Package org.apache.hadoop.hbase.wal

Enum Class WALTailingReader.State

java.lang.Object

java.lang.Enum<WALTailingReader.State>

org.apache.hadoop.hbase.wal.WALTailingReader.State

All Implemented Interfaces:

Serializable, Comparable<WALTailingReader.State>, Constable

Enclosing interface:

WALTailingReader

public static enum WALTailingReader.State
extends Enum<WALTailingReader.State>

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
EOF_AND_RESET	This means we reach the EOF and the upper layer need to reset to see if there is more data.
EOF_AND_RESET_COMPRESSION	Mostly the same with the above EOF_AND_RESET, the difference is that here we also mess up the compression dictionary when reading data, so the upper layer should also clear the compression context when reseting, which means when calling resetTo method, we need to skip to the position instead of just seek to, which will impact performance.
EOF_WITH_TRAILER	This means the WAL file has a trailer and we have reached it, which means we have finished reading this file normally
ERROR_AND_RESET	This means we meet an error so the upper layer need to reset to read again
ERROR_AND_RESET_COMPRESSION	Mostly the same with the above ERROR_AND_RESET, the difference is that here we also mess up the compression dictionary when reading data, so the upper layer should also clear the compression context when reseting, which means when calling resetTo method, we need to skip to the position instead of just seek to, which will impact performance.
NORMAL	This means we read an Entry without any error

Field Summary

Fields

Modifier and Type	Field	Description
private WALTailingReader.Result	result	A dummy result for returning, as except NORMAL, for other state we do not need to provide fields other than state in the returned WALTailingReader.Result.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	State()

Method Summary

Modifier and Type	Method	Description
boolean	eof()
WALTailingReader.Result	getResult()
boolean	resetCompression()
static WALTailingReader.State	valueOf(String name)	Returns the enum constant of this class with the specified name.
static WALTailingReader.State[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

NORMAL

public static final WALTailingReader.State NORMAL

This means we read an Entry without any error

EOF_WITH_TRAILER

public static final WALTailingReader.State EOF_WITH_TRAILER

This means the WAL file has a trailer and we have reached it, which means we have finished reading this file normally

ERROR_AND_RESET

public static final WALTailingReader.State ERROR_AND_RESET

This means we meet an error so the upper layer need to reset to read again

ERROR_AND_RESET_COMPRESSION

public static final WALTailingReader.State ERROR_AND_RESET_COMPRESSION

Mostly the same with the above ERROR_AND_RESET, the difference is that here we also mess up the compression dictionary when reading data, so the upper layer should also clear the compression context when reseting, which means when calling resetTo method, we need to skip to the position instead of just seek to, which will impact performance.

EOF_AND_RESET

public static final WALTailingReader.State EOF_AND_RESET

This means we reach the EOF and the upper layer need to reset to see if there is more data. Notice that this does not mean that there is necessarily more data, the upper layer should determine whether they need to reset and read again.

EOF_AND_RESET_COMPRESSION

public static final WALTailingReader.State EOF_AND_RESET_COMPRESSION

Mostly the same with the above EOF_AND_RESET, the difference is that here we also mess up the compression dictionary when reading data, so the upper layer should also clear the compression context when reseting, which means when calling resetTo method, we need to skip to the position instead of just seek to, which will impact performance. The implementation should try its best to not fall into this situation.

Field Details

result

private WALTailingReader.Result result

A dummy result for returning, as except NORMAL, for other state we do not need to provide fields other than state in the returned WALTailingReader.Result.

Constructor Details

State

private State()

Method Details

values

public static WALTailingReader.State[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static WALTailingReader.State valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

getResult

public WALTailingReader.Result getResult()

resetCompression

public boolean resetCompression()

eof

public boolean eof()