
BaseMessage(Address dest)	Constructs a message given a destination address

Method Summary

Modifier and Type	Method	Description
Message	clearFlag(Message.Flag... flags)	Clears a number of flags in a message
Message	clearFlag(Message.TransientFlag... flags)	Removes a number of transient flags from the message.
Message	clearHeaders()	Removes all headers: use carefully!
Message	copy(boolean copy_payload, boolean copy_headers)	Copies the source- and destination addresses, flags and headers (if copy_headers is true). If copy_payload is set, then method copyPayload(Message) of the subclass will be called, which is responsible for copying the payload specific to that message type. Note that for headers, only the arrays holding references to the headers are copied, not the headers themselves ! The consequence is that the headers array of the copy hold the *same* references as the original, so do *not* modify the headers ! If you want to change a header, copy it and call Message.putHeader(short,Header) again.
protected Message	copyPayload(Message copy)	Copies the payload
protected static Header[]	createHeaders(int size)
Address	getDest()	Returns the destination address to send the message to.
short	getFlags(boolean transient_flags)	Returns the internal representation of flags.
<T extends Header> T	getHeader(short id)	Gets a header from the message
java.util.Map<java.lang.Short,Header>	getHeaders()	Returns a hashmap of all header IDs and their associated headers
int	getNumHeaders()	Returns the number of headers
<T> T	getPayload()	Returns the payload without any conversion (e.g.
Address	getSrc()	Returns the address of the sender
Header[]	headers()
Message	headers(Header[] hdrs)
boolean	isFlagSet(Message.Flag flag)	Checks if a given flag is set
boolean	isFlagSet(Message.TransientFlag flag)	Returns true if a transient flag is set, false otherwise
java.lang.String	printHeaders()	Returns a pretty-printed string of the headers
Message	putHeader(short id, Header hdr)	Puts a header given an ID into the hashmap.
void	readFrom(java.io.DataInput in)	Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed
int	serializedSize()	Returns the size (in bytes) of the marshalled object
Message	setDest(Address new_dest)	Sets the destination address to send the message to.
Message	setFlag(short flag, boolean transient_flags, boolean xor)	Sets the flags as a short; this way, multiple flags can be set in one operation
Message	setFlag(Message.Flag... flags)	Sets a number of flags in a message
Message	setFlag(Message.TransientFlag... flags)	Same as setFlag(Flag...) except that transient flags are not marshalled
boolean	setFlagIfAbsent(Message.TransientFlag flag)	Atomically checks if a given flag is set and - if not - sets it.
Message	setPayload(java.lang.Object pl)	Sets the payload
Message	setSrc(Address new_src)	Sets the address of the sender of this message
int	size()	Returns the exact size of the marshalled message
java.lang.String	toString()
void	writeTo(java.io.DataOutput out)	Write the entire state of the current object (including superclasses) to outstream.
void	writeToNoAddrs(Address src, java.io.DataOutput out, short... excluded_headers)	Writes the message to an output stream excluding the destination (and possibly source) address, plus a number of headers

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jgroups.Constructable

create

Methods inherited from interface org.jgroups.Message

dest, dest, getArray, getFlags, getLength, getObject, getOffset, getType, hasArray, hasPayload, readPayload, setArray, setArray, setArray, setFlag, setObject, src, src, writePayload

Field Detail

dest

protected Address dest

sender

protected Address sender

headers

protected volatile Header[] headers

flags

protected volatile short flags

transient_flags

protected volatile byte transient_flags

Constructor Detail

BaseMessage

public BaseMessage()

BaseMessage

public BaseMessage(Address dest)

Constructs a message given a destination address

Parameters:

dest - The Address of the receiver. If it is null, then the message is sent to the group. Otherwise, it is sent to a single member.

Method Detail

getDest

public Address getDest()

Description copied from interface: Message

Returns the destination address to send the message to. A null value sends the message to all cluster members

Specified by:

getDest in interface Message

setDest

public Message setDest(Address new_dest)

Description copied from interface: Message

Sets the destination address to send the message to. A null value sends the message to all cluster members

Specified by:

setDest in interface Message

getSrc

public Address getSrc()

Description copied from interface: Message

Returns the address of the sender

Specified by:

getSrc in interface Message

setSrc

public Message setSrc(Address new_src)

Description copied from interface: Message

Sets the address of the sender of this message

Specified by:

setSrc in interface Message

getNumHeaders

public int getNumHeaders()

Description copied from interface: Message

Returns the number of headers

Specified by:

getNumHeaders in interface Message

getHeaders

public java.util.Map<java.lang.Short,Header> getHeaders()

Description copied from interface: Message

Returns a hashmap of all header IDs and their associated headers

Specified by:

getHeaders in interface Message

headers

public Header[] headers()

headers

public Message headers(Header[] hdrs)

printHeaders

public java.lang.String printHeaders()

Description copied from interface: Message

Returns a pretty-printed string of the headers

Specified by:

printHeaders in interface Message

setFlag

public Message setFlag(Message.Flag... flags)

Sets a number of flags in a message

Specified by:

setFlag in interface Message

Parameters:

flags - The flag or flags

Returns:

A reference to the message

setFlag

public Message setFlag(Message.TransientFlag... flags)

Same as setFlag(Flag...) except that transient flags are not marshalled

Specified by:

setFlag in interface Message

Parameters:

flags - The flag

setFlag

public Message setFlag(short flag,
                       boolean transient_flags,
                       boolean xor)

Description copied from interface: Message

Sets the flags as a short; this way, multiple flags can be set in one operation

Specified by:

setFlag in interface Message

Parameters:

flag - The flag to be set (as a short). Overrides existing flags (no xor-ing)

transient_flags - True if the flag is transient, false otherwise

xor - When true, existing flags will be xor-ed with flag, otherwise not

getFlags

public short getFlags(boolean transient_flags)

Returns the internal representation of flags. Don't use this, as the internal format might change at any time ! This is only used by unit test code

Specified by:

getFlags in interface Message

Parameters:

transient_flags - Returns transient flags if true, else regular flags

Returns:

clearFlag

public Message clearFlag(Message.Flag... flags)

Clears a number of flags in a message

Specified by:

clearFlag in interface Message

Parameters:

flags - The flags

Returns:

A reference to the message

clearFlag

public Message clearFlag(Message.TransientFlag... flags)

Description copied from interface: Message

Removes a number of transient flags from the message. No-op for a flag if it is not set

Specified by:

clearFlag in interface Message

isFlagSet

public boolean isFlagSet(Message.Flag flag)

Checks if a given flag is set

Specified by:

isFlagSet in interface Message

Parameters:

flag - The flag

Returns:

Whether the flag is currently set

isFlagSet

public boolean isFlagSet(Message.TransientFlag flag)

Description copied from interface: Message

Returns true if a transient flag is set, false otherwise

Specified by:

isFlagSet in interface Message

setFlagIfAbsent

public boolean setFlagIfAbsent(Message.TransientFlag flag)

Atomically checks if a given flag is set and - if not - sets it. When multiple threads concurrently call this method with the same flag, only one of them will be able to set the flag

Specified by:

setFlagIfAbsent in interface Message

Parameters:

flag -

Returns:

True if the flag could be set, false if not (was already set)

copy

public Message copy(boolean copy_payload,
                    boolean copy_headers)

Copies the source- and destination addresses, flags and headers (if copy_headers is true).
If copy_payload is set, then method copyPayload(Message) of the subclass will be called, which is responsible for copying the payload specific to that message type.
Note that for headers, only the arrays holding references to the headers are copied, not the headers themselves ! The consequence is that the headers array of the copy hold the *same* references as the original, so do *not* modify the headers ! If you want to change a header, copy it and call Message.putHeader(short,Header) again.

Specified by:

copy in interface Message

Parameters:

copy_payload - If true, the payload is copied, else it is null in the copied message

copy_headers - If true, the headers are copied

putHeader

public Message putHeader(short id,
                         Header hdr)

Puts a header given an ID into the hashmap. Overwrites potential existing entry.

Specified by:

putHeader in interface Message

getHeader

public <T extends Header> T getHeader(short id)

Description copied from interface: Message

Gets a header from the message

Specified by:

getHeader in interface Message

clearHeaders

public Message clearHeaders()

Removes all headers: use carefully!

Specified by:

clearHeaders in interface Message

getPayload

public <T> T getPayload()

Description copied from interface: Message

Returns the payload without any conversion (e.g. as in Message.getObject() or Message.getArray())

Specified by:

getPayload in interface Message

Type Parameters:

T - The type of the object

Returns:

The payload

setPayload

public Message setPayload(java.lang.Object pl)

Description copied from interface: Message

Sets the payload

Specified by:

setPayload in interface Message

Parameters:

pl - The paylolad

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

serializedSize

public int serializedSize()

Description copied from interface: SizeStreamable

Returns the size (in bytes) of the marshalled object

Specified by:

serializedSize in interface SizeStreamable

size

public int size()

Description copied from interface: Message

Returns the exact size of the marshalled message

Specified by:

size in interface Message

Returns:

The number of bytes for the marshalled message

writeTo

public void writeTo(java.io.DataOutput out)
             throws java.io.IOException

Description copied from interface: Streamable

Write the entire state of the current object (including superclasses) to outstream. Note that the output stream must not be closed

Specified by:

writeTo in interface Streamable

Throws:

java.io.IOException

writeToNoAddrs

public void writeToNoAddrs(Address src,
                           java.io.DataOutput out,
                           short... excluded_headers)
                    throws java.io.IOException

Description copied from interface: Message

Writes the message to an output stream excluding the destination (and possibly source) address, plus a number of headers

Specified by:

writeToNoAddrs in interface Message

Throws:

java.io.IOException

readFrom

public void readFrom(java.io.DataInput in)
              throws java.io.IOException,
                     java.lang.ClassNotFoundException

Description copied from interface: Streamable

Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed

Specified by:

readFrom in interface Streamable

Throws:

java.io.IOException

java.lang.ClassNotFoundException

copyPayload

protected Message copyPayload(Message copy)

Copies the payload

createHeaders

protected static Header[] createHeaders(int size)