com.hazelcast.nio

Class Packet

java.lang.Object

com.hazelcast.internal.serialization.impl.HeapData

com.hazelcast.nio.Packet

All Implemented Interfaces:

OutboundFrame, Data

@PrivateApi
public final class Packet
extends HeapData
implements OutboundFrame

A Packet is a piece of data sent over the wire. The Packet is used for member to member communication. The Packet extends HeapData instead of wrapping it. From a design point of view this is often not the preferred solution (prefer composition over inheritance), but in this case that would mean more object litter. Since the Packet isn't used throughout the system, this design choice is visible locally.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Packet.Type

Field Summary

Fields

Modifier and Type	Field and Description
static int	FLAG_JET_FLOW_CONTROL Marks a Jet packet as Flow control
static int	FLAG_OP_CONTROL Marks an Operation packet as Operation control (like invocation-heartbeats)
static int	FLAG_OP_RESPONSE Marks an Operation packet as Response
static int	FLAG_URGENT Marks the packet as Urgent
static byte	VERSION

Fields inherited from class com.hazelcast.internal.serialization.impl.HeapData

DATA_OFFSET, HEAP_DATA_OVERHEAD, PARTITION_HASH_OFFSET, payload, TYPE_OFFSET

Constructor Summary

Constructors

Constructor and Description
Packet()
Packet(byte[] payload)
Packet(byte[] payload, int partitionId)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Connection	getConn() Gets the Connection this Packet was send with.
char	getFlags()
Packet.Type	getPacketType()
int	getPartitionId() Returns the partition ID of this packet.
int	hashCode()
boolean	isFlagRaised(int flagsToCheck) Returns true if any of the flags supplied in the argument are set.
boolean	isUrgent() Checks if this Frame is urgent.
int	packetSize() Returns an estimation of the packet, including its payload, in bytes.
Packet	raiseFlags(int flagsToRaise) Raises all the flags raised in the argument.
boolean	readFrom(ByteBuffer src) Reads the packet data from the supplied ByteBuffer.
void	reset() The methods readFrom(ByteBuffer) and writeTo(ByteBuffer) do not complete their I/O operation within a single call, and between calls there is some progress state to keep within this instance.
Packet	resetFlagsTo(int flagsToSet) Resets the entire flags bitfield to the supplied value.
Packet	setConn(Connection conn) Sets the Connection this Packet is send with.
Packet	setPacketType(Packet.Type type) Sets the packet type by updating the packet type bits in the flags bitfield.
String	toString()
boolean	writeTo(ByteBuffer dst) Writes the packet data to the supplied ByteBuffer, up to the buffer's limit.

Methods inherited from class com.hazelcast.internal.serialization.impl.HeapData

copyTo, dataSize, getHeapCost, getPartitionHash, getType, hash64, hasPartitionHash, isPortable, toByteArray, totalSize

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

VERSION

public static final byte VERSION

See Also:

Constant Field Values

FLAG_URGENT

public static final int FLAG_URGENT

Marks the packet as Urgent

See Also:

Constant Field Values

FLAG_OP_RESPONSE

public static final int FLAG_OP_RESPONSE

Marks an Operation packet as Response

See Also:

Constant Field Values

FLAG_OP_CONTROL

public static final int FLAG_OP_CONTROL

Marks an Operation packet as Operation control (like invocation-heartbeats)

See Also:

Constant Field Values

FLAG_JET_FLOW_CONTROL

public static final int FLAG_JET_FLOW_CONTROL

Marks a Jet packet as Flow control

See Also:

Constant Field Values

Constructor Detail

Packet

public Packet()

Packet

public Packet(byte[] payload)

Packet

public Packet(byte[] payload,
              int partitionId)

Method Detail

getConn

public Connection getConn()

Gets the Connection this Packet was send with.

Returns:

the Connection. Could be null.

setConn

public Packet setConn(Connection conn)

Sets the Connection this Packet is send with.

This is done on the reading side of the Packet to make it possible to retrieve information about the sender of the Packet.

Parameters:

conn - the connection.

Returns:

this (for fluent interface)

getPacketType

public Packet.Type getPacketType()

setPacketType

public Packet setPacketType(Packet.Type type)

Sets the packet type by updating the packet type bits in the flags bitfield. Other bits are unaffected.

Parameters:

type - the type to set

Returns:

this (for fluent interface)

raiseFlags

public Packet raiseFlags(int flagsToRaise)

Raises all the flags raised in the argument. Does not lower any flags.

Parameters:

flagsToRaise - the flags to raise

Returns:

this (for fluent interface)

resetFlagsTo

public Packet resetFlagsTo(int flagsToSet)

Resets the entire flags bitfield to the supplied value. This also affects the packet type bits.

Parameters:

flagsToSet - the flags. Only the least significant two bytes of the argument are used.

Returns:

this (for fluent interface)

isFlagRaised

public boolean isFlagRaised(int flagsToCheck)

Returns true if any of the flags supplied in the argument are set.

Parameters:

flagsToCheck - the flags to check

Returns:

true if any of the flags is set, false otherwise.

getFlags

public char getFlags()

Returns:

the complete flags bitfield as a char.

getPartitionId

public int getPartitionId()

Returns the partition ID of this packet. If this packet is not for a particular partition, -1 is returned.

Returns:

the partition ID.

isUrgent

public boolean isUrgent()

Description copied from interface: OutboundFrame

Checks if this Frame is urgent. Frames that are urgent, have priority above regular frames. This is useful to implement System Operations so that they can be send faster than regular operations; especially when the system is under load you want these operations have precedence.

Specified by:

isUrgent in interface OutboundFrame

Returns:

true if urgent, false otherwise.

reset

public void reset()

The methods readFrom(ByteBuffer) and writeTo(ByteBuffer) do not complete their I/O operation within a single call, and between calls there is some progress state to keep within this instance. Calling this method resets the state back to "no bytes read/written yet".

writeTo

public boolean writeTo(ByteBuffer dst)

Writes the packet data to the supplied ByteBuffer, up to the buffer's limit. If it returns false, it should be called again to write the remaining data.

Parameters:

dst - the destination byte buffer

Returns:

true if all the packet's data is now written out; false otherwise.

readFrom

public boolean readFrom(ByteBuffer src)

Reads the packet data from the supplied ByteBuffer. The buffer may not contain the complete packet. If this method returns false, it should be called again to read more packet data.

Parameters:

src - the source byte buffer

Returns:

true if all the packet's data is now read; false otherwise.

packetSize

public int packetSize()

Returns an estimation of the packet, including its payload, in bytes.

Returns:

the size of the packet.

equals

public boolean equals(Object o)

Overrides:

equals in class HeapData

hashCode

public int hashCode()

Overrides:

hashCode in class HeapData

toString

public String toString()

Overrides:

toString in class HeapData