org.apache.hadoop.hbase
Class HMsg

java.lang.Object
  org.apache.hadoop.hbase.HMsg

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public class HMsg
extends java.lang.Object
implements org.apache.hadoop.io.Writable

HMsg is used to send messages between master and regionservers. Messages are sent as payload on the regionserver-to-master heartbeats. Region assignment does not use this mechanism. It goes via zookeeper.

Most of the time the messages are simple but some messages are accompanied by the region affected. HMsg may also carry an optional message.

TODO: Clean out all messages that go from master to regionserver; by design, these are to go via zk from here on out.

Nested Class Summary

static class

HMsg.Type

Field Summary

static HMsg[]	EMPTY_HMSG_ARRAY
static HMsg[]	STOP_REGIONSERVER_ARRAY

Constructor Summary

HMsg()
Default constructor.

HMsg(HMsg.Type type)
Construct a message with the specified message and empty HRegionInfo

HMsg(HMsg.Type type, HRegionInfo hri)
Construct a message with the specified message and HRegionInfo

HMsg(HMsg.Type type, HRegionInfo hri, byte[] msg)
Construct a message with the specified message and HRegionInfo

HMsg(HMsg.Type type, HRegionInfo hri, HRegionInfo daughterA, HRegionInfo daughterB, byte[] msg)
Construct a message with the specified message and HRegionInfo

Method Summary

boolean	equals(java.lang.Object obj)
HRegionInfo	getDaughterA()
HRegionInfo	getDaughterB()
byte[]	getMessage()
HRegionInfo	getRegionInfo()
HMsg.Type	getType()
int	hashCode()
boolean	isType(HMsg.Type other)
void	readFields(java.io.DataInput in)
java.lang.String	toString()
void	write(java.io.DataOutput out)

Methods inherited from class java.lang.Object

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

Field Detail

STOP_REGIONSERVER_ARRAY

public static final HMsg[] STOP_REGIONSERVER_ARRAY

EMPTY_HMSG_ARRAY

public static final HMsg[] EMPTY_HMSG_ARRAY

Constructor Detail

HMsg

public HMsg()

Default constructor. Used during deserialization

HMsg

public HMsg(HMsg.Type type)

Construct a message with the specified message and empty HRegionInfo

Parameters:

type - Message type

HMsg

public HMsg(HMsg.Type type,
            HRegionInfo hri)

Construct a message with the specified message and HRegionInfo

Parameters:

type - Message type

hri - Region to which message type applies

HMsg

public HMsg(HMsg.Type type,
            HRegionInfo hri,
            byte[] msg)

Construct a message with the specified message and HRegionInfo

Parameters:

type - Message type

hri - Region to which message type applies. Cannot be null. If no info associated, used other Constructor.

msg - Optional message (Stringified exception, etc.)

HMsg

public HMsg(HMsg.Type type,
            HRegionInfo hri,
            HRegionInfo daughterA,
            HRegionInfo daughterB,
            byte[] msg)

Construct a message with the specified message and HRegionInfo

Parameters:

type - Message type

hri - Region to which message type applies. Cannot be null. If no info associated, used other Constructor.

daughterA -

daughterB -

msg - Optional message (Stringified exception, etc.)

Method Detail

getRegionInfo

public HRegionInfo getRegionInfo()

Returns:

Region info or null if none associated with this message type.

getType

public HMsg.Type getType()

Returns:

the type of message

isType

public boolean isType(HMsg.Type other)

Parameters:

other - Message type to compare to

Returns:

True if we are of same message type as other

getMessage

public byte[] getMessage()

Returns:

the message type

getDaughterA

public HRegionInfo getDaughterA()

Returns:

First daughter if Type is MSG_REPORT_SPLIT_INCLUDES_DAUGHTERS else null

getDaughterB

public HRegionInfo getDaughterB()

Returns:

Second daughter if Type is MSG_REPORT_SPLIT_INCLUDES_DAUGHTERS else null

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()

write

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

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

See Also:

Writable.write(java.io.DataOutput)

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

See Also:

Writable.readFields(java.io.DataInput)